Research Of Permanent Magnet Synchronous Motor Drive Pumping Unit Energy Storage Technology

Because of the mechanism feature and the downhole load instability while working,the motor of a Beam pumping unit is always in a recurrent state in which electromotion and power generation occur alternately.The electric energy generated by the motor can not be absorbed by the power grid.The quality of power supply on the power grid is reduced and the motor's power factor is also decayed.If the generated power from the motor of a Beam pumping unit can be kept in reserve and recycled,not only the quality of power supply can be improved,the energy can be saved as well.Therefore,the development of a system which can store energy on an oil pumping machine is great of practical significance.Aiming at the power generation of the motor while the permanent magnet synchronous motor driven Beam pumping unit is working,the purpose of this paper is to design an energy storage system which can keep the motor's generated power in reserve and put it in use on the dc bus while the motor is doing positive work.As a consequence,voltage on the dc bus can be steadied,power factor of the oil pumping machine motor can be raised,energy can be saved and producing cost of oilfield enterprise can be reduced.This paper firstly analyzed the function of the energy storage system.In the clear on the basis of the main functions of the energy storage system,the overall plan of the system is worked out.After each factor is considered,supercapacitor is selected as a energy storing installation.Secondly,a representative oil well is selected in Daqing Oilfield.After searching the information of the specific structure of an oil pumping machine and the parameter of the well condition,MATLAB/Simulink is used to simulate the power characteristic.The quantity of electricity generated by the motor in an operational cycle time is calculated the motor's power characteristic curve in an operational cycle time is received.It is also compared with the actual measured data to checkout the validity of the simulation and provide a theoretical basis for the reasonable calculation of the supercapacitor bank.Moreover,according to the overall design scheme and the overall functional requirement,the hardware circuit and the software program are designed and written detailedly.The hardware circuit includes the voltage detection circuit,the current detectioncircuit,the communication circuit,the drive circuit,the charge and discharge circuit and so on.The software program includes the voltage test procedure,the current test procedure,the communication program,the PWM output program and so on.