链式三角形静止同步补偿器子模块冗余容错方案  

Sub-module Redundant Fault-tolerant Scheme of Delta-connected Cascaded STATCOM

作　　者：赵宇 苟锐锋 涂小刚 ZHAO Yu1＇2 , G(1. Xi＇an XDPower Systems Co. IAd 2. Xi＇an Gentle Mellow Technology Co. ., Xi＇an 710075, China; IAd., Xi＇an 710075, China)

机构地区：[1]西安西电电力系统有限公司,陕西省西安市710075 [2]西安端怡科技有限公司,陕西省西安市710075

出　　处：《电力系统自动化》2018年第7期23-29,122,共8页Automation of Electric Power Systems

基　　金：国家重点研发计划资助项目(2016YFB0901003)~~

摘　　要：三角形静止同步补偿器(STATCOM)子模块冗余容错技术主要对直流电压环、调制算法进行改进,但缺乏对暂态调制比、传递函数的研究。提出新型动态虚拟阻抗技术改善其暂态响应。首先,指出直流电压抬升分为调制比的暂态调节、稳态运行两个阶段,分析了传递函数的变化。其次,通过实时跟踪直流电压的突变获得动态调制比,设计出前馈型虚拟阻抗改进电流环路;通过动态调节比例—积分(PI)控制器的参数改进直流电压环路。针对故障过程的扰动进行实时补偿,保持暂态过程中系统传递函数的稳定。通过波特图曲线论证了虚拟阻抗的可行性。最后,利用PSCAD建立了35kV STATCOM的模型,所述新方案优化了装置的暂态电流和功率响应。Sub-module redundant fault-tolerant scheme of delta-connected cascaded static synchronous compensator （STATC（）M） is mainly used to improve the CC voltage loop and modulation algorithm. However it lacks tile research of tile transient modulation ratio and transfer function. A new kind of dynamic virtual impedance technology is proposed to improve the transient response. Firstly, it is pointed out that the DC voltage instruction uplih process is divided into the transient adjustment and the steady state of tile modulation ratio, and the system transient transfer function is analyzed. Secondly, the dynamic modulation ratio is obtained by the real time tracking of the DC voltage＇ s abrupt change, and the feed-forward virtual impedance is used to improve tile current loop. The I）C voltage loop is improved by the parameters＇ dynamical adjustment of the proportional integral controller. The transient transfer function is remained slable by compensating the disturbance of the fault process in real time. The feasibility of virtual impedance technology is demonstrated by the bode diagram. Finally, the 35 kV STATCOM model is established by PSCAD. The new scheme has improved the transient current and the power response of the device.

关 键 词：子模块 冗余容错 直流电压 调制比 虚拟阻抗 

分 类 号：TM761.12[电气工程—电力系统及自动化]