Control And Design Of UPS PWM Rectifier For Chemical Equipment

In order to reduce the loss caused by power supply interruption in large petrochemical enterprises and realize the stable operation of chemical equipment,UPS power supply is an important peripheral device for process control,field instrument,fire control,computer information system,communication equipment,data network center and so on in the chemical production process device.It is specialized in providing stable and uninterrupted power supply,and has made great contributions to improving the quality of the power grid and the harm caused to users by the power failure.As one of the main components of UPS power supply,the research of PWM rectifier with high reliability has important practical significance for industrial production.Based on the chemical equipment UPS PWM rectifier as the research object,the control strategy of three-phase voltage source PWM rectifier three made a detailed research and design,specific work is as follows:Firstly,simple traces the development of the rectifier,and the topology of the PWM rectifier is analyzed three-phase voltage source PWM rectifier mathematical modeling,and the controller of the system carried on the thorough theory research,it is concluded that the ac circuit of three-phase static coordinate system time-varying current voltage,no steady-state error control to be fit for control system design.According to the coordinate transformation theory,the mathematical model of PWM rectifier in the three-phase stationary coordinate system is transformed to the two-phase stationary and two-phase synchronous rotating coordinate system,and the equivalent circuit mathematical model is constructed to eliminate the influence of time-varying ac on the ac side.On this basis,a dual closed-loop control simulation model of PWM rectifier was designed in MATLAB/Simulink software to verify the main performance of the control strategy simulation waveform and confirm its feasibility.Secondly,on voltage space vector control,the basic principle of SVPWM was introduced in detail,the theoretical analysis of the algorithm implementation process,including sectors N judgment,T1,T2,intermediate variable XYZ calculation,switch time of calculation,the final output PWM signal,and set up simulation model of SVPWM calculation process,simplify the system output PWM waveform.At last,the optimal design of PWM rectifier's double closed-loop control is made,and twobetter control strategies,direct power control and predictive direct power control,are introduced in turn.Finally,the experiment platform was built with DSP development board,and the system design of three-phase voltage PWM rectifier system,including hardware design and software design,was designed,and the experimental results were obtained through repeated debugging.The results show that the system design based on control strategy is practical and feasible.