An important advantage of SEMA motor technology is the capability to provide very high output efficiencies over a broad torque/speed range. Elimination of iron from the motor core means that iron-related losses are also eliminated. A number of distributed power applications from 2 kW portable power to 3 MW wind powered systems have been studied, with several generator units currently fielded by commercial partners. In the larger systems, efficiencies in excess of 99% are achieveable.
The axial-flux SEMA design offers the capability to design a single unit that can accommodate a wide range of output power requirements by stacking multiple identical “slices” on a common output shaft. The high rotor inertia typical to SEMA motors also helps system stability during load pickup. The use of permanent-magnet brushless DC systems in distributed power generation offers much better regulation of the system output power for end-line power factor correction or building UPS systems for power-quality sensitive applications.
At this time, Lynx is working with commercial partners to develop 75 and 150 kW distributed power units based on ironless SEMA technology. Test units in this line have been tested to well over 98% generator efficiency at rated power.