The Application Of Brushless DC Motor In Energy Saving In Pumping Unit

The electricity consumption of pumping unit was very large, account for40%of the total consumption in oilfield. The Cyclical Fluctuation of pumping unit’s load, caused the low efficiency of the whole system and the waste of electric energy. The pumping unit motor conversation had great significance.Based on the pumping unit motor characteristics, this paper analyzed the advantage of the brushless DC motor in using of pumping. And then this paper summarized the electromagnetic design principles of permanent brushless DC motor(PMBLDCM). With proposing required energy-saving parameters, according to the principles up, by the calculation, a electromagnetic design program of22kW PMBLDCM was proposed in this paper.Dynamic simulink was done to this motor with ANSOFT external circuit, analyze the unloaded back EMF, unloaded air gap flux density, torque, current velocity. The motor current was set at rated current, then add the function type load and simulating the motor.The brushless DC motor would generated torque ripple, which would reduced the performance of the motor and increased energy consumption. Torque ripple could lead power fluctuation, which was negative to energy saving. According to the auxiliary slot method which was used to suppress the cogging torque, studied the infection of the depth of auxiliary slot, breadth, amount and axis angle to motor cogging torque. The simulation result showed that the cogging torque is minimum when the number was two, the breadth is0.3tooth breadth, the axis angle was4°Connect the next switch tube advance made the winding’s current which in weak magnetic region was translated to the next winding which in the higher magnetic destiny. Thus current could bring compensating torque and decrease the torque ripple. Setting up the connect breadth of external circuit to realize the overlapping commutation. Simulating analysis showed that the commutation torque ripple is minimum when the motor overlapping commutation was1.5°The paper made the parameters between the designed brushless motor and a three-phase induction motor. The designed motor could run in a lower power level, which showed it had its advantages in energy-saving...