EDTI's Technical Guideline for Interconnection of Generators to The
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TECHNICAL GUIDELINE FOR THE INTERCONNECTION OF DISTRIBUTED ENERGY RESOURCES TO EPCOR DISTRIBUTION AND TRANSMISSION INC.’S DISTRIBUTION SYSTEM January 5, 2017 Francesco Mannarino SVP, Electricity Operations Mansur Bitar Director, Distribution Kirstine Hull Director, Planning & Engineering Darren McCrank Director, System Operations Rob Reimer Director, Metering & Wholesale Energy Suresh Sharma Director, Transmission EPCOR acknowledges the use of other documents developed by the utility industry and industry committees as the framework and sources in producing this technical guideline. Technical Guideline for Interconnection of Distributed Energy Resources to EDTI’s Distribution System Version 3 2 CONTENTS INTRODUCTION AND LIMITATION 6 1.0 GENERAL INTERCONNECTION AND PROTECTION REQUIREMENTS 9 1.1 EDTI’S DISTRIBUTION SYSTEM 10 1.1.1 General Characteristics 11 1.1.2 System Frequency 11 1.1.3 Voltage Regulation 11 1.1.4 Power Quality 12 1.1.5 Voltage Unbalance 12 1.1.6 Fault Levels 12 1.1.7 System Grounding 12 1.1.8 Fault and Line Clearing 12 1.1.9 Limit for DER Connection 13 1.2 DER FACILITY 13 1.2.1 Smart Inverters 1.2.2 Mitigation of Adverse Effects 13 1.2.3 Synchronism 13 1.2.4 Voltage Regulation and Power Factor 14 1.2.5 Frequency Control 15 1.2.6 Voltage Unbalance 16 1.2.7 Grounding 16 1.2.8 Resonance and Self-Excitation of Induction Generators 16 1.2.9 Single-Phase DER Facilities 16 Technical Guideline for Interconnection of Distributed Energy Resources to EDTI’s Distribution System Version 3 3 1.3 INTERCONNECTION 17 1.3.1 Safety 17 1.3.2 Point of Common Coupling 17 1.3.3 Point of Disconnection 17 1.3.4 Phasing 19 1.3.5 Voltage Flicker 19 1.3.6 Harmonics 19 1.3.7 Inadvertent Energization of EDTI’s Facilities 20 1.3.8 Network System Interconnection 20 1.3.9 Dedicated Transformer 21 1.3.10 Interconnection Grounding 21 1.3.11 Interrupting Device Ratings and Fault Levels 21 1.3.12 Phase and Ground Fault Protection 22 1.3.13 Overvoltage and Undervoltage Protection 22 1.3.14 Overfrequency and Underfrequency Protection 23 1.3.15 Unbalanced Phase Protection 23 1.3.16 Anti-Islanding Protection 23 1.3.17 Requirements for Transfer Trip 24 1.3.18 Reverse Power Relay Protection 25 1.3.19 Visibility and Controllability 25 1.3.20 Protection from Electromagnetic Interference 26 1.3.21 Surge Withstand Performance 26 1.3.22 Special Interconnection Protection 26 1.4 TYPICAL INTERCONNECTION PROTECTIVE REQUIREMENTS 26 1.4.1 Single-Phase Generators 29 1.4.2 Three-Phase Synchronous Generators 29 1.4.3 Three-Phase Induction Generators and Three-Phase Inverter Systems 30 1.4.4 Generators Paralleling for Six Cycles or Less (Closed Transition Switching) 30 1.4.5 Mitigation of Protection System Failure 30 1.5 INTERCONNECTION PROTECTION APPROVAL 31 2.0 METERING 32 2.1 GENERAL 33 2.2 METERING REQUIREMENTS 33 2.3 MEASUREMENT TRANSFORMERS 33 2.4 REMOTE COMMUNICATIONS EQUIPMENT 34 2.5 SAFETY REQUIREMENTS 34 3.0 CONSTRUCTION 35 4.0 INSPECTION 37 Technical Guideline for Interconnection of Distributed Energy Resources to EDTI’s Distribution System Version 3 4 5.0 TESTING 39 5.1 GENERAL 40 5.2 CERTIFICATION CRITERIA 41 5.3 TYPE TESTING 42 5.3.1 Inverters 42 5.3.2 Synchronous Generators 42 5.3.3 Induction Generators 42 5.3.4 Anti-Islanding Test 43 5.3.5 Export Limit Test 43 5.3.6 In-Rush Current Test 43 5.3.7 Synchronization Test 43 5.4 COMMISSIONING TEST 43 5.4.1 Certified Equipment 44 5.4.2 Non-Certified Equipment 44 5.4.3 Verification of Settings 45 5.4.4 Trip Tests 45 5.4.5 On-Load Tests 45 5.4.6 Switchgear and Metering 45 5.5 PERIODIC TESTING 46 6.0 DATA REQUIREMENTS 47 7.0 MARKING AND TAGGING 49 8.0 MAINTENANCE 51 TERMS AND DEFINITIONS 53 APPENDICES 59 Appendix 1 Interconnection Review Study Outline 60 Appendix 2 Single-Line Diagram for Delta-Wye Secondary Interconnection 61 Appendix 3 Single Line Diagram for Wye-Wye Secondary Interconnection 62 Appendix 4 Single Line Diagram for Primary Interconnection 63 Appendix 5 Schedule of Accuracies for Metering Equipment 64 Appendix 6 Example Test Procedures 65 Appendix 7 Reference Notes 69 Appendix 8 Applicable Codes and Standards 70 Technical Guideline for Interconnection of Distributed Energy Resources to EDTI’s Distribution System Version 3 5 INTRODUCTION AND LIMITATION Technical Guideline for Interconnection of Distributed Energy Resources to EDTI’s Distribution System Version 3 6 INTRODUCTION A distributed energy resource (DER) is any technology that produces power and is connected to an electric distribution system (including, but not limited to, distributed generation, microgeneration and battery energy resources)1. A DER can use a variety of energy -sources, including, but not limited to, liquid petroleum fuels, biofuels, natural gas, solar, hydro, wind and geothermal. Electricity storage devices are also DERs. This guideline establishes criteria and requirements for the interconnection of DERs within the electric distribution system of EPCOR Distribution and Transmission Inc. (EDTI). Specifically, this guideline defines the technical requirements for