Grid Interactive Inverters with Export Control up to 200 kw

Transcription

1 TECHNICAL REQUIREMENTS Grid Interactive Inverters with Export Control up to 200 kw Scope The scope of this document is to outline the technical requirements, Certification and documentation required for pre-approval of Inverters with Export Control for connection to CitiPower/Powercor s distribution network. Applies To This document applies to manufacturers of inverters and inverter energy systems (IES) up to 200 kva seeking pre-approval of their products for use on CitiPower/Powercor s distribution network. Document Author: Document Approver: Document no: CP0002 Issue no: 2 Review date: 30/03/2015 Page 1 of 18

2 Version Control Issue Changes Date 1 Original Issue 4/08/ Revised Document Title Revised Device Categories Revised Export Limit test requirements Removed Anti-islanding requirements Removed Testing Requirement for Power factor Control 30/03/2015 Document no: CP0002 Issue no: 2 Review date: 30/03/2015 Page 2 of 16

3 Relevant Standards & Documents AS Instrument transformers - Current transformers AS AS Electricity metering equipment (AC) - Particular requirements Part 21: Static meters for active energy (classes 1 and 2) (IEC , Ed.1.0 (2003) MOD) Grid connection of energy systems via inverters AS IEC IEC Electricity metering equipment (AC) - General requirements, tests and test conditions - Metering equipment Part 11: Metering equipment (IEC , Ed.1.0 (2003) MOD) Safety of power converters for use in photovoltaic power systems - Part 1: General requirements Safety of power converters for use in photovoltaic power systems - Part 1: General requirements CEC Approved Inverters List of compliant inverters and power conditioning published by the Clean Energy Council. DRAFT AS/NZS Grid connection of energy systems via inverters References in this document are to the Draft standard version dated 19/06/2013. Victorian SIR Victorian Electricity Distributors Service & Installation rules Document no: CP0002 Issue no: 2 Review date: 30/03/2015 Page 3 of 16

4 Definitions CEC Clean energy Council Grid Interactive Inverter An inverter or inverter function intended to operate in parallel to the grid for export or self-consumption of energy generated by the inverter energy system. Inverter Inverter Energy System (IES) A device that uses semiconductor devices to transfer power between a DC source or load and an AC source or load. For the purposes of this document the term, inverter also refers to the following systems: AC to AC converters transferring power between non-grid energy sources and an AC source or load that use semiconductor devices are considered to be inverters. A simple inverter system that is not capable of exporting power to the Grid i.e. a battery powered UPS with break-before-make connection arrangements. A system comprising of one or more inverters together with one or more energy sources (which may include batteries for energy storage), and a control system that includes functionality described in this document. The testing and performance requirements outlined in this document apply to the specific combination of devices making up the IES as nominated in the Application documentation. UPS Uninterruptable Power Supply MPPT Maximum Power Point Tracking A method by which an inverter or IES connected to a solar PV can vary its output. Document no: CP0002 Issue no: 2 Review date: 30/03/2015 Page 4 of 16

5 Requirements Summary of Technical Requirements The following table lists the high level requirements for various categories of inverters. Specific details of each of these requirements are discussed in the subsequent sections. TABLE 1 SUMMARY OF REQUIREMENTS FOR INVERTERS AND IES Device Type CEC Approved Power Factor Control Export Limiting IES (zero-export) IES (export controlled) IES Controller Definitions of the above categories are as follows: IES (zero-export) A grid interactive IES that controls the export to the grid via a control algorithm such that export to the network is zero. Since such a system would only be exporting onto to the grid for the short periods of time governed by its Export Limit response time, the additional Power Factor Control requirements within this document are not applicable. IES (export controlled) A grid interactive IES that controls the export to the grid via a control algorithm such that export to the network remains below a set non-zero value. IES Controller A standalone device used to monitor export and control a separate Inverter or IES for the purpose of export limiting. If approved, such a device may be listed on the Pre-Approved Device List along with specific limitations on which inverters it may be used with. As a minimum requirement, any inverter coupled with an approved IES Controller shall be CEC approved. CEC Approval All Inverters and IES shall be included on the CEC s published list of compliant inverters and power conditioning equipment. Document no: CP0002 Issue no: 2 Review date: 30/03/2015 Page 5 of 16

