摘要
分析了电网三相不平衡时电压源换流器高压直流输电(VSC-HVDC)系统的谐波传递特性,设计了一种基于瞬时对称分量法的序分量检测技术,适用于VSC-HVDC系统的正、负序双回路的双闭环控制策略。该控制策略利用瞬时对称分量变换获取电压和电流的无延迟正、负序分量,不仅在时域范围内对传统对称分量法进行了扩展,而且也解决了正、负序分解时所带来的延迟问题。另外,提出在三相不平衡电力系统的控制中增加一个不平衡指令补偿模块,改善VSC-HVDC系统在电网三相不平衡时的运行特性。最后,在仿真软件PSCAD/EMTDC的环境下建立了一个VSC-HVDC系统及相关控制策略,验证了所设计控制策略的正确性。
The harmonic transfer characteristics of VSC-HVDC system in three-phase imbalance are analyzed and a dual-circuit and dual-loop current control strategy based on the detection technique of instantaneous symmetrical components is proposed for it,which acquires the sequence components of voltage and current without time delay by the instantaneous symmetrical component transformation and extends the conventional symmetrical component method in time domain.An imbalance instruction compensator is added to improve the operating characteristics of VSC-HVDC system in three-phase imbalance.A VSC-HVDC system and its control strategy are built with PSCAD/EMTDC and the simulative results show the correctness of the proposed strategy.
出处
《电力自动化设备》
EI
CSCD
北大核心
2010年第9期1-5,共5页
Electric Power Automation Equipment
基金
贵州省科学技术基金资助项目(黔科合J字[2008]2212号)~~
