Controller Design of a Three-phase Bidirectional Charger using Optimal State Feedback Control

This thesis presents a controller design of a three-phase bidirectional charger using optimal state feedback control AC-DC battery charger for electric vehicle. The bidirectional charger also allows to use the full electric vehicle as an energy storage system for the electric grid, charging the in the peak-of times and delivering the energy back to the AC source in peak times of electrical consumption. In discharging mode, the bidirectional charger maintains constant active power flow to grid with a given reference. The proposed control consists of inner-loop optimal state and outer-loop conventional PI control. For the inner-loop optimal state, a state feedback controller with integral action is employed in dq-synchronous frame. The set of stabilizing gains of this controller are determined by a Linear Matrix Inequality (LMI)-based optimization so that the convergence time to steady state is minimized. The efficacy of the proposed controller is verified through simulations.