A D-Q rotating frame DC-bus voltage controller for bi-directional single-phase AC/DC converters

Abstract

This paper presents a closed-loop control technique in D-Q rotating frame for bi-directional single-phase AC/DC converters. The proposed control system allows the active and reactive power control in both directions from grid to vehicle and vehicle to grid, while controlling the DC-bus voltage. Due to the lack of freedom degrees required for orthogonal systems, using the D-Q frame is a challenge in single-phase power conditioning systems. In this paper, an all-pass filter has been used to generate the orthogonal signals in the closed-loop control system. This method generates the orthogonal signals without degrading the dynamics of the closed-loop control system and with less noise in comparison to the other common methods such as differentiators. A DC-bus voltage estimator based on adaptive filter has also been used in this paper to remove the double frequency ripple and in turn increase the reliability and speed of the proposed controller. The proposed control scheme is used to implement the smart charging and power management strategies of the residential loads using electric vehicles as a storage system. Simulation and experimental results demonstrate the transient and steady-state performance of the proposed controller in different modes of operation. Also the performance of the proposed DC-bus voltage estimator in removing the double frequency ripple as well as the application of the proposed control scheme in implementation of power management strategies in a typical household, has been shown by using simulation results.