A kind of train LCU protection circuit and its fault detection method

Abstract

The invention discloses a train LCU protection circuit and a fault detection method thereof, wherein the train LCU protection circuit comprises: at least one high-side drive circuit, which is connected in series between the load and the load power supply, and is connected in series between the load and the load power supply. disconnecting the electrical connection between the load and the load power supply when the current flowing through the high-side drive circuit is greater than or equal to a first threshold value; a slow-blow fuse is used to be connected in series between the load and the load power supply , the fusing current of the slow-blow fuse is less than the first threshold. In the present invention, the high-side drive circuit is disconnected when the load is short-circuited, thereby cutting off the current flowing through the load; when the load is over-current, the slow-blow fuse plays a role, and after the over-current continues for a period of time, the slow-blow fuse is blown, cutting off the current flowing through the load. load current, so as to avoid long-term overcurrent damage to the load while ensuring a certain overcurrent capability of the circuit.

Description

technical field [0001] The invention relates to the technical field of LCU, in particular to a train LCU protection circuit and a fault detection method thereof. Background technique [0002] In the current train LCU products, the output circuit of the output IO board can only be designed with either short-circuit protection or over-current protection, and there is no protection method compatible with both over-current protection and short-circuit protection. If the short-circuit protection method is selected, the over-current capability of the output circuit will be large, and the capacitive load capability will be strong, but the over-current protection is lacking, which cannot prevent the damage to the equipment caused by the continuous over-current output; if over-current protection is selected In this way, the output circuit has weak capacitive load capacity, and the high current of the output circuit can easily damage the current sampling circuit when it is short-circu...

AI Technical Summary

Problems solved by technology

If you choose the short-circuit protection method, the overcurrent capability of the output circuit will be very large, and the capacity with capacitive load is strong, but there is a lack of overcurrent protection, which cannot prevent the damage to the equipment caused by continuous overcurrent output; if you choose overcurrent protection In this way, the output circuit has a weak capacitive load capacity, and when the output circuit is short-circuited, the large current can easily damage the current sampling circuit, resulting in damage to the board.

If the first MOS tube is damaged, the control failure rate of the output circuit will be doubled. If the other first MOS tube also fails at this time, the entire circuit will be out of control, which is a fatal problem for safety control products.

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