PD testing of motors for hostile environments

Abstract

The use of electrical motors in hostile environments continues to increase. One example is electrical submersible pumps used for oil and gas production. Additionally, ESPs are being used in wells with increasingly more expensive intervention costs and high productivity. As intervention costs increase, the necessity for longer downhole equipment life also increases. Go/No-Go tests such as hipot, surge test, insulation resistance and winding resistance are good to evaluate the actual (at the factory) condition or integrity of the equipment but they inadequately address longterm aging issues associated with the motor. The use of Partial Discharge testing for hostile environment motors, particularly in factory acceptance tests, may give users and manufacturers additional insight into the quality of construction of the motor and potential life shortening discrepancies in the winding insulation. Additionally, due to the construction of the motors