Research Of Closed-loop Control Of Two-stage Matrix Converter Based On Auto-disturbance Rejection Controller

Two-stage matrix converter(TSMC)is a novel matrix converter,which developes from conventional matrix converter(CMC).Besides of adopting many ideal characteristics of CMC,TSMC also has many other merits,such as:fewer power switchings,more simplified clamp circuit,simple and reliable inversion,much simple control strategy,etc. After introducing the topology structure and modulation strategy of the TSMC, this paper sets the closed-loop control of the output voltage of TSMC by using the auto-disturbance rejection controller(ADRC) .The main works include:The topology structure and the switching function of the TSMC,the widely employed space vector modulation(SVM) strategy without zero vector at rectifier stage and the transrectification of the TSMC were introduced.According to the influences of no-ideal operation conditions and disturbances to the output voltage in applications , this paper raised the methoe of closed-loop control of the instant output voltage ot TSMC.The inverter stage of TSMC was regarded as controller plant,input disturbances were regarded as DC disturbances.Refering to the non-linearity and strong coupling characteristics of TSMC, the control method of Proportional-Interal- Derivative (PID) doesn't work well in the closed-loop control of TSMC.ADRC is a nonlinear-robust controller which reduces the errors based on process errors ,it modifies the deficiency of the classical PID method and has been widely used in estimation and control of the uncertainty systems.The steady model of TSMC based on synchronous rotating coordinate(dq coordiate)was constructed by dq transformation.A second-order ADRC was set up to obverse and compensate the uncertainties and disturbances of TSMC dynamicly.Two closed loop control models of TSMC based on ADRC and PID were set up to make comparation. The results of simulation indicated that the closed-loop control of TSMC based on ADRC has good static and dynamic performances,it can ensure the steady state performance of the output under circumstances of unbalanced input and output.Compared to the simulation results of PID controller,the performance of ADRC is obviously better under the same disturbances.