Implementation of a universal logic system of generating commutating pulses in matrix converters using FPGAs

Matrix converter, which is essentially a forced commutated cycloconverter, has most of the desirable features for any power frequency changers like simple and compact power circuits, generation of load voltage with arbitrary amplitude and frequency, sinusoidal input and output currents, adjustable power factor for any load, regeneration capability and harmonics reduction. A critical issue in control of this converter is current commutation as no freewheel path is available for the load current. In this paper, FPGA implementation of a semi-soft four-step commutation technique based on output current direction in matrix converter is presented. The same program can be used for implementing a three-step commutation process. A universal and synchronous commutation scheme for all the IGBTs is devised so that commutation can smoothly take place as and when required within the minimum possible time depending on the switching times of the IGBT used. The program logic is tested with the program simulator under various critical conditions.