Research On Voltage Source Three-phase High Frequency Link Matrix Rectifier And Modulation Strategy

On the basis of the matrix converter topology,the high frequency link matrix rectifier adds a high frequency transformer and a bridge rectifier circuit,which can realize the unity power factor of the grid,the AC current sinusoidal and the constant DC voltage output.And the high frequency link matrix rectifier has the advantages of electrical isolation,flexible voltage change and the like and is favorable to realize the high frequency and light weight of the system.Because of its outstanding characteristics,the high frequency link matrix rectifier in aerospace,offshore wind power and other fields widely concerned in recent years.Firstly,the de-re-coupling analysis idea of the matrix rectifier and the theory and algorithm of voltage space vector modulation are introduced in this paper.De-re-coupling vector modulation for matrix rectifier is proposed basing on the combination of dere-coupling analysis idea and voltage source space vector modulation.The method has the characteristics both of "de-re-decoupling" idea and vector modulation,which makes the analysis and control of the bidirectional switches of the matrix converter easy and flexible.Secondly,aiming at the circuit topology of three phase non-isolated matrix rectifier,the de-re-coupling SVM modulation method based on positive and negative voltage switching command signal for matrix converter is introduced in this paper.And the modulation method is theoretically expounded and the operating mode is analyzed.The strategy can make the voltage type three-phase non isolated matrix rectifier have the ability to output DC voltage with positive and negative two polarity.Then,based on the idea of de-re-decoupling analysis,the mathematical model of three phase high frequency link matrix rectifier is established.And in order to ensure the accurate phase information of grid voltage,a new double fundamental frequency PLL technique is applied to the experiment of matrix rectifier for the first time in this paper,aiming at the existence of unbalanced three-phase voltage sometimes.According to the contrast experiment,the reliability of the new PLL method is proved.Finally,the hardware circuit and software system are designed respectively,and the experimental platform of the three-phase high frequency link matrix rectifier is built.Based on this platform,the experimental verification of the voltage source three phase non isolated matrix rectifier and the voltage source three-phase high frequency link matrix rectifier is completed.The experimental results demonstrate the feasibility and effectiveness of the proposed method.