HomeMy WebLinkAboutRESO 9651161108 jb 6053873 1
Resolution No. 9651
Resolution of the Council of the City of Palo Alto Amending Utilities Rule
and Regulation 27 (Generating Facility Interconnections)
R E C I T A L S
A.Pursuant to Chapter 12.20.010 of the Palo Alto Municipal Code, the Council of the City of
Palo Alto may by resolution adopt rules and regulations governing utility services, fees and charges.
The Council of the City of Palo Alto hereby RESOLVES as follows:
SECTION 1. Pursuant to Section 12.20.010 of the Palo Alto Municipal Code, Utilities Rule and
Regulation 27 (Generating Facility Interconnections) is hereby amended as attached and
incorporated. Utility Rule and Regulation 27, as amended, shall become effective December 12,
2016.
SECTION 2. The adoption of this resolution amending Utilities Rule and Regulation 27 (Generating
Facility Interconnections) is not a project requiring California Environmental Quality Act (CEQA) review,
under California Public Resources Code Sec. 21065, 21080(b)(8), and CEQA Guidelines Section
15378(b)(5), because it is an administrative governmental activity which will not cause a direct or indirect
physical change in the environment.
INTRODUCED AND PASSED: December 12, 2016
AYES: BURT, DUBOIS, FILSETH, HOLMAN, KNISS, SCHARFF, SCHMID, WOLBACH
NOES: ABSENT:
ABSTENTIONS:
ATTEST:
City Clerk Mayor
APPROVED AS TO FORM: APPROVED:
Senior Deputy City Attorney City Manager
Director of Utilities
Director of Administrative Services
DocuSign Envelope ID: C39AAA71-1F28-4E1D-AB4D-AC8DFDD12BD3
GENERATING FACILITY INTERCONNECTIONS
RULE AND REGULATION 27
CITY OF PALO ALTO
UTILITIES RULES AND REGULATIONS
Issued by the City Council
Effective 12-12-2016
Sheet No. 1
TABLE OF CONTENTS:
A. APPLICABILITY .........................................................................................................................................................2
B. GENERAL RULES, RIGHTS AND OBLIGATIONS ................................................................................................. 2
C. APPLICATION AND INTERCONNECTION PROCESS ...........................................................................................5
1. APPLICATION PROCESS ............................................................................................................................5
2. OVERVIEW OF THE INTERCONNECTION REVIEW PROCESS............................................................5
3. COMMISSIONING TESTING AND PARALLEL OPERATION...............................................................10
4. WITHDRAWAL / CANCELLATION .........................................................................................................11
D. GENERATING FACILITY DESIGN AND OPERATING REQUIREMENTS ........................................................11
1. GENERAL INTERCONNECTION AND PROTECTION FUNCTION REQUIREMENTS ......................12
2. PREVENTION OF INTERFERENCE .........................................................................................................14
3. TECHNOLOGY SPECIFIC REQUIREMENTS ..........................................................................................19
4. SUPPLEMENTAL GENERATING FACILITY REQUIREMENTS ...........................................................20
5. SMART INVERTER GENERATING FACILITY DESIGN AND OPERATING REQUIREMENTS .......21
E. INTERCONNECTION FACILITIES AND DISTRIBUTION SYSTEM MODIFICATIONS OWNERSHIP AND
COST ALLOCATION ................................................................................................................................................31
1. SCOPE AND OWNERSHIP OF INTERCONNECTION FACILITIES AND DISTRIBUTION SYSTEM
MODIFICATIONS .......................................................................................................................................31
2. RESPONSIBILITY OF COSTS OF INTERCONNECTING A GENERATING FACILITY......................32
3. INSTALLATION AND FINANCING OF INTERCONNECTION FACILITIES AND DISTRIBUTION
SYSTEM MODIFICATIONS .......................................................................................................................32
F. METERING, MONITORING AND TELEMETRY ...................................................................................................33
1. GENERAL REQUIREMENTS.....................................................................................................................33
2. METERING BY CPAU ................................................................................................................................33
3. NET GENERATION METERING ...............................................................................................................34
4. POINT OF COMMON COUPLING METERING .......................................................................................34
5. TELEMETERING ........................................................................................................................................34
6. LOCATION ..................................................................................................................................................35
7. COSTS OF METERING ...............................................................................................................................35
(SGY7MKR)RZIPSTI-( ' %%%* )(%&(%' (*((&(
GENERATING FACILITY INTERCONNECTIONS
RULE AND REGULATION 27
CITY OF PALO ALTO
UTILITIES RULES AND REGULATIONS
Issued by the City Council
Effective 12-12-2016
Sheet No. 2
A. APPLICABILITY
This Rule describes the Interconnection, Metering and operating requirements for Generating
Facilities to be connected to the City of Palo Alto Utilities (CPAU) Electric Distribution System.
In order to provide for uniformity and to encourage the Interconnection of renewable energy
generation, this Rule is intended to be generally consistent with the technical requirements of
California Public Utilities Commission Rule 21 and IEEE 1547, as amended.
Language from IEEE 1547 that has been adopted directly (as opposed to paraphrased) is followed by
a citation that lists the clause from which the language derived. For example, IEEE 1547-4.1.1 is a
reference to Clause 4.1.1.
In the event of any conflict between this Rule and any of the CPUC Rule 21 and IEEE 1547
standards listed herein, the requirements of this Rule shall take precedence.
B. GENERAL RULES, RIGHTS AND OBLIGATIONS
1.Prior Authorization Required to Interconnect and Operate. An executed Interconnection
Agreement or Net Energy Metering and Interconnection Agreement, as applicable, is
required in addition to receiving efore Parallel
Operation of a Generating Facility CPAU shall apply this
Rule in a non-discriminatory manner and shall not unreasonably withhold its permission for
Parallel Operation of Generating Facilities
2.Separate Agreements Required for Other Services. Separate Agreements are required for the
provision of other Electric Services from CPAU including, but not limited to, Distribution
Service provided by CPAU during periods of Curtailment or interruption of a Generating
.
3.Service Not Provided With Interconnection.Interconnection with CPAU's Distribution
System under this Rule provides no rights to utilize CPAU's Distribution System for the
transmission, distribution, or wheeling of electric power.
4.Compliance with Laws, Rules & Regulations and Utility Rates. Applicants shall ascertain
and comply with applicable CPAU Rules & Regulations and Utility Rates; applicable Federal
Energy Regulatory Commission (FERC) approved rules, tariffs and regulations; and any
local, state or federal Law, statute or regulation which applies to the design, siting,
(SGY7MKR)RZIPSTI-( ' %%%* )(%&(%' (*((&(
GENERATING FACILITY INTERCONNECTIONS
RULE AND REGULATION 27
CITY OF PALO ALTO
UTILITIES RULES AND REGULATIONS
Issued by the City Council
Effective 12-12-2016
Sheet No. 3
construction, installation, operation, or any other aspect of the Applicant Generating
Facility and Interconnection Facilities.
5.Design Reviews and Inspections. CPAU has the right to review the design of a
Generating Facility and Interconnection Facilities and to inspect the Generating Facility
and/or Interconnection Facilities prior to the commencement of Parallel Operation with
CPAU may require Applicants to make modifications as
necessary to comply with the requirements of CPAU Rules and Regulations or other
reasonable requirements
be construed as confirming or endorsing the design or as warranting the
Generating Facility
is not responsible for the adequacy or capacity of such Facilities.
6.Right to Access. Customer Generating and Interconnection Facilities shall be accessible to
CPAU personnel whenever necessary for CPAU to perform its duties and exercise its rights
under its Rules and Regulations and any Interconnection Agreement, including the Net
Energy Metering and Interconnection Agreement.
7.Prudent Operation and Maintenance Required. The Customer shall operate and maintain its
Generating Facility and Interconnection Facilities in accordance with Prudent Electrical
Practices and shall maintain compliance with CPAU Rules and Regulations.
8.Curtailment and Disconnection. CPAU may limit the operation, disconnect or require the
disconnection of a
time, with or without notice, in the event of an Emergency, or to correct Unsafe Operating
Conditions. CPAU may also limit the operation, disconnect or require the disconnection of a
with reasonable written
Generating Facility
is not in compliance with any CPAU Rules and Regulations; or (3) upon termination of the
applicable Interconnection Agreement or Net Energy Metering and Interconnection
Agreement. Within a reasonable period after the written request, CPAU will
provide a written explanation of the reason for such Curtailment or disconnection.
(SGY7MKR)RZIPSTI-( ' %%%* )(%&(%' (*((&(
GENERATING FACILITY INTERCONNECTIONS
RULE AND REGULATION 27
CITY OF PALO ALTO
UTILITIES RULES AND REGULATIONS
Issued by the City Council
Effective 12-12-2016
Sheet No. 4
9.Coordination with Affected Systems. CPAU will notify the Affected System Operators that
are (s). CPAU will coordinate
the conduct of any studies required to determine the impact of the Interconnection Request
on Affected Systems with Affected System Operators and, if possible, include those results
in its Interconnection Study. CPAU will invite such Affected System Operators to all
meetings held with Applicant as required by this Rule. Applicants and transmission providers
which may be an Affected System shall cooperate with CPAU in all matters related to the
conduct of relevant studies and the determination of modifications to Affected Systems.
Applicant shall enter into an agreement with the owner of the Affected System, as applicable
and upon request by CPAU. The agreement will specify the terms governing payments to be
made by Applicant to the owner of the Affected System as well as the repayment, if
applicable, by the owner of the Affected System.
