Oil pumping system using a switched reluctance motor to drive a screw pump

Abstract

An oil-pumping system includes a pumping-well unit, a controller composed of a main control circuit, a power converter, a current sensor and a position sensor, a switched reluctance motor mounted at the pumping-well unit and electrically coupled to the controller, a casing connected to the pumping-well unit, an oil suction pipe mounted in the casing, a pumping rod disposed in the oil suction pipe and connected to the switched reluctance motor, and a screw pump connected to the pumping rod in the oil suction pipe.

What the invention claimed is: 
     
         1 . An oil-pumping system, comprising:
 a pumping-well unit, a controller, a switched reluctance motor mounted at a top side of said pumping-well unit and electrically coupled to said controller, a casing connected to a bottom side of said pumping-well unit, an oil suction pipe mounted in said casing, a pumping rod disposed in said oil suction pipe and connected to said switched reluctance motor, and a screw pump connected to a bottom end of said pumping rod in said oil suction pipe, said switched reluctance motor comprising a shaft connected to said pumping rod in said oil suction pipe, a stator, a rotor fixedly mounted at said shaft and surrounded by said stator, said stator comprising a plurality of winding poles respectively electrically conductable for generating a magnetic attractive force subject to the control of said controller, said rotor comprising a plurality of rotor teeth attractable by the magnetic attractive force generated by said winding poles, said controller comprising a main control circuit, a power converter, a current sensor and a position sensor, said position sensor and said current sensor being adapted to detect power on/off status of each said winding pole of said stator of said switched reluctance motor, said main control circuit receiving and analyzing sensing signals indicative of power on/off status of said winding poles of said stator provided by said position sensor and said current sensor and providing a corresponding control signal to power on/off said winding poles of said stator, said power converter converting the control signal provided by said main control circuit into a power signal for driving said switched reluctance motor.