New simplified harmonic source model for harmonic analysis and mitigation

To facilitate the work in harmonic analysis and mitigation, a new simplified harmonic source model is proposed to represent the V-I characteristics of nonlinear electric loads. Based on the investigation of the relationship between the reference time and the corresponding harmonic phase angles of periodic voltage or current waveform, it is pointed out that the property of a harmonic source can be fully determined by a zero fundamental voltage phase angle. From engineering point of view, a new simplified model is proposed to approximate the property of harmonic sources for the case with a zero fundamental voltage phase angle. In this model, the real and imaginary parts of harmonic currents are modeled by linear polynomials of the rectangle coordinate components of harmonic voltages. Then a more general model is introduced for any nonzero fundamental voltage phase angle cases. Least squares approximation method is used to establish the simplified model. Test results on several kinds of typical harmonic sources reveal that this simplified model is of sufficient precision, and is superior to other existing models.