10.Transferability of Interconnection Request. An Applicant may transfer its Interconnection
Request to another entity only if such entity acquires the proposed Generating Facility
identified in the Interconnection Request and the Point of Interconnection and operating
parameters do not change. CPAU at its discretion may deny such requests if CPAU
determines applicable requirements will not be met as a result of the transfer.
11.Special Provisions Applicable to Net Energy Metering Applicants (NEM). Notwithstanding
any other provision in this Rule:
a.For Generating Facilities qualifying for service under PUC Sections 2827, 2827.8
and 2827.10, as amended, the Applicant is not responsible for payment of study
costs.
b. For Generating Facilities qualifying for service under PUC Sections 2827 and
2827.8, as amended, CPAU approval for Interconnection will normally be
processed not later than thirty (30) Business Days following CPAU :
i.a completed Net Energy Metering Interconnection Request including all
supporting documents and required payments;
ii.a completed signed Net Energy Metering Generator Interconnection
Agreement; and
iii. final electric inspection clearance from the Palo Alto
Building Department.
(SGY7MKR)RZIPSTI-( ' %%%* )(%&(%' (*((&(
GENERATING FACILITY INTERCONNECTIONS
RULE AND REGULATION 27
CITY OF PALO ALTO
UTILITIES RULES AND REGULATIONS
Issued by the City Council
Effective 12-12-2016
Sheet No. 5
If the 30-day period cannot be met, CPAU will notify Applicant of the reason for the
inability to process the Interconnection Request and the expected completion date.
Applicants with PUC Section 2827 Generating Facilities that include non-inverter
based Generators and/or Generators with non-Certified Equipment should submit a
completed Net Energy Metering Interconnection Request, including all supporting
documents sufficient for CPAU to start the review process, without waiting for the
final inspection clearance. Applicants with such Generating Facilities are advised to
submit their Interconnection Request at least six (6) months in advance of their
planned Commercial Operation Date. Depending on the size and location of these
Generating Facilities, additional time for review and study may be required.
C. APPLICATION AND INTERCONNECTION PROCESS
1. APPLICATION PROCESS
a. Utility Service Application (Application). All Applicants must complete and submit
the Application and three (3) sets of plan drawings at the Development Center
located at 285 Hamilton Avenue.
2. OVERVIEW OF THE INTERCONNECTION REVIEW PROCESS
a.Valid Interconnection Request. After an Application is received and deemed
complete and valid, CPAU will start the interconnection review process. See Section
B.11 for special provisions related to the timeframe and costs applicable to NEM
Applicants.
b.Initial Review. Upon receipt of a complete and valid Application and plans, CPAU
shall perform an Initial Review. The Initial Review determines if (i) the Generating
Facility qualifies for a Simplified Interconnection, or (ii) the Generating Facility
requires a Supplemental Review. Absent extraordinary circumstances, CPAU shall
notify Applicant in writing of the results of Initial Review within ten (10) Business
Days following validation of an Interconnection Request.
i.Passage of Initial Review. For Interconnection Requests that pass the Initial
(SGY7MKR)RZIPSTI-( ' %%%* )(%&(%' (*((&(
GENERATING FACILITY INTERCONNECTIONS
RULE AND REGULATION 27
CITY OF PALO ALTO
UTILITIES RULES AND REGULATIONS
Issued by the City Council
Effective 12-12-2016
Sheet No. 6
Review and do not require Interconnection Facilities or Distribution
Upgrades, CPAU will provide the Applicant with a Generator
Interconnection Agreement or Generator Interconnection Agreement and Net
Energy Metering Agreement, if applicable, within fifteen (15) Business Days
of providing notice of Initial Review results. For Interconnection Requests
that pass the Initial Review but also require Interconnection Facilities or
Distribution upgrades, CPAU will provide Applicant with a non-binding cost
estimate of the Interconnection Facilities or Distribution upgrades within
thirty (30) Business Days of providing notice of Initial Review results.These
facilities may be treated as Special Facilities (depending on circumstance) for
the purpose of determining Applicant costs. The applicant can then proceed
with executing an Interconnection Agreement in accordance with Section
C.1.e below.
ii.Failure of Initial Review. For Interconnection Requests that fail Initial
Review, CPAU will provide the technical reason, data and analysis
supporting the Initial Review results in writing and provide Applicant the
option to proceed directly to a Supplemental Review. The Applicant shall
notify CPAU within ten (10) Business Days following such notification
whether to (i) proceed to a Supplemental Review, or (ii) withdraw the
Interconnection Request. Applicants that elect to proceed to a Supplemental
Review shall provide a nonrefundable Advance Engineering Fee set forth in
Rate Schedule E-15 with their response. CPAU will proceed with the
Supplemental Review once payment of the required Advance Engineering
Fee has been received. If Applicant fails to notify CPAU within ten (10)
Business Days of such notification, the Interconnection Request will be
deemed withdrawn.
iii.Additional Initial Review Information. No changes may be made to the
planned Point of Interconnection or Generating Facility size included in the
Interconnection Request during the review process, unless such changes are
agreed to by CPAU. Where agreement has not been reached, Applicants
choosing to change the Point of Interconnection or Generating Facility size
must reapply and submit a new Interconnection Request.
(SGY7MKR)RZIPSTI-( ' %%%* )(%&(%' (*((&(
GENERATING FACILITY INTERCONNECTIONS
RULE AND REGULATION 27
CITY OF PALO ALTO
UTILITIES RULES AND REGULATIONS
Issued by the City Council
Effective 12-12-2016
Sheet No. 7
c.Supplemental Review.
If Applicant requests a Supplemental Review and submits an Advance
Engineering Fee as described in Rate Schedule E-15, if required, CPAU will
perform the Supplemental Review using the review process in Section H.2., and
complete the Supplemental Review within twenty (20) Business Days, absent
extraordinary circumstances, following authorization and receipt of the fee. The
Supplemental Review will determine if (i) the Generating Facility qualifies for
interconnection, or interconnection with additional requirements, or (ii) the
Generating Facility requires a Detailed Study.
The Applicant must provide the following data to CPAU when requesting a
Supplemental Review:
Generator:
1. MVA Rating
2. kV Rating
3. Base MVA
4. Base kV
5. Xd" (direct axis subtransient reactance)
6. Xd' (direct axis transient reactance)
7. Xd (Synchronous reactance)
8. X2 (Negative Sequence reactance)
9. X0 (Zero Sequence reactance)
Generating Facility Transformer Data:
1. Winding configuration (delta-Wye gnd or Wye gnd-Delta)
2. MVA Rating
3. KV Rating
4. Base MVA
5. Base KV
6. Z1 HV-LV
7. Z0 HV-LV
(SGY7MKR)RZIPSTI-( ' %%%* )(%&(%' (*((&(
GENERATING FACILITY INTERCONNECTIONS
RULE AND REGULATION 27
CITY OF PALO ALTO
UTILITIES RULES AND REGULATIONS
Issued by the City Council
Effective 12-12-2016
Sheet No. 8
Line Data:
1. Impedance data for line from Transformer to POI (if applicable)
2. Z1
3. Z0
4. Point of Interconnection (POI) Location
i.Passage of Supplemental Review. For Interconnection Requests that pass a
Supplemental Review and do not require Interconnection Facilities or
Distribution Upgrades, CPAU will provide Applicant with a Generator
Interconnection Agreement within fifteen (15) Business Days of providing
notice of the Supplemental Review results. For Interconnection Requests
that pass a Supplemental Review but also require Interconnection
Facilities or Distribution upgrades, CPAU will provide Applicant with a
non-binding cost estimate of the Interconnection Facilities or Distribution
upgrades within thirty (30) Business Days of providing notice of the
Supplemental Review results. These facilities may be treated as Special
Facilities (depending on circumstance) for the purpose of determining
Applicant costs. The Applicant can then proceed with executing an
Interconnection Agreement in accordance with Section C.1.e below.
ii.Failure of Supplemental Review. For Interconnection Requests that fail a
Supplemental Review, CPAU will provide the technical reason, data and
analysis supporting the Supplemental Review results in writing and
provide Applicant the option to proceed directly to a cost estimate and
schedule for a Detailed Study. The Applicant shall notify CPAU within
fifteen (15) Business Days following such notification whether to (i)
proceed to a cost estimate and schedule for a Detailed Study, or (ii)
withdraw the Interconnection Request. If the Applicant elects to proceed
with the cost estimate and schedule for a Detailed Study, CPAU shall
provide Applicant with a non-binding cost estimate and schedule within
thirty (30) Business Days of the Applicant providing notice to proceed. If
Applicant fails to notify CPAU within fifteen (15) Business Days of such
notification, the Interconnection Request shall be deemed withdrawn.
(SGY7MKR)RZIPSTI-( ' %%%* )(%&(%' (*((&(
GENERATING FACILITY INTERCONNECTIONS
RULE AND REGULATION 27
CITY OF PALO ALTO
UTILITIES RULES AND REGULATIONS
Issued by the City Council
Effective 12-12-2016
Sheet No. 9
d. Detailed Study.
