Dr. Emmanuel Agamloh, senior motors and drives consultant, will be presenting at the upcoming Motor & Drive Systems Conference 2018 in Orlando, Florida. His session, “Practical Considerations for Torque Testing of Electric Motors,” will discuss the techniques for accurately measuring the torque of induction and permanent magnet motors.
An electric motor’s torque is its rotational or turning force. This force moves the shaft, the part of the motor connected to end-use equipment, such as a fan, blower, compressor, conveyer belt, generator, etc. Torque is of primary concern for both manufacturers and users. Manufacturers build motors of varying torque quantities for use in particular applications. At the same time, users need to know that the motor they are getting will provide enough torque to power their equipment.
Design standards specify how much torque a motor of a certain size can produce in three particular situations: 1) when the motor is first starting, 2) when it is fully loaded and 3) when it reaches maximum capacity, cannot tolerate the load imposed and shuts down. For example, consider an induction motor powering an elevator. The motor has to initially provide enough torque to start the elevator with or without people (1). When people crowd in and the elevator meets its weight limit, the motor must once again be able to get the elevator going and continue to power it (2). However, if even more people squeeze on, the motor might reach its maximum torque and be unable to produce enough to move the elevator (3). Every motor is designed to meet particular torque standards reflecting these typical scenarios.
Despite the importance of torque, it remains difficult to measure accurately. For example, a motor’s maximum torque is an unstable point in the torque profile, and special caution is needed to capture it exactly. Furthermore, the starting torque measurement can be harsh on measuring equipment, so steps must be taken to balance the desire to protect equipment with gaining accurate results. Unlike with motor efficiency testing, no standards exist for testing certain torque quantities. Therefore, in his presentation, Emmanuel will provide guidance on how to perform torque testing in two kinds of motors: induction motors and permanent magnet motors. Induction motors are significantly more common in industrial applications, but permanent magnet motors are beginning to emerge with their uses in electric vehicles.
The Motor & Drive Systems Conference 2018 brings together executives, technical managers and engineering professionals from original equipment manufacturers, system developers and integrators, dealers and component providers. Attendees share ideas, discuss the latest technological developments, and learn from one another to explore ways to improve performance, energy efficiency and cost savings in several arenas.
The event runs from Feb. 8-9. You can see Emmanuel’s presentation on Thursday, Feb. 8, at 11:05 a.m.