Research On Hysteresis Voltage Control Strategies Of Inverter In Mixed Conduction Mode

The loss of inverter restricts the improvement of inverter's efficiency,so how to reduce the loss of switch module is the problem that must be solved to improve the efficiency of inverter output.In industrial application,the switching loss is often reduced by adding additional resonant circuit or using soft switching control strategy.Adding additional resonant circuit can reduce the loss of switch but in consequence increases the loss of resonant circuit,as a result using the control strategy of soft switching has more universal value.The traditional inverter control strategy makes the filter inductance current working in continuous conduction mode.If it works in discontinuous conduction mode,it can reduce the switching loss of switch tube.In this paper,the author proposes an optimization fast calculation method of the switching loss in order to solve the problem that the traditional fast calculating has,which is the ignorance of current overshoot when the switch is turned on and current tail when it's turned off.What's more the paper proposes a set of constant band inverter voltage hysteresis control strategy,the strategy can make the filter inductor current working in discontinuous conduction mode to reduce switching losses,but the switch frequency is not fixed.In order to solve this problem,this paper proposes a conjecture of constant cycle control constant duty control method and points out the application conditions of it.Furthermore,this paper introduces a model building method based on the charge of the filter capacitor.The method can obtain a unified approach to establish the model both working on continuous conduction mode and discontinuous conduction mode.On this basis,this paper put forward an inverter control method based on model predictive control,which can get better control effect compared with PID control.Moreover,a hysteresis optimization control idea has been proposed,which can further reduce the switching times of switch tubes.The simulation results of Matlab/Simulink and the experimental results of a 110V/50 Hz prototype verify the correctness of the theoretical analysis and the effectiveness of the control strategy.