基于级联有源滤波器与静止无功补偿器的综合补偿控制方案

级联多电平有源滤波器(CS-APF)与静止无功补偿器(SVC)同时运行存在稳定性及无功补偿控制优化等问题。文中提出一种统一控制策略,结合SVC和CS-APF的功能特点,使SVC对负载正序无功分量及负序分量的补偿进行前馈控制和电网电纳(不包含CS-APF分量)反馈控制;CS-APF对晶闸管相控电抗器(TCR)与电网负载谐波的补偿进行前馈控制,并去除SVC中固定电容分量,进行电网电流反馈控制,同时对SVC无功补偿进行二次优化补偿。另外,提出一种TCR谐波电流预计算方法,根据TCR触发角当前值与电网电压锁相环相位,构建TCR谐波电流,实现对TCR谐波的预计算。仿真和实验研究表明,在该综合控制方案下,SVC与CS-APF控制不存在闭环,系统稳定性高,TCR谐波补偿无滞后,无功补偿响应较快,补偿能力强。

A Universal Compensation Control Scheme Based on Cascade Active Power Filter and Static Var Compensator

How to keep system stability and optimize var compensation capability is the key issue in the combined system based on cascade multilevel active power filter(CS-APF) and static var compensator(SVC).A universal control strategy is proposed for the combined system.For the SVC,a feed forward control for the compensation of positive sequence reactive component and negative sequence component of the load is adopted.The network susceptance(with no components of CS-APF) feedback control is applied to decrease the compensation error.For the CS-APF control,a feed forward control of harmonic compensation for thyristor control reactor(TCR) and the load is applied.The network harmonic current feedback control is applied to decrease the compensation error.The fixed capacitor(in SVC) current component is removed from the network current feedback control loop of CS-APF to improve the stability of the combined system.The var compensation capability of CS-APF is enabled to optimize the performance of SVC.Moreover,a novel pre-calculation method for the TCR harmonic current detection is proposed.According to the triggering angle of the thyristor in TCR and the network voltage phase,the harmonic current is constructed with no time delay.Finally,the simulation and experimental results show that: 1)the system stability is high without closed loop between the control of CS-APF and SVC;2)the real-time harmonic compensation of TCR is realized;3)the system responsibility is quick;and 4)the capability of var compensation of SVC is improved.