EPRI´s program with large horsepower single-phase written-pole motors

EPRI is continuing the commercialization of many advanced technologies. One such effort is in the area of large horsepower single-phase written pole motor design and development. This project has a number of benefits, especially in the rural utility sector, where single-phase distribution systems are commonplace, and their conversion to three-phase would be cost prohibitive. Additionally, large horsepower written-pole motors provide energy-efficient motors that are also tolerant to short duration voltage variations. Since the majority of rural distribution feeders are of the overhead type, they are more susceptible to power quality events. A motor that can ride-through such events presents several attractive application opportunities to the end-users. Precise Power Corporation (PPC) and five EPRI member utilities initiated a project in 1993 to develop single-phase written-pole motor designs up to 60 HP. The author briefly discusses the development of the written pole synchronous motor technology and its advantages