Study of AC modulated hysteresis current controller for a single phase voltage source inverter

The performances of AC current supplies depend on the characteristics of its current controller. In this paper, we study a large bandwidth AC-current controller combining the robustness properties of a hysteresis controller with constant switching frequency of PWM technique. A high frequency average model is proposed for this modulated hysteresis regulator to study its dynamic properties. A second approach of modeling, based on the construction of a three-dimensional bifurcation diagram allows studying the nature of the cycle described by the state trajectory and to prove that the system operates with a fixed switching frequency. Design rules of control parameters of this controller are explained and its robustness properties are tested by numerical simulation.