The soft starters

This article deals with the adjustable-speed drives for multiple megawatt rated motors required by the petrochemical industry. The associated motors are often large enough for soft starting or may also be so large to dictate the requirement of soft starting. Soft starting may also be required because of the nature of the process or the driven equipment. One or more large drives in a process plant can often benefit from the adjustable-speed operation for improved process control or energy savings. The reliability of the process is, however, extremely important because outages frequently result in major production or financial losses. Therefore, a reliable, flexible, safe, and cost-effective system is required.