The Modeling And Simulation Of Common DC Bus System Based On PWM Rectifier

In the multi-inverter load governing system,power electronic converter is an essential part of device.Using the traditional wiring program of each motor is equipped with a rectifier and inverter device is a waste of resources,and it is often the case that the power which is feedback by the motor is consumed by the braking resistor,resulting in waste of energy.However,the use of multi-inverter wiring with a common DC bus, make the power feeding back can be absorbed by other electric motor,and the excess electricity can also be feedback to the power grid through the feedback device,so that power can be fully utilized.As a result of the traditional diode/thyristor rectifier is a major source of pollution to the power grid,and if the not-controlled/semi-controlled rectifier is used in the common DC bus system,a feedback device is necessary,it makes the system become more complex.PWM rectifier has the characteristics that controllable power factor at the side of power grid and no low order harmonic ideally etc,so that it give a more effective solution to the pollution which is brought by rectifier.At the same time,it also has the advantage of two-way flow of energy,to be used in common DC bus system,feedback devices could be saved,so that the structure of the system is to be simplified.This article focuses on the work of the PWM rectifier's principle,topology and mathematical model,its principle of SVPWM control strategy and implementation,and its control system which is based on direct-current control,and the simulation of the PWM rectifier system under Simulink.It also introduces the digital realization and modeling in Simulink environment of SVPWM.On the composition of common DC bus system,a simple model of DC bus system has been given to describe the system, given a method in estimates of rectifier capacity which is in accordance with the changes of load,and the calculation of the area for the DC bus.In the laboratory environment,take TI's chip TMS320LF2407 as the core of the control system,realizes the low-power prototype of PWM rectifier.