Design And Realization Of Voltage Source PWM Rectifier Based On ADRC

PWM rectifier has been widely used in more and more fields with the development of PWM technology. It has the advantages of low harmonic pollution, sinusoidal current of AC-side, constant DC-side voltage and bidirectional energy flow, which has really realized the aim of "green transition" of electric energy. In the control strategy, the DC-controlled PWM rectifier adopts Space Vector Modulation and double-loop control structure using the method of linear control theory simultaneously. These strategies improve system’s dynamic performance and the utilization coefficient of direct voltage, consequently resulting in a wide application.However, voltage source PWM rectifier is a nonlinear hybrid control system. With the research method of lineal control, its performance cannot meet the needs of industrial production and daily life. In order to restrain the effects of load disturbances on DC-side voltage of PWM rectifier,and to improve the effects of PID controller in nonlinear system, the idea of ADRC(Auto Disturbances Rejection Controller, ADRC) is proposed on the improves nonlinear PID controller. Based on ESO(Extended State Observer, ESO), the ADRC technology regards both internal and external disturbance as system compensation, which reveals better robustness and flexibility for controlled objects with nonlinear,large time delay and strong uncertainty.In this paper, the mathematical model of PWM rectifier is established on the basis of topological structure of the three-phase voltage source PWM rectifier. Meanwhile the control strategies and modulator approach of PWM rectifier are presented, and the voltage control loop which is based on ADRC has been realized in the three-phase voltage source PWM rectifier. Afterwards, a simulation model is made with MATLAB/SIMULINK. It is improved that the ADRC strategy is feasible through the analysis of simulation waveform. Finally according to the simulation of the system a main circuit and a control circuit are built. For the main circuit, its main task is setting and calculating the parameters of the AC-side inductance, the DC-side capacitor and the IGBT based on control algorithm and the performance of the system. The control section is based on TMS320F2812that a DSP chip product of TI Company, including voltage and current detection-conversion module, the power switc driver module, PWM output module. It is introduced in this paper that the ideas of modu(?) design and the process of working in details. Then debugging and analyzing are implemente according to the requirement of the system and the performance of DSP chip.The experimental results show that the system can response rapidly and achieve th stable value in a short time, and it can better achieve previously PID control.