4-leg matrix converter interface for a variable-speed diesel generation system

Variable-speed diesel generation systems have advantages when compared to fixed-speed generators. For example reduced fuel consumption at some operating points, less maintenance, increased life of the engine because it is operated with a lower thermal signature. Moreover, higher power output can be obtained by operating the diesel engine at high rotational speeds, improving the power to size ratio. A 4-leg matrix converter can be used to feed a stand-alone load or isolated grid, providing a path for the circulation of the zero sequence load current. In this work the control systems appropriate for variable-speed diesel engines feeding a 4-leg matrix converter are discussed. Control systems based on two revolving axes and zero sequence controllers are discussed in this work. Experimental results obtained from a prototype are presented and fully analysed.