If the Applicant requests to proceed with the cost estimate and schedule for a
Detailed Study as provided by CPAU in Section C.1.c.ii above, CPAU and the
Applicant may enter into a Detailed Study agreement that provides for CPAU to
perform additional studies, facility design and engineering, and to provide an
estimate for the actual cost of CPAU provided Interconnection Facilities or
Distribution Upgrades as required to allow for the interconnection of the
Note: the Detailed Study fee shall be waived for NEM applicants meeting the
requirements of Section B.11. Following payment of the cost estimate by the
Applicant, CPAU will proceed with the Detail Study in accordance with the
agreed upon time schedule, and upon completion of the Detailed Study, CPAU
will provide the results in writing to the Applicant along with the final cost
estimate of any required Interconnection or Distribution Facilities. These facilities
may be treated as Special Facilities (depending on circumstance) for the purpose
of determining Applicant costs. The applicant can then proceed with executing an
Interconnection Agreement in accordance with Section C.1.e below.
e. Execution of the Generator Interconnection Agreement.
i. Following the receipt of a cost estimate for any Distribution Upgrades
and/or Interconnection Facilities that have been identified (Applicants that
did not require a cost estimate may proceed to Section C.1.e.ii below),
Applicant shall notify CPAU within fifteen (15) Business Days whether
Applicant: (i) requests a Generator Interconnection Agreement, or (ii)
withdraws its Interconnection Request. If Applicant fails to notify CPAU
within fifteen (15) Business Days, the Interconnection Request shall be
deemed withdrawn. If Applicant elects to proceed to a Generator
Interconnection Agreement, CPAU will provide Applicant with a
Generator Interconnection Agreement for
fifteen (15) Business Days of
ii. Upon receipt of a draft Generator Interconnection Agreement, Applicant
has ninety (90) Calendar Days to sign and return the Generator
(SGY7MKR)RZIPSTI-( ' %%%* )(%&(%' (*((&(
GENERATING FACILITY INTERCONNECTIONS
RULE AND REGULATION 27
CITY OF PALO ALTO
UTILITIES RULES AND REGULATIONS
Issued by the City Council
Effective 12-12-2016
Sheet No. 10
Interconnection Agreement. Applicant shall provide to CPAU written
comments, or notification of a lack of any comments, on the draft
Generator Interconnection Agreement and appendices within thirty (30)
Calendar Days. At the request of Applicant, CPAU shall begin
negotiations with Applicant at any time after CPAU provides Applicant
with the draft Generator Interconnection Agreement, which contains in its
appendices the cost estimate for any Distribution Upgrades and/or
Interconnection Facilities that have been identified by CPAU. If Applicant
fails to execute the Generator Interconnection Agreement within the ninety
(90) Calendar Days described in this section, the Interconnection Request
shall be deemed withdrawn.
iii. After Applicant has executed the Generator Interconnection Agreement
and paid the final invoice for estimated cost of Distribution Upgrades
and/or Interconnection Facilities, CPAU will commence with the design,
procurement, construction and installation of required facilities identified
in the Generator Interconnection Agreement. (Note: once the Applicant
executes the agreement, the Applicant is thereafter referred to as a
Producer) CPAU and Producer will use good faith efforts to meet
schedules and estimated costs in accordance with the requirements of the
Generator Interconnection Agreement. Producer is responsible for all costs
associated with Parallel Operation to support the safe and reliable
operation of the Distribution System and Transmission System.
3. COMMISSIONING TESTING AND PARALLEL OPERATION
a. Commissioning Testing. Producer is responsible for commissioning and testing
new Generating Facilities and associated Interconnection Facilities to ensure
compliance with the safety and reliability provisions of this Rule prior to being
operated in parallel with Distribution or Transmission System. For non-
Certified Equipment, Producer shall develop a written testing plan to be submitted
to CPAU for its review and acceptance. Where applicable, the testing plan shall
include the installation test procedures published by the manufacturer of the
Generating Facility or Interconnection Facilities. Facility testing shall be
conducted at a mutually agreeable time, and CPAU shall be given the opportunity
to witness the tests.
(SGY7MKR)RZIPSTI-( ' %%%* )(%&(%' (*((&(
GENERATING FACILITY INTERCONNECTIONS
RULE AND REGULATION 27
CITY OF PALO ALTO
UTILITIES RULES AND REGULATIONS
Issued by the City Council
Effective 12-12-2016
Sheet No. 11
b. Parallel Operation or Momentary Parallel Operation. Producer shall not
commence Parallel Operation of its Generating Facility with system
unless it has received express written permission to do so. CPAU will
Generating Facility for Parallel Operation or momentary
Parallel Operation with Distribution or Transmission System, in writing,
within five (5) Calendar Days of satisfactory compliance with the terms of all
applicable agreements.
4. WITHDRAWAL / CANCELLATION
Applicant may withdraw its Interconnection Request at any time by written notice of such
withdrawal to CPAU. In addition, after receipt of the Interconnection Request, if
Applicant fails to adhere to the requirements and timelines of this rule, CPAU shall deem
the Interconnection Request to be withdrawn and shall provide written notice to
Applicant of the deemed withdrawal within five (5) Business Days and an explanation of
the reasons for such deemed withdrawal. Upon receipt of such written notice, Applicant
shall have five (5) Business Days in which to either respond with information or action
that either cures the deficiency or supports its position that the deemed withdrawal was
erroneous.
Application receipt) without resulting
in a signed Interconnection Agreement or Net Energy Metering and Interconnection
Agreement, or approval for Parallel Operation of a Generating Facility within one year of
completion of all applicable review and/or studies, are subject to cancellation by CPAU.
D. GENERATING FACILITY DESIGN AND OPERATING REQUIREMENTS
This section D. has been revised to be consistent with the requirements of ANSI/IEEE 1547-2003
Standard for Interconnecting Distributed Resources with Electric Power Systems (IEEE 1547).
Exceptions are taken to IEEE 1547 Clauses 4.1.4.2 Distribution Secondary Spot Networks and
Clauses 4.1.8.1 or 5.1.3.1, which address Protection from Electromagnetic Interference. Note
that this Rule and Regulation 27 does not adopt the Generating Facility power limitation of 10
MW incorporated in IEEE 1547.
(SGY7MKR)RZIPSTI-( ' %%%* )(%&(%' (*((&(
GENERATING FACILITY INTERCONNECTIONS
RULE AND REGULATION 27
CITY OF PALO ALTO
UTILITIES RULES AND REGULATIONS
Issued by the City Council
Effective 12-12-2016
Sheet No. 12
1. GENERAL INTERCONNECTION AND PROTECTION FUNCTION
REQUIREMENTS
Distribution System and not the Generating Facility. Customer shall be solely responsible
for providing adequate protection for its Generating Facility and Interconnection Facilities.
The Protective Functions shall not impact the operation of other Protective
capability of providing reliable service to its Customers.
a. Protective Functions Required. A Generating Facility operating in parallel with
Distribution System and cause
the Generating Facility t
Distribution System inappropriately:
i. Over and under voltage trip functions and over and under frequency trip
functions;
ii. A voltage and frequency sensing and time-delay Function to prevent the
Generating Facility from energizing a de-energized Distribution System
Distribution System unless CPAU
frequency is within the ANSI C84.1-1995 Table 1 Range B Voltage Range of
106V to 127V on a 120V basis, inclusive, and a frequency range of 59.3 Hz
to 60.5 Hz, inclusive, and are stable for at least 60 seconds, and;
iii. A Function to prevent the Generating Facility from contributing to the
formation of an Unintended Island, and cease to energize the CPAU system
within two seconds of the formation of an Unintended Island.
The Generating Facility shall cease to ene
(IEEE1547-
Distribution circuit prior to re-
(SGY7MKR)RZIPSTI-( ' %%%* )(%&(%' (*((&(
GENERATING FACILITY INTERCONNECTIONS
RULE AND REGULATION 27
CITY OF PALO ALTO
UTILITIES RULES AND REGULATIONS
Issued by the City Council
Effective 12-12-2016
Sheet No. 13
equipment (IEEE1547-4.2.2).
b. Momentary
L
Protective
Functions required for Parallel Operation.
c. Suitable Equipment Required. Circuit breakers or other interrupting devices located
at the Point of Common Coupling must be Certified or "Listed" (as defined in
Article 100, the Definitions Section of the National Electrical Code) as suitable for
their intended application. This includes being capable of interrupting the maximum
Interconnection Facilities shall be designed so that the failure of any one device shall
The Generating Facility paralleling-device shall be capable of withstanding 220%
of the Interconnection Facilit rated voltage (IEEE 1547-4.1.8.3). The
Interconnection Facilities shall have the capability to withstand voltage and current
surges in accordance with the environments defined in IEEE Std C62.41.2-2002 or
IEEE Std C37.90.1-2002 as applicable and as described in IEEE 1547-4.1.8.2.
d. Visible Disconnect Required: The Producer shall furnish and install a ganged,
manually-operated isolating switch (or a comparable device mutually agreed upon by
CPAU and the Producer) near the Point of Interconnection to isolate the Generating
overcurrent protection.
