Method of Multiple Reference Frames Applied to the Analysis of a Rectifier - Inverter Induction Motor Drive

The method of multiple reference frames and the equations of transformation of the inverter are employed to establish a method of calculating the inverter current in a rectifier - inverter drive system. Since the method of multiple reference frames does not use phasors or complex impedances, the calculation of the inverter current is simple and direct. Also presented is a method of approximating the 6th harmonic variation in the capacitor voltage of the filter, connected between the rectifier and the inverter. This method permits a simplified means of rapidly obtaining a first- order approximation of the variation in the capacitor voltage. The analysis establishes a straightforward method of calculating variables in a rectifier - inverter drive system, which are difficult to determine by conventional methods of analysis.