A New Algorithm for Random Harmonic Current Detection Based on Mathematical Morphology

Active power filter is an important device in eliminating harmonic pollution and the key problem in APF is how to detect the harmonic current accurately. In this paper a mathematical morphology algorithm for random harmonic current detection is presented. This algorithm which is based on instantaneous reactive power theory can detect positive and negative sequence component of random harmonic current fast and accurately. To different harmonic currents, the lengths of the structural elements can be automatically adjusted to the optimal value in this algorithm. In addition, the algorithm conquers the error which is caused by fixed structure element and has a high precision and high stability. Analysis and simulation prove the correctness of the algorithm.