高压大容量有源电力滤波器并联运行研究

由于功率器件耐压水平和载流能力的限制,传统有源滤波器难以实现对高压大容量非线性负载的谐波补偿.本文提出一种有源电力滤波器,它由几个采用二极管钳位型多电平拓扑结构的滤波器模块组成.该滤波器模块采用多电平拓扑结构,很适合于匹配高电压等级,而且当补偿量超出实际输出容量时,能根据自身容量对电网谐波进行抑制.这种有源滤波器通过并联几个滤波器模块充分抑制电网谐波,使得每个滤波器模块不需要很大容量,运行独立灵活,解决了容量灵活扩充的问题.除了对该有源滤波器进行理论分析,本文还对其闭环控制策略进行研究.理论分析和仿真结果表明,所提方案很适合应用于高电压、大容量谐波补偿.

Research on Parallel Operation of Active Power Filters Applied to High-Voltage High-Power System

Due to the limitation of voltage level and current capability of power devices,it is very difficult to handle nonlinear loads for the traditional active power filter (APF) in high-voltage high-power grid. In this paper,an active power filter is presented,which is composed of APF modules with a multi-level NPC inverter. This module is very suitable for high voltage system. Moreover,this module has the capacity limitation function of compensating load harmonics,when the demand current exceeds the limit current of the module. The proposed APF fully compensates load harmonics by connecting some modules in parallel such that the PWM converter of each module needs not to handle high power. It operates independently and has expansion flexibility. In addition to describe the theoretic bases of the proposed APF,this paper also researches the close loop control algorithm of the APF. Theory analysis and simulation results illustrate that the performance of the proposed APF is suitable for harmonic loads with high voltage and large capacity.