无需锁相环的柔直变流器负序电流补偿方法  

Negative-sequence Current Compensation Method for Flexible DC Converter without Phase-locked Loop

作　　者：余江盛 吴轲 苏涛 罗卫华 吴彬兵 YU Jiangsheng;WU Ke;SU Tao;LUO Weihua;WU Binbing(Dongguan Power Supply Bureau,Guangdong Power Grid Company,Dongguan 523000,China;NR Electric Co.,Ltd,Nanjing 211102,China;School of Electric Power Engineering,Nanjing Institute of Technology,Nanjing 211167,China)

机构地区：[1]广东电网有限责任公司东莞供电局,东莞523000 [2]南京南瑞继保电气有限公司,南京211102 [3]南京工程学院电力工程学院,南京211167

出　　处：《电源学报》2024年第6期163-169,共7页Journal of Power Supply

摘　　要：电网电压不平衡时,锁相环PLL(phase-locked loop)需对电网电压进行重新追踪,此时锁相不准或锁相时间过长均会造成后续柔性直流输电系统中控制性能降低。为了避免锁相环带来的不利影响,提出1种无锁相环的改进型变流器控制策略。首先对传统锁相方案与无锁相方案的本质区别进行分析,进一步在无锁相环环境下提出1种瞬时正、负序分量提取方案;其次对无锁相环的变流器控制系统进行设计,并以补偿负序电流为控制目标;最后在实验样机下验证所提策略的正确性与有效性。When the grid voltage is unbalanced,the phase-locked loop(PLL)needs to retrack the grid voltage.At this moment,an inaccurate phase lock or an overlong phase lock time will cause the degradation of control performance for the subsequent flexible DC transmission system.Therefore,to avoid the adverse effects caused by PLL,an improved control strategy for converter without PLL is proposed.First,the difference between the traditional PLL scheme and the proposed scheme without PLL is analyzed,and an instantaneous positive-and negative-sequence component extraction scheme is put forward in an environment without PLL.Second,a converter control system without PLL is designed,and the compensation of negative-sequence current is taken as its control target.Finally,the validity and correctness of the proposed strategy was verified by the experimental results of a prototype.

关 键 词：高压直流输电 无锁相环 电压不平衡 负序电流 

分 类 号：TM721[电气工程—电力系统及自动化]