High-voltage system insulation detecting method and device, and electric vehicle

Abstract

The invention provides a high-voltage system insulation detecting method and device, and an electric vehicle, which relates to the technical field of high-voltage systems, and is applied to the electric vehicle. An insulation detecting circuit is arranged between the positive pole and the negative pole of a power battery of the electric vehicle; the insulation detecting circuit includes a first resistor connected between the positive pole of the power battery and the vehicle body ground, a gate relay and a third resistor connected in series between the positive pole of the power battery and the vehicle body ground, and a second resistor connected between the negative pole of the power battery and the vehicle body ground. The high-voltage system insulation detecting method comprises the following steps: controlling a heating relay and a main negative relay in the battery pack of the electric vehicle to be closed after the electric vehicle is connected with a charging post; collecting avoltage across the first resistor and a voltage across the second resistor separately before and after the gate relay is closed; and determining the insulation of the high-voltage system according tothe collected voltages. The scheme provided by the invention realizes the insulation detection of the high-voltage system of the battery pack during the preheating process, and avoids electric shock to the personnel.

Description

technical field [0001] The invention belongs to the technical field of high-voltage systems of electric vehicles, and in particular relates to a high-voltage system insulation detection method and device and an electric vehicle. Background technique [0002] Electric vehicles are powered by high-voltage power batteries to drive motor systems, such as image 3 As shown, it is a schematic diagram of the connection between the power battery and the high-voltage system. In the prior art, if the ambient temperature of the battery pack is low, preheating is required before charging the power battery U, that is, the heating relay K4 is closed, and by heating The resistor R1 heats the battery pack 1. During the preheating process, since the main positive relay K1 and the main negative relay K2 are both in the disconnected state, the insulation detection circuit 1 cannot detect the insulation of the high-voltage system. If there is an insulation fault in the system, there is a risk o...

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Problems solved by technology

[0003] The purpose of the embodiment of the present invention is to provide a high-voltage system insulation detection method, device and electric vehicle, so as to solve the problem in the prior art that the insulation of the high-voltage system cannot be detected when the battery pack is preheated, resulting in the risk of electric shock and injury

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