Research On Control System Of The Three-phase Voltage-source PWM Rectifier

In recent years, with the rapid rise of inverter technology, inverter products arewidely used in the field production and our life, but the society put forward higherrequirements to current transformer products, especially harmonic suppression andgovernance requirements. Traditional way of rectifying is to using uncontrolled dioderectify, however, this method has problems of low energy transmission power factorand large side current distortion, leading to serious influence to grid. Three-phase halfbridge PWM rectifier of voltage type is of many advantages, such as unity powerfactor operation, side voltage and current synchronization and sinusoidal, it can meetthe demands of green power development and it is the hotspot in recent years.Therefore, this article will arrange the content from the following several aspects.First, The basic working principle of three-phase half bridge PWM rectifier ofvoltage type is introduced simply, through considering engineering practicability, thethree-phase half bridge PWM rectifier of voltage type topology is determined,mathematical analysis based on this topology is carried out, and the mathematicalmodel of rotating synchronous dq coordinates is established. Based on themathematical model of rotating synchronous dq coordinates.The paper introducesseveral common control strategies, and do the analysis and study to them. Accordingto the characters that three-phase half bridge PWM rectifier of voltage type isnonlinear and have strong coupling features as well as the difficulty of engineeringrealization, the article put forward a new type of double close-loop control strategy.Voltage outer loop adopts sliding mode variable structure control, achieved a stableand adjustable DC voltage; while current inner loop combines non-linear PI controlwith non-inductive argument L feed-forward decoupling, realized the fast followresponse of the system, and making the system has strong anti-interference ability. Asimulation research in Matlab/Simulink has carried out and the feasibility andsuperiority of this kind of control was verified.Secondly, according to requirements of the simulation and engineering designparameters, hardware and procedures of control system were designed. Hardwaredesign mainly introduces the mathematical calculation and type selection of eachdevice in main circuit and design of each circuit modules, etc. Program design mainlyintroduces the main program of the system, system subroutines and control strategysubroutine, etc.; System debugging and the physical platform of rectifier were introduced after that, and experimental waveform and corresponding conclusionswere given through the system debugging.Finally, the physical platform of rectifier system and its debugging and runningsituation is introduced, and the debugging experimental waveforms of this system aswell as corresponding conclusions is given, the accuracy and superiority ofthree-phase half bridge PWM rectifier of voltage type is verified.