Application Considerations for Varichron Drive Systems - Adjustable Frequency Synchronous Motor Drives

The interest in energy conservation has focused attention on adjustable speed electrical drives for loads traditionally driven by single speed motors with mechanical methods of load modulation. With large motor ratings, starting systems to reduce the impact on the power supply system are increasing in interest. Large size (above 2000 hp) adjustable frequency synchronous motor systems, called varichron drives for simplicity, are discussed. These drives are totally soft start systems and have the highest operating efficiency available. Eight major considerations which must be addressed in the application of these drives in industry are outlined and described.