Improved Power Control Strategy of Single-Phase CHFL Converter for V2G Applications

Abstract

This paper presents a virtual d-q frame-based power control strategy of a cycloconverter-type high frequency link converter for vehicle-to-grid applications in single-phase power systems. It is difficult to achieve sufficient performance for conventional power control methods based on stationary frames due to the nonlinearity of ac signals. The proposed algorithm divides the power component into active and reactive power components using the virtual d-q transform technique and independently controlling the two components in the linear region. Compared to the conventional method, the proposed power control allows the usage of simple proportional-integral controllers for achieving zero steady-state error for the fundamental components. As a result, satisfactory dynamics and steady-state responses in P-Q controls are guaranteed even under limited-bandwidth compensators. The effects of the proposed power control are verified by MATLAB simulation.