System Design And Control Algorithm Research Of Three-phase Boost Inverter Power Supply

In modern society,as people’s demand for electricity increases,various power electronic devices are widely used.When the user needs to use three-phase power due to a mains power outage or there is no mains power in the environment,the boost inverter power supply comes into being.Large-capacity storage batteries are often used as a backup power source.The static variable power supply device boosts the DC voltage output by the storage battery and then uses it as the bus voltage of the inverter to get AC power.In this paper,the rated voltage value of the battery is 24 V and it is used as the input of the boost inverter.The push-pull converter is used in the front stage to boost the DC voltage,and the three-phase inverter with SVPWM is used in the rear stage to obtain the power frequency three-phase AC power.The closed-loop control algorithm of SVPWM modulated three-phase inverter is analyzed and improved,and the hardware circuits of the front stage and rear stage are designed,and the prototype is set up for experiments by Simulink.This paper focuses on the SVPWM modulation of three-phase inverter and the closed-loop control algorithm of response.Firstly,based on SVPWM technology,the working process is analyzed meticulously.Then,the feedforward decoupling closed-loop control algorithm’s mathematical model of the three-phase inverter is established,and the traditional control algorithm with voltage PI as the outer loop and current PI as the inner loop is analyzed,and the Simulink simulation experiment is completed.Aiming at the problem of high low-order harmonics in traditional double-closed-loop output voltage,on the basis of feedforward decoupling,a quasi-PR regulator is added to the PI loop of voltage instantaneous value to eliminate specific harmonics.The inner loop adopts current P loop to improve the response speed.In view of the unstable output voltage under heavy load,a voltage RMS PI loop is added outside the double-closed-loop.The proposed triple-closed-loop model is established and analyzed,and the effectiveness of the proposed triple-closed-loop algorithm for the three-phase inverter with SVPWM modulation is verified by Simulink simulation.Front stage push-pull DC-DC converter’s hardware circuit is designed which includes the main circuit of push-pull converter power supply,MOSFET peak absorption circuit,high-frequency transformer parameter design,filtering circuit,push-pull PWM signal generation and drive circuit of the control portion and an isolation voltage sampling feedback circuit.Hardware circuit of three phase inverter is also designed which includes a main circuit and an IGBT peak suppression circuit,TMS320F28335 is used as the main controller of the inverter,an isolated drive circuit with output protection is designed to amplify the SVPWM signal generated by the DSP.The AC detection and adjustment circuit is designed to transmit the collected AC value to the DSP for feedback.All functions and closed-loop algorithms are programmed by the DSP.Finally,the prototype is created for testing,and the rationality of the design is verified by the test.