Research Of New Gearless Traction Pumping Unit

One of focus points that study the energy-efficient field of pumping unit is the low speed electric motor which does not need the low speed organization direct drive. This kind of research of the pumping unit of organization has important scientific meaning and practical value. Domestic for this kind of pumping unit is in yet to start stage.This paper has analyzed the mechanical structures of novel gearless traction pumping unit, according to technical index and the major function of the system of pumping unit, also introduced the technical requirements of low speed and high torque PMSM. This generator supplies power with the SPWM power source of frequency conversion directly drives the drag of driving sheave to draw sucker rod and matches weight, being completed to take out oil demerit. This generator which does not need mechanical deceleration organization can make new the mechanical structure of novel gearless traction machine of pumping unit become very simple, have alleviated heavy daily maintenance work greatly, and increase systematic reliability considerably. Since having not slowed down structure, organization has no corresponding mechanical wastage, has raised systematic mechanical transmission efficiency greatly. On the other hand, because use high efficiency PMSM, the generator has reduced generator wastage and also enhanced the system overall efficiency.This paper uses Matlab calculation software establishment program to calculate the design scheme of oil field pumping unit with the 20kW low speed and high torque PMSM, then applies the Maxwell 2D two-dimensional finite element analysis software of electromagnetic field to carry out the analysis of magnetic field for PMSM, and has analyzed them in no load turn over electromotive force and the magnetism of air gap dense.This paper adopts electromechanical integration design for the control system of pumping unit of frequency conversion, PLC is the control core. This design realizes motor frequency control through control frequency converter. This paper has studied the motor control pattern of rotational speed, solved the mechanical impact problem in the inverting of pumping unit, and reduced mechanical wear. The PID closed-loop control for frequency conversion control system of pumping unit has been designed for realizing stroke, rush and about stroke time continuously adjustable in specified scope, this makes the pumping unit apply to the different operating mode oil well.The modeling and the simulation has been carried out to the novel gearless traction type pumping unit control system. The simulation result indicates that the model establishment is correct, the control method is feasible, these have offered good theoretical basis for this generator control systematic hardware parameter designs.