APPROACH OF IDENTIFICATION AND SEPARATION OF HARMONIC SOURCES
Xia Dao-zhi · Proceedings of the CSEE · 2002
Based on the comparison of v-i characteristics of linear and nonlinear loads, it is pointed out in this paper that the intrinsic difference between linear and nonlinear loads is that harmonic currents of a linear load are in linear proportion to its supply harmonic voltages of the same order, whereas the harmonic currents of a nonlinear load are complex nonlinear functions of its supply fundamental and harmonic voltages of all orders. Based on a simplified harmonic source model with the real and imaginary parts of harmonic currents of the nonlinear load modeled by linear polynomials of the rectangular coordinate components of harmonic voltages while neglecting the currents caused by the harmonic voltage of the same order as they are far less than the total amounts, a new principle for identifying harmonic sources is proposed. By using this method, not only the existence of harmonic source in a composite load can be determined, but also the contributions of the source and the linear part of the load can be accurately separated. Detailed procedure of harmonic source identification and harmonic contribution separation based on least squares approximation is given. Test results on a composite nonlinear load illustrate the effectiveness of this approach.