Technical Standard - TS 129. Small Inverter Energy Systems (IES) - Capacity not exceeding 30kW. SA Power Networks. Published: November 2017

Transcription

1 TS 130: Inverter Energy Systems (IES) - capacity up to or equal to 200 kw Technical Standard - TS 129 Small Inverter Energy Systems (IES) - Capacity not exceeding 30kW Published: November 2017 SA Power Networks SA Power Networks 2017 Page 1 of 16

2 Revision Notice: Date Details Author Authorised 30 November 2017 Replaces Small Embedded Generation Technical Guidelines A. Lee J. Ali To obtain an electronic copy of this technical standard document, please click here: SA Power Networks: SA Power Networks, ABN , a partnership of: Spark Infrastructure SA (No.1) Pty Ltd, ABN Spark Infrastructure SA (No.2) Pty Ltd, ABN Spark Infrastructure SA (No.3) Pty Ltd, ABN each incorporated in Australia CKI Utilities Development Limited, ABN PAI Utilities Development Limited, ABN each incorporated in The Bahamas 1 Anzac Highway, Keswick, South Australia, SA Power Networks Disclaimer: 1. The use of the information contained in this document is at your sole risk. 2. The Information within this document is subject to change without notice. 3. SA Power Networks, its agents, instrumentalities, officers and employees: 3.1. Make no representations, express or implied, as to the accuracy of the information contained within this document; 3.2. Accept no liability for any use of the said information or reliance placed on it; and 3.3. Make no representations, either expressed or implied, as to the suitability of the said information for any particular purpose. 4. SA Power Networks and its agencies and instrumentalities do not endorse or in any respect warrant any third-party products or services by virtue of any information, material or content referred to or included on, or linked to this document. SA Power Networks Copyright 2017: This publication is copyright protected. SA Power Networks reserves to itself all rights in such material. You shall not reproduce any content of this document by any process without first obtaining the SA Power Networks permission, except as permitted under the Copyright Act All rights reserved. SA Power Networks 2017 Page 2 of 16

3 Contents 1. Purpose Scope Technical Requirements Inverter Phase Limits Single Phase Systems Three Phase Systems SWER Systems Inverters and Grid protection devices Connection Point Isolation Switches Residual current devices (RCDs) Isolation of inverter from energy source Signs and labels Cable Identification Multiple Mode Inverter (MMI) Battery Systems Electric Vehicles Overcurrent Protection Fault level Metering Protection Requirements Anti-Islanding Under/Over Frequency Under/Over Voltage Voltage Unbalance Power Quality Response Modes Quality of Supply Voltage and Frequency Ranges of Operation Voltage Frequency Testing Compliance Monitoring and Maintenance Who you should talk to? SA Power Networks 2017 Page 3 of 16

4 Appendices Appendix A: Definitions Appendix B: References SA Power Networks 2017 Page 4 of 16

5 1. Purpose This technical standard provides designers, contractors and consultants with an understanding of the technical connection requirements for small inverter energy systems (IES), with a nameplate capacity not exceeding 30kW, connected to SA Power Networks distribution network. 2. Scope This standard outlines the equipment and installation requirements for small inverter energy systems (IES) not exceeding a total name plate rating of 30kW at a single connection point, that are intended to be connected to and capable of operating in parallel with SA Power Networks distribution network. This document shall be read in conjunction with NICC 269: Connection Requirements of Small Embedded Generation and Service and Installation Rules (S&IR), which are available at ( and shall be in accordance with the relevant AS/NZS standards (eg AS/NZS 4777 series, AS/NZS 3000, AS/NZS 5033). For large embedded generating systems, refer to TS130 : Large Inverter Energy Systems (IES) 30kW kw or TS 131: Large Inverter Energy Systems (IES) above 200kW or Rotating Generating Systems. 3. Technical Requirements 3.1 Inverter Phase Limits Single Phase Systems SA Power Networks has adopted the updated AS/NZS4777 to allow a maximum total inverter system size of 5kW for a single-phase system, however, up to 10kW of inverter capacity may be installed provided it s export limited to 5kW as shown in the tables for the different scenarios. PV Panels Scenario 1: New PV only single-phase installation PV Inverter Inverter Size Export to Grid 5kW 5kW Permitted > 5kW and 10kW 5kW Permitted > 5kW and 10kW > 5kW Not Permitted for single phase * > 10kW 5kW Not Permitted for single phase * * three-phase supply conversion may be required Grid SA Power Networks 2017 Page 5 of 16

