Improving the Energy Efficiency of the Sucker-rod Pump via Its Optimal Counterbalancing

The paper discusses energy-efficient and sensorless method of a pumping unit optimal counterbalancing, which uses torque and speed calculations from the side of prime mover that is induction motor. The parameters necessary for the calculations were obtained by dint of special observers. The extra torque computation method that provides less active power consumption from induction motor is proposed. The principles of energy efficiency of sucker-rod pump control methods and algorithms that used no sensors and via estimation the maximum torque at crankshaft from counterweight are shown. The adaptive algorithm for observation of variables, which needs for electromagnetic torque calculation from the side of the induction motor is used. For the proposed system it is shown that motor torque and crank angle are enough variables for optimal counterbalancing. The overall efficiency of pump unit, that achieved from the proposed method of optimal counterbalancing were confirmed by the results of simulation tests.