commissioning standard for embedded generators in …

PCM Reference: Perform Testing and Certification of Generator

SCOT Study Committee Number/Name: Plant Operating Steering Committee

Standard Technology

Title: COMMISSIONING STANDARD FOR EMBEDDED GENERATORS IN LOW VOLT INSTALLATIONS

Unique Identifier: 240-103407540

Alternative Reference Number: <n/a>

Area of Applicability: Engineering

Documentation Type: Standard

Revision: 1

Total Pages: 13

Next Review Date: February 2021

Disclosure Classification: Controlled Disclosure

Compiled by Approved by Authorized by

Koos Kraftt

Senior Consultant

Dumisani Mtolo

Chief Engineer

Prince Moyo

Power Delivery Engineering GM

Date: Date: Date:

Supported by SCOT/SC

Colin Smith

Plant Operating SC

Date:

Document Classification: Controlled Disclosure

COMMISSIONING STANDARD FOR EMBEDDED GENERATORS IN LOW VOLT INSTALLATIONS


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When downloaded from the WEB, this document is uncontrolled and the responsibility rests with the user

to ensure it is in line with the authorized version on the WEB.

Content

Page

1. Introduction .................................................................................................................................................. 3

2. Supporting Clauses ..................................................................................................................................... 3

2.1 Scope ................................................................................................................................................. 3

2.1.1 Purpose .................................................................................................................................. 3

2.1.2 Applicability ............................................................................................................................ 3

2.2 Normative/Informative References ..................................................................................................... 3

2.2.1 Normative ............................................................................................................................... 3

2.2.2 Informative ............................................................................................................................. 3

2.3 Definitions ........................................................................................................................................... 4

2.3.1 General .................................................................................................................................. 4

2.3.2 Disclosure Classification ........................................................................................................ 4

2.4 Abbreviations ...................................................................................................................................... 4

2.5 Roles and Responsibilities ................................................................................................................. 4

2.6 Process for monitoring ....................................................................................................................... 4

2.7 Related/Supporting Documents ......................................................................................................... 5

3. Document Content ....................................................................................................................................... 5

3.1 Compliance Management .................................................................................................................. 5

3.1.1 Compliance Criteria and Application ...................................................................................... 5

3.2 Compliance assessment process ...................................................................................................... 5

3.2.1 Pre-commissioning verification .............................................................................................. 5

3.2.2 Commissioning tests .............................................................................................................. 5

3.2.3 Compliance Assurance Documentation ................................................................................. 5

3.3 Installation Compliance ...................................................................................................................... 6

3.3.1 Pre-commissioning Verification.............................................................................................. 6

3.3.2 Commissioning Test .............................................................................................................. 7

3.3.3 General OHSA Requirements................................................................................................ 8

4. Authorisation ................................................................................................................................................ 9

5. Revisions ..................................................................................................................................................... 9

6. Development team ...................................................................................................................................... 9

7. Acknowledgements ..................................................................................................................................... 9

Annex A – Commissioning Check Sheet .......................................................................................................... 10




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1. Introduction

A key constraint to the implementation of grid-connected small-scale renewable energy in South Africa is the lack of pre-approved, generic standards for utility engineers and system promoters to apply in designing and approving the utility interface. This document set a standard for the commissioning of embedded generators in low Volt installations to the Eskom network.

2. Supporting Clauses

2.1 Scope

This Commissioning Standard applies to embedded generators of nominal capacity less than 1000 kW, connected to a single-phase, dual-phase, or three-phase low-voltage utility network via a transformer dedicated to such load and/or generator. This applies in particular to installations where a single Embedded Generator and/or load is connected to a dedicated transformer

2.1.1 Purpose

This document shall assist and guide the technical assessment and compliance certification of Embedded Generators onto the Distribution network.

2.1.2 Applicability

This document shall apply throughout Eskom Holdings Limited Divisions.

