Hysteresis current controlled PWM converter for AC/AC voltage control

Current controlled strategies can be adopted in pulse width modulated (PWM) AC-AC power converters to regulate the load current having ripples within a band. Hysteresis current control techniques are widely used in high performance AC-DC-AC power converter fed drives. In this paper, a novel hysteresis current controller for an AC-AC buck power converter with regulated load current is presented. Two topologies of the proposed controller and converter in four quadrant and two quadrant modes of operation are analyzed. Sample controllers for both the topologies are simulated and realized. Details of simulation and practical controller implementation with integrated circuits are given. The proposed schemes have been found to offer high performance and are suitable for applications of all power levels.