Abstract In order to improve the control performance of DC/DC Buck-Boost power converters, a nonlinear optimal control strategy of differential geometry is combined with the traditional PID. The nonlinear PID optimal controller is designed to regulate the output voltage. This controller consists of two parts: one is the PI feedback control of the output voltage, to track the desired output accurately; the other part is the system state of linear accurate feedback model, realize the system optimal control. The controller retains the advantages of PID control, simple structure, easy to implement. It also can shorten the transition process, improve the steady-state accuracy, and enhance the system to the parameters of the robustness due to the nonlinear integral feedback of the output voltage. Compared with the traditional PID control method, the simulation results show that the system with the nonlinear PID optimal controller strategy, has small static error and superior performance, and has strong robustness to the input voltage disturbance and the load disturbance.
2018, Vol. 19 