2.2 Normative/Informative References

Parties using this document shall apply the most recent edition of the documents listed in the following paragraphs.

2.2.1 Normative

[1] Occupational Health and Safety Act 85 of 1993

[2] GNR. 242 of 6 March 2009: Electrical Installation Regulations

[3] GNR 250 of 25 March 2011: Electrical Machine Regulation

[4] GNR 1010 of 18 July 2003: Construction Regulation

[5] GNR 1521 of 5 August 2008” General Machine Regulation

[6] SANS 10142-1 of 2012: Wiring of premises Part 1: Low Volt Installations

[7] Eskom Distribution Supplementary Agreement To The Large Power User Electricity Supply Agreement With Small And Micro Generators

[8] NRS 097-2-1: Grid Interconnection of Embedded Generation - Part 2: Small-scale embedded generation - Section 1: Utility interface

[9] NRS 097 -2 -3: Grid Interconnection of Embedded Generation – Part 2 – Section 3: Simplified utility connection criteria for low-voltage connected generators

[10] 34-1195 Handing Over Documentation Major Distribution Minor Distribution &Electrification

2.2.2 Informative

None




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2.3 Definitions

2.3.1 General

Definition Description

Customers competent Agent

A suitably certified person delegated by, and that represents the EG user or lessor

Embedded Generator One or more energy generation sources that include(s) the energy conversion device (devices), the static power converter (converters), if applicable, and the control and protection gear within a customer’s network that operates in synchronism with the utility’s supply

Point of Control Means the pointat which an electrical installation on or in any premisecan be switched off by a user or lessor from the electricity supplied from the point of suppl, ot the point at which a particular part of the electrical installation on or in any premise can be switched off where different users occupy different portions of such premises

2.3.2 Disclosure Classification

Controlled disclosure: controlled disclosure to external parties (either enforced by law, or discretionary).

2.4 Abbreviations

Abbreviation Description

AC Alternating Current

CoC Certificate of Compliance in terms of the Electrical Installation Regulation 7

DC Direct Current

EG Embedded Generation

GMR General Machine Regulation (GNR. 1521 of 5 August 1988

MCB Miniature Circuit Breaker

POC Point of Control

POS Point of Supply

PUC Point of Utility Coupling

2.5 Roles and Responsibilities

Power Delivery Engineering shall maintain and update this standard in accordance with the SCOT process and in consultation with the Grid Access Team as and when required.

The Maintenance and Operating function in the respective Operating Units will ensure that this document is complied with. An installation will be commissioned and the compliance checks sheet signed off by an appointed GMR 2(1) or GMR 2(7), in accordance with this regulation.

Network Planning and Network Optimisation Engineers will collaborate to analyse the network capacity to host the EG and set the operating limits and parameters that the EG shall be subject to.

2.6 Process for monitoring

Not applicable.




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2.7 Related/Supporting Documents

Not applicable.

3. Document Content

3.1 Compliance Management

Critical requirements for embedded generator synchronising with the Eskom network are extracted below and will serve as key criteria for grid synchronisation. To consistently apply the requirements the following criteria and evaluation will be used:

3.1.1 Compliance Criteria and Application

a) Fully Compliant Installations: A Generator that meets all requirements contained in documents listed as normative references above and is commissioned to maintain its condition and performance over the design period.

A fully compliant Installation may be connected to and synchronised with the grid.

b) Partially Compliant Installations: A Generator that does not meet all requirements contained in documents listed as normative references above, but where the non-conformance noted will not deteriorate the Health and safety of man, animals or supply quality.

A partially compliant installation may be connected to and synchronised with the Utility network provided that the user or lessor of the machine is advised of the partial non-compliance in writing and directed to restore/standardise the condition or performance within a period that takes cognisance of the risk.

c) Non-compliant Installations: A Generator that does not meet all requirements contained in documents listed as normative references above and where the non-conformance pose a threat to the health and safety of man, animals, asset and supply quality.