6 For a two-phase system (ie two single phase inverters connected to different phases), each inverter must be similarly limited to 5kW export as shown in scenario 1 above. Scenario 2: New PV & battery single-phase installation PV Panels Battery Hybrid Inverter Hybrid Inverter Size Export to Grid 5kW 5kW Permitted > 5kW and 10kW 5kW Permitted > 5kW and 10kW > 5kW Not Permitted for single phase * > 10kW 5kW Not Permitted for single phase * * three-phase supply conversion may be required A battery storage system can be added to an existing PV installation provided the total size of all inverter systems is 10kW or less, and exports must be limited to no more than 5kW. If the required hybrid system is larger, a three-phase system will generally need to be installed. However, if the existing approved PV inverter allows the export to the grid in excess of 5kW, the existing PV export capability may remain (ie if the current approved PV system is 6kW then the allowable limit will remain at 6kW). To assist in managing the export requirements, a battery storage system with zero export capabilities must be installed (refer to scenario 3). Grid SA Power Networks 2017 Page 6 of 16

7 Scenario 3: Adding battery storage to existing PV single-phase installation PV Panels Battery Existing PV Inverter New Battery Size Inverter Size 5kW Up to total inverter capacity of 10kW > 5kW and 10kW Up to total inverter capacity of 10kW Three-Phase Systems For three-phase systems, the IES must have a balanced output with the unbalance between phases being no greater than 5kW. For small embedded generating systems, the maximum capacity for a three-phase system is 30kW SWER Systems PV Inverter Battery Inverter PV Export to Grid As per existing approved export limit As per existing approved export limit Battery Export to Grid Combined PV and battery export 5kW 0kW Permitted Permitted For SWER systems within the distribution network, the maximum size inverter system that will be connected is 5kW. Grid SA Power Networks 2017 Page 7 of 16

8 3.2 Inverters and Grid protection devices The inverter shall comply with the requirements of AS/NZS The IES shall incorporate a grid protection device, which shall comply with the requirements of AS/NZS The grid protection device may be integral with the inverter. The protection settings of the grid protection device shall not exceed the capabilities of the inverter. All inverters and grid protection devices must be tested by an authorised testing laboratory and certified as being compliant with AS/NZS 4777 and issued with an accreditation number. The Clean Energy Council (CEC) maintains a list of approved solar modules and inverters that meet Australian Standards for use in the design and installation of solar PV systems. 3.3 Connection Point The IES shall be connected by fixed wiring to a dedicated circuit on a switchboard. It is preferable that an IES be connected directly to the main switchboard. In installations where this is not possible, the nearest distribution board shall be used and all distribution boards between the inverter energy system and the main switchboard including the main switchboard shall be labelled. See section on labelling/signage. The rating of the inverter circuit cables and all the cables between any distribution boards and the main switchboard which carry inverter output must be rated for at least the full output of the inverter energy system in accordance with AS/NZS Isolation Switches There shall be a visible and accessible method of ensuring that the inverter energy system is disconnected from the distribution network and disconnected from the customer s installation. The main switch for the switchboard, to which the inverter energy system is directly connected, shall be a lockable switch in the OFF position, which operates in all live conductors. The operation of this switch shall also isolate the inverter energy system from that switchboard. Note: This switch is to provide isolation of the inverter energy system for persons working on other parts of the electrical installation. The switch located on the main switchboard which controls any sub-circuit from the distribution board to which the inverter energy system connects must be lockable. Note: This switch is for the use of utility staff working on the distribution network as means of isolation of the inverter energy system. The isolation switches shall be installed to the requirements governing main switches in AS/NZS 3000, irrespective from where the inverter energy system circuit emanates. 3.5 Residual current devices (RCDs) The inverter energy system shall be connected to the electrical installation on the grid side of any residual current devices. 3.6 Isolation of inverter from energy source The labelled isolation devices, with the capability of safely breaking voltage and current under both normal and fault conditions, shall be installed between any energy source and the inverter, complying with AS/NZS 3000 requirements. The ideal location for installing isolation device shall be adjacent to the inverter energy source port and be readily available. Where there are multiple inverter energy source ports, each port shall have an isolator for each connected energy source. SA Power Networks 2017 Page 8 of 16

