Research On PWM Rectifier Based On Finite Control Set Model Predictive Control

With the development of science and technology,more and more electric and electronic equipment have been applied to the industrial production and national life.The resulting harmonic pollution problem is becoming more and more serious and how to improve the power quality has become a common concern.Three phase voltage source PWM rectifier has been widely concerned and applied due to its advantages of operation with unity power factor,sinusoidal current on the grid side and bidirectional flow of energy.Finite Control Set Model Predictive Control(FCS-MPC)is a PWM converter control strategy developed over the past decade,which has superior performance.It controls the converter by utilizing the discrete characteristics and the finite switching state of PWM converter.This paper takes the three phase voltage source PWM rectifier as research object and studies in FCS-MPC algorithm deeply.This paper firstly introduces the mathematical model of three-phase voltage source PWM rectifier in three phase static coordinate and two phase static coordinate.Based on that,the working principle of FCS-MPC algorithm is analyzed in detail,and the control block diagram of the algorithm is given.After that,the generation mechanism of FCS-MPC delay problem is studied deeply,and the two step prediction method is used to compensate the control delay.And then,an improved Finite Control Set Model Power Predictive Control(FCS-MPPC)strategy is proposed for the large amount of online computing in FCS-MPC algorithm,which reduces the computational efforts of the algorithm and shortens the time consuming.Simulation models of the control strategies are built in the Matlab/Simulink environment,and the feasibility and effectiveness of the algorithm are verified.On the basis of simulation models,an experimental platform with TMS320-F28335DSP as the core is built,which mainly consists of two parts,the main circuit and the control circuit.In this paper,the selection of the main circuit devices,the determination of the parameters and the working principle of each part of the control circuit are introduced in detail.Then the experiment program is written in the CCS3.3 development environment according to the program flow chart of each functional module.After that,the experimental verifications of the FCS-MPC algorithm,the FCS-MPC algorithm with delay compensation and the improved FCS-MPPC strategy for reducing the computational efforts are carried on.By analyzing the experimental results,the validity of the algorithms used in this paper is proved.