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Method and apparatus for matching the power output of a high slip motor to the demand requirement of a pumpjack unit. The stators of the high slip motor are automatically connected in various different configurations to provide the optimum torque as required by the pumpjack unit due to the downhole

Method and apparatus for matching the power output of a high slip motor to the demand requirement of a pumpjack unit. The stators of the high slip motor are automatically connected in various different configurations to provide the optimum torque as required by the pumpjack unit due to the downhole pumping conditions. A novel control circuitry is connected between the motor starter and the motor stators. The control measures the power drawn by the stators and selects the most optimum configuration thereof for the load required by the pumpjack. This selection operates the motor in the lowest possible torque mode, which is considered the best electrical and mechanical operation of the pumpjack apparatus.

대표청구항 ▼

A motor control unit for automatically controlling the torque output of a high slip motor for powering a cyclic load which varies from below to above the motor rated current load, said motor including motor starter means connected to motor stator windings and means for altering the electrical config

A motor control unit for automatically controlling the torque output of a high slip motor for powering a cyclic load which varies from below to above the motor rated current load, said motor including motor starter means connected to motor stator windings and means for altering the electrical configuration of said stator windings, said motor control comprising: sensor means for detecting the magnitude of the current flow through said motor stator windings during a multiplicity of cyclic loads; first circuit means for connecting said motor stator windings in a first electrical configuration; first overload means responsive to said sensor means for automatically altering the electrical configuration of said motor stator windings from said first electrical configuration to a second electrical configuration to increase motor torque output when said current flow exceeds a first preselected value; first timing means for sensing the time period said motor stator windings are connected in said second electrical configuration; and first switching means for automatically altering said motor stator windings from said second electrical configuration to another electrical configuration to reduce motor torque output in response to said first timing means reaching a preselected value in excess of a multiplicity of cyclic loads.