9 Where the energy storage and the inverter are physically integral, then compliance with AS is required and for the energy source as a PV array, the isolation switches and isolation arrangements shall comply with AS/NZS For more details on Isolation Devices, refer to AS/NZS Signs and labels The IES must include warning signage to clearly indicate that the electrical installation has multiple supplies and identify which circuits are affected by these supplies. Signage shall as a minimum be placed: On the switchboard that has the inverter energy system directly connected to it On all switchboards including main switchboard and distribution board(s) between the main switchboard and the board that has the inverter energy system directly connected to it In all meter boxes containing the distributor s metering equipment Signage should describe the actual type of generation source installed. The installer of the inverter energy system shall supply and install appropriate signage on the installation in accordance with requirements as required by AS/ANZ Cable Identification AS/NZS states that, all energy source (DC or AC) cables shall be clearly identified as energy source cables at intervals not exceeding 2m. Cable identification shall be permanent, legible, indelible and include type of energy source. If fixed to a surface, the identification shall be visible after mounting. For more details on Cable and Wiring Enclosures Identification, refer to AS/NZS Multiple Mode Inverter (MMI) The IES may comprise of, one or more inverters together, with one or more Energy Sources (which may include Batteries for energy storage) and controls. Where energy storage functionality is required, then the IES shall be a Multiple Mode Inverter (MMI) type that satisfies the requirements as prescribed in AS/NZS The Multiple Mode Inverter (MMI) operates in more than one mode, for example, having Grid-Interactive Functionality when grid voltage is present, and Stand-Alone Functionality when the grid is de-energised or disconnected. Inverters with battery storage ports are considered as MMI. Specifically note that, only inverters that have been tested by an authorised testing laboratory and certified as being compliant with AS/NZS and issued with an accreditation number will be regarded as an approved inverter. SA Power Networks reserve all rights to refuse connection for any non-compliant MMI installation Battery Systems A battery storage system which has the ability operate in parallel with the grid via an inverter, regardless of whether charged directly from the grid or through energy produced from a local generation source must use a AS/NZS 4777 compliant inverter. A battery storage system which operates in parallel with the grid via an inverter is considered part of the inverter energy system and its inverter size must be included in the maximum total inverter capacity as outlined in section 4.1. SA Power Networks 2017 Page 9 of 16

10 Switches to isolate the battery storage system from the main switchboard shall be clearly identified and accessible Electric Vehicles An electric vehicle is considered an embedded generating unit if it has the capability of exporting energy into the proponent s premises or into the grid and therefore must comply with the requirements outlined in this technical standard. Electric Vehicles that are only capable of charging from the grid are not considered an embedded generating unit Overcurrent Protection For installations using a PV array as an energy source, the overcurrent protection and its locations requirements shall be determined as per AS/NZS For all other energy source(s), cabling shall be protected against overcurrent, in accordance with AS/NZS Fault level As IES systems connected via grid connected inverters generally limit the fault current contribution to their full load current or a near zero value, SA Power Networks permits the connection of inverter energy systems to the distribution network without additional fault level protection and control equipment Metering An import/export meter is a requirement for all grid connected inverter installations under the electricity regulations. 4. Protection Requirements The protection systems shall be designed in accordance with Acts, Regulations and SA Power Networks standards. The inverter grid protection shall comply with the requirements of AS Anti-Islanding In accordance with the grid protection requirements of AS Table 13, the inverter must incorporate under- and over-voltage and under- and over-frequency protection. In addition, the inverter must include at least one method of active anti-islanding protection, which will operate to disconnect the device within 2 seconds. Any additional anti-islanding protection installed by the customer must be capable of automatically reconnecting to the Network once the network voltage and frequency have been maintained with their tolerable range for a minimum of 1 minute Under/Over Frequency Under and over frequency protection must be installed at the connection point. The inverter must be disconnected from the Network for the following settings: Under-frequency (f) = 47Hz with 1 sec delay Over-frequency (f) = 52Hz with 0.2 sec delay If the frequency exceeds 50.25Hz, the inverter shall reduce the power output linearly with an increase of frequency until the +4% limit is reached. SA Power Networks 2017 Page 10 of 16

