Resonant controller of single-stage off-board EV charger in G2V and V2G modes

摘要

This study presents the control design and implementation of a three-phase single-stage off-board electric vehicle (EV) charger. The charger is controlled to perform four quadrants operation in active-reactive ( P-Q) power plane. Generally, the control of the EV charger consists of two control loops, i.e. exterior (slow) loop and fast-acting interior loop. Since the signals to be regulated in outer loop are DC in nature, they can be easily handled by regular proportional plus integral regulators. The inner loop control may also be performed in the DC domain, but inaccuracy involved in determining the parameter-dependent decoupling terms and difficulty in setting the gain for fast-acting inner loops make it unfavourable. Therefore, the inner control is performed in AC domain, where the signals are periodic. The proportional plus resonant controller is found to be very useful in tracking such type of periodic signals of fixed frequency, and accordingly, it has been designed and successfully implemented for the proposed work. The proposed methodology has been tested for eight different modes in the P-Q-plane. The system is simulated in MATLAB/Simulink environment and implemented in real time with a scaled-down hardware prototype.