A method and device for controlling soft stop of a direct drive screw pump

Abstract

The invention discloses a control method and equipment for direct-driving screw pump soft stop. The method comprises the following steps of: after a halt detection unit detects a direct-driving screw pump halt command input by an external part, starting a multi-section speed regulation unit; according to preset multi-section speed, carrying out multi-section speed regulation on a motor of the direct-driving screw pump by the multi-section speed regulation unit so as to enable the motor to be subjected to deceleration operation; in the process of speed regulation of the motor of the direct-driving screw pump by the multi-section speed regulation unit, detecting bus voltage and torque output by the direct-driving screw pump in real time by a bus voltage / torque detection unit; carrying out the current PI (proportion and integral) regulation of the frequency converter of the direct-driving screw pump in real time by a current PI regulation unit by the detection result of the bus voltage / torque detection unit so as to enable mechanical energy stored by the direct-driving screw pump to be gradually released; and after the mechanical energy stored by the direct-driving screw pump is released to a preset degree, triggering a motor driving unit by a direct-current brake unit to control the motor of the direct-driving screw pump to realize quick braking. According to the invention, the use safety and practicality of the direct-driving screw pump equipment can be improved.

Description

technical field [0001] The invention relates to the field of direct drive screw pump control, in particular to a control method and device for soft stop of a direct drive screw pump. Background technique [0002] As a mechanical oil extraction equipment, the direct drive screw pump has advantages that cannot be replaced by other oil extraction equipment. At present, China has made great progress in the manufacture and application of direct drive screw pumps. [0003] However, due to the long screw of the direct-drive screw pump, the mechanical energy storage is very large when it is shut down, and the screw reverse phenomenon is very easy to occur, resulting in the screw being bent or broken during high-speed rotation, which is harmful to personnel and equipment. Cause damage, which greatly restricts the development of direct drive screw pump. Contents of the invention [0004] The technical problem to be solved by the present invention is to provide a control method and...

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Problems solved by technology

[0004] The technical problem to be solved by the present invention is to provide a control method and device for the soft stop of the direct drive screw pump, which can effectively solve the problem that the existing screw pump is prone to screw reversal due to the large mechanical energy storage when it stops The problem of causing damage makes the application of screw pumps more mature and more practical

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