Research On Control Strategy Of Three Phase PWM Rectifier Under Unbalanced Voltage Conditions

Power electronics technology is changing the application of electricity optimizationtechniques.Rectifiers various power electronic devices as an interface with the grid, and itsdevelopment direction is to combine inverter technology, microelectronic technology andautomatic control technology.PWM Rectifier techniques is one of the best strategy rectifier,to achieve unity power factor rectification circuit operation. Currently deflector extensive useof the various areas of the quality of power supply constitutes a serious impact. Ourlaboratory study of high-performance hybrid integrated power inverter, inverter designsummary products for effectively and reducing harmonic interference power electronicconverters to improve power factor converter and system reliability, power electronicsindustry to improve our level of technology has great significance.The traditional double-loop control strategy has good control performance in an idealphase AC grid. In reality, the three-phase grid voltage imbalance often is in the operating stateIn this case, if the traditional control strategy, will give AC side current and DC voltagebring a lot of harmonics, even when serious burn unit.This paper studies for PWM Rectifier under unbalanced grid is not running a state issue,first established under the unbalanced grid state, traditional control algorithm to control thePWM rectifier in synchronous rotating coordinate system (a, b, c) mathematical model toanalyze the the main factors that affect the normal work of the rectifier, and the DC sideimpact results are caused by the AC side. Then the power of positive and negative sequencevoltage and current symmetric vector decomposition, the establishment of a two-phasesynchronous rotation (d, q) coordinate system mathematical model, made the positive andnegative sequence synchronous rotating coordinate system, respectively, positive andnegative sequence voltage oriented vector control strategy, positive and negative sequencecomponent of the current feedforward eliminate fluctuation component power transmission.Using Matlab software simulation platform, built voltage loop current loop controlsystem mathematical model on the basis of the control structure of the double inner currentloop current control simulation experiments...