New method for temperature rise test of high power moto-ventilated induction motors

The motor manufacturers have generally the necessary equipment for the temperature rise test, at the rated conditions, of the motors below 6 MW. Today, high power induction motors up to 25 MW, supplied by PWM converters are installed, specially in marine propulsion applications. As the motor manufacturers´ factory electric network is not designed to provide such high powers, many indirect test methods have been proposed and a few of them are included in IEC 60034 -29 ed. 1 standard . These methods need : additional rotating machines, not always available or , bi-directional static converters, causing high pulsating, and bi-directional power exchange with the factory network. The paper proposes a new method, using only the motor & converter under test without any additional machine. The factory network will provide a low and constant electrical power. No power is regenerated back, to the supply network. The new temperature rise test method, called ldquoStatic Torque Testrdquo is now fully approved by all the major classification societies (DNV-LRS-BV-ABS-RINA).