Four-quadrant explosion-proof frequency converter with reactive compensation function and control method

Abstract

The invention discloses a four-quadrant explosion-proof frequency converter with a reactive compensation function. The frequency converter comprises an AC filtering unit, a controllable rectificationpower supply, a DC filtering unit, an inversion unit, a rectification controller and an inversion controller. The input end of the inversion unit is connected to the output end of the controllable rectification unit; the output end of the inversion unit is connected to a motor load, the rectification controller controls IGBTs in the controllable rectification unit to achieve rectification and reactive compensation, and the inversion controller controls the IGBTs in the inversion unit to achieve variable frequency speed regulation of the motor load. According to the frequency converter and thecontrol method, four-quadrant operation of rectification, inversion, inductive reactive power and capacitive reactive power in the true sense is achieved, the working conditions of load electric operation and feedback operation can be met, reactive power compensation can be considered, the problem of electric energy quality caused by reactive power can be solved while a motor load is dragged to operate normally, and the utilization rate of equipment is greatly increased.

Description

technical field [0001] The present invention relates to a frequency converter and its control method, more specifically, to a four-quadrant explosion-proof frequency converter with reactive power compensation function and its control method. Background technique [0002] With the improvement of the mechanization of underground coal mining, large-scale use of high-power motors, a large amount of reactive power continues to circulate between various inductive loads and electrical equipment and power supply, resulting in low power factor and large voltage fluctuations in the underground power grid. Quality deteriorates. The power factor is low, and the farther the power supply distance is, the greater the system voltage loss is, which is likely to cause voltage fluctuations. At the same time, there is a large amount of reactive power on the line, resulting in increased line loss. In short, the problem of reactive power has seriously affected the safe and normal operation of th...

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Problems solved by technology

[0002] With the improvement of the mechanization of underground coal mining, large-scale use of high-power motors, a large amount of reactive power continues to circulate between various inductive loads and electrical equipment and power supply, resulting in low power factor and large voltage fluctuations in the underground power grid. quality deterioration

The power factor is low, the farther the power supply distance is, the greater the system voltage loss is, and it is easy to cause voltage fluctuations. At the same time, there is a large amount of reactive power on the line, resulting in increased line loss

In short, the problem of reactive power has seriously affected the safe and normal operation of the underground power grid and electrical equipment

With the development of dynamic reactive power compensation technology (SVG), a complete set of SVG devices has been equipped underground to control the reactive power problem of the power grid, but this will undoubtedly increase the cost and maintenance workload of the system

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