Abstract: Aiming at the problem that the input side current of matrix converters can be easily affected by the power supply voltage fluctuation and the load change,a new back-stepping control strategy is proposed and implemented on a matrix converter.The matrix converter is converted into a mathematical model under the dq coordinate through the PARK transformation,and the controller for the input side current of the matrix converter is designed by adop- ting the proposed back-stepping control strategy and it is compared with that of the matrix converter with a PI con- troller by tests.Simulation results show that the controller using the proposed back-stepping control strategy can quickly follow the input currents under the conditions of both the change of load and the descent of three-phase power.Harmonic analysis indicates that the back-stepping control causes a low total harmonic distortion.Finally,the proposed back-stepping control strategy is encoded on the digital signal processor TMS320F2812,with an exper- iment involving resistance-inductance load being conducted.The results show that the input side current waveform of the matrix converter keeps a good sinusoidal characteristic.Simulation and experimental results demonstrate that the proposed back-stepping control strategy is both effective and feasible.

Key words: back-stepping method, PARK transformation, total harmonic distortion, digital signal processor 2812, matrix converter