connecting DERs that are not exclusively owned by EDTI, but are connected to EDTI’s distribution system with a primary operating voltage of 25,000 V (25 kV) or less. Requirements relevant to the safety, operation, performance, testing and maintenance of the interconnection are provided. The requirements established in this document cover a broad spectrum of interests. The addition of DERs to the distribution system may change the system and its response. Attaining a technically sound, strong and safe interconnection between DERs and the distribution system mandates diligence on the part of everyone involved in the interconnection. The requirements in this guideline need to be cooperatively understood and met by everyone involved in the interconnection, including designers, manufacturers, users, owners and operators of both DERs and distribution systems. This guideline has been developed with reference to national and international standards such as Canadian Standards Association (CSA) C22.3 No. 9-08, Interconnection of Distributed Resources and Electricity Supply Systems, and the Institute of Electrical and Electronic Engineers (IEEE) standard 1547, Standard for Interconnecting Distributed Resources with Electric Power Systems. This document does not constitute a design handbook. Distributed energy resource providers (DERPs) who are considering the development of a DER facility intended for connection to EDTI’s distribution system should engage the services of a professional engineer or a registered consulting firm qualified to provide design and consulting services for electrical interconnection facilities. For inquiries relating to the connection of DERs, please contact EDTI Customer Engineering Services at [email protected]. 1 Alberta Electric System Operator (AESO) Distributed Energy Resources Policy Recommendations Technical Guideline for Interconnection of Distributed Energy Resources to EDTI’s Distribution System Version 3 7 LIMITATION The criteria and requirements in this document are applicable to all distributed energy resource technologies and to the primary and secondary voltages of EDTI’s distribution systems. Installation of DERs on radial primary and secondary distribution systems is the main emphasis of this guideline (restrictions relating to EDTI’s downtown secondary network distribution system are described in section 1.3.8). The requirements in this document shall be met at the point of common coupling, although the location of the protective devices may not necessarily be at that point. This interconnection guideline is a minimum requirement for the interconnection of DERs. Additional requirements may have to be met by both the DERP and EDTI to ensure that the final interconnection design meets all local, national and international standards and codes, and is safe for the application intended. This guideline does not address any liability provisions agreed to elsewhere by both parties in a commercial agreement or tariff terms and conditions. Technical Guideline for Interconnection of Distributed Energy Resources to EDTI’s Distribution System Version 3 8 1.0 GENERAL INTERCONNECTION AND PROTECTION REQUIREMENTS Technical Guideline for Interconnection of Distributed Energy Resources to EDTI’s Distribution System Version 3 9 1.0 GENERAL INTERCONNECTION AND PROTECTION REQUIREMENTS A DERP’s DERs and interconnection installation must meet all applicable international, national, provincial and local construction and safety codes. Any DERP may operate 60 Hz, three-phase or single-phase generating equipment, in parallel with EDTI’s distribution system and in accordance with the EDTI Interconnection Operating and Maintenance Agreement, provided that the equipment and DERP meet or exceed the requirements of this guideline. Sections 1.1, 1.2 and 1.3, respectively, define the following technical requirements: • The distribution system’s technical requirements (the DERP’s equipment must be able to operate within the ranges specified in this section) • Technical requirements to be met by the DERP • Technical requirements to be met by the facilities interconnecting the producing facility with the distribution system These requirements promote safe operation and minimize the impact on electrical equipment within the EDTI distribution system, including other customers. These requirements do not address the protection for the DERP’s DER equipment. It is the responsibility of the DERP to provide such protection. The DERP is responsible for protecting its DER equipment in such a manner that utility system outages, short-circuits or other disturbances, including excessive zero-sequence currents and ferroresonant overvoltages, do not damage the DERP’s DER equipment. As required in this guideline, the DERP’s protective equipment must also prevent excessive or unnecessary tripping that would affect EDTI’s reliability and the quality of power provided to other customers. The DERP is required to install, operate and maintain, in good order and repair and in conformity with good electrical practice, the facilities required by this guideline for safe parallel operation with EDTI’s distribution system.