A Controller Based on Electric-Charger Balance Theory for Front-End Converters

Aiming at the problem that between the second harmonic current i(2nd) and dynamic response characteristic of the middle bus voltage u(b) of the two stage inverter, the charge balancing controller integrated with the traditional double-loop controller is proposed. The traditional controller operates as load stable to suppress the secondary harmonic current i(2nd), but the load switched by the new controller. Based on the traditional double-loop controller, the design of the voltage-loop controller that meeting requirements of i(2nd) is expounded, containing the influence of cross frequency omega(c) on Delta(ub) and the final dynamic response time t(s) of u(b). The working principle of the electric-charge-balancing controller and some other key design issue are described. A prototype of 450 W is built to verify the correctness of the theoretical analysis and the feasibility of the new converter.