High-voltage power supply protection circuit and pre-charging resistance calculation method thereof

Abstract

The invention relates to the technical field of high-voltage driving systems, and discloses a high-voltage power supply protection circuit. The device specifically comprises a main positive relay KM1 which is provided with a first coil and a first normally open contact; the pre-charging relay KM3 is provided with a second coil and a second normally open contact; the power supply branch is connected in series with the first normally open contact and is connected in series between the positive electrode of the power battery pack and a load Rc; the pre-charging branch circuit is connected in series with the second normally open contact and is connected in parallel with the first normally open contact; the current transformer TA is used for generating a fault signal when the current at the parallel node is greater than a preset threshold value; the control unit BMU is respectively connected with the first coil and the second coil, and the control unit BMU is used for keeping the first coil in a power-off state when a fault signal is generated; according to the invention, the power supply of the power battery pack to the load can be cut off in time when a large current is generated on the power supply branch, so that the high-voltage power supply can be effectively carried out.

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