The device must:
i. Allow visible verification that separation has been accomplished. (This
requirement may be met by opening the enclosure to observe contact
separation.) Molded case circuit breakers do not meet the visible contact
requirement and are not acceptable as a Visible Disconnect device.
ii. Include markings or signage that clearly indicates open and closed positions.
iii. Be capable of being reached quickly and conveniently 24 hours a day by
(SGY7MKR)RZIPSTI-( ' %%%* )(%&(%' (*((&(
GENERATING FACILITY INTERCONNECTIONS
RULE AND REGULATION 27
CITY OF PALO ALTO
UTILITIES RULES AND REGULATIONS
Issued by the City Council
Effective 12-12-2016
Sheet No. 14
CPAU personnel for construction, maintenance, inspection, testing or
reading, without obstacles or requiring those seeking access to obtain keys,
special permission, or security clearances.
iv. Be capable of being locked in the open position.
v. Be clearly marked on the submitted Single Line Diagram and its type and
location approved by CPAU prior to installation. If the device is not adjacent
to the Point of Common Coupling (PCC), permanent signage must be
installed at a CPAU-approved location providing a clear description of the
location of the device. Generating Facilities with Non-Islanding inverters
totaling one (1) kilovolt-ampere (kVA) or less are exempt from this
requirement.
e. Drawings Required. Prior to Parallel Operation or Momentary Parallel Operation of
the Generating Facility, CPAU shall approve the Producer's Protective Function and
control diagrams. A Generating Facility equipped with a Protective Function and
control scheme previously approved by CPAU for system-wide application or only
Certified Equipment may satisfy this requirement by reference to previously
approved drawings and diagrams.
f. Generating Facility Conditions Not Identified. In the event this Rule does not
address the Interconnection conditions for a particular Generating Facility, CPAU
and Producer may agree upon other arrangements, to be approved by CPAU.
2. PREVENTION OF INTERFERENCE
The Producer shall not operate a Generating Facility or Interconnection Facilities that
CPAU operations, service to CPAU Customers, or communication facilities. If such
interference occurs, the Producer must diligently pursue and take corrective action at its
own expense after being given notice and reasonable time to do so by CPAU. If the
Producer does not take corrective action in a timely manner, or continues to operate the
facilities causing interference without restriction or limit, CPAU may, without liability,
Section B.8 of this Rule. To eliminate undesirable interference caused by its operation,
(SGY7MKR)RZIPSTI-( ' %%%* )(%&(%' (*((&(
GENERATING FACILITY INTERCONNECTIONS
RULE AND REGULATION 27
CITY OF PALO ALTO
UTILITIES RULES AND REGULATIONS
Issued by the City Council
Effective 12-12-2016
Sheet No. 15
each Generating Facility shall meet the following criteria:
a. Voltage Regulation. The Generating Facility shall not actively regulate the voltage at
the PCC while in parallel with CPAU
shall not cause the service voltage at other Customers to go outside the requirements
of ANSI C84.1-1995, Range A (IEEE 1547-4.1.1).
b.Operating Voltage Range. The voltage ranges in Table D.1 define protective trip
limits for the Protective Function and are not intended to define or imply a voltage
regulation Function. A Generating Facility shall cease to energize CPAU
Distribution System within the prescribed trip time whenever the voltage at the PCC
deviates from the allowable voltage operating range. The Protective Function shall
detect and respond to voltage on all phases to which the Generating Facility is
connected.
i. Generating Facilities. Generating Facilities shall be capable of operating
within the voltage range normally experienced on CPAU
System from plus to minus 5% of the nominal voltage (e.g. 114 volts to 126
volts on a 120 volt base), at the service panel or PCC. The trip settings at the
generator terminals shall be selected in a manner that minimizes nuisance
tripping between 106 volts and 132 volts on a 120-volt base (88-110% of
nominal voltage) to compensate for voltage drop between the generator
terminals and the PCC. Voltage shall be detected at either the PCC or the
Point of Interconnection. However, the voltage range at the PCC with the
generator on-line shall stay within +/-5% of nominal.
ii.
PCC varies from and remains outside normal (nominally 120 volts) by the
predetermined amounts set forth in Table D.1,
Protective Functions shall cause the Generator(s) to become isolated from
(SGY7MKR)RZIPSTI-( ' %%%* )(%&(%' (*((&(
GENERATING FACILITY INTERCONNECTIONS
RULE AND REGULATION 27
CITY OF PALO ALTO
UTILITIES RULES AND REGULATIONS
Issued by the City Council
Effective 12-12-2016
Sheet No. 16
TABLE D.1: Voltage Trip Settings
Voltage at Point of Common Coupling Maximum Trip Time(1)
Assuming 120 V Base % of Nominal Voltage
# of Cycles
(Assuming 60 Hz
Nominal)
Seconds
Less than 60 Volts Less than 50% 10 Cycles 0.16 Seconds
Greater than or equal to
60 Volts but less than
106 Volts
Greater than or equal to
50% but less than 88% 120 Cycles 2 Seconds
Greater than or equal to
106 Volts but less than or
equal to 132 Volts
Greater than or equal to
88% but less than or
equal to 110%
Normal Operation
Greater than 132 Volts
but less than or
equal to 144 Volts
Greater than 110% but
less than or equal to
120%
60 Cycles 1 Second
Greater than 144 Volts Greater than 120% 10 Cycles 0.16 Seconds
(1)
ystem to allow sensing of
-term disturbances to avoid nuisance tripping. Set
points shall not be user adjustable (though they may be field adjustable by qualified personnel).
c.
without causing a voltage fluctuation at the PCC greater than ±5% of the prevailing
voltage
requirements of D.2.d.
d. Flicker. The Generating Facility shall not create objectionable flicker for other
C ffects
experienced by other Customers (IEEE 1547-4.3.2), flicker at the PCC caused by the
-1992 (IEEE Recommended
Practices and Requirements for Harmonic Control in Electric Power Systems, IEEE
STD 519-1992). This requirement is necessary to minimize the adverse voltage
(SGY7MKR)RZIPSTI-( ' %%%* )(%&(%' (*((&(
GENERATING FACILITY INTERCONNECTIONS
RULE AND REGULATION 27
CITY OF PALO ALTO
UTILITIES RULES AND REGULATIONS
Issued by the City Council
Effective 12-12-2016
Sheet No. 17
affects experienced by others C
Generators may be connected and brought up to synchronous speed (as an induction
motor) provided these flicker limits are not exceeded.
e.
the Generating Facility shall not cause over-voltages that exceed the rating of the
1547-4.1.2).
f. Frequency. T
Di
varies from and remains outside normal (nominally 60 Hz) by the predetermined
cease to energiz
TABLE D.2: Frequency Trip Settings
Generating Facility Rating Frequency Range
(Assuming 60 Hz Nominal)
Maximum Trip Time (1)
(Assuming 60 Cycles per
Second
Less or equal to 30 kW
Less than 59.3 Hz 10 Cycles
Greater than 60.5 Hz 10 Cycles
Greater than 30 kW
Less than 57 Hz 10 Cycles
Less than an adjustable value
between 59.8 Hz and 57 Hz
but greater than 57 Hz (2)
Adjustable between 10 and
18,000 Cycles (2),(3)
Greater than 60.5 Hz 10 Cycles
1)
equipment and circuits may remain connected to CPA
-term disturbances to avoid nuisance tripping.
Set points shall not be user adjustable (though they may be field adjustable by qualified
personnel).
(SGY7MKR)RZIPSTI-( ' %%%* )(%&(%' (*((&(
GENERATING FACILITY INTERCONNECTIONS
RULE AND REGULATION 27
CITY OF PALO ALTO
UTILITIES RULES AND REGULATIONS
Issued by the City Council
Effective 12-12-2016
Sheet No. 18
(2) Unless otherwise required by CPAU, a trip frequency of 59.3 Hz and a maximum trip time of 10
cycles shall be used.
(3) When a 10-cycle maximum trip time is used, a second under frequency trip setting is not required.
g. Harmonics. When the Generating Facility is serving balanced linear Loads, harmonic
limits stated below in Table D.3. The harmonic current injections shall be exclusive
of any harmonic currents due to harmonic voltage distortion present in CP
Distribution System without the Generating Facility connected (IEEE 1547-4.3.3).
evaluated using the same criteria as for the Host Loads.
Table D.3 Maximum Harmonic Current Distortion in Percent of Current (I)(1,2)
Individual
Harmonic Order h,
(odd harmonics) (3)
h<11 11 h < 17 17 h < 23 23 h < 35 35 h
Total
Demand
distortion
(TDD)
Max Distortion (%) 4.0 2.0 1.5 0.6 0.3 5.0
(1) IEEE 1547-4.3.3
(2) I = the greater of the maximum Host Load current average Demand over 15 or 30 minutes without the GF, or the GF rated current capacity (transformed to the PCC when a transformer exists between the GF and the PCC).
(3) Even harmonics are limited to 25% of the odd harmonic limits above.
h. Direct Current Injection. Generating Facilities should not inject direct current greater
i. Power Factor. Each Generator in a Generating Facility shall be capable of operating
at some point within a Power Factor range from 0.9 leading to 0.9 lagging. Operation
outside this range is acceptable provided the reactive power of the Generating
Facility is used to meet the reactive power needs of the Host Loads or that reactive
power is otherwise provided under tariff by CPAU. The Producer shall notify CPAU
if it is using the Generating Facility for Power Factor correction. Unless otherwise
agreed upon by the Producer and CPAU, Generating Facilities shall automatically
(SGY7MKR)RZIPSTI-( ' %%%* )(%&(%' (*((&(
GENERATING FACILITY INTERCONNECTIONS
RULE AND REGULATION 27
CITY OF PALO ALTO
UTILITIES RULES AND REGULATIONS
Issued by the City Council
Effective 12-12-2016
Sheet No. 19
regulate Power F
Distribution System.
