A there-level AC chopper with clock-interleaved constant frequency integration control

Multilevel converter has been widely used in DC / DC converter, inverter and rectifier, but it is rarely used in AC chopper. In the very few reports of multilevel AC chopper, the attention stress is limited on the study of the circuit topology and working principle. The report about the closed-loop control of multilevel AC chopper has not been seen yet. In this paper, on the basis of a three-level AC chopper principle of an in-depth analysis, the closed-loop controls of multilevel AC chopper are primary studied. Compare with common PI control, unified frequency integration control have fast dynamic response, good tracing ability, good regulating capacity and simple structure. Clock-interleaved unified frequency integration control is proposed to implement the closed-loop control of three-level AC chopper. The proposed control method not only can be applied to the mentioned three-level circuit, but also used in others three-level AC chopper. Even for the high number of circuit topology, it is easy to expand. The simulation experiment result proves the feasibility and validity of the proposed control method.