Research on the control strategy of bidirectional DC-DC converter for battery formation and grading system

Battery formation and grading system mainly complete the constant-current and constant-voltage charging and discharging of newly produced batteries to activate them and test their capacity. However, the bidirectional DC-DC converter is commonly used in battery formation equipment due to the large hysteresis of the traditional single voltage loop and the increasingly complex model of the controlled object. At the same time, the system parameters change from time to time. It is difficult for the conventional PID controller to adapt to its changes and cannot obtain the best control effect. Therefore, this design uses fuzzy PI double closed-loop control to solve the problems of traditional linear PID control for nonlinear systems that are difficult to model and lack experience in manual adjustment. After simulation, it is verified that the fuzzy PI has good robustness, anti-interference ability, and fast response speed, and the output is stable under the lithium battery formation and grading system.