New energy vehicle and insulation detection method and system thereof

Abstract

The application discloses a new energy vehicle and an insulation detection method and a system thereof. The method comprises the following steps: inputting an original injection pulse to a new energy vehicle, and collecting a pulse signal currently output by the new energy vehicle to get a real-time recovery pulse; judging whether the voltage amplitude of the real-time recovery pulse is beyond a measurable range, and if the voltage amplitude of the real-time recovery pulse is beyond the measurable range, adjusting the voltage correspondingly to enable the voltage amplitude of the real-time recovery pulse fall into the measurable range; and judging whether the influence of the current voltage of a Y capacitor on the real-time recovery pulse can be neglected, and if the influence of the current voltage of the Y capacitor on the real-time recovery pulse can be neglected, determining a shortest pulse signal time for completing insulation detection, taking the time as the pulse time period of the current injection pulse, inputting an injection pulse corresponding to the pulse time period to the pulse input end, collecting a recovery pulse corresponding to the injection pulse, and calculating the value of insulation resistance according to the injection pulse and the recovery pulse. The insulation detection speed of new energy vehicles can be improved.

Description

technical field [0001] The invention relates to the technical field of new energy vehicles, in particular to a new energy vehicle and its insulation detection method and system. Background technique [0002] At present, the voltage of the power battery in new energy vehicles is far beyond the range of personal safety voltage. When the insulation performance of the power battery or the high-voltage system of the vehicle is degraded, personal safety will be endangered, and the insulation performance of the internal battery module of the power battery will cause the power battery to be damaged. Internal faults affect the performance of the whole vehicle. Therefore, it is very important to test the insulation performance of new energy vehicles. [0003] At present, the insulation detection unit in the power battery management system is mainly responsible for monitoring the insulation performance of the high-voltage system of the vehicle. By detecting the insulation resistance va...

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Problems solved by technology

[0004] However, since there are Y capacitors with different capacitances in the power system of the new energy vehicle, the pulse signal injected into the new energy vehicle will be affected by the RC charging characteristics of the Y capacitor, thereby reducing the accuracy of insulation detection

The existing pulse injection detection method will set a long enough fixed time to avoid the influence of the Y capacitor on the insulation detection, but this will make it take 10s or even longer to complete an insulation resistance detection, and the detection speed is quite slow

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