Intelligent control method capable of reducing higher harmonics for pumping unit

Abstract

The invention relates to a pumping unit controller, particularly to an intelligent control method capable of reducing higher harmonics for a pumping unit. The pumping unit is powered by a three-phase asynchronous motor, a multi-stage variable-speed motor or a permanent magnetic synchronous motor. A filter circuit, a direct current voltage and current detection circuit, a phase reference circuit, an autodyne phase adjusting circuit, a digital signal processor (DSP) control circuit, an alternating current (AC) detection circuit and a sine pulse width modulation (SPWM) unit are included. The intelligent control method is characterized in that the SPWM unit comprises a microprocessor, a synchronous square wave generator, a sine-wave generator, an arithmetic unit, a bi-phase SPWM5, a controllable inverter, a filter circuit, a motor and a voltage and current sensor, wherein the arithmetic unit and output square wave signals control the controllable inverter to work through the bi-phase SPWM5, so that the area of the output impulse voltage is equal to that of expected sine waves in a corresponding interval.

Description

technical field [0001] The invention relates to a controller for a pumping unit, in particular to an intelligent control method for a pumping unit capable of reducing high-order harmonics. The pumping unit is powered by three-phase asynchronous motor, multi-stage variable speed motor and permanent magnet synchronous motor. Background technique [0002] At present, in my country's onshore oil exploration and production industry, except for self-injection oil wells, other oil wells must use various types of motors to provide power to extract crude oil, and a considerable part of the oil wells have an oil quality of 65, 65, and heavy oil areas are poor oil wells. It is necessary to timely adjust the stroke times of the pumping unit. There are roughly three traditional methods: one is to use a multi-speed motor; the other is to replace the pulley, which is time-consuming, laborious and reduces production; The power grid is seriously disturbed, directly endangering oil well equipm...

AI Technical Summary

Problems solved by technology

[0002] At present, in my country's onshore oil exploration and production industry, except for self-injection oil wells, other oil wells must use various types of motors to provide power to extract crude oil, and a considerable part of the oil wells have an oil quality of 65, 65, and heavy oil areas are poor oil wells. It is necessary to timely adjust the stroke times of the pumping unit. There are roughly three traditional methods: one is to use a multi-speed motor; the other is to replace the pulley, which is time-consuming, laborious and reduces production; Serious interference to the power grid directly endangers oil well equipment and power grid equipment

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