A non-compliant installation shall not be allowed to be connected or synchronised with the utility network.

3.2 Compliance assessment process

3.2.1 Pre-commissioning verification

Pre-commissioning verification will be performed by the designated Supervisor of Machinery (GMR 2(1)) or their delegates in consultation with the Customer Services Agent handling the grid connection application. The relevant documentation shall be obtained by the customer services agent and presented to the GMR 2(1) for his scrutiny. Should all requirements listed in this document be complied with, the GMR 2(1) shall update and sign the applicable section of the Technical Commissioning sheet. Where required, a concern will be resolved with the customer and their competent agent.

3.2.2 Commissioning tests

The tests directed in this document will be conducted, either by an Eskom employee designated by the GMR 2(1) or by the Customers Competent Agent and verified by the designated Eskom employee. On completion of each test, the relevant section of the commissioning check sheet will be completed and signed off by the delegated employee.

3.2.3 Compliance Assurance Documentation

The text below defines the inspection points, reference material that details the performance criteria and detail information that the Embedded Generation should conform to. The inspection check list and compliance certification is published in 34-1195: Handing over Documentation Major Distribution Minor Distribution & Electrification.




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3.3 Installation Compliance

3.3.1 Pre-commissioning Verification

a) Commissioning verification 1: Network planning anal ysis: In response of the network constraints, a network analysis will be conducted to determine the feasibility of an Embedded Generator in any location on the network. This analysis will include:

1) A Network Planning Study: and

2) A Quality of Supply Study: and

3) A Network Optimisation Study

During commissioning and certification of the embedded generator, particular attention will be paid to the limits, constraints, system configuration and invertor setting requirements recommended in the study. All conditions for normal and contingency network conditions will be met prior to installation certification. The comparison between the network planning analysis and EG type test certification shall include:

4) The EG capacity (kW)

5) Nominal Voltage (Single and three phase)

6) The number of phases that the EG connect to the Eskom network

7) A PV system diagram will be used to confirm the PV and Invertor configuration

b) Commissioning verification 2: NRS 097-2-1: Par 4.1.1.5 requires that “The embedded generator shall be type approved, unless otherwise agreed upon with the utility”. A copy of the approval issued by an Accredited Standards Authority shall be obtained and retained in the installation commissioning: customer service pack.

c) Commissioning verification 3: NRS 097 -2-1: Par 4.2.2.3.2 requires that “The embedded generator shall cease to energize the utility distribution system should the network voltage deviate outside the conditions specified in table 2. This applies to any phase of a multiphase system. The system shall sense abnormal voltage and respond. The following conditions shall be met, with voltages in R.M.S. and measured at the PUC”.

Voltage Range Maximum Trip time

V , 50% 0.2 S

50 % ≤ V < 85 % 2 S

85 % ≤ V ≤ 110 % Continuous operation

110 % < V < 120 % 2 S

120 % ≤ V 0,16 s

The Voltage out of Range compliance will be verified by confirming the results documented in the Type Test Certificate for the specific generator.

d) Commissioning verification 3: NRS 097-2-1: Par 4.1.1.8 requires “A customer with a multiphase connection shall split the embedded generator over all phases if the EG is larger than 6 kW”. The EG will connect and generate over the utility phases as follows.

EG Capacity (kW) Eskom MCB Rating (A)

Phases

1.2 20 1ɸ

3.5 60 1ɸ

4.6 80 1ɸ

13.8 80 3ɸ

>13.8 # 3ɸ




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e) Commissioning verification 4: Electrical Installation Compliance

1) Electrical Installation Regulation 7(1): “Customer to produce a valid CoC for the installation of interest”:

and/or

2) Electrical Installation Regulation 7(4): “Customer to produce a valid CoC for the extension (E.G.) to the installation”

3) The CoC will be issued by a registered person in terms of the Electrical Installation Regulation 11. A copy of this registration will be attached to the Commissioning Jacket

NOTE: This certificate will exclude the Embedded Generator components but include all components of the circuit from the Customer Distribution Board up and too the terminals at the end of the cable connected to the Embedded Generator. The embedded generator shall be certified to comply will all prescriptions by a Registered Professional Engineer.

