单相有源电力滤波器单极调制控制策略的改进

Improved unipolar modulation scheme of single-phase APF

阐述了单相有源电力滤波器双极调制和单极调制2种单周控制策略。根据单极调制控制有源电力滤波器工作原理,改变开关器件的动作过程,提出一种改进的单极调制控制策略,详细分析系统工作过程的等效电路,并推导其控制目标方程,同时设计了单周控制电路和开关器件驱动信号逻辑选择电路。该方法不需要变压器和加法器,简化了单极调制的单周控制电路和逻辑选择电路。最后,运用Matlab对带非线性负载时各模型进行仿真。仿真结果表明,改进型单极调制控制策略可以补偿电源电流直流分量,并且在相同开关频率条件下其电流纹波大小约为双极调制的一半。

Two schemes of OCC（One-Cycle Control） modulation for single-phase APF（Active Power Filter） are analyzed：the bipolar modulation and the unipolar modulation.An improved unipolar modulation scheme is presented by changing the operating process of its switching device.The equivalent circuit of system operating process is analyzed and its control objective equation is deduced.The one-cycle control circuit and logic selection circuit of driving signal for switching device are designed without transformer and adder,which are greatly simplified.Different models with nonlinear load are simulated with Matlab and results show that,the DC component of source is compensated and the current ripple is about the half of that by the bipolar modulation scheme with same switching frequency.