Submersible servodrive system

Abstract

A submersible servodrive system comprises a pump and a servo motor system connected with the pump. The system is characterized in that a ground control device is connected with ground power supply by a cable; the cable is connected with the servo motor system; the ground power supply is controlled by the ground control device to supply power to a servo motor and the pump; the servo motor system comprises the servo motor and a servo controller; a motor shaft of the servo motor is provided with a photoelectric coder at the tail; the head of the motor shaft with the photoelectric coder is sealed and stretches into a shell of the servo controller; the photoelectric coder outputs the detected position signal to the servo controller; and the servo controller controls the servo motor to run. The system has high power factor, high energy saving rate and high flexibility, further saves power, can realize flexible production and reduces the operation cost. When being started, a pumping unit can provide large torque, combine with soft start and reduce the power of a matching motor of the pumping unit.

Description

technical field [0001] The invention relates to a drag system, in particular to a submersible servo drag system. Background technique [0002] At present, in my country and other oil-producing countries in the world, submersible motors are widely used in oilfields to drive submersible electric pumps to draw crude oil. The power source of traditional electric submersible pump systems is mainly two-pole three-phase asynchronous motors. There are three problems in the oil recovery system in the process of oil recovery: [0003] One is that when it is matched with a centrifugal submersible pump, because the motor speed is lower than the synchronous speed, the motor efficiency and power factor are low; [0004] Second, when it is matched with the submersible screw pump, the speed is too high to reduce the speed to the speed suitable for the screw pump through the tachometer. Even if the reducer is used, the cost of oil production will be greatly increased and the efficiency of th...

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Problems solved by technology

[0003] One is that when it is matched with a centrifugal submersible pump, because the motor speed is lower than the synchronous speed, the motor efficiency and power factor are low;

[0004] Second, when it is matched with the submersible screw pump, the speed is too high to reduce the speed to the speed suitable for the screw pump through the tachometer. Even if the reducer is used, the cost of oil production will be greatly increased and the efficiency of the system will be reduced. The frequency conversion speed control device is used to keep the motor in a low-frequency working state for a long time, and it is easy to cause the temperature rise of the motor to accelerate, causing motor failure

The system cannot realize flexible control, and the efficiency is low

[0005] Third, even if the traditional submersible electric pump system adopts frequency conversion control, its motor control cabinet is often placed on the ground. When the AC power is transmitted to the motor due to long-distance transmission, the energy loss is serious, which further reduces the efficiency of the system.

Although there is still the problem of low energy saving rate when combined with frequency conversion controller

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