Cycloconverter for high speed permanent magnet generator units

Abstract

A generator-converter unit, consisting of a high speed permanent magnet generator and a high frequency cycloconverter, is developed. The generator-converter unit is intended for use in total energy systems connected to the utility grid, or hybrid systems in vehicles, or vessels. It will be driven by a high speed high efficiency gas turbine. The advantages of this variable speed constant frequency (VSCF) system, such as optimal turbine speed and small size and weight, are discussed. The 6-pulse cycloconverter, used to change the 800 Hz generator frequency to 50 Hz, is described in detail. A new combination of control methods results in a substantial improvement of the power factor load of the generator. Individual pulse control of the cycloconverter by means of digital signal processing results in excellent control properties of the generator-converter unit. Measurements are given on a 50 kW experimental system, consisting of a 600 Hz test generator and a single phase cycloconverter.