基于时域的电流检测新算法的进一步研究

针对传统电流检测算法存在的问题,提出了一种基于时域的电流检测算法.采用该算法的并联型有源电力滤波器可抑制谐波、校正功率因数、消除三相不平衡等.着重分析了该算法中各分量对应的物理意义,这对有源电力滤波器容量的选择具有指导意义.根据负载是否平衡,采用不同窗口宽度的滑动窗作为低通滤波器,保证了新的电流检测算法具有良好的检测精度和动态性能.实验结果证明,采用该算法的有源电力滤波器能够满足不同的补偿目的,且具有良好的精度(静态补偿实验时,补偿谐波后电流总畸变率为1 31%)和动态性能(动态补偿实验时,动态过程中电流总畸变率小于4%,且不会引起直流侧电压波动).

Further Study to Novel Time-Domain Current Detection Algorithm

The performance of active power filter adopting traditional current detection algorithm is degraded. In contrast with traditional current detection algorithm, a novel current detection algorithm, based on time domain for a three-phase shunt active power filter to eliminate harmonics and/or correct power-factor and/or balance the nonlinear unbalanced loads, is presented. The physical implication of every component and the effect on the capacity of active power filter are explained in detail. The higher detection accuracy and better dynamic performance are ensured by adopting sliding window with different width as low pass filter according to the balanced or unbalanced load. The experimental results validate that the active power filter based on the proposed algorithm can serve different compensation purposes well, and has satisfied accuracy (total harmonic distortion of current after compensation reaches to 1.31% in steady-state experiments) and dynamic performance (total harmonic distortion of current after compensation is lower than 4% in dynamic experiments and the DC link voltage is almost not affected).