三电平静止无功发生器补偿控制研究

The Research on Compensation Control for Three-level Static Var Generator

针对90°坐标系空间矢量脉宽调制(SVPWM)计算复杂的问题,采用了改进60°坐标系SVPWM的方法,该方法利用坐标变换和标幺化减少了三角函数的计算量,通过归一化简化了算法的运算过程。经过与90°和常规60°SVPWM补偿结果对比,验证了所采用方法的正确性。针对PI控制对周期性信号跟踪性差,且重复控制中延时的控制在负载突变时,导致补偿后电流发生畸变的问题,引入加权式并联型重复控制。仿真和实验表明,通过选择最佳权值比来均衡PI和重复控制的作用,改进60°坐标系的SVPWM和加权式并联型重复控制的三电平静止无功发生器(SVG),能够消除补偿电流信号的畸变,并能较好地完成无功补偿。

In order to solve the complex computational problem of space vector pulse width modulation(SVPWM)in 90°coordinate system,an improved SVPWM in 60°coordinate system was adopted.The calculation of trigonometric function by coordinate transformation and standardization was reduced,and the normalization method was used to simplify the operation process of the algorithm.The correctness of the proposed modulation method was verified by comparing the compensation results of SVPWM in 90°and conventional 60°coordinate systems.Aiming at the problem that PI control has poor tracking ability for periodic signals and that the delay control in repetitive control leads to current distortion after compensation when the load changed abruptly,weighted parallel repetitive control was adopted.The simulation and experiment results show that by choosing the best weight ratio to balance the role of PI and repetitive control,the three-level static var generator(SVG)with improved SVWM and weighted parallel repetitive control in 60 degree coordinate system can eliminate the distortion of compensating current signal and achieve better reactive power compensation.