Special voltage stabilizer for three-phase permanent magnet synchronous motor (PMSM) for producing well in oil field

Abstract

The invention discloses a special voltage stabilizer for a three-phase permanent magnet synchronous motor (PMSM) for a producing well in an oil field, which solves the electric power waste phenomenon caused by voltage fluctuation of the existing three-phase PMSM for the producing well in the oil field. The voltage stabilizer is arranged between a three-phase supply and the three-phase PMSM and is provided with a voltage compensation circuit and a measurement and control circuit. The input end of the voltage compensation circuit is connected with in-phase voltage lines (three-phase input of an A1 phase, a B1 phase and a C1 phase), and the output end of the voltage compensation circuit is connected with out-phase voltage lines (three-phase output of an A2 phase, a B2 phase and a C2 phase); and the input end of the measurement and control circuit is connected with out-phase voltage lines (an A1 phase, a B1 phase and a C1 phase), and the output end of the measurement and control circuit is connected with the voltage compensation circuit. The voltage stabilizer of the invention can track the counter electromotive force of the three-phase PMSM in a real time by full-automatic voltage stabilization, so that a beam-pumping unit in the oil field can reach a very high power factor, thereby improving the efficiency, reducing the reactive power loss, increasing the power grid tolerance and saving the electric charge.

Description

technical field [0001] The invention relates to a voltage stabilizer, in particular to a special voltage stabilizer for a three-phase permanent magnet synchronous motor of an oil production well in an oil field. Background technique [0002] In onshore oilfield oil extraction, motors are usually used as power to drive oil well pumping devices to pump oil out of the ground and then transported to predetermined locations through pipelines. Because the condition of the oil well is complicated, there are often situations such as sand blocking, so a large starting torque is required. However, under normal circumstances, the required torque is several times smaller than that of starting and sand blocking. If three-phase Asynchronous motors, in order to adapt to the high torque requirements during start-up and sand blocking, the power of the motors often selected is large, but most of the torque required in the normal pumping process is small, and there will be a phenomenon of powe...

AI Technical Summary

Problems solved by technology

At present, there are mainly two traditional solutions: one is to use reactive power compensation, because the three-phase permanent magnet synchronous motor exhibits capacitive power when it is running at a low voltage, while it is capacitive when it is running at a high voltage. Inductive, so the compensation circuit needs two kinds of compensation of power capacitance and reactance, the circuit is complicated and the cost is high; due to factors such as differences in motor manufacturing process, different oil well loads, voltage fluctuations or motor aging, demagnetization, etc., the required compensation amount for each oil well motor is Different and often changing, so the compensation method cannot fully meet the requirements, and it often happens that the compensation is not enough or the compensation is over

The second is to use a voltage stabilizer. Usually, the traditional voltage stabilizer is fixed after the output voltage value is manually set before use. Also due to differences in motor manufacturing process, oil well load changes, voltage fluctuations or motor aging, Due to factors such as demagnetization, the back electromotive force of each oil well motor is different and changes, which cannot make the motor work in the best state.

The three-phase permanent magnet synchronous motor is very sensitive to voltage, and the output value of the voltage regulator deviates from its counter electromotive force by 2V (equivalent to 0.5%), and the reactive power will increase significantly

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