New control strategy and its DSP implementation for a naturally commutated matrix converter in a variable speed constant frequency generating system

Several industrial applications require the production of an accurately regulated frequency power output, from a variable frequency power source; such as variable speed constant frequency generating systems (VSCF) for aircraft and mobile power supplies. A new control strategy based on the cosine wave crossing control is applied to a naturally commutated matrix converter in a VSCF generating system. A VSCF generating system is obtained by using a new and innovative topology composed by a six phases permanent magnet synchronous generator (PMSG) and a six to three phase naturally commutated matrix converter (NCMC). This kind of generator is used with the aim of avoiding mechanical gear-box and improves gas turbine efficiency. 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. With the progress of high speed, lower cost digital signal processing (DSP), there has been a blossoming use of DSP techniques especially in power converters control. The proposed control strategy was successfully simulated and implemented on a fixed point TMS320LF2407 Texas Instruments device. Comparison of simulation results with experimental test results are given in this paper