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Pumping units are the main production machinery in the oilfield, and the electrical energy consumed accounts for about 60% of the electrical energy consumed by the oilfield. The requirements of the pumping unit for the electric motor are large starting torque, high efficiency, and wide economic operation range. If an induction motor is used, in order to meet the requirements of the large starting torque of the pumping unit, a large-capacity induction motor needs to be configured. However, the average load rate during normal operation is low, and the efficiency and power factor are low, resulting in a large amount of waste of electrical energy. Compared with induction motors, applying permanent magnet synchronous motors to pumping units has the following advantages:
① After the reasonable design, a large starting torque can be obtained. Therefore, a permanent magnet synchronous motor with a small frame size can be used to replace an induction motor with a frame size of 1 or 2 larger than that of the permanent magnet synchronous motor, which reduces the volume of the permanent magnet synchronous motor while increasing the load rate;
② High efficiency and high power factor can be obtained;
③ Wide range of economic operations.