3. TECHNOLOGY SPECIFIC REQUIREMENTS
a. Three-Phase Synchronous Generators. For three-phase Generators, the Generating
Facility circuit breakers shall be three-phase devices with electronic or
electromechanical control. The Producer shall be responsible for properly
s of
either manual or automatic synchronizing equipment. Automatic synchronizing is
required for all synchronous Generators that have a Short Circuit Contribution Ratio
(SCCR) exceeding 0.05. Loss of synchronism protection is not required except as
may be necessary to meet D.2.d (Flicker) (IEEE 1547-4.2.5). Unless otherwise
agreed upon by the Producer and CPAU, synchronous Generators shall automatically
regulate Power F
Distribution System. A power system stabilization function is specifically not
required for Generating Facilities under 10 MW Net Nameplate Rating. Ground Fault
Protection is required for generators > 40 kW. Voltage Restraint Overcurrent or
Voltage Controlled Overcurrent relays are required for generators or a group of
generators > 400 kW.
b. Induction Generators. Induction Generators (except self-excited Induction
Generators) do not require a synchronizing Function. Starting or rapid Load
fluctuations on induction G
System's voltage. Corrective step-switched capacitors or other techniques may be
necessary and may cause undesirable ferroresonance. When these counter measures
(e.g. additional capacitors) are installed on the Producer's side of the Point of
Common Coupling, CPAU must review these measures. Additional equipment may
be required as determined in a Supplemental Review or a Detailed Study.
Ground Fault Protection is required for generators > 40 kW. Voltage Restraint
Overcurrent or Voltage Controlled Overcurrent relays are required for generators or a
group of generators > 400 kW.
c. Inverters. Only Certified inverters are approved for interconnection. Utility-
interactive inverters do not require separate synchronizing equipment. Non-utility-
-
(SGY7MKR)RZIPSTI-( ' %%%* )(%&(%' (*((&(
GENERATING FACILITY INTERCONNECTIONS
RULE AND REGULATION 27
CITY OF PALO ALTO
UTILITIES RULES AND REGULATIONS
Issued by the City Council
Effective 12-12-2016
Sheet No. 20
System. Inverters or a group of inverters > 400 kW require
Ground Fault Protection.
Inverter based systems may continue to be
installed per Section D.3.c until September 8, 2017, which is twelve (12) months
after the date the Supplement SA of UL-1741 (with California requirements) was
approved. Section D.5 may be used in all or in part, for inverter based technologies
by mutual agreement of CPAU and the Applicant.
The replacement of an existing inverter to an inverter that is of equal or greater
ability than the original is allowed per Section D.3.c. Section D.5 may be used in all
or in part, for replacement inverter based technologies by mutual agreement of CPAU
and the Applicant.
d. Single-Phase Generators. For single-phase Generators connected to a shared
single-phase secondary system, the maximum Net Nameplate Rating of the
Generating Facilities shall be 20 kVA. Generators connected to a center-tapped
service neutral must be installed such that no more than 6 kVA of unbalanced power
The current in the most heavily loaded leg
must not exceed twice that of the other leg. For Dedicated Distribution Transformer
Services, the maximum Net Nameplate Rating of a single-phase Generating Facility
shall be the transformer nameplate rating.
4. SUPPLEMENTAL GENERATING FACILITY REQUIREMENTS
a. Fault Detection. A Generating Facility with an SCCR exceeding 0.1 or one that does
two seconds of the
formation of an Unintended Island shall be equipped with Protective Functions
designed to detect Distribution System faults, both line-to-line and line-to-ground,
of the
initiation of a fault.
b. Transfer Trip. For a Generating Facility that cannot detect Distribution System faults
(both line-to-line and line-to-ground) or the formation of an Unintended Island, and
in two seconds, CPAU may
require a Transfer Trip system or an equivalent Protective Function. For net metered
(SGY7MKR)RZIPSTI-( ' %%%* )(%&(%' (*((&(
GENERATING FACILITY INTERCONNECTIONS
RULE AND REGULATION 27
CITY OF PALO ALTO
UTILITIES RULES AND REGULATIONS
Issued by the City Council
Effective 12-12-2016
Sheet No. 21
or non-net metered Generating Facilities, the Facility will be considered capable of
supporting an Unintended Island if the aggregate distributed generation output is 80%
or more of the Distribution System real--side
Distribution Protection Device.
c. Reclose Blocking. Where the aggregate Generating Facility capacity exceeds 15% of
the peak Load on any automatic reclosing device, CPAU may require additional
Protective Functions, including, but not limited to reclose-blocking on some of the
automatic reclosing devices.
5. SMART INVERTER GENERATING FACILITY DESIGN AND OPERATING
REQUIREMENTS
Section D.3.c shall continue to be used for interconnection of inverter based technologies
until September 8, 2017, twelve (12) months after the date the Supplement SA of UL-1741
(with CA requirements) was approved by the full UL-1741 Standards Technical Panel(STP).
Following such date, Section D.5 shall apply for interconnection of inverter based
technologies. Until such date, Section D.5 may be used in all or in part, for inverter based
technologies by mutual agreement of the CPAU and the Applicant.
The inverter requirements are intended to be consistent with ANSI/IEEE 1547- 2003 and
1547a Standard for Interconnecting Distributed Resources with Electric Power Systems
(IEEE 1547 including amendment 1547a). In the event of conflict between this Rule and
IEEE 1547-2003, this Rule shall take precedence. Exceptions are taken to IEEE 1547
Clauses 4.1.4.2 Distribution Secondary Spot Networks and Clauses 4.1.8.1 or 5.1.3.1, which
address Protection from Electromagnetic Interference. Rule 27 does not adopt the Generating
Facility power limitation of 10 MW incorporated in IEEE1547.
a. Protective Functions Required. Smart Inverters operating in parallel with
Distribution System shall be equipped with the following Protective Functions to
sense abnormal conditions on CPAU the Smart
Inverter to be automatically disconnected from Distribution System or to
prevent the Smart Inverter from being connected to CPAU Distribution System
inappropriately:
(SGY7MKR)RZIPSTI-( ' %%%* )(%&(%' (*((&(
GENERATING FACILITY INTERCONNECTIONS
RULE AND REGULATION 27
CITY OF PALO ALTO
UTILITIES RULES AND REGULATIONS
Issued by the City Council
Effective 12-12-2016
Sheet No. 22
i.Over and under voltage trip functions and over and under frequency trip
functions;
ii. A voltage and frequency sensing and time-delay function to prevent the Smart
Inverter from energizing a de-energized Distribution System circuit and to
prevent the Smart Inverter from reconnecting with CPAU System unless
CPAU Distribution System service voltage and frequency is within the
ANSI C84.1-1995 Table 1 Range B voltage Range of 106 volts to 127 volts
(on a 120 volt basis), inclusive, and a frequency range of 59.3 Hz to 60.5 Hz,
inclusive, and are stable for at least 15 seconds; and
iii. A function to prevent the Smart Inverter from contributing to the formation of
an Unintended Island, and cease to energize CPAU
within two seconds of the formation of an Unintended Island.
iv. Only Certified Smart Inverters are approved for interconnection. Smart
Inverters or a group of Smart Inverters > 400 kW require Ground Fault
Protection.
The Smart Inverter shall cease to energize CPAU Distribution System for
faults on CPAU System circuit to which it is connected (IEEE
1547-4.2.1). The Smart Inverter shall cease to energize CPAU
circuit prior to reclosing by CPAU equipment (IEEE
1547-4.2.2).
b. Momentary Paralleling Generating Facilities. With CPAU
switch or scheme CPAU Distribution
may be used in lieu of the Protective
Functions required for Parallel Operation.
c. Suitable Equipment Required. Circuit breakers or other interrupting equipment
located at the Article 100, the
Definitions Section of the National Electrical Code) as suitable for their intended
application. This includes being capable of interrupting the maximum available fault
current expected at their
Facilities shall be designed so that the failure of any single device or componentshall
(SGY7MKR)RZIPSTI-( ' %%%* )(%&(%' (*((&(
GENERATING FACILITY INTERCONNECTIONS
RULE AND REGULATION 27
CITY OF PALO ALTO
UTILITIES RULES AND REGULATIONS
Issued by the City Council
Effective 12-12-2016
Sheet No. 23
not potentially compromise the safety and reliability of CPAU
The Smart Inverter paralleling-device shall be capable of withstanding 220% of the
Interconnection Facility rated voltage (IEEE 1547- 4.1.8.3). The Interconnection
Facility shall have the capability to withstand voltage and current surges in
accordance with the environments defined in IEEE Std. C62.41.2-2002 or IEEE Std.
C37.90.1-2002 as applicable and as described in L.3.e (IEEE 1547- 4.1.8.2).
d. Visible Disconnect Required. Producer shall furnish and install a ganged, manually-
operated isolating switch (or a comparable device mutually agreed upon by CPAU
and Producer) near the Point of Common Coupling to isolate the Smart Inverter from
Distribution System. The device does not have to provide over-current
protection.
