High voltage loop relay adhesion diagnosis circuit and diagnosis method

Abstract

The invention relates to the circuit detection field. In the prior art, a diagnostic technology can not be used to clearly determine which relay is adhesive. The invention aims at solving the above problem and provides a high voltage loop relay adhesion diagnosis circuit and a diagnosis method. The diagnosis circuit of the high voltage loop relay adhesion diagnosis circuit comprises a first voltage detection branch, a second voltage detection branch, a third voltage detection branch, a fourth branch and a fifth branch. The fourth branch is connected between a U_pl potential point and a whole vehicle grounding position GND. The fourth branch comprises a switch device SW_pg and an insurance device F_pg which are connected in series. The fifth branch is connected between the U_pl potential point and the module group grounding position GND_Mn of a whole vehicle. The fifth branch comprises a switch device SW_pm and an insurance device F_pm which are connected in series. The diagnosis circuit also comprises a signal detection unit. The signal detection unit is used for detecting the electric signal of the fifth branch. By using the diagnosis circuit and the diagnosis method of the invention, whether relay adhesion exists and / or which relay is adhesive can be clearly diagnosed and acquired.

Description

technical field [0001] The invention relates to the field of circuit detection, in particular to a high-voltage circuit relay adhesion diagnosis circuit and a diagnosis method. Background technique [0002] In electric vehicles, the relay is used to control the opening and closing of the high-voltage circuit. In order to ensure the safety of the high-voltage circuit, it is necessary to detect whether the relay is stuck before closing the relay. The technology used here is relay diagnostic technology. [0003] However, there is at least one defect in the existing diagnostic technology: it is impossible to clearly determine which relay is stuck; when diagnosing the main and negative relay sticking, it is necessary to close the pre-charging relay, which will lead to disconnection during the diagnosis process. The risk of the external high-voltage circuit; the circuit design is complex, and the requirements for the switching devices on the branch are strict. Contents of the in...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to provide a high-voltage circuit relay adhesion diagnosis circuit to solve the problem that the diagnosis technology in the prior art cannot clearly determine which relay is adhesion

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