6 IES Controllers shall be included on the CEC s published list of compliant inverters and power conditioning equipment under the category of Grid control devices. At the time of publication of this revision the CEC was in the process of determining the requirements for compliance in this category and therefore the list was yet to be populated. Power Factor Control Requirements As a minimum, the IES shall be fitted with a Power Factor control function that meets the requirements of AS clause 4.4. A wider setting range is highly desirable and should be stated on the Pre-Approval Application form. Export Limit Control Requirements Export Limiting functionality may be required to prevent or limit potential voltage rise that may exceed the limits set out in the Distribution Code. Where the IES includes such functionality it shall comply with the following requirements. Export Limit Control Device Export Limitation may be performed by any of the following devices: Four quadrant inverter with a suitable control device Inverter utilizing MPPT that is settable between rated output and zero Security Any terminals or connections associated with the IES including measurement devices and any ancillary equipment shall be tamper-proof such that only a qualified and authorized person may access them. Refer to the SIR clauses 5.6, and for further security requirements. IES settings shall be either; Factory set such that they cannot be modified, or Suitably password protected such that only a qualified and authorized person may input or modify them. CitiPower/Powercor s preference is that the settings be factory set. If the settings are password protected evidence shall be provided of a suitably rigorous process preventing unauthorised persons from obtaining password access. The method of setting (password protection or factory set) shall be clearly identified on the Application Form. Power Measurement Measuring devices or systems shall comply with Class I of AS Current transformers shall have Accuracy Class 1 or better for measuring current transformers as stipulated in AS Document no: CP0002 Issue no: 2 Review date: 30/03/2015 Page 6 of 16

7 Failure Mode In the event of failure of or loss of signal from the measuring device the inverter shall reduce its output to be no greater than the set export limit. If the limiting device is a standalone IES Controller it shall issue a signal to the inverter to either reduce its output to the export limit setting or disconnect the system from the grid. Testing Performance Requirements The system shall be Type Tested as per test regimes specified in Appendix A & B and certification provided demonstrating compliance. Labelling The IES shall have clear, accessible labelling stating the following: Rated output Export Limit Setting If the export limit setting is set by the installer clear instructions on labelling shall be provided by the manufacturer. Type Testing and Certification Test Lab Accreditation Requirements Any Type Testing required shall be performed either: By a NATA 1 accredited testing laboratory on the manufacturer s premises and witnessed by a company NATA accredited to witness testing in client facilities By a Test Lab outside Australia that holds accreditation issued by an accreditation body that has a Mutual Recognition Arrangement with NATA Type Tests Evidence of the Certified Type Tests shall be provided by the manufacturer showing compliance with the testing requirements contained in this document. Application Process The Applicant shall submit a completed Application Form (see Appendix C) and all relevant Type Test and Standards Certification documents as specified in this document to the P.O. Box address on the Application Form. Upon receipt of a complete Application Form the Applicant will be invoiced. Applications will generally be reviewed within 4 weeks of receipt of payment of the Application Fee but under periods of heavy workload review may take up to 6 weeks. Following review, a formal response will be issued by CitiPower/Powercor stating the approval status and any ongoing obligations and responsibilities that the Applicant may have. The published list of approved devices will be updated to 1 The term NATA accredited refers to a Test Lab facility with NATA accreditation for the current published AS and AS Document no: CP0002 Issue no: 2 Review date: 30/03/2015 Page 7 of 16

8 include newly approved devices within 10 business days. Technical Requirements Review Process From time to time the technical requirements for pre-approval of devices may vary due to changes in network constraints, published standards or technology developments. In the event that this document requires review a new version will be published and Applicants may be required to submit additional certification or information in order to remain on the pre-approved list. The pre-approved list will remain unchanged for a grace period of 3-12 months (to be defined at release of reviewed document) depending on the magnitude, complexity or urgency of the changes to the requirements. Consideration will be given to Applicants who commenced the approval process prior to the release of the revised requirements. An Applicant seeking such consideration should provide evidence of testing commencement date with their Application. Any equipment already installed, having achieved compliance with an earlier version of the technical requirements document, will generally be allowed to remain in place. However if the changes to the Technical Requirements are born out of a genuine risk to CitiPower/Powercor s electricity network some may require removal. Once the review grace period is over all new installations will be subject to the latest technical requirements at the time of system design/installation. Document no: CP0002 Issue no: 2 Review date: 30/03/2015 Page 8 of 16