3.3.2 Commissioning Test

a) Commissioning test 1: NRS 097 -2-1: Par 4.2.2.4.5 requires “ that an islanding condition shall cause the embedded generator to cease to energize the utility network within 2 s, irrespective of connected loads or other embedded generators. The embedded generator shall comply with the requirements of IEC 62116 (ed. 1).

This feature will be physically tested on first energisation by synchronising the Embedded Generator to the Eskom network whilst measuring the Voltage over any two phases on the load side of the Eskom MCB. After at least 5 minutes, a loss of network condition by switching off the Eskom MCB in the meter box to be mimicked. The reading of the volt meter will drop to Zero Volt within 2 seconds of the MCB being switched off.

The test shall be performed by the Customer’s Agent, in the presence of the GMR 2(1) or his delegate

b) Commissioning test 2: NRS 097 -2-1: Par 4.2.3 requires that “After a voltage or frequency out-of-range condition that has caused the embedded generator to cease energizing the utility network, the generator shall not re-energize the utility network for 60 s after the utility service voltage and frequency have recovered to within the specified ranges.

This feature will be verified directly after the test in b) above. With the Eskom MCB switched off and invertors not generating an AC clamp Amp meter will be applied to an EG supply cable core. The Eskom supply will be restored and 1 minute will pass before a current is recorded on the clamp Amp meter.

The test shall be performed by the Customer’s Agent in the presence of the GMR 2(1) or his delegate

c) Commissioning test 3: NRS 097 -2-1: Par 4.1.4 requires that “The static power converter of the embedded generator shall not inject DC current exceeding 1 % of the rated AC output current into the utility AC interface under any operating condition in accordance with IEC 61727. This relates specifically to Embedded Generators where the static power converter has no simple separation from the utility network (e.g. inverters that are transformer-less)”.

The customer agent will measure the DC current injected onto the Eskom network for compliance using a “halls effect” clamp Amp meter in the presence of the Eskom GMR 2(1) or his delegate.

d) Commissioning Test 4: NRS 097 -2-1: Par 4.2.4.1 states that “The embedded generator shall provide a means of isolating from the utility interface in order to allow for safe maintenance of the EG. The disconnection device shall be a double pole for a single-phase EG, a three-pole for a three-phase delta-connected EG, and a four-pole for a three phase star-connected EG. The grid supply side shall be wired as the source”.

This point of isolation will be identified and the function verified, by testing and verifying that the inverters are actually switched off and on from this point.




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e) Eskom Distribution Supplementary Agreement to the L arge Power User Electricity Supply Agreement with Small and Micro Generators Annex B: Paragraph 6 requires: A point of control for use by both ESKOM and the CUSTOMER between the EG installation and POS shall be constructed by the CUSTOMER in following way:

1) Commissioning check 5 : “This POC is to be constructed as close as possible to the ESKOM POS and in a location that is agreed with ESKOM. The location is to be freely accessible to both ESKOM and the CUSTOMER. Confirmation of the agreed location shall be included in the Compliance Certificate to be provided by the CUSTOMER to ESKOM in accordance with Clause 7 of the Supplementary Agreement”;

2) Commissioning check 6 : “The design and construction specifications for the POC including but not limited to; the housing, electrical wiring, foundation and support structure and locking mechanism, shall be done in accordance with SANS 10142 - Section 6.1.2.2 and shall be confirmed in the Compliance Certificate to be provided by the CUSTOMER to ESKOM in accordance with Clause 7 of the Supplementary Agreement” ;

3) Commissioning check 7 : “The POC is to be clearly marked and designed as a controlled isolation point”;

