Matlab Simulation Of LLC Resonant Microwave Oven Power Supply Unit

With the development of China’s economy, household appliances are more popular. The microwave oven has become increasingly widespread use. The way of traditional power supply for magnetron has some disadvantages such as large volume and can not be continuously adjusted. Therefore, the power supply in this paper is based on the LLC resonant converter and voltage doubler rectifier circuit.The focus of this article is the Matlab simulation of LLC resonant power for the microwave oven. The simulation includes the circuit, the output voltage feedback section, the control section, and the PWM pulse generation module. The circuit section includes rectifier, filter, LLC resonant converter, high-frequency transformer, voltage doubler rectifier and the secondary filtering section.Firstly, through the study of LLC resonant convert, analyzing the voltages and currents of different parts of the LLC resonant converter when the switching frequency of the LLC resonant converter in fm<fs<fr and fs>fT.Derived the relationship between switching frequency and DC gain and the ZVS conduction conditions. Secondly, use the Matlab standard library to Simulink the Microwave LLC resonant power system. Calculate the value of every device and Simulink it. The voltage across the load is collected and fed back to the control section. The control section uses the PI control that with two inputs the set values and the feedback voltage. PI controller signals are fed to the PWM pulse generator, the PWM pulse generator output pulse to the LLC resonant converter switch tube. When structuring the PI control model should consider the system stability and PI parameter tuning. When the Simulink model is stable, obtaining the waveforms of LLC resonant power for the microwave oven. Though the analysis of those waveforms, we can adjust the parameters of the model to meet the needs. Finally generating the code of the control part in order for the actual programing,...