A Method for Supraharmonic Source Determination Based on Complex ICA

Abstract

Harmonic distortion in the frequency range 2 to 150 kHz is referred to as supraharmonic. The influence of supraharmonic on power grid has become a concern with increasing modern power electronic devices connected into power grid. Determining responsibility is the premise for controlling and managing supraharmonic. Since harmonics of a point of common coupling (PCC) are commonly produced by both utility side and customer side, it is important to determine which side is the dominant harmonic source and quantify their respective responsibilities. Considering supraharmonic sources of both sides are approximately independent, the complex independent component analysis (Complex ICA) method is used to obtain the mixed matrix and supraharmonic impedances of both sides. Meanwhile, a new index for judging dominant supraharmonic source is proposed by vector projection technique. Project the supraharmonic voltages, which are produced respectively by the supraharmonic sources of the utility side and the customer side, to the measured voltage of a PCC. By comparing the value of the projection, if the value of one side is larger than half of the supraharmonic voltage of the PCC, it can be considered to be a dominant harmonic source. The method can determine the position of dominant supraharmonic source and quantify the responsibility, which provides new ideas for the supraharmonic source tracing. Validity and effectiveness are verified by simulation analysis.