Motor Drive Applications

Oil and Gas Downhole Motor Controllers

Downhole servo amplifiers provide motor control for a variety of oil and gas applications such as MWD, LWD, wireline systems, directional and horizontal drilling, and artificial lift pumps. Performance Controls’ amplifiers operate at 350 deg F (175 deg C), with or without a motor feedback sensor.

When operating thousands of feet below ground the last thing a service provider wants is to have their drill stop because of a component failure, particularly with the high financial and reputation costs associated with recovery.  One of the most common failure modes for brushless motors when operating in a harsh down-hole environment is not the motor itself, but the feedback device.  Hall effect sensors are the most common choice for oil services tool applications because of size, but there are tradeoffs in performance and reliability.  A resolver can provide increased reliability, but they are often as large as the motor and add complexity to the drive electronics.     

Down-hole services companies have been in search of a sensorless solution because typical sensorless motor drives have been unsatisfactory.   The most significant drawback to sensorless designs has been the high current needed to start a sensorless motor, while power efficiency and performance are also important.

In response to these demands Performance Controls developed the DHT series controller incorporating several proprietary capablities for down hole applications.