Control Of Three-Phase PWM Inverters

Along with the conventional energy is gradually dry up, the world will have to payattention on the photovoltaic, wind power and other renewable energy above,China showssolictude for these newenergy as well. The inverter is playing an important role among thepower electronic equipment. and the control stratagem is the key point of it.This paper mainly focus on the control of three phase inverter under the dq coordinatesystem, and choose two control strategys, one is PI plus repetitive control method,which ismore commonly used, with higher demond of the system model and better control effect ofwaveform quality.The other is auto-disturbance-rejection control(ADRC), the modelaccuracy depends on lower controller parameters, there is no simple theory, the generaldesign method by engineering experience setting and simulation trial and error, and thedynamic characteristics is good and with higher robustness.First of all, the establishment of the inverter in the static coordinate system of themathematical model, based on this to launch dq0rotating coordinate system of themathematical model. Given the design of main circuit prototype process, at the same timeusing frequency response method to measure the actual prototype frequency characteristiccurve, to lay the foundation of the repetitive controller design.Then, this paper introduces the basic principle of two kinds of controller, analyzes theiradvantages and disadvantages, and the prototype is given as an example, the controller ofthe specific design method, the theoretical explanation repetitive control to suppressharmonic wave and auto-disturbances-rejection controller to realize decoupling controlprinciple.Finally, the method is proved by Matlab/Simulink result and prototype test on a80kVAthree-phase inverter.