Harmonic model of electronically controlled loads

Abstract

The use of electronically controlled loads is the way used to improve the efficiency as well as the power factor of normal elec- tric loads, obtaining thus energy efficient loads. This electronic con- trol changes the load’s global behavior resulting in a strongly non- linear one, at this regards, the available models used to represent loads are not accurate enough, especially in the context of an iterative frequency domain harmonic penetration program/algorithm. In this article, we propose an extension of the crossed-frequency admittance matrix, in order to get a better representation of these electronic loads. The extension is done by adding another dimension to the matrix, the harmonic phase. The model is obtained using a programmable power source connected to a PC, and by means of an acquisition board, we measure voltage and intensity. Due to the large number of tests needed we have developed a software tool that auto- mates the process giving as result the load model. Therefore, the proposed model linearizes loads according to three variables: Amplitude, Frequency and Phase of the harmonic with regard to the fundamental.