Small-Signal Model of a High-Power-Factor, Three-Phase AC-DC Converter with High-Frequency Resonant Current Injection

The derivation and validation is described of a small-signal model for a high-power-factor, three-phase AC-DC converter that uses high-frequency resonant current injection. Fundamental frequency techniques are used to model the high frequency resonant stage of the system, whilst a d-q transformation is used to eliminate the time varying switching functions in the input rectifier stage. The model is linearised under small-signal conditions and the results are validated by comparison with detailed micro-cap simulations and measurements from a 2 kW prototype