9 Appendix A - Export Control Testing Requirements The following test requirements are adapted from similar tests stipulated in the DRAFT AS Test Circuit General For the export control/limit test, the inverter and export control device shall be connected into a test circuit similar to that of Figure A1. DEVICE UNDER TEST Input Power Power Analyser. 1 Supply. Inverter. Limiting.. Device. Load Power Analyser. 1 IES FIGURE A1. EXPORT LIMIT TEST SETUP Test Load A test load circuit similar to that in Figure A2 shall be used. R V C V L V Grid Source FIGURE A2. TEST LOAD SETUP The Grid Source shall be as per requirements in Appendix A, Section A3 of the DRAFT AS standard. A copy of this sections A3 and A4 are included in Appendix B of this document. Document no: CP0002 Issue no: 2 Review date: 30/03/2015 Page 9 of 16

10 Export Limit Test Requirements General Requirements The test shall be carried out using different load and supply conditions as detailed in Table A1. For each test the reactive component of the load, L and C, shall be such that a power factor of 0.8 lagging (inductive) is achieved. Under all test conditions the device under test shall not permit export greater than the export limit setting. TABLE A1 LOAD AND SUPPLY PARAMETERS FOR TESTING EXPORT LIMIT FUNCTION Input supply [% Inverter Rating] 25% 50% 75% 100% Load [% Inverter Rating] 0% PASS/FAIL PASS/FAIL PASS/FAIL PASS/FAIL 25% PASS/FAIL PASS/FAIL PASS/FAIL PASS/FAIL 50% PASS/FAIL PASS/FAIL PASS/FAIL PASS/FAIL 75% PASS/FAIL PASS/FAIL PASS/FAIL PASS/FAIL 100% PASS/FAIL PASS/FAIL PASS/FAIL PASS/FAIL 125% PASS/FAIL PASS/FAIL PASS/FAIL PASS/FAIL Export Limit Settings With the export limit function set at 75% of the Inverter rating the export control function shall reduce the export power to below the set value for all load and supply combinations shown in Table A1. The tests shall be repeated for export limit settings of 50%, 25% and 0% rated inverter or IES output. If the device under test has a factory set export limit value that cannot be changed the test need only be performed at the factory setting. Document no: CP0002 Issue no: 2 Review date: 30/03/2015 Page 10 of 16

11 System Response Test Requirements General Requirements For the System Response test, the inverter and export control device shall be connected into a test circuit similar to that of Figure A1. The load shall be varied such that a step change decrease in load is seen by the system under test while the power export is monitored. For step changes in load a test load circuit similar to that in Figure A3 shall be used. C L R 1 R 2 R 3 R 4 FIGURE A3. STEP CHANGE TEST SETUP For each test the reactive component of the load, L and C, shall be fixed to a value that results in a power factor of 0.8 lagging (inductive) at 25% rated load. Test System Settings The export limit function shall be set at 75% of the Inverter rating. The input supply shall be set at the lower of: 100% of the inverter rating or, the initial load plus export limit setting Test Procedure The load shall be decreased from the initial load to the final load as shown in Table A2. Expected Action The export control function shall manage the input supply such that the export power is below the export limit setting within the relevant timeframe for all step decreases in load shown in Table A2. Note: Some tests will not require any action from the export control function. The tests shall be repeated for export limit settings of 50%, 25% and 0% rated inverter or IES output. Document no: CP0002 Issue no: 2 Review date: 30/03/2015 Page 11 of 16

