Control method and control device of power supply soft launch for intermittent power supply by balance beam type pumping unit

Abstract

The invention discloses a power supply soft input controlling method and the controlling device for a walking-beam pumping unit under intermittent power supplying. The method of the invention measures the rotation speed of an electromotor by detecting the residual voltage of a stator winding after blackout when the electromotor supplies power intermittently, can complete the soft input of the power supply within a short time using a silicon controlled rectifier switch component to exert voltage step by step when the real speed of the electromotor approaches the synchronous speed. The controlling device of the invention includes a man-machine interface, a detection unit, a main controller, and a switching component. The invention measures the rotation speed of the electromotor by detecting the residual voltage of the stator winding after blackout, dispenses with a rotation speed sensor, and has high speed and precision. The silicon controlled rectifier component controls the on-off of the intermittent power supply, eliminates the overvoltage during the breakout due to the characteristic that the current is shut down when exceeding zero. Controlling the trigger of the silicon controlled rectifier around the synchronous speed when the electricity is turned on can implement the rapid soft input of the power supply, and then the impact current and the mechanical vibration can be avoided.

Description

technical field [0001] The invention belongs to the field of petroleum exploitation machinery, and in particular relates to a method and a control device for soft input control of a beam pumping unit under intermittent power supply. Background technique [0002] A working condition cycle of beam pumping unit motor includes heavy-load working condition, light-load working condition, no-load working condition and generating working condition. [0003] The intermittent power supply of the motor of the pumping unit refers to disconnecting the power supply during the no-load and power generation conditions, so that the load of the pumping unit can continue to run by inertia during this period. The power loss is equal to zero or close to zero, thus achieving a very significant energy-saving effect; when the pumping unit rotates through a certain angle and requires the motor to provide torque under light load and heavy load conditions, the power is turned on through a controllable ...

AI Technical Summary

Problems solved by technology

[0004] In the process of intermittent power supply, a key problem to be solved is the inrush current, vibration and noise of the motor when the power is turned on again. Reaching more than 10 times the rated current, not only will the energy saved by the intermittent power supply be lost, but the mechanical impact will also greatly reduce the life of the motor and its transmission system.

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