Recent developments in the design and application of large, high performance cycloconvertor drive systems

Development of high speed microprocessor-based controllers and their application to thyristor convertors, together with optimised machine designs, has led to an AC drive system which can meet the power and dynamic performance demanded of the most severe industrial drive applications. New degrees of freedom in machine/controller interaction and machine design have been established to enhance performance. Techniques have been developed and subsequently integrated to form a comprehensive software simulation package to optimise the design of cycloconvertor drive systems in terms of steady state and transient performance. Following a brief description of a typical drive system, the main modules of the software package are described and their interaction is discussed. Typical steady state and transient torque characteristics for a 6-pulse induction motor drive system are presented and discussed with reference to applications in the mining and metals industries, and applications demanding particularly low air-gap torque pulsations