Modeling and analysis of line-frequency converters by double-Fourier series methods

This paper presents modeling of line-frequency converters with and without phase control. The operation of the converters can be described by two algebraic equations based on defined mapping functions. Unlike previous work that develops the mapping functions using direct Fourier expansion, double-Fourier series method is applied to avoid the assumption on the perturbation frequency. The resulting mapping functions are not limited to small-signal perturbation as in the previous models and can be used to predict harmonic distortion as well as small-signal impedance. The method is applied to both uncontrolled and phase-controlled multipulse rectifiers and the resulting mapping function is also used to model the input impedance of phase-controlled converters.