External rotor PM motor fed by a load commutated inverter for fan applications

An important market for brushless permanent magnet (BLPM) motors is fan applications. External rotor motors are especially advantageous for space-saving fan-motor-units. Synchronous machines fed by a load-commutated inverter (LCI) have been used for many years for drive systems in the highest power range. The utilization of this system in the lower power range for washing machines by using PM motors was also proposed. The present paper examines an LCI-fed external-rotor PM motor for fan applications.