Model Predictive Control In Two-stage Matrix Converter

The matrix converter is a new type of green AC-AC power converter.Compared with the traditional AC-DC-AC power conversion device,the advantage is that the intermediate energy storage link is eliminated,the volume is reduced,and the control algorithm is simplified.A twostage matrix converter is a special structure of a matrix converter.It separates the rectifier stage and the inverter stage,which is of great significance to the innovation of control algorithms and the expansion of variable structures.In this paper,the advanced control algorithm of two-stage matrix converter is derived and simulated theoretically.This paper analyzes the control algorithm of the two-stage matrix converter from the classical power electronic control theory,deduces the mathematical model of the structure of the two-stage matrix converter.And this paper also summarizes the relationship between the switching state and the output voltage and the input current,introduces the concept of vector modulation,and explains the principle of space vector modulation.Secondly,the control of the model predictive control on the two-stage matrix converter is studied.The mathematical prediction models of the input filter and load are deduced and the paper uses value function to determine the optimal switching state to complete the predictive control of the converter.Output current feedback is used in predictive control to achieve closedloop control of the system entirely.To make the model predictive control switch with fixed frequency,in this paper a modulated predictive control algorithm is used to control the two-stage matrix converter.This algorithm combines the characteristics of predictive control and space vector modulation.In this chapter,it is proposed to use modulated predictive control to reduce the peak value of the common-mode voltage in the system,and it achieves effective results.The last part of the paper starts from the fixed switching frequency and analyzes the beat control algorithm.The idea of deadbeat control directly calculates the optimal vector group by using the prediction model and synthesizes the target vector by using the principle of vector modulation.The calculation of the reference value of the power supply current and the derivation of the predicted value of the two beats are also presented in detail.All the above algorithms have been verified by theory and simulation.