Alternating current excitation insulation detection circuit

Abstract

The invention discloses an alternating current excitation insulation detection circuit which comprises anode insulation resistance Rz and cathode insulation resistance Rf from a total positive end and a total negative end of a power supply battery set to an electrocar body, and further comprises an alternating current signal source, a sampling module and a data processing module which are used for detecting the insulation resistance value between the electrocar body and the power supply battery set so as to determine the insulation state of the electrocar. Compared with the prior art, the alternating current excitation insulation detection circuit has the advantages that low-voltage detection is adopted, signals cannot be disturbed easily, accuracy of detection of the insulation resistance value is improved, and the circuit is relatively simple and easy to produce and use.

Description

technical field [0001] The invention relates to an insulation detection circuit of an electric vehicle, in particular to an insulation detection circuit using AC excitation. Background technique [0002] The electric vehicle is a complex electromechanical device, and the working conditions of the electric vehicle are relatively harsh. The sharp changes in vibration, temperature and humidity may cause the power cables and other insulating materials to age rapidly or even damage the insulation, which will reduce the insulation performance of the equipment. This not only It will affect the normal control of the vehicle and endanger personal safety. [0003] At present, the insulation detection is through the resistance voltage division method or the DC injection method. Both methods need to detect the insulation resistance value by connecting the resistance voltage division method, which will introduce a voltage to the car body, and the car body has high voltage for the safety ...

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Problems solved by technology

[0002] The electric vehicle is a complex electromechanical device, and the working conditions of the electric vehicle are relatively harsh. The sharp changes in vibration, temperature and humidity may cause the power cables and other insulating materials to age rapidly or even damage the insulation, which will reduce the insulation performance of the equipment. This not only It will affect the normal control of the vehicle and endanger personal safety

[0003] At present, the insulation detection is through the resistance voltage division method or the DC injection method. Both methods need to detect the insulation resistance value by connecting the resistance voltage division method, which will introduce a voltage to the car body, and the car body has high voltage for the safety of the car. It brings certain hidden dangers and cannot test symmetrical insulation; the voltage used for DC injection detection must also be higher than the battery pack voltage, and equipment with such a large voltage will be larger in size and inconvenient to use

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