Electric vehicle relay adhesion detection circuit and detection method thereof

Abstract

The invention discloses an electric vehicle relay adhesion detection circuit and a detection method thereof. The electric vehicle relay adhesion detection circuit comprises a main positive relay S1 connected in series in a positive bus, a main negative relay S2 connected in series in a negative bus, a first induction branch connected in parallel with the main positive relay S1, a second inductionbranch connected in parallel with the main negative relay S2, an isolation transformer T1 and an adhesion judgment module, wherein a first winding N1 and a second winding N2 of the isolation transformer T1 are respectively connected in series in the first induction branch and the second induction branch, a third winding N3 is connected in series in the adhesion judgment module, and the adhesion judgment module feeds back resistance values in the first induction branch and the second induction branch through the third winding N3 and judges whether the main positive relay S1 and the main negative relay S2 are adhered or not according to a sampling result; the relay adhesion detection does not need to be carried out by closing the main negative and main positive relays step by step, the system complexity can be greatly reduced, and the detection time is shortened.

Description

technical field [0001] The invention relates to a relay control circuit, in particular to a new energy electric vehicle relay adhesion detection circuit and a detection method thereof. Background technique [0002] With the demand for energy saving and emission reduction, as well as the control of air pollution, new energy vehicles are gradually commercialized in the market, and electric vehicles are the main force of new energy vehicles. [0003] The high-voltage main circuit relay of electric vehicles controls the discharge of the battery system, and its reliability is directly related to the safety of electric vehicles. The high-voltage relay cannot be disconnected in a controlled manner in the sticking state, and cannot be disconnected in the fault state, which may cause serious safety accidents. Therefore, the vehicle system needs to reliably detect whether the relay is stuck. [0004] figure 1 Shown is a schematic structural view of the high-voltage main circuit of ...

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Problems solved by technology

For example, although the detection method described in CN205665378U has realized separation from the battery load circuit, it also needs an additional isolated current detection branch

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