58 J. LETTL, S. FLÍGL, ELECTROMAGNETIC COMPATIBILITY OF MATRIX CONVERTER SYSTEM Electromagnetic Compatibility of Matrix Converter System Jiří LETTL, Stanislav FLÍGL Dept. of Electric Drives and Traction, Czech Technical University, Technická 2, 166 27 Prague 6, Czech Republic lettl@fel.cvut.cz, xfligl@centrum.cz Abstract. The presented paper deals with matrix converters pulse width modulation strategies design with emphasis on the electromagnetic compatibility. Matrix converters provide an all-silicon solution to the problem of converting AC power from one frequency to another, offering almost all the features required of an ideal static frequency changer. They possess many advantages compared to the conventional voltage or current source inverters. A matrix converter does not require energy storage components as a bulky capacitor or an inductance in the DC-link, and enables the bi-directional power flow between the power supply and load. The most of the contemporary modulation strategies are able to provide practically sinusoidal waveforms of the input and output currents with negligible low order harmonics, and to control the input displacement factor. The perspective of matrix converters regarding EMC in comparison with other types of converters is brightly evident because it is no need to use any equipment for power factor correction and current and voltage harmonics reduction. Such converter with proper control is properly compatible both with the supply mains and with the supplied load. A special digital control system was developed for the realized experimental test bed which makes it possible to achieve greater throughput of the digital control system and its variability. Keywords Matrix converter, electromagnetic compatibility, pulse width modulation strategy, control system. mains u R u S u T VPK00071 IM i A i B i C S AR S BR S CR S AS S BS S CS S AT S BT S CT bidirectional switch matrix load filter C F L F clamp circuit source Fig. 1. Basic power circuit of the realized three-phase to three-phase matrix converter system.