SSCB-based coal mine power grid fast fault current limiter

Abstract

The invention relates to an SSCB-based coal mine power grid fast fault current limiter which is mainly used for limiting the current of a coal mine power supply network. The fast fault current limiter is connected in series to a power supply line of a coal mine power grid to limit the short-circuit current of the coal mine power grid. The fast fault current limiter comprises a normal flow loop, a fault current limiting circuit, and a fault judging part. The normal flow loop includes a main switch-off loop and an auxiliary switch-off loop. The main switch-off loop adopts a diode bridge rectifier circuit to convert alternating current into direct current for control, and on-off control of the direct-current loop part is realized by an insulated gate bipolar transistor. The auxiliary switch-off loop is a fast switch-off auxiliary loop composed of a resistor, a capacitor and a gate turn-off thyristor, and is used to quickly switch off the normal flow loop. The invention provides an SSCB-based coal mine power grid fast fault current limiter which reduces the short-circuit current in the case of failure to improve the residual voltage of a bus when a coal mine power grid fails and further ensure normal power supply of other lines connected to the bus.

Description

technical field [0001] The invention belongs to the field of power supply, and in particular relates to an SSCB-based fast fault current limiter for a coal mine power grid used to limit the fault current level and increase the residual voltage level of the busbar of the coal mine power grid when a fault occurs. Background technique [0002] At present, my country's coal mines mostly use electricity as the power source for underground production machinery. Therefore, the coal mine power supply network is responsible for providing energy for underground production equipment. role. The underground space of coal mines is narrow, the load is concentrated, and the production environment is harsh. The power supply network of coal mines is in a harsh working environment, and various faults such as short circuits and leakage are prone to occur. When a small fault occurs in the power grid, other chain reactions are caused due to untimely handling and equipment problems, which expands ...

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Problems solved by technology

[0004] Through the calculation and statistics of the power consumption of the current-limiting reactor, it is found that if the current-limiting reactor is directly connected in series with the high-voltage downhole cable, a large amount of electric energy will be consumed during the operation process, which will make the economic efficiency of coal mine production worse, so it is necessary to adopt a new The fault current limiting method of

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