Solak Krzysztof, Rebizant Waldemar, Mieske Frank
Faculty of Electrical Engineering, Wroclaw University of Science and Technology, 50-370 Wrocław, Poland.
Siemens AG, 13599 Berlin, Germany.
Sensors (Basel). 2024 May 14;24(10):3126. doi: 10.3390/s24103126.
The electrical protection of power networks with fault contribution from inverter-based power sources imposes new application challenges that have to be dealt with by protection engineers. This paper describes the development of a study case model of an HVDC-MMC link for testing the protection behaviour of connected converter transformers. The paper summarises the implementation and validation of the converter control as well as enhancements to provide Fault Ride-Through capability and fast fault current injection as required by the German Technical Connection Rules for HVDC. The grid code standard requires positive- and negative-sequence reactive current injection in the case of grid faults. A Doubled Decoupled Synchronous Reference Frame Phase Locked Loop (DDSRF-PLL) for Vector Current Control (VCC) is implemented. Additionally, a Fault Detection and Fault Ride-Through Reference Generator with a Current Limitation strategy is introduced. Though these techniques are well described in the literature, the DDSRF is improved for current control stability. The relationship between the parameters of the PLL and the control, as well as the behaviour of the protection system, are demonstrated. Grid faults with large voltage dips pose a significant challenge to the stability of the control system. Nevertheless, it is shown that with the developed model, it is possible to make general statements about the protection behaviour in an inverter-based environment.
来自基于逆变器的电源的故障对电网进行电气保护带来了新的应用挑战，保护工程师必须应对这些挑战。本文描述了一个用于测试连接的换流变压器保护行为的高压直流 - 模块化多电平换流器（HVDC - MMC）链路研究案例模型的开发。本文总结了换流器控制的实现与验证，以及为满足德国高压直流技术连接规则要求而进行的增强功能，以提供故障穿越能力和快速故障电流注入。电网规范标准要求在电网故障情况下注入正序和负序无功电流。实现了一种用于矢量电流控制（VCC）的双解耦同步参考帧锁相环（DDSRF - PLL）。此外，引入了一种具有电流限制策略的故障检测和故障穿越参考发生器。尽管这些技术在文献中有详细描述，但对DDSRF进行了改进以提高电流控制稳定性。展示了锁相环参数与控制之间的关系以及保护系统的行为。具有大电压跌落的电网故障对控制系统的稳定性构成了重大挑战。然而，结果表明，利用所开发的模型，可以对基于逆变器的环境中的保护行为做出一般性陈述。
