柔性互联配电网换流器控制模式平滑切换策略  

Smooth Switching Strategy of Control Mode for Converter in Flexible Interconnected Distribution Network

作　　者：王建建[1] 孙凯祺[1] 李可军[1] 刘智杰[1] 孙媛媛[1] WANG Jianjian;SUN Kaiqi;LI Kejun;LIU Zhijie;SUN Yuanyuan(School of Electrical Engineering,Shandong University,Jinan 250061,China)

机构地区：[1]山东大学电气工程学院,山东省济南市250061

出　　处：《电力系统自动化》2022年第14期63-72,共10页Automation of Electric Power Systems

基　　金：国家自然科学基金资助项目(U2166202)。

摘　　要：电流矢量控制与功率同步控制是广泛应用于柔性互联配电网中电压源换流器的2种控制模式。由于运行原理和运行特性不同,大多数传统换流器只配备一种控制模式,导致在交流电网强度变化时其运行灵活性受到限制,并在极端事故下可能带来严重问题。为扩大换流器在柔性互联配电网中的运行范围和增强其运行灵活性,首先对比了电流矢量控制和功率同步控制在不同交流电网强度下的稳定性,并分析了2种控制模式间切换的必要性。然后,考虑到事故下和事故恢复中交流电网强度变化的完整过程,提出了一种电流矢量控制与功率同步控制的平滑切换策略,并通过在功率同步环增加功率前馈环节,进一步削弱了系统强度变化造成的扰动。最后,以PSCAD/EMTDC中搭建的双端柔性互联系统为例,验证了所提策略的有效性。Current vector control(CVC) and power synchronization control(PSC) are two widely adopted control modes for voltage source converters(VSCs) in the flexible interconnected distribution networks. Due to the different control principles and the operating characteristics, most conventional VSCs are only equipped with one type of control mode, which limits their operating flexibility when AC grid strength changes and may cause serious problems in extreme accidents. To enlarge the operating range and enhance the operating flexibility of the VSCs, the stability of the CVC and PSC under different AC grid strengths are firstly compared and the necessity of smooth switching of two control modes is analyzed. Then, a smooth switching strategy between CVC and PSC is proposed considering the complete process of AC grid strength changes in the accident and during accident recovery. By adding an active power feedforward function in the power synchronization loop, the disturbance caused by the change of grid strength is further weakened. Finally, based on a two-terminal flexible interconnection system built in PSCAD/EMTDC,the validity and correctness of the proposed strategy are verified.

关 键 词：柔性互联配电网 电流矢量控制 功率同步控制 平滑切换策略 

分 类 号：TM46[电气工程—电器]