Wide Input Voltage DC-DC Converter Based On Model Predictive Controller

In the field of fuel cell power supply system,new energy power generation system and so on,a wide range of input DC converter has been widely used,in which the.Twoswitch Buck-Boost converter has the same input and output voltage polarity,low switching tube voltage stress Become a research hotspot.The traditional control method of the two-switch Buck-Boost converter selects the working mode according to the input voltage range.In this paper,the model is used to predict the design of the controller of the wide range input DC converter by selecting the optimal working mode by online optimization.Based on the working principle of the two-switch Buck-Boost converter,the different working modes of the converter are analyzed.Based on the real-time variation of the inductor current,the prediction model of the two-switch Buck-Boost converter in the Buck mode and the Boost mode is established by solving the system state equation,which provides the basis for the design of the controller.In order to reduce the switching loss,a hybrid operation mode is proposed instead of the Buck-Boost working mode,based on the traditional three-mode control method,combining with the characteristics of the two-switch Buck-Boost converter and the model predictive control.According to the different working modes,the cost function of the output voltage and the inductor current is constructed.Based on the model predictive control,we designed the 0-1 simplification algorithm,which only considered the opening and closing of the switch.In order to solve the problem that the 0-1 simplified algorithm has large ripple of the inductor current,we designed the case without increasing the amount of calculation The algorithm of calculating the duty cycle is designed based on the system state and cost function.Simulink software platform for simulation,compared the control of the three algorithms.The hardware parameters of the two-switch Buck-Boost converter are designed.The experimental platform of two-switch Buck-Boost converter with 18 V ~ 72 V input and 36 V output is built.The model is used to predict and control the proposed algorithm.The experimental results show that it is feasible and effective to apply the model predictive control to the wide range DC converter control system.