11 4.1.2 Under/Over Voltage 4.2 Voltage Unbalance Under and over voltage protection must be installed to monitor all three phases at the connection point. The inverter must be disconnected from the Network for the following settings: Under-voltage (V) = 180V with 1 sec delay Over-voltage 1 (V) = 260V with 1 sec delay Over-voltage 2 (V) = 265V with 0.2 sec delay Three phase inverters must be configured to ensure the maximum unbalance between phases is 5kW whilst connected to our distribution systems. All three phases of the inverter must simultaneously disconnect from, or connect to, our distribution system in response to protection or automatic controls (eg anti-islanding trip and subsequent reconnection). Where multiple single-phase inverters are connected to more than one phase, the inverters must be interlocked and configured to behave as an integrated multiphase inverter providing balanced output (maximum unbalance between phases of 5kW) to all connected phases whilst connected to our distribution systems. Alternatively, where inverters cannot be interlocked by internal controls, the installation must be protected by a phase imbalance relay which must immediately isolate the inverter in the absence of reasonable balance. The inverters must be physically prevented from operating independently and all installed inverters must simultaneously disconnect from, or connect to, our distribution systems in response to protection or automatic controls (eg anti-islanding trip and subsequent reconnection). 4.3 Power Quality Response Modes The Proponent/electrical contractor/installer must ensure the South Australian power quality response mode has been set in the inverter(s) and must not be changed without written approval from SA Power Networks. These settings must be validated and tested by the electrical contractor/seg installer. The South Australian power quality response modes are: Volt-VAr response mode (AS/NZS Table 11) (Mandatory) Volt-Watt response mode (AS/NZS Table 10) Settings for the power quality response modes are shown below. Reference Voltage in Volts VAr % Rated VA V (default) 31% leading (sourcing vars, 2.4%/volt) V (default) 0 V V % lagging (sinking vars, 8.8%/volt) Table 1: Mandatory: Volt-VAr response mode SA Power Networks 2017 Page 11 of 16

12 Reference Voltage in Volts Power % rated Power V (default) 100% (default) V (default) 100% (default) V (default) 100% (default) V (default) 20% (default, 5.3%/volt) Reference V nom-max Table 2: Volt-Watt response mode Voltage 258 volts Table 3: Sustained Operation for Voltage Variations Power quality response mode settings shall be the same for all inverters at site where such capabilities exist. While all new inverters shall operate with the required South Australian power quality response modes, multiple power quality response mode settings are allowed where the following is satisfied: All inverters installed on or after 1 December 2017 operate with the required South Australian power quality response modes. Inverters installed prior to 1 December 2017 which are not capable of operating with an approved power quality response mode are operating at unity power factor. Replacement inverters, including warranty replacements, shall be configured to operate with the required South Australian power quality response modes. 5. Quality of Supply The IES must not impact on the quality of supply to SA Power Networks other network users. The inverter energy systems must comply with all applicable requirements of the NER, the EDC and SA Power Networks Service and Installation Rules (S&IR), including but not limited to: Network stability Network infrastructure thermal capacity Network voltage control Generating systems reactive capability (power factor) Voltage fluctuations Harmonics Voltage balance 5.1 Voltage and Frequency Ranges of Operation The inverter and customer installation must be designed, installed, and maintained in a manner that ensures that the maximum steady state voltage at any socket outlet or fixed equipment (other than the inverter) within the installation complies at all times with the requirements of AS/NZS and AS/NZS The following specific voltage and frequency settings must be programmed into the inverter: SA Power Networks 2017 Page 12 of 16