The device must:
i. Allow visible verification that separation has been accomplished. (This
requirement may be met by opening the enclosure to observe contact
separation.) Molded case circuit breakers do not meet the visible contact
requirement and are not acceptable as a Visible Disconnect device.
ii. Include markings or signage that clearly indicates open and closed positions.
iii. Be capable of being reached quickly and conveniently 24 hours a day by
CPAU personnel for construction, maintenance, inspection, testing or
reading, without obstacles or requiring those seeking access to obtain keys,
special permission, or security clearances.
iv. Be capable of being locked in the open position.
v. Be clearly marked on the submitted single line diagram and its type and
location approved by CPAU prior to installation. If the device is not adjacent
to the PCC, permanent signage must be installed at a CPAU approved
location providing a clear description of the location of the device. If the
switch is not accessible outside the locked premises, signage with contact
information and a CPAU approved locking device for the premises shall be
installed. Generating Facilities with Non-Islanding inverters totaling one (1)
(SGY7MKR)RZIPSTI-( ' %%%* )(%&(%' (*((&(
GENERATING FACILITY INTERCONNECTIONS
RULE AND REGULATION 27
CITY OF PALO ALTO
UTILITIES RULES AND REGULATIONS
Issued by the City Council
Effective 12-12-2016
Sheet No. 24
kilovolt-ampere (kVA) or less are exempt from this requirement.
e. Drawings Required. Prior to Parallel Operation or Momentary Parallel Operation of
the Smart Inverter, CPAU Protective Function and control
diagrams. Generating Facilities equipped with Protective Functions and a control
scheme previously approved by CPAU for system-wide application or only
Certified Equipment may satisfy this requirement by reference to previously
approved drawings and diagrams.
f. Generating Facility Conditions Not Identified. In the event this Rule does not address
the Interconnection conditions for a particular Smart Inverter, CPAU and Producer
may agree upon other arrangements, to be approved by CPAU.
g. Prevention of Interference. Producer shall not operate Smart Inverters that
superimpose a voltage or current upon Distribution System that interferes
with CPAU operations, service to CPAU Customers or communication facilities. If
such interference occurs, Producer must diligently pursue and take corrective action
at its own expense after being given notice and reasonable time to do so by CPAU. If
Producer does not take corrective action in a timely manner, or continues to operate
the facilities causing interference without restriction or limit, CPAU may, without
liability, disconnect Producer's facilities from CPAU
accordance with Section B.8 of this Rule.
h. Voltage Regulation. If approved by CPAU, the Smart Inverter may actively regulate
the voltage at the Point of Common Coupling (PCC) while in parallel with CPAU
Distribution System. The Smart Inverter shall not cause the service voltage at other
customers to go outside the requirements of ANSI C84.1-1995, Range A (IEEE
1547-4.1.1).
i. Voltage Trip and Ride-Through Settings. The voltage ranges in Table D.4 define
protective trip limits for the Protective Function and are not intended to define or
imply a voltage regulation Function. Generating Facilities shall cease to energize
CPAU Distribution System within the prescribed trip time whenever the voltage at
the PCC deviates from the allowable voltage operating range. The Protection
Function shall detect and respond to voltage on all phases to which the Generating
Facility is connected.
(SGY7MKR)RZIPSTI-( ' %%%* )(%&(%' (*((&(
GENERATING FACILITY INTERCONNECTIONS
RULE AND REGULATION 27
CITY OF PALO ALTO
UTILITIES RULES AND REGULATIONS
Issued by the City Council
Effective 12-12-2016
Sheet No. 25
j. Smart Inverters. Smart Inverters shall be capable of operating within the voltage
range normally experienced on CPAU System from plus to minus 5%
of the nominal voltage (e.g. 114 volts to 126 volts, on a 120 volt base), at the service
panel or PCC. The trip settings at the generator terminals may be selected in a
manner that minimizes nuisance tripping in accordance with Table D.4 to
compensate for voltage drop between the generator terminals and the PCC. Voltage
may be detected at either the PCC or the Point of Interconnection. However, the
voltage range at the PCC, with the generator on-line, shall stay within +/-5% of
nominal.
k. Voltage Disturbances. Whenever CPAU the PCC
varies from and remains outside Near Nominal voltage for the predetermined
parameters set forth in Table D.4, the
cause the Smart Inverter(s) to become isolated from Distribution System:
i.The Smart Inverter shall stay connected to CPAU
while the grid --time range
Mode .
ii.For voltage excursions beyond the near Nominal (NN) magnitude range and
within the range of the HV1 or LV3 regions, the Smart Inverter shall
momentarily cease to energize within 0.16 seconds.
iii. In the HV1 region, the Smart Inverter is permitted to reduce power output as
a function of voltage under mutual agreement between the Producer and
CPAU.
iv. If the distribution system voltage does not exit the ride-through region and
recovers to normal system voltage, the Smart Inverter shall restore continuous
operation within 2 seconds.
v. If the Distribution System voltage does not exit the ride-through
region and returns from the LV3 region to the LV2 or LV1 region, the Smart
Inverter shall restore available current within 2 seconds.
(SGY7MKR)RZIPSTI-( ' %%%* )(%&(%' (*((&(
GENERATING FACILITY INTERCONNECTIONS
RULE AND REGULATION 27
CITY OF PALO ALTO
UTILITIES RULES AND REGULATIONS
Issued by the City Council
Effective 12-12-2016
Sheet No. 26
vi. Different voltage-time settings could be permitted by CPAU.
Table D.4: Voltage Ride-Through Table
Region Voltage at Point
of Common
Coupling (%
Nominal Volts)
Ride-Through
Until
Operating Mode Maximum Trip
Time
High Voltage 2
(HV2)
V > 120 0.16 seconds
High Voltage 1
(HV1)
110 < V < 120 12 seconds Momentary
Cessation
13 seconds
Near Nominal
(NN)
88 < V < 110 Indefinite Continuous
Operation
Not Applicable
Low Voltage 1
(LV1)
70 < V < 88 20 seconds Mandatory
Operation
21 seconds
Low Voltage 2
(LV2)
50 < V < 70 10 seconds Mandatory
Operation
11 seconds
Low Voltage 3
(LV3)
V < 50 1 second Momentary
Cessation
1.5 seconds
l. Paralleling. The Generating Facility shall parallel with CPAU Distribution System
without causing a voltage fluctuation at the PCC greater than plus/minus 5% of the
prevailing voltage level of Distribution System at the PCC, and meet the
flicker requirements of Section D.5.m below.
m. Flicker. The Generating Facility shall not create objectionable flicker for other
customers on Distribution System. To minimize the adverse voltage effects
experienced by other customers (IEEE 1547-4.3.2), flicker at the PCC caused by the
Generating Facility should not exceed the limits defined by the "Maximum
Borderline of Irritation Curve" identified in IEEE 519-1992 (IEEE Recommended
Practices and Requirements for Harmonic Control in Electric Power Systems, IEEE
STD 519-1992). This requirement is necessary to minimize the adverse voltage
affects experienced by other Customers Distribution System. Generators
may be connected and brought up to synchronous speed (as an induction motor)
(SGY7MKR)RZIPSTI-( ' %%%* )(%&(%' (*((&(
GENERATING FACILITY INTERCONNECTIONS
RULE AND REGULATION 27
CITY OF PALO ALTO
UTILITIES RULES AND REGULATIONS
Issued by the City Council
Effective 12-12-2016
Sheet No. 27
provided these flicker limits are not exceeded.
n. Integration with Distribution System Grounding. The grounding scheme of
the Generating Facility shall not cause over-voltages that exceed the rating of the
equipment connected to Distribution System and shall not disrupt the
coordination of the ground fault protection on Distribution System (IEEE
1547-4.1.2).
o.Frequency. CPAU controls system frequency, and the Generating Facility shall
operate in synchronism with Distribution System. Whenever
Distribution System frequency at the PCC varies from and remains outside normal
(nominally 60 Hz) by the predetermined amounts set forth in Table D.2, the
Generating ll cease to energize
Distribution System within the stated maximum trip time.
p. Frequency Ride-Through Requirements. Smart Inverter based systems shall remain
connected to Distribution System while the grid is within the frequency-time
range indicated in Table D.5, and shall disconnect from the electric grid during a high
or low frequency event that is outside that frequency-time range. The frequency
values are shown in Table D.5. These values provide default interconnection system
response to abnormal frequencies. The inverter shall disconnect by the default
clearing times. In the high frequency range between 60.2 Hz and 61.5 Hz, or some
other mutually agreed range, the Smart Inverter is permitted to reduce real power
output until it ceases to export power by 61.5 Hz, or other frequency value mutually
agreed between the generating facility operator and CPAU. Islands and microgrids
may need different default frequency settings.
