Design, Control and Application of Modular Multilevel Converters for HVDC Transmission Systems by Kamran Sharifabadi, Lennart Harnefors, Hans-Peter

Transcription

1 1 Design, Control and Application of Modular Multilevel Converters for HVDC Transmission Systems by Kamran Sharifabadi, Lennart Harnefors, Hans-Peter Nee, Staffan Norrga, Remus Teodorescu ISBN-10: Copyright Wiley 2016 Chapter 8 MMC-HVDC Standards and Commissioning Procedures

2 Outline (1) Introduction 8.2 CIGRE and IEC Activities for the Standardization of MMC-HVDC Technology Hierarchy of Available and Applicable Codes, Standards and Best Practice Recommendations for MMC-HVDC Projects 8.3 MMC-HVDC Commissioning and Factory and Site Acceptance Tests Pre-Commissioning Offsite Commissioning Tests or Factory Acceptance Tests Onsite Testing and Site Acceptance Tests Onsite Energizing Tests 8.4 Summary 2

3 Introduction Most of the modular multilevel converter high-voltage direct current (MMC- HVDC) projects are planned and developed as point-to-point transmission scheme projects, where the HVDC equipment are designed, manufactured, and installed by the same HVDC original equipment manufacturer (OEM). The HVDC project customers define the functional requirements, including the grid-code requirements that must be fulfilled by the procured equipment. During the bidding process, the HVDC OEM normally will document the compliance of the tendered HVDC scheme with the customer requirements through adequate system studies and simulations. This chapter provides an overview of standards applicable to HVDC equipment developed by professional associations in the field of MMC- HVDC technology. In addition, best practice recommendations for factory and site acceptance tests are presented. 3

4 CIGRE and IEC Activities for the Standardization of MMC-HVDC Technology Worldwide, various professional associations have taken initiatives to facilitate and develop the necessary recommendations and standards. Professional associations such as IEC, CIGRE, CENELEC, and IEEE are promoting and facilitating activities toward the standardization of MMC-HVDC technology worldwide. CIGRE, the Council on Large Electric Systems, was founded in 1921 and is an international non-profit association for promoting collaboration with experts from around the world by sharing knowledge and joining forces to improve the electric power systems of today and tomorrow. CIGRE Study Committee B4 (SC B4) addresses all aspects of power electronics, HVDC, and FACTS. 4

5 Hierarchy of Available and Applicable Standards for MMC-HVDC Projects IEC Instrument Transformers: Part 1: Current Transformers IEC Insulation Coordination IEC Power Transformers IEC Gapless Metal Oxide Surge Arresters for AC Systems IEC Surge Arresters: Selection and Application Recommendations IEC Insulated Bushings for AC Voltages above 1000 V IEC Voltage Sourced Converter (VSC) Valves for High Voltage Direct Current (HVDC) Power Transmission, Electrical Testing IEC Semiconductor Converters: General Requirements and Line Commutated Converters IEC Reactors IEC Coupling Capacitors and Capacitor Dividers IEC Terminology for HVDC Transmission IEC Common Specifications for High-Voltage Switchgear and Controlgear Standards IEC Power Electronic Capacitors: General IEC Determination of Power Losses in HVDC Converter Stations IEC Power Electronics for Electrical Transmission and Distribution Systems: Testing of Thyristors Valves for SVCs IEC Guide for Selection of Insulators in respect of Polluted Conditions IEC Characteristics of Indoor and Outdoor Post Insulators for Systems with Nominal Voltages greater than 1000 V IEC High-Voltage Fuses IEC Low-Voltage Switchgear and Controlgear Assemblies IEC Dimensions of Low-Voltage Switchgear and Controlgear IEC AC Disconnectors and Earthing Switches IEC High-Voltage Switches IEC : 2002 Radiated RF Immunity IEC : 2004 Conducted RF Immunity IEC : 2002 Fast Transients Immunity IEC : 2005 Damped Oscillatory Wave Immunity IEC : 2000 Dielectric Strength Immunity IEC : 2000 Impulse Voltage Withstand Immunity IEC : 2001 Electrostatic Discharge Immunity IEC Surge Protection IEC Surge Protection ISO 9001 Quality Systems Model for Quality Assurance in Final Design, Development, Production, Installation and Servicing NEMA CC-1 Electric Power Connectors for Substations IEEE 837 Standard for Qualifying Permanent Connections Used in Substation Grounding 5

6 MMC-HVDC Commissioning and Factory and Site Acceptance Tests The commissioning process consists of factory acceptance tests (FATs), or offsite tests, and site acceptance tests (SATs), or onsite tests. During the commissioning process, the HVDC manufacturer, together with the representatives of the customer, verifies and demonstrates the full functionality, operation, and compliance of the procured and installed equipment according to the functional requirements and specifications. 6

7 Typical test programs during FAT and SAT offsite testing (e.g. components and subsystem tests including control and protection tests, auxiliary equipment tests, dynamic performance tests); verification of onsite installation; onsite HVDC terminal energizing tests; operation of the HVDC terminal in STATCOM mode; controlled start-up and shutdown tests and emergency shutdown tests; steady-state power transmission tests, including power ramping; power quality and interference tests; black-start operation and loss of auxiliary (disturbance) tests. end-to-end system tests; AC network interaction tests (e.g. grid-code compliance tests, staged faults, reactive power and voltage control tests, and run-back and protection function tests). 7

8 Pre-Commissioning The offsite commissioning starts with the pre-commissioning procedure. This consists of the inspection and documentation of manufactured equipment and subsystem test preparations. Subsystem tests include electrical and mechanical tests and simple functional tests confined to a subsystem. The objectives of these tests are to inspect the equipment s condition and verify the manufacturing, installation, and operation according to the technical requirements and standards. 8

9 Offsite Commissioning Tests or Factory Acceptance Tests Offsite commissioning tests (FATs) include end-to-end tests and verification of all subsystems, including complete HVDC control and protection systems. Normally at this stage, the high-voltage equipment and the ac networks are modeled and simulated with a real-time simulation RTS) tool. For the test actual control and protection cubicles will be wired to the RTS, and tested. The FATs should cover the steady-state operation and dynamic performance behavior of the HVDC converter during ac and dc network fault conditions. For these tests, different ac and dc network fault conditions are simulated, and the HVDC control and protection functionalities are verified and documented. 9

10 Onsite Testing and Site Acceptance Tests SATs normally consist of the following stages: mechanical and electrical verification of installed equipment; individual subsystem tests; single terminal energizing tests; operation in STATCOM mode; grid-code compliance tests; end-to-end power flow tests; heat run and the trial operation test. During SATs, as a minimum, the normal operation of all subsystems and the signaling between them are controlled, monitored, and documented, before high-voltage energizing tests are initiated.

11 Onsite Energizing Tests (1) After the approval and signoff of the onsite subsystem acceptance tests, the energizing of the HVDC terminal can be initiated. The energizing tests are normally initiated by energizing the ac switchyard and the substation transformers. The converter terminal tests constitute a set of verifications of the acbus-voltage control and reactive power control modes (STATCOM mode of operation) that are to be conducted when the converter terminal is connected to the adjacent ac network for the first time.

12 Onsite Energizing Tests (2) During the end-to-end tests, the following control modes should be verified: AC-bus-voltage control at both terminals; reactive power control at both terminals; DC-bus-voltage control at both terminals; DC power flow and step control response; independent control of active (P) and reactive (Q) powers at both terminals; system redundancy and changeover tests; trip tests; communication and operator control tests (e.g. transfer of HMI station and system functions between individual control locations, including local station control at both terminals).