THE CONNECTION OF CONVERTERS INSTEAD OF SEMICONDUCTOR POWER DEVICES -A HIGH-PERFORMANCE SOLUTION FOR THE MVA RANGE OF POWER CONVERTERS

Recently, there is an increased demand for high power, high performanc e converters for power system applications, motor drives, etc. The low switching frequency of the existing semiconductor power devices poses a severe limitation that can be overcome by the use of interconnected smaller power converters (multiconverter) with appropriate control. T his paper gives an overview of the state of the art of multiconverters , followed by a comparison based on analytically calculated values of the spectra, RMS and peak values of their ripple currents, and the pea k values of the transformer's flux. Special attention has been given t o show that the transformerless parallel connection of converters is f easible and offers features such as simplicity, gracefully degrading o perating, high reliability, easy expandability and easy maintenance.