13 5.1.1 Voltage Where the Inverter has a maximum voltage limit for sustained operation (based on averaged measurements over periods 10 minutes or less), this parameter must be set no higher than 258V (phase to neutral). If the Inverter does not have a maximum voltage limit for sustained operation setting, the anti-islanding maximum voltage trip point (based on a short-term measurement) must be set to a low enough voltage (depending on the installation characteristics), to ensure compliance. Failure to design for this requirement may expose appliances and fixed equipment to potentially damaging voltages Frequency 6. Testing (a) Minimum frequency trip point (Fmin) is 47Hz. (b) Maximum frequency trip point (Fmax) is 52Hz. If voltage and/or frequency fall outside the set limits, the generating systems must be automatically disconnected from our network. The reconnection procedure for the inverter must comply with AS/NZS Upon, or at any time after, completion of the installation of the small inverter energy system, SA Power Networks may request access to the premises at a reasonable time to conduct a test of the system for the purpose of establishing compliance. The test will consist of: 1. disconnection of the premises from our distribution system; 2. reconnection of the premises to our distribution system; and 3. inspection and such testing of the small generator as we consider necessary for compliance. 7. Compliance Monitoring and Maintenance The proponent/owner of the IES is responsible for, and must: maintain the electrical installation at the supply address in a safe condition ensure that any changes to the electrical installation at the supply address are performed by an electrician lawfully permitted to do the work and that the customer holds a Certificate of Compliance issued in respect of any of the changes ensure that the electrical installation at the supply address, including the IES installation, complies at all times with the requirements in the Network Connection Agreement ensure the protection of any SA Power Networks equipment located at the supply address seek approval prior to altering the IES capacity or inverter. SA Power Networks will advise if additional work is required and the associated cost (if any) ensure that any electrical maintenance function on the IES or any other part of the customer s electrical equipment are appropriately qualified and licensed to perform such work comply with all legislation, codes, Rules or other regulatory instruments (as amended) 8. Who you should talk to? If you have any questions or you wish to investigate the potential connection of a small embedded generator to our network seg@sapowernetworks.com.au SA Power Networks 2017 Page 13 of 16

14 Appendices Appendix A: Definitions Connection Point: Contractor: Distribution Network/Systems: DNSP: Electricity Distribution Code (EDC): Embedded Generating Unit: ESCOSA: Generating Systems: Generating Unit: Generator/Proponent (and/or Customer): Inverter: Inverter Energy Systems (IES) Large embedded generation system A connection point to a transmission or distribution network. For this document, the connection point also has the same meaning as Point of Supply as defined in AS/NZS A contractor and or their sub-contractor who is engaged by SA Power Networks to conduct works on or near SA Power Networks infrastructure. Has the meaning given to that term in the Electricity Act 1996, namely the whole or a part of a systems for the distribution of electricity, but does not include anything declared by regulation not to be a distribution network or part of a distribution network. For the purposes of these rules references to Distribution Network means the network poles, wires, underground cables, transformers, substations etc, operated by SA Power Networks, which transports electricity from the transmission systems to a connection point. Distribution Network Service Provider. Electricity Distribution Code made by ESCOSA pursuant to Section 28 of the Essential Services Commission Act A generating unit connected within a distribution network and not having direct access to a transmission network. Essential Services Commission of South Australia All generating units, inverters and the associated control and protection equipment that is located on the generator/proponent's side of the connection point. The plant used in the production of electricity, including all related equipment essential to its function as a single entity. A person/entity who engages in the activity of owning, controlling, or operating a generating system that supplies electricity to, or who otherwise supplies electricity to, a transmission or distribution network. The device that forms part of the generating system which uses semiconductor devices to transfer power between a DC source(s) or load and an AC source(s) or load. The systems comprising of one or more inverters together with one or more energy sources (which may include batteries for energy storage) and controls. An installation complying with the requirements of the Australian Standard AS/NZS 4777 series, Grid connection of energy systems via inverters, Part 1: Installation Requirements, and Part 2: Inverter Requirements; and This definition includes but is not necessarily limited to generating systems such as: photovoltaic (PV) installations; small wind turbine generating units connected via Inverter; and small fuel-cell installations. An embedded generation system greater than 30kW SA Power Networks 2017 Page 14 of 16

