Three-phase boost rectifier average model independent of connection mode and waveform properties of AC sources

To remedy the defects possessed by the existing average models of three-phase boost rectifiers, a general-formed model unnecessary to consider connection mode and waveform properties of AC sources is proposed. During establishing the switching model, the numbers of independent state variables and independent state equations are strictly defined to avoid redundant equations as dealing with circuits containing pure inductor cut set. In deriving the average model, the redundant variables and redundant equations are properly introduced to obtain an intuitive model. No extra assumptions are needed except Kirchhoff's current law (KCL) and Kirchhoff's voltage law (KVL). The requirements for waveform properties of three-phase AC voltages are removed, therefore the proposed model is suitable for any input voltage waveforms, regardless whether they are sinusoidal or non-sinusoidal, balanced or unbalanced, symmetrical or asymmetrical. Simulation examples are provided to verify the validity of the model. The further discussions show that the proposed model is compatible with the existing ones in sinusoidal situations.