The Research On The Control Method Of 3-phase High Power Converter

The more application of power electronics equipment, the more harmonic pollution, since eliminating harmonic pollution and improving power factor are the quite important task in the field of power electronics.Through reading lots of national and native conference documents, the whole understanding to the current researches of the 3-phase high power factor PWM rectifier are obtained, in the same time, the profound comprehend to the features of the different control strategy and control methods are acquired.After analyzing some kinds of PWM control technology and its application in the 3-phase rectifier, the principle of PWM rectifier is introduced in details. On the basis of deducing the rectifier's mathematical model, the MATLAB simulation model is achieved, and the validity of the mathematical model are confirmed by simulation result.The key step to achieve high power factor PWM rectifier is how to make the input current's initial phase equal to the input voltage's, where the key step to achieve the same initial phase is how to get the suitable voltage space vector. Its application in the PWM rectifier and theory are described in details, and simulation result indicates that the method has a robust performance.Based on analyzing the various control methods and strategies, a few important control methods and the more-applying engineering designing methods are introduced. Especially the paper introduces the dual-close-loop engineering designing method: firstly the ABC 3-phase stationary coordinate is translated into 2-phase stationary by the PARK transformation, secondly the PI adjustor's parameter of current and voltage loop's is designed, lately the correction of the designed parameter is testified by simulation results.As the traditional PID controller is difficult to achieve the optimum control, on the basis of introducing the principle, optimum design and PID alter of the GA, the paper adopts the GA's PID to identify the parameters of the PWM rectifier. Simulation results verify the validity of the scheme and the improvements to the PWM rectifier .