The Research On The PWM Rectifier Based On Current Reconstructed

Pulse Width Modulation(PWM)rectifier has been widely used in the power electronics industry due to the advantages of less power pollution,bidirectional energy transfer,unity power factor operation,controllable bus voltage and so on.The traditional control system of Three-phase Voltage Source PWM Rectifier(VSR)requires various of current and voltage sensors,these sensors makes make the system bulky and bring high economic costs,and the fault of the sensor also reduces the reliability of the system.To solve these problems,a voltage and current closed-loop control scheme based on AC side current reconstruction is proposed,which can reduce the number of sensors in the system and improve the control performance of the rectifier while reducing system cost.Firstly,on the basis of deep analysis of the topology and operation principle of three-phase voltage source PWM rectifier,the Space Vector Pulse Width Modulation(SVPWM)technique are analyzed and the relationship between DC bus current and AC current is deduced during the SVPWM modulation process,and the three-phase AC current reconstruction is completed based on SVPWM modulation;the current reconfiguration strategies with coordinate transformation and DC filter is proposed to solve the problem of non-reconfiguration region in each sector.This reconfiguration strategy can not only operate as a part of three-phase VSR control system,but also can be a standby control scheme when the sensors in the traditional PWM rectifier fail,which can reduce the influence caused by the fault of sensors and improve the system fault tolerant ability.Secondly,The simulink simulation model of three-phase VSR system based on current reconstruction is established through research on the principle of the whole system and the design of circuit parameters,and the simulation study of current reconstruction module and a three-phase VSR system is curried out.Finally,the DSP control program based on TMS320F2812 digital processing chip is designed and the experiment platform based RT-LAB real-time semi-physical testing system is built to conduct experimental verification of the entire system.The simulationand experimental result shows that,the current reconstruction scheme based on coordinate transformation and DC filter can realize the reconstruction of the three-phase AC current and overcome the current distortion of the non reconstruction region.This control system can realize unit power factor operation of the system without AC current sensor,which can achieve the control performance of the traditional sensor system and has a strong practical value.