二极管钳位型多电平有源电力滤波器的仿真

Simulation of the Active Filter with a Multilevel NPC Inverter

由于功率器件耐压水平的限制,传统的2电平拓扑结构有源电力滤波器(APF)难以实现对高压非线性负载的谐波补偿。文中采用二极管钳位型多电平变换器,提出了其作为APF运行的方案。对该APF进行了理论分析,提出一种基于重复预测型观测器的无差拍控制方案。该方案采用重复预测型观测器,对指令谐波电流进行预测,可在相同的采样频率下提供更精确的谐波电流预测值,因而可以改善整个系统的控制效果。仿真结果表明该APF适用于高电压及大容量谐波补偿。

Due to the overvoltage limitation of the power devices, it is very difficult to mitigate harmonic prouuced frp,the nonlinear loads in hrgh voltage grids with the help of a traditional active power filter （APF） with two-level inverter. An approach using an active power filter with a multi-level NPC inverter is therefore proposed. As the basic principles of the APF described, a repetitive predictor based deadbeat control scheme is given to predict harmonic current. The repetitive predictor can achieve a better prediction of the harmoniccurrent with same sampling frequency, thus improves the overall performances of the system. The simulation results illustrate that the proposed APF is suitable for mitigating harmonic under conditions of a high voltage and a large capacity.