(SGY7MKR)RZIPSTI-( ' %%%* )(%&(%' (*((&(
GENERATING FACILITY INTERCONNECTIONS
RULE AND REGULATION 27
CITY OF PALO ALTO
UTILITIES RULES AND REGULATIONS
Issued by the City Council
Effective 12-12-2016
Sheet No. 28
Table D.5: Frequency Ride-Through and Trip Settings Table
System
Frequency
Default Settings
(Hz)
Minimum Range
of Adjustability
(Hz)
Ride-Through
Until
Ride Through
Operational
Mode
Maximum Trip
Time
f > 62 62 64 No Ride Through Not Applicable 0.16 seconds
60.5 < f < 62 60.1 62 299 seconds Mandatory
Operation
300 seconds
58.5 < f < 60.5 Not Applicable Indefinite Continuous
Operation
Not Applicable
57.0 < f < 58.5 57 59.9 299 seconds Mandatory
Operation
300 seconds
f < 57.0 53 57 No Ride Through Not Applicable 0.16 seconds
q. Harmonics. When the Smart Inverter is serving balanced linear loads, harmonic
current injection into Distribution System at the PCC shall not exceed the
limits stated in Table D.3. The harmonic current injections shall be exclusive of any
harmonic currents due to harmonic voltage distortion present in
Distribution System without the Smart Inverter connected (IEEE 1547-
4.3.3.). The harmonic distortion of a Smart Inverter shall be evaluated using the same
criteria as for the Host Loads.
r. Direct Current Injection. Smart Inverter should not inject direct current greater than
0.5% of rated output current into Distribution System.
s. Power Factor. Producer shall provide adequate reactive power compensation on site
to maintain the Smart Inverter power factor near unity at rated output or a CPAU
specified power factor in accordance with the following requirements:
i. Default Power Factor setting: 1.0 +/- 0.01 (0.99 Lagging to 0.99 Leading).
ii. Aggregate generating facility is greater than 15 kW: 1.0 +/- 0.15 (0.85
(SGY7MKR)RZIPSTI-( ' %%%* )(%&(%' (*((&(
GENERATING FACILITY INTERCONNECTIONS
RULE AND REGULATION 27
CITY OF PALO ALTO
UTILITIES RULES AND REGULATIONS
Issued by the City Council
Effective 12-12-2016
Sheet No. 29
Lagging to 0.85 Leading) down to 20% rated power based on available
reactive power.
iii. Aggregate generating facility is less than or equal to 15 kW: 1.0 +/- 0.10
(0.90 Lagging to 0.90 Leading) down to 20% rated power based on available
reactive power.
t. Dynamic Volt/VAR Operations. The Smart Inverter shall be capable of operating
dynamically within a power factor range of +/- 0.85 PF for larger (>15 kW) systems,
down to 20% of rated power, and +/- down to
20% of rated power, based on available reactive power. This dynamic Volt/VAR
capability shall be able to be activated or deactivated in accordance with CPAU
requirements.
CPAU may permit or require the Smart Inverter systems to operate in larger power
factor ranges, including in 4-quadrant operations for storage systems with the
implementation of additional anti-islanding protection as determined by CPAU.
The Smart Inverter shall be capable of providing dynamic reactive power
compensation (dynamic Volt/VAR operation) within the following constraints:
The Smart Inverter shall not cause the line voltage at the point of common
coupling to go outside the requirements of the latest version of ANSI C84.1,
Range A.
The Smart Inverter shall be able to consume reactive power in response to an
increase in line voltage, and produce reactive power in response to a decrease
in line voltage.
The reactive power provided shall be based on available reactive power, but
the maximum reactive power provided to the system shall be as directed by
CPAU.
u. Ramp Rate Requirements. The Smart Inverter is required to have the following ramp
controls for at least the following two conditions. These functions can be established
by multiple control functions or by one general ramp rate control function. Ramp
(SGY7MKR)RZIPSTI-( ' %%%* )(%&(%' (*((&(
GENERATING FACILITY INTERCONNECTIONS
RULE AND REGULATION 27
CITY OF PALO ALTO
UTILITIES RULES AND REGULATIONS
Issued by the City Council
Effective 12-12-2016
Sheet No. 30
rates are contingent upon sufficient energy available from the Smart Inverter.
Normal ramp-up rate: For transitions between energy output levels over the
normal course of operation. The default value is 100% of maximum current
output per second with a range of adjustment between 1% to 100%, with
specific settings as mutually agreed by the CPAU and the Producer.
Connect/Reconnect Ramp-up rate:Upon starting to inject power into the grid,
following a period of inactivity or a disconnection, the inverter shall be able
to control its rate of increase of power from 1 to 100% maximum current per
second, with specific settings as mutually agreed upon by CPAU and the
Producer.
v. Default Activation States for Phase 1 Functions. Unless otherwise provided by
CPAU, the default settings will be as follows:
Anti-islanding activated
Low/High Voltage Ride-Through activated
Low/High Frequency Ride-Through activated
Dynamic Volt/VAR operations deactivated
Ramp rates activated
Fixed power factor activated
- activated
These default activation states may be modified by mutual agreement between CPAU
and Producer.
w. Automatic Transfer (Load Shedding or Transfer). The voltage and frequency ride-
through requirements of D.5.i and D.5.m shall not apply if either: a) The real power
across the Point of Common Coupling is continuously maintained at a value less than
(SGY7MKR)RZIPSTI-( ' %%%* )(%&(%' (*((&(
GENERATING FACILITY INTERCONNECTIONS
RULE AND REGULATION 27
CITY OF PALO ALTO
UTILITIES RULES AND REGULATIONS
Issued by the City Council
Effective 12-12-2016
Sheet No. 31
10% of the aggregate rating of the Smart Inverters connected to the Generation
Facility prior to any voltage disturbance, and the Generation Facility disconnects
from distribution system, along with Generation Facility load, such that the
net change in real power flow from or to CPAU is less than 10% of the aggregate
Smart Inverter capacity; or b) Generation Facility load real power demand equal to
90% to 120% of the pre-disturbance aggregate Smart Inverter real power output is
shed within 0.1 seconds of Smart Inverter disconnection.
x. Fault Detection. A Smart Inverter with an SCCR exceeding 0.1 or one that does not
cease to energize CPAU
of an Unintended Island shall be equipped with Protective Functions designed to
detect Distribution System faults, both line-to-line and line-to-ground, and cease to
energize Distribution System within two seconds of the initiation of a fault.
y. Transfer Trip. For a Generating Facility that cannot detect Distribution System faults
(both line-to-line and line-to-ground) or the formation of an Unintended Island, and
cease to energize Distribution System within two seconds, CPAU may
require a Transfer Trip system or an equivalent Protective Function.
z. Reclose Blocking. Where the aggregate Generating Facility capacity exceeds 15% of
the peak load on any automatic reclosing device, CPAU may require additional
Protective Functions, including, but not limited to reclose-blocking on some of the
automatic reclosing devices.
E. INTERCONNECTION FACILITIES AND DISTRIBUTION SYSTEM
MODIFICATIONS OWNERSHIP AND COST ALLOCATION
1. SCOPE AND OWNERSHIP OF INTERCONNECTION FACILITIES AND
DISTRIBUTION SYSTEM MODIFICATIONS
a. Scope. Parallel Operation of Generating Facilities may require Interconnection
Distribution System modifications shall be consistent with this Rule and determined
through the Supplemental Review and/or Interconnection Studies described in
Section C.
(SGY7MKR)RZIPSTI-( ' %%%* )(%&(%' (*((&(
GENERATING FACILITY INTERCONNECTIONS
RULE AND REGULATION 27
CITY OF PALO ALTO
UTILITIES RULES AND REGULATIONS
Issued by the City Council
Effective 12-12-2016
Sheet No. 32
b. Ownership.
be owned, operated and maintained by the Producer or CPAU. Interconnection
modifications shall be owned, operated and maintained only by CPAU.
2. RESPONSIBILITY OF COSTS OF INTERCONNECTING A GENERATING
FACILITY
a. Study and Review Costs. A Producer shall be responsible for the reasonably incurred
costs of the reviews and studies conducted pursuant to Section C.1 of this Rule.
b. Facility Costs. A Producer shall be responsible for all costs associated with
Interconnection Facilities owned by the Producer. The Producer shall also be
responsible for any costs reasonably incurred by CPAU in providing, operating, or
maintaining the Interconnection Facilities and Distribution System modifications
Distribution System.
c. Separation of Costs. Should CPAU combine the installation of Interconnection
Facilities or Distribution System modifications required for the Interconnection of a
Customers or Producers, CPAU shall not include the costs of such separate or
incremental facilities in the amounts billed to the Producer.
d.Payments. The Producer must pay applicable costs prior to the scheduling of any
engineering reviews and studies; construction of distribution system modifications; or
3. INSTALLATION AND FINANCING OF INTERCONNECTION FACILITIES AND
DISTRIBUTION SYSTEM MODIFICATIONS
a.Agreement Required. The costs for Interconnection Facilities and Distribution
System modifications shall be paid by the Producer pursuant to the Provisions
contained in the Special Facilities Agreement. Where the type and extent of the
(SGY7MKR)RZIPSTI-( ' %%%* )(%&(%' (*((&(
GENERATING FACILITY INTERCONNECTIONS
RULE AND REGULATION 27
CITY OF PALO ALTO
UTILITIES RULES AND REGULATIONS
Issued by the City Council
Effective 12-12-2016
Sheet No. 33
Interconnection Facilities or Distribution System modifications warrant additional
detail, Producer and CPAU shall execute separate agreement(s) to more fully
maintaining the Interconnection Facilities and Distribution System modifications.
b.Interconnection Facilities and Distribution System Modifications. Interconnection
Distribution System modifications shall be provided, installed, owned and
maintained by CPAU at
c.Reservation of Unused Facilities. When a Producer wishes to reserve CPAU-owned
Interconnection Facilities or Distribution System modifications installed and operated
led by a change in
the operation of the Producer's Generating Facility or otherwise, Producer may elect
to abandon or reserve such facilities consistent with the terms of its agreement with
CPAU. If Producer elects to reserve idle Interconnection Facilities or Distribution
System modifications, CPAU shall be entitled to continue to Charge Producer for the
costs related to the ongoing operation and maintenance of the Special Facilities.
d.Refund of Salvage Value. When a Producer elects to abandon the Special Facilities
for which it has either advanced the installed costs or constructed and transferred to
CPAU, the Producer shall not receive a credit for the net salvage value of the Special
Facilities.
