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).