AC-cycloconverter drives for cold and hot rolling mill applications

It is pointed out that there are several possibilities to realize an AC variable speed drive with cycloconverters. The motor can be an asynchronous or a synchronous type and the cycloconverter can be operated with or without circulating current. The author presents the characteristics of the different solutions and compares their performance in rolling mill main drive applications. The comparison is based on real applications in hot and cold rolling mills and on additional simulations. It is shown that the decision for the optimal configurations depends on the individual requirements of the technological process. For example, the required peak load and constant power range may have a remarkable influence on the design of the drive system, depending on the motor type. A short report about practical applications in hot and cold, reversing and finishing rolling mills is given.<>