12 Note: If the device under test has a factory set export limit value the test need only be performed at this setting. TABLE A2 LOAD AND SUPPLY PARAMETERS FOR TESTING EXPORT LIMIT FUNCTION Initial Load [% Inverter Rating] 100% 75% 50% 25% Final Load [% Inverter Rating] 75% 5 s N/A N/A N/A 50% 6.5 s 5 s N/A N/A 25% 8 s 6.5 s 5 s N/A 0% 9.5 s 8 s 6.5 s 5 s Document no: CP0002 Issue no: 2 Review date: 30/03/2015 Page 12 of 16

13 Failure Mode Test Requirements A test shall be performed to verify that upon failure or disconnection of the measurement device the export limiting device operates as outlined in this document. A test circuit similar to Figure A4 shall be used for this purpose. DEVICE UNDER TEST Input Power Power Analyser. 1 Supply. Inverter. Limiting.. Device. Load. Measuring Device Power Analyser. 2 IES FIGURE A4. EXPORT LIMIT FAILURE MODE TEST SETUP Document no: CP0002 Issue no: 2 Review date: 30/03/2015 Page 13 of 16

14 Appendix B Excerpts from DRAFT AS The excerpts from DRAFT AS , below, are specifically referenced in this document. Document no: CP0002 Issue no: 2 Review date: 30/03/2015 Page 14 of 16

15 Document no: CP0002 Issue no: 2 Review date: 30/03/2015 Page 15 of 16

16 Appendix C Application Form The following pages contain the Application Form that is to be submitted along with accompanying documentation for technical review by CitiPower/Powercor. Document no: CP0002 Issue no: 2 Review date: 30/03/2015 Page 16 of 16

17 and Grid Interactive Inverters up to 200 kw Details for Pre-Approval Assessment This document provides details of the minimum information required to be submitted to CitiPower/Powercor for assessment of a Grid Interactive inverter or Inverter Energy System (IES) for preapproval for use on CitiPower/Powercor s distribution network. Please fill out this form in black pen and tick the boxes where appropriate. Attach all available documents where requested. If there is insufficient space provided, an attached note may be referred to in the relevant section. Return this form to: Customer Projects P.O Box 572 Ballarat 3353 An assessment fee applies for the review of this application. Upon submission of this application form an invoice will be sent to the undersigned. Provision of assessment Technical Assessment - Grid Interactive Inverters up to 200 kw Fee (GST Excl) Service Requested $1000 BILLING ACCEPTANCE: CitiPower/Powercor will issue a tax invoice to the undersigned. I accept and agree to pay the current costs for the service provided. Signature Print Name Position Company Name Billing Address Date Page 1 of 2 Warning: HARD COPIES OF THIS DOCUMENT MAY NOT BE THE LATEST VERSION. The most up-to-date document is located on the

18 SECTION 1: DEVICE DETAILS Device Make & Model Number of Phases Single phase 230V Three phase 400V Device Power Rating (1 hour or continuous rating) kw Export Power Limit Range Zero Min: kw Max: kw SECTION 2: SUPPORTING DOCUMENTS CHECKLIST Tick included box if relevant documentation is included in Application. Single Line Diagram (SLD) of typical connection arrangements Included The SLD includes: Disconnecting Device Included N/A Generating Equipment Included N/A Protective Devices Included N/A CTs & VTs Included N/A Metering Included N/A CEC Approval yes no Settings security Power Factor Control Setting Range (if device is 4-quadrant state 4-quadrant ) Export Limiting Control as per CitiPower/Powercor Standard - Grid Interactive Inverters with Export Control up to 200 kw Power Limit test System Response test Failure Mode test Password protected Included Included Included Included Factory set Accompanying additional information Included N/A Applicant Name: Applicant Signature: Date: PRIVACY STATEMENT: The personal information you provide in this form will be collected by CitiPower/Powercor for the purpose of assessing pre approval of your grid interactive Inverter or IES. This information will be used and disclosed by CitiPower/Powercor in accordance with its privacy policy. You can find more information on the privacy policy on our website. Page 2 of 2 Warning: HARD COPIES OF THIS DOCUMENT MAY NOT BE THE LATEST VERSION. The most up-to-date document is located on the