Robust Adaptive Control of a CACZVS Three-Phase PFC Converter for Power Supply of Silicon Growth Furnace

The compound active-clamp zero-voltage switching three-phase power factor correction (PFC) converter is used as the first stage converter of the heating power supply in the monocrystalline silicon growth furnace to achieve high efficiency and high power factor. Parameter uncertainty and variation are the main problems for the controller design of the converter. The conventional methods, including proportional-integral (PI) control, exact feedback linearization (EFL) control, etc., cannot deal with such problems. In this paper, we propose a model reference adaptive control for voltage outer loop to achieve adaptation for the load and capacitor variations, as well as a variable structure control with shrinking boundary layer for current inner loop to improve robustness to the parameters uncertainty. The simulation and experiment results show that the proposed controller improves the power factor and efficiency of the system, and it has better transient and steady-state performance with respect to the load variation, as compared with the traditional PI control method and the EFL control method.