15 Large IES: Must: Nameplate Capacity: NER: PV: Retailer: Shall: Should: Small embedded generation system Supply: Supply address: Transmission Network: Includes but is not necessarily limited to such initiatives as: Inverter installations greater than 30 kw synchronous generating units The final mentioned category includes any commercial plant which is operated and connected in parallel with the distribution network by arrangement with SA Power Networks for demand management or for routine on-load testing. Is to be understood as mandatory. The maximum continuous output or consumption in kw of an item of equipment as specified by the manufacturer, or as subsequently modified; National Electricity Rules Photo voltaic. The generation of electrical power by converting solar radiation into direct current electricity. Means the holder of an electricity retail licence granted under the Electricity Act, 1996, who is contracted to sell electricity to the Customer at the Supply Address. Mandatory Is to be understood as non mandatory, ie advisory or recommended. A single phase or three phase inverter connected embedded generation system up to 30kW. The delivery of electricity. The address at which the proponent is connected to SA Power Networks distribution network. ElectraNet s electricity transmission network. SA Power Networks 2017 Page 15 of 16

16 Appendix B: References The following listed documents are for additional information and other documentation may be required on a project specific basis. Please Note: It is your responsibility to ensure you have complied with all applicable, SA Legislative Regulations (under Acts), ESCOSA/ENA/AEMC/IEC documentations, relevant AS/NZS standards, the SA Power Networks publications, and you have ensured their current publications, before implementing them. South Australian Legislations: Example Electricity (General) Regulations, Work Health & Safety Regulations Essential Services Commission of South Australia (ESCOSA) Codes: SA Electricity Distribution Code (EDC) SA Electricity Metering Code (EMTC) Energy Networks Association (ENA) Publications: ENA NENS 03: National Guidelines for Safe Access to Electrical and Mechanical Apparatus ENA NENS 04: National Guidelines for Safe Approach Distances to Electrical and Mech. Apparatus Australian Energy Market Commission (AEMC) Publications: National Electricity Rules (NER) Standards Australia Publications: AS Rotating Electrical Machines - General Requirements Part 0: Introduction and list of parts AS Standard voltages AS/NZS Electrical Installations (known as the wiring rules) AS/NZS Electrical Installations - Selection of cables Part 1.1: Cables for altering voltages up to and including 0.6/1 kv - Typical Australian installation conditions AS/NZS Electrical Installations - Generating sets AS/NZS Electrical installations - Testing User Guides AS/NZS Approval and test specification - General requirements for electrical AS/NZS Earth potential rise Part 1: Protection of telecommunications network users, Equipment personnel and plant AS/NZS Grid connection of energy systems via inverters Part 1: Installation requirements AS/NZS Grid connection of energy systems via inverters Part 2: Inverter requirements AS/NZS Installation and safety requirements for photovoltaic (PV) arrays SA Power Networks Documents: Manual 14: Safety, Reliability, Maintenance & Technical Management Plan Manual 18: Network Tariff & Negotiated Services Manual 32: Service and Installation Rules Technical Standards & NICC Brochures, in particular: o NICC 269: Connection Requirements of Small Embedded Generation o NICC 270: Connection Requirements of Large Embedded Generation o TS130: Large Inverter Energy Systems (IES) above 30kW and up to 200kW o TS 131: Large Inverter Energy Systems (IES) above 200 kw or Rotating Generating Systems SA Power Networks 2017 Page 16 of 16