Design And Research On Speed Control System In Pumping Unit Based On SRM

The oil well motors have been in light load state, low load rate, high power-loss, seriousenergy waste and inconvenient regulation on stroke for a long time. The switched reluctancemotor, having the function of energy saving and adjust-speed, is an ideal driving equipmenton beam pumping unit for low output well, heavy oil well and non-injection well. In order toimprove oil recovery and energy-saving efficiency, paper studies and develops a kind ofspeedcontroldevicebasedonSRM especiallyforbeampumpingunit.Based on studying the problem and the operating principle of beam pumping unit,coupled with the operating principle of control system of SRM, it focuses on the matchrelationship between SRM and beam pumping unit, designs to adopt the current chop controlwith improving the ceiling value in starting process and the separate stroke control inoperation process. Considering the operating characteristics of pumping unit, it uses thequick-filed and the slow-release to be an example. In up-stroke, it lies in the electric state andadopts the voltage control with adjusting the PWM duty cycle. In down-stroke, it lies in theinvertedpowerstateandadoptsthecurrent-chopcontrolwithadjustingtheceilingvalue.The hardware circuit of the speed control system contains two parts. One is powerconversion main circuit, including power converter which uses IGBT module as the switchesofthepowerconverter,uncontrollablefull-bridgerectifier,drivercircuitandprotectioncircuit.Theother is control circuit,includingthe coreof thecontroller which is TMS320LF2407AofTI, power conversion circuit, voltageconversion circuit, logic output circuit, pulse blockadecircuit,andsoon.After having finished the hardware circuit, it designs system procedure, which includesthe initialization procedure, the output procedure of PWM, pulse blockade procedure, thecommuting procedure, speed detection procedure and showing procedure. So it could guarantee the work of SRM. It designs the soft start procedure and the separate stroke controlproceduretoresolvethematchrelationshipbetweenSRMandbeampumpingunit.Inordertoget control effect better, it introduces the self-adjusting fuzzy control, which uses the motorspeedastheinputandthe PWMdutycycleastheoutput.Finally it constructs an experimental platform in order to online debugging. It can notfinish the close-loop control because of poorlaboratorysource. So it simulates the close-loopjust by MATLAB. Simulation results confirm the superiority and feasibility of the speedclosed-loopcontrolstrategy,whichisbasedonthefuzzycontrol.