基于直流侧电压周期离散控制的单相并联有源滤波器

针对有源滤波器电流谐波分量检测运算复杂,且在负荷电流变化时出现电源电流畸变现象,从直流侧电容电压与交、直流侧功率传递的关系出发,并结合有功电流的周期性特点,提出了基于直流侧电容电压周期离散控制的新型有源滤波器控制方法.该方法以电网电压为同步信号,在电网电压信号的过零点采样直流侧电容电压,并通过周期离散控制可以获得负荷电流有功分量.采用该周期离散控制方法可实现对直流侧电容电压的线性化控制,并使有源滤波器对谐波的补偿是瞬时的.该文给出了单相并联有源滤波器的直流侧模型,基于该模型推导出周期离散控制方法.以该方法研制了10kVA有源滤波器样机,仿真和实验结果表明该方法控制简单,稳定性好,谐波补偿速度快,能够有效地避免负荷变化时的电流畸变现象.

A SINGLE-PHASE SHUNT ACTIVE FILTER BASED ON CYCLE DISCRETE CONTROL FOR DC-SIDE VOLTAGE

Based on the periodicity of active current and the DC-bus voltage variation characteristic with the power flowing between AC source and DC-side capacitor of APE this paper presents a new linear cycle discrete control method for DC-bus voltage. The new control way can realize linear control for DC-bus voltage and get the fundamental component of the load current synchronously with a little of calculation. In addition, the source current distortion produced by the fluctuation of load is eliminated. The simulation by EMTDC/PSCAD is illustrated and evaluated. The experiment result obtained from a DSP-based APF are also presented in this paper. This control way is simple and the compensating ability of this APF is high in accuracy and responsiveness.