Feedback Linearization Control Of PWM Rectifier Based On LCL Filter

With the constant development of modern industry, more and more occasions theneed for conversion of energy. The traditional rectifier converter main use of thyristor ordiode realization of phase controlled or uncontrolled rectifier, its structure is relativelysimple, mature technology, has been the dominant position with the rectifier transform.With the current state of green energy promotion and development. Traditional phasecontrol and non control rectification technology disadvantages gradually reflected.Including low energy utilization、harmonic pollution on grid、energy cannot bebi-directional flow disadvantage. So the whole controlled type switching device as thePWM rectifier converter arise spontaneously. Through the control of switching device,Implementation of the green transformation of energy open a new chapter for energyutilization.In this article the three-phase voltage type PWM rectifier is used LCL filter insteadof L filter connect to the grid. With a smaller inductance, capacitance to achieve goodfilter effect. Due to the introduction of AC side capacitor branch, makes the traditionalcontrol strategy is difficult to achieve good control effect. This article choice the leadingnonlinear of input-output feedback linearization method to design the controller. Andthe voltage type PWM rectifier based on LCL launched a comprehensive study.In-depth analysis of the feedback linearization control theory and control methodof the input and output nonlinear control system, and the two feedback linearizationcontrol method is deduced. Combined with the output feedback linearization controltheory input, established the control model of PWM rectifier based on LCL, presents amulti input multi output system control structure, according to the zero pole placementmethod of control theory, deduced the tracker feedback coefficient and derived the LCLfilter resonance frequency.Finally, in the Simulink simulation environment of Matlab, the input-outputfeedback linearization control method and the traditional PI control method based onPWM rectifier system structure model of LCL are build. Through the comparison oftwo control methods of the grid voltage, current waveform, dc bus voltage waveformand the active and inactive current waveform. The system in the input-output feedbacklinearization control method has the dc bus voltage dynamic response faster, shorterregulating time, smaller overshoot, better tracking performance, current fluctuationssmaller etc. than in the traditional PI control method.