A three-phase AC/AC high-frequency link matrix converter for VSCF applications

In this paper, a new three-phase high-frequency link matrix converter is discussed and the topology of conventional matrix converter is modified with the addition of a transformer for a variable speed constant frequency (VSCF) application. The proposed approach accomplishes voltage transfer ratio more than unity, galvanic isolation between both voltage sources and higher power density by employing a high-frequency transformer into the intermediate stage of the dual bridge matrix converter. It has a bidirectional power flow capability, controllable displacement power factor and lower harmonic distortion at both variable speed source and fixed frequency utility. Further, asynchronous or synchronous PWM can be employed depending on the frequency modulation ratio in the primary side converter and it guarantees full input voltage utilization for DC-link and near symmetric square wave pulse trains applied to high frequency transformer regardless of varying input frequency. The proposed approach is a competitive solution for VSCF distributed generating application such as wind-turbine and micro-turbine application. Simulation results are shown to demonstrate the advantages of the proposed system. Experimental results on a 230V, 3kVA 400 Hz to 60 Hz VSCF system based on DSP controller are presented.