Approximate 2-degree-of-freedom digital control for a PFC boost converter

Abstract

A PFC boost converter is a non-linear system whose small perturbation model is changed at each operating point depending on a duty ratio. The robust controller for the PFC boost converter is needed to suppress the output voltage change at load sudden change while attaining high power factor and low harmonic. In this paper, the combining method and design methods of two approximate 2-degree-offreedom (A2DOF) controllers which simplify the overall controller and attain good robustness are proposed. The proposed controller is actually implemented on a Micro-processor and is connected to the PFC boost converter. Experimental studies demonstrate that the proposed robust controller is effective to suppress the output voltage change to improve power factor and to decrease harmonic.

Robust Digital Control for Interleaved PFC Boost Converters Using an Approximate 2DOF Current Controller

“…Authors proposed an Approximate 2-degree-offreedom (A2DOF) control method of buck converters previously [9][10]. Moreover, this method was applied to PFC boost converters, and the digital control method using a A2DOF current controller and a A2DOF voltage controller was proposed [11][12]. In this design method, rst, when the current A2DOF controller is designed, the zeros of the controlled object near 1 in the unit circle is canceled by one of the poles in the model matching system in order to elimi- In this paper, the digital control method using the A2DOF current controller and the PI voltage controller is proposed.…”