4) Commissioning Check 8 : “The POC is to have a robust isolator / miniature circuit breaker approved by the South African Bureau of Standards. The MCB should handle a DC current of 1% of the embedded generators current capacity under normal conditions. The PUC is to have detection and isolation mechanisms to ensure that the DC off-set is kept below 1% of EG current capacity under normal conditions”; and

5) Commissioning check 9 : “The PUC is to use a barrel bolt locking system as agreed with the ESKOM responsible persons with an ESKOM lock (provide by ESKOM) on one end and the CUSTOMER's lock on the other end. The system shall be capable to have two locks per side”.

f) Commissioning Check 10: NRS 097 -2-1: Par 4.2.4.2 states that “ The breaking capacity of the isolation circuit- breaker closest to the point of utility connection shall have a minimum fault current level of 6 kA in accordance with SANS 60947-2”.

g) Commissioning Test 11: Eskom Distribution Supplemen tary Agreement to the Large Power User Electricity Supply Agreement with Small and Mi cro Generators Annex B : Paragraph 7.3 requires that “On first commissioning ESKOM will determine the phase rotation and will indicate the phase rotation inside the ESKOM meter box with a permanent marker for future reference. ESKOM will communicate the phase rotation to the CUSTOMER. Should the phase rotation change, the CUSTOMER shall request ESKOM, via the ESKOM contact centre, to reset the phase rotation”.

h) Commissioning Check 12: Eskom Distribution Suppleme ntary Agreement to the Large Power User Electricity Supply Agreement with Small and Micro Generators Annex B: Paragraph 6.1 requires that “The following will be applicable whether the EG installation is visible to the ESKOM employees or not, feature warning labels in accordance with SANS (141, 1091, 2286 and 1274) specifications to alert to the existence of an EG shall be affixed by the CUSTOMER under supervision of ESKOM operators, during a scheduled network outage (dead network), as requested by CUSTOMER. The warning labels shall be affixed to the ESKOM transformer installation (support structures or transformer room doors as determined by the ESKOM authorised person), ESKOM and CUSTOMER meter boxes and the PUC. Confirmation of compliance with this Section 6.1.1 shall be recorded in the Compliance Certificate to be provided by the CUSTOMER to ESKOM in accordance with Clause 7 of the Supplementary Agreement.

3.3.3 General OHSA Requirements

a) OHSA compliance check 1: General Machine Regulation 3(b): r equires “Machinery fenced and enclosed with suitable technology”.




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b) OHSA compliance checks 2: Electrical Machine Regula tion 5 Requires “Notices applied to fenced off areas containing embedded generation technology”.

1) Prohibit unauthorised persons from entering such premises

2) Prohibit unauthorised persons from handling or interfering with electrical machinery

3) Contain direction of procedure in case of fire

4) Contains directions on how to resuscitate persons suffering from the effects of electric shock

c) OHSA compliance check 15: OHSA Section 8(2) (e): requires “Customer to produce a copy of information and instructions to ensure the health and safety of his employees in conjunction with the installation”

4. Authorisation

This document has been seen and accepted by:

Name and surname Designation

Dr Hendri Geldenhuys Corporate Specialist - engineering

Dumisani Mtolo Chief Engineer – PDE:DBOUS

Ravi Moonsamy Senior Advisor Independent Power

5. Revisions

Date Rev Compiler Remarks

Feb 2016 1 Koos Kraftt Commissioning Standard.

