A novel modulation strategy for three-phase four-leg matrix converters

A novel modulation strategy for three-phase four-leg matrix converters (3×4 MC) is proposed in this paper. A 3×4 MC consists of 12 bi-directional switches, one leg more than the conventional three-leg matrix converters (3×3 MC). The 4th leg provides a circulation loop for unbalanced components of load currents, as the neutral wire in three-phase four-wire power supplies. Existing control methods for 3×4 MC, such as space vector modulation (SVM), etc., are facing complexity of control and large amounts of calculation. Hence, they're difficult to be implemented. In this paper, an average model of common mode output voltage of MC based on the method of two line voltage synthesis (TLVS) is built, which helps to predict the neutral-point voltage needed in each sampling period. The neutral-point voltage is obtained on the 4th leg by conducting its switches properly, thus realizing three-phase four-wire output. This method inherits the advantages of TLVS; moreover, it's much simpler and easier for hardware implementation. At last, the vadility and feasibility of this method has been verified via simulation by MATLAB.

[1]  Ma Xiang-qian.  A RESEARCH ON COMMON-MODE VOLTAGE FOR MATRIX CONVERTER BASED ON TWO LINE VOLTAGE SYNTHESIS , 2004 .

[2]  P.W. Wheeler,et al.  A Utility Power Supply Based on a Four-Output Leg Matrix Converter , 2008, IEEE Transactions on Industry Applications.

[3]  Roberto Cárdenas,et al.  Experimental Validation of a Space-Vector-Modulation Algorithm for Four-Leg Matrix Converters , 2011, IEEE Transactions on Industrial Electronics.

[4]  Pat Wheeler,et al.  A space vector modulation algorithm for 4-leg matrix converters , 2010, 2010 IEEE International Conference on Industrial Technology.

[5]  Nam-Sup Choi,et al.  Carrier Based Pulse Width Modulation for Matrix Converters , 2009, 2009 Twenty-Fourth Annual IEEE Applied Power Electronics Conference and Exposition.

[6]  P.W. Wheeler,et al.  A new control method of single-stage 4-leg matrix converter , 2007, 2007 European Conference on Power Electronics and Applications.

[7]  Takeshi Furuhashi,et al.  A novel control method for forced commutated cycloconverters using instantaneous values of input line-to-line voltages , 1991 .