Indirect Matrix Converter Based Open-End Winding AC Drives With Zero Common-Mode Voltage

Common-mode voltage (CMV) generated by semiconductor switching causes stray currents and mechanical failure in modern drive systems. Solutions employed to attenuate or isolate the common-mode voltage (CMV) require additional components, and may still fail to eliminate the detrimental effects. Matrix converter based open-end winding drives, when modulated using synchronous vectors, do not generate CMV to begin with. Additionally, these drives do not rely upon a large DC capacitor that is used in the state-of-the-art systems; and are therefore expected to be more compact and reliable. This paper will present prototypes of two distinct indirect matrix converter based open-end winding drives that eliminate output common-mode voltage, provide high voltage transfer ratio (up to 1.5), and allow input power factor control. These indirect drives have the additional advantages of clamp circuit elimination, lower voltage stress on the devices, naturally intelligent commutation, and natural low-voltage ride-through integration over their direct matrix converter counterpart. Experimental evidence of the voltage transfer ratio and input power factor control will be provided. Compared to 2-level and 3-level inverters, significant reduction in the CMV induced shaft voltage and ground currents will be shown. An optimal third-order grid filter applicable to all matrix converter based drives will also be discussed. This filter will be used with the presented drives to validate its superior performance.