A new control strategy of quasi-cycloconverter fed induction motor drive

The utilization of microcomputer based control devices has led to highly sophisticated power converters and to an increasing use of AC-drive systems. However, microcomputer control devices assist in creating power converters which are characterized by a most simple structure and for that reason low manufacturing costs. From the power electronic point of view current source inverters are known as very simple, reliable and economical converters. Moreover, they permit the recuperation of energy. On the other hand, the need for a large inductance in the DC-circuit in order to decouple the net converter from the machine converter represents a considerable disadvantage. The authors aim at decoupling by using a special control strategy of both the net converter and the machine converter. Because of the direct coupling of them without using energy stocking elements, the presented system is called the quasi-cycloconverter. It is shown that quasi-cycloconverter fed AC-drives are able to cope with high dynamic requirements if field oriented control is used