Voltage transformation system with instantaneous quick-break protection function, and quick-break protection method thereof

Abstract

The invention relates to a transformation system with an instantaneous quick-break protection function. The system comprises a quick-break transformation device, wherein the output side of the quick-break transformation device is provided with a direct current-alternating current conversion unit which has a reverse H-bridge structure and is formed by IGBT modules, the IGBT modules on the output sides of the direct current-alternating current conversion unit are respectively provided with a shunting bypass, and a thyristor is arranged on each shunting bypass. The invention further relates to a quick-break protection method of the voltage transformation system. When an electric leakage fault is judged, the thyristors are controlled to be switched on, so the output-side IGBT modules in the direct current-alternating current conversion unit are switched off automatically, each shunting bypass adopts an over-damping circuit to quickly attenuate current to zero, the thyristors are switched off automatically, and power supply of an alternating current power supply system is cut off. The time for cutting off the power supply of the alternating current power supply system does not exceed 0.35 millisecond, personal electric shock safety accidents caused by electric leakage or short circuit of a low-voltage power supply system in an underground coal mine can be effectively prevented, and the safety, controllability and stability of the power supply system are improved.

Description

technical field [0001] The invention relates to a power electronic voltage transformation technology suitable for a low-voltage AC system under a coal mine, in particular to a voltage transformation system with an instantaneous quick-break protection function and a quick-break protection method thereof. Background technique [0002] Underground coal mine low-voltage 1140V, 660V and 127V power supply systems are located in the most complex environment, with the most electrical equipment for manual operation. At the same time, with the advancement of excavation and mining, the underground mobile substation should be as small as possible and easy to move. Moreover, most of the underground low-voltage electrical equipment is an inductive load. When the electrical equipment is started, the starting current is large, so it is easy to cause misjudgment of leakage or short-circuit faults and does not have instantaneous quick-break protection when leakage or short-circuit faults occu...

AI Technical Summary

Problems solved by technology

Moreover, most of the underground low-voltage electrical equipment is an inductive load. When the electrical equipment is started, the starting current is large, so it is easy to cause misjudgment of leakage or short-circuit faults and does not have instantaneous quick-break protection when leakage or short-circuit faults occur. It is easy to cause personal electric shock safety accidents, which not only affects the safety of the power supply system, but also affects its controllability and stability

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