6. Development team

The following people were involved in the development of this document:

• Dr Hendri Geldenhuys

• Dumisani Mtolo

• David Ntombela

• Ravi Moonsamy

7. Acknowledgements

• Northern Cape Operating Unit: Maintenance and Operating Staff

• Western Cape Operating Unit: Maintenance and Operating Staff




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Annex A – Commissioning Check Sheet

1) Installation Identification

Customer Name

Installation Name

Project Number

Power Line Name

Electrical Address/Pole Number

Installation GPS location ° ‘ “ (S) ° ‘ “ (E)

Installation Number

Physical address

2) Pre-commissioning verification by GMR 2(1) or de legate

a) Network Planning Specifications/Limitations for EG

2.1.1 EG Capacity (kW)

2.1.2 EG nominal Voltage Single Phase (V) Three Phase (V)

2.1.3 Number of LV Phases Single Phase Three Phase

2.1.4 Number of inverters in the installation

2.1.5 Total number of PV panels per inverter

2.1.6 Per invertor: Number of PV panels in series

2.1.7 Per Invertor: Number of PV panels in parallel

2.1.8 Eskom phase connected (for single phase only) Rɸ Wɸ Bɸ

NOTE 1: A system diagram of the EG shall be attached to this check sheet

b) “As built” Specifications of EG

2.2.1 EG Capacity (kW)

2.2.2 EG nominal Voltage Single Phase (V) Three Phase (V)

2.2.3 Number of LV Phases Single Phase Three Phase

2.2.4 Number of inverters in the installation

2.2.5 Total number of PV panels per invertor

2.2.6 Per invertor: Number of PV panels in series

2.2.7 Per Invertor: Number of PV panels in parallel

2.1.9 Manufacturer name and model of inverter

2.1.10 Manufacturer name and model of PV panels




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c) Invertor type testing certificate

A generic type test certificate for every different make and model of inverter installed shall be sufficient, providing that the make and models installed is verified during commissioning.

i. Inverters

A Invertors serial numbers

B Manufacturers name

C Model Name/number

D Nominal Voltage DC (Installed)

E Nominal Voltage AC (Installed)

F Authority issuing the Certificate

G Date of certification

H Automatic Voltage separation Compliance (See par 3.3.1 c))

Compliant Non-compliant

ii. Installation Certificate of Compliance (Electri cal Installation GNR. 242 of 6 March 2009)

Name of Issuing Authority

Name of Registered person

Registration Number

Accreditation Level Single Phase Tester Installation Electrician Master Installation

Electrician

Scope of CoC EIR 7(1) Complete installation EIR 7(4) EG Extension only

iii. Pre-commission Compliance verifier

Name

Designation

Date

Signature




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3) Commissioning Tests

Compliance Test No

Performance Requirement Compliance

1 Anti-islanding separation within 2 seconds Yes No

2 After separation synchronisation delay longer than 1 min after Eskom switch on

Yes No

3 EG - DC current component less than 1 % of EG current capacity

Yes No

4 EG POC isolating the EG system when MCB is switched off

Yes No

5 EG/Installation - Point of Control freely accessible and near Eskom Point of supply

Yes No

6 The construction of the POC cubicle is sturdy and meet the requirements of SANS 10142-1

Yes No

7 The POC is clearly marked as the installation POC Yes No

8 The POC isolator/MCB meets the requirement of SANS 10142-1.

Yes No

9 The POC is locked with a barrel lock system and contain both the customer and Eskom standard locks

Yes No

10 The POC isolator/MCB have a fault current rating of 6 kA or more

Yes No

11 The three phase installation phase rotation is measured and rotation direction is drawn onto the installation with a permanent marker pen in the meter box

Yes No

12 All warning labels are affixed in accordance with paragraph 3.3.2 h)

Yes No

4) General OHSA Compliance

OHSA Requirement Compliance

The EG machinery and installation is suitably fenced off

Yes No

The EG fence contains the following that : Prohibit unauthorised persons from entering such premises

Prohibit unauthorised persons from handling or interfering with electrical machinery

Contain direction of procedure in case of fire

Contains directions on how to resuscitate persons suffering from the effects of electric shock

Yes No

The customer produced a copy of his safe operating practices for the EG

Yes No




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a) Commissioning Compliance verifier

Name

Eskom Unique or RSA identification number

Designation

Date

Signature