F. METERING, MONITORING AND TELEMETRY
1. GENERAL REQUIREMENTS
All Generating Facilities shall be metered in accordance with this Section F and shall
published CPAU manuals dealing with Metering specifications. For general metering
requirements, see CPAU Rule and Regulation 15. For net metering requirements, see
CPAU Rule and Regulation 29.
2. METERING BY CPAU
The ownership, installation, operation, reading and testing of revenue Metering Equipment
(SGY7MKR)RZIPSTI-( ' %%%* )(%&(%' (*((&(
GENERATING FACILITY INTERCONNECTIONS
RULE AND REGULATION 27
CITY OF PALO ALTO
UTILITIES RULES AND REGULATIONS
Issued by the City Council
Effective 12-12-2016
Sheet No. 34
for Generating Facilities shall be by CPAU only.
3. NET GENERATION METERING
For purposes of monitoring Generating Facility operation to determine standby Charges and
applicable non-bypassable C
planning and operations, consistent with Section B.4 of this Rule, CPAU shall have the right
to specify the type, and require the installation of Net Generation Metering equipment.
CPAU shall only require Net Generation Metering to the extent that less intrusive and/or
more cost effective options for providing the necessary Generating Facility output data are
not available. In exercising its discretion to require Net Generation Metering, CPAU shall
consider all relevant factors, including but not limited to:
a. Data requirements in proportion to need for information;
b.
operational requirements;
c. Accuracy and type of required Metering consistent with purposes of collecting data;
d. Cost of Metering relative to the need for and accuracy of the data;
e.
f. Other means of obtaining the data (e.g., Generating Facility logs, proxy data etc.);
and
g. Requirements under any Interconnection Agreement with the Producer.
4. POINT OF COMMON COUPLING METERING
For purposes of assessing CPAU C
shall be reviewed by CPAU, and if required, replaced to ensure that it will appropriately
measure Electric power according to the P Electric Service tariff.
Meter may be replaced with a bi-directional meter
ded.
Alternately, the Producer may, at its sole option and cost, require CPAU to install Multi-
Metering E
and retail purchases from CPAU. Where necessary, such PCC Metering shall be designed to
prevent reverse registration.
5. TELEMETERING
(SGY7MKR)RZIPSTI-( ' %%%* )(%&(%' (*((&(
GENERATING FACILITY INTERCONNECTIONS
RULE AND REGULATION 27
CITY OF PALO ALTO
UTILITIES RULES AND REGULATIONS
Issued by the City Council
Effective 12-12-2016
Sheet No. 35
If the nameplate rating of the Generating Facility is 1 MW or greater, telemetering equipment
at the Net Generator Metering location may be required at the Producer's expense. If the
Generating Facility is interconnected Distribution System operating
at a voltage below 10 kV, then Telemetering equipment may be required on Generating
Facilities 250 kW or greater. CPAU shall only require Telemetering to the extent that less
intrusive and/or more cost effective options for providing the necessary data in real time are
not available
6. LOCATION
Where CPAU-Premises, Producer shall
provide, at no expense to CPAU, a suitable location for all such Metering Equipment as set
forth in CPAU Rule and Regulation 15.
7. COSTS OF METERING
The Producer will bear all costs of the Metering required by this Rule, including the
incremental costs of operating and maintaining the Metering Equipment.
(END)
(SGY7MKR)RZIPSTI-( ' %%%* )(%&(%' (*((&(
'IVXMJMGEXI3J'SQTPIXMSR
)RZIPSTI-H ' %%%* )(%&(%' (*((&( 7XEXYW 'SQTPIXIH
7YFNIGX 4PIEWI(SGY7MKRXLIWIHSGYQIRXW 6)73 6YPI+IRIVEXMRK*EGMPMX]-RXIVGSRRIGXMSRTHJ6)73
7SYVGI)RZIPSTI
(SGYQIRX4EKIW 7MKREXYVIW )RZIPSTI3VMKMREXSV
7YTTPIQIRXEP(SGYQIRX4EKIW -RMXMEPW /MQ0YRX
'IVXMJMGEXI4EKIW
%YXS2EZ )REFPIH
)RZIPSTI-H7XEQTMRK )REFPIH
8MQI>SRI 98'
4EGMJMG8MQI 97
'EREHE
4E]QIRXW ,EQMPXSR%ZI
4EPS%PXS'%
OMQFIVP]PYRX$GMX]SJTEPSEPXSSVK
-4%HHVIWW
6IGSVH8VEGOMRK
7XEXYW 3VMKMREP
%1
,SPHIV /MQ0YRX
OMQFIVP]PYRX$GMX]SJTEPSEPXSSVK
0SGEXMSR (SGY7MKR
7MKRIV)ZIRXW 7MKREXYVI 8MQIWXEQT
%Q]&EVXIPP
%Q]&EVXIPP$'MX]SJ4EPS%PXSSVK
7IRMSV(ITYX]'MX]%XXSVRI]
'MX]SJ4EPS%PXS
7IGYVMX]0IZIP )QEMP%GGSYRX%YXLIRXMGEXMSR
2SRI
9WMRK-4%HHVIWW
7IRX %1
:MI[IH %1
7MKRIH %1
)PIGXVSRMG6IGSVHERH7MKREXYVI(MWGPSWYVI
%GGITXIH %1
-( H IGFHIJ G HIE
0EPS4IVI^
0EPS4IVI^$'MX]SJ4EPS%PXSSVK
'LMIJ*MRERGMEP3JJMGIV
'MX]SJ4EPS%PXS
7IGYVMX]0IZIP )QEMP%GGSYRX%YXLIRXMGEXMSR
2SRI
9WMRK-4%HHVIWW
7MKRIHYWMRKQSFMPI
7IRX %1
:MI[IH 41
7MKRIH 41
)PIGXVSRMG6IGSVHERH7MKREXYVI(MWGPSWYVI
2SX3JJIVIHZME(SGY7MKR
-(
)H7LMOEHE
IHWLMOEHE$GMX]SJTEPSEPXSSVK
%WWMWXERX'MX]1EREKIV
'MX]SJ4EPS%PXS
7IGYVMX]0IZIP )QEMP%GGSYRX%YXLIRXMGEXMSR
2SRI
9WMRK-4%HHVIWW
7MKRIHYWMRKQSFMPI
7IRX 41
:MI[IH 41
7MKRIH 41
)PIGXVSRMG6IGSVHERH7MKREXYVI(MWGPSWYVI
2SX3JJIVIHZME(SGY7MKR
-(
.EQIW/IIRI
NEQIWOIIRI$GMX]SJTEPSEPXSSVK
'MX]1EREKIV
'MX]SJ4EPS%PXS
7IGYVMX]0IZIP )QEMP%GGSYRX%YXLIRXMGEXMSR
2SRI
9WMRK-4%HHVIWW
7MKRIHYWMRKQSFMPI
7IRX 41
:MI[IH 41
7MKRIH 41
)PIGXVSRMG6IGSVHERH7MKREXYVI(MWGPSWYVI
%GGITXIH 41
-( JIEE GFFH EG I
7MKRIV)ZIRXW 7MKREXYVI 8MQIWXEQT
4EXVMGO&YVX
TEXFYVX$KQEMPGSQ
7IGYVMX]0IZIP )QEMP%GGSYRX%YXLIRXMGEXMSR
2SRI
9WMRK-4%HHVIWW
7IRX 41
:MI[IH 41
7MKRIH 41
)PIGXVSRMG6IGSVHERH7MKREXYVI(MWGPSWYVI
2SX3JJIVIHZME(SGY7MKR
-(
&IXL1MRSV
&IXL1MRSV$'MX]SJ4EPS%PXSSVK
'MX]'PIVO
'MX]SJ4EPS%PXS
7IGYVMX]0IZIP )QEMP%GGSYRX%YXLIRXMGEXMSR
2SRI
9WMRK-4%HHVIWW
7IRX 41
:MI[IH 41
7MKRIH 41
)PIGXVSRMG6IGSVHERH7MKREXYVI(MWGPSWYVI
2SX3JJIVIHZME(SGY7MKR
-(
-R4IVWSR7MKRIV)ZIRXW 7MKREXYVI 8MQIWXEQT
)HMXSV(IPMZIV])ZIRXW 7XEXYW 8MQIWXEQT
%KIRX(IPMZIV])ZIRXW 7XEXYW 8MQIWXEQT
-RXIVQIHMEV](IPMZIV])ZIRXW 7XEXYW 8MQIWXEQT
'IVXMJMIH(IPMZIV])ZIRXW 7XEXYW 8MQIWXEQT
'EVFSR'ST])ZIRXW 7XEXYW 8MQIWXEQT
2SXEV])ZIRXW 8MQIWXEQT
)RZIPSTI7YQQEV])ZIRXW 7XEXYW 8MQIWXEQTW
)RZIPSTI7IRX ,EWLIH)RGV]TXIH 41
'IVXMJMIH(IPMZIVIH 7IGYVMX]'LIGOIH 41
7MKRMRK'SQTPIXI 7IGYVMX]'LIGOIH 41
'SQTPIXIH 7IGYVMX]'LIGOIH 41
4E]QIRX)ZIRXW 7XEXYW 8MQIWXEQTW
)PIGXVSRMG6IGSVHERH7MKREXYVI(MWGPSWYVI