Study On Control Technology Of Four-Quadrant Converter Based On DSVM

With the continuous development of human society,energy conservation has become the focus of modern society.Conventional inverter rectifier part uses ordinary diode,so that the energy generated in the process of the motor cannot be fed back to the grid,inverter cannot reach the effect of energy saving.The four quadrant inverter replaces the traditional diode with a reversible IGBT,which has the characteristics of energy flow in two directions and achieve the purpose of energy saving.In this article,the four quadrant inverter is divided into voltage source rectifier(VSR)and voltage source inverter(VSI).Combined with the discrete space vector modulation(DSVM)technique,the control methods are analyzed respectively,the matching of the VSR and VSI are achieved through the study of the four quadrant inverter integrated control technology.Firstly,the topology of four quadrant inverter is given,and the working principle of the four quadrant inverter is analyzed in detail.The ways of four quadrant operation of frequency inverter and permanent magnet synchronous motor are introduced in this chapter,the mathematical model of VSR and permanent magnet synchronous motor are established based on two phase synchronized rotation reference frame.Secondly,the basic principle and realization method of traditional space vector pulse width modulation(SVM)technology are analyzed.To solve the problem,a discrete space vector modulation technique is proposed,and the cause of the loss of the frequency inverter and its solution are studied.The simulation results show that the DSVM control technology can reduce the inverter loss,prolong the service life of frequency inverter,achieve the purpose of saving green.Thirdly,the VSR and the VSI are taken as the object to study the traditional direct power and direct torque control technology,they are used to obtain the switching signals of the drive frequency inverter IGBT by hysteresis comparator and switch table.The simulation results show that the traditional control method has the disadvantages of large fluctuation of output waveform,poor stability and no fixed switching frequency.Considering these deficiencies,direct power and direct torque control based on DSVM are studied,the PI regulator is used instead of the hysteresis comparator,and switch table is replaced by DSVM module.The simulation results show that the proposed method can not only reduce the loss of frequency inverter,but also enhance the system's ability to resist disturbance,reduce the ripple of the output waveform,and make the flux locus smoother.Finally,the power feed-forward control is introduced into the four quadrant inverter integrated control technology,so that the instantaneous active power can be changed with the change of electromagnetic power.The simulation results show that the system has superior stability,and the bidirectional flow of energy is realized,which are consistent with the expectations.