Monitoring device and monitoring method for high-voltage busbar of electric vehicle

Abstract

The invention provides a monitoring device and a monitoring method for a high-voltage busbar of an electric vehicle. A sampling resistance voltage signal is acquired by a current sampling circuit anda sampling resistance, a voltage dividing signal is acquired by a voltage acquisition circuit and a voltage-dividing resistance array, a capacitor voltage signal is acquired by an insulation detectioncircuit, a microprocessor is used for processing the received signals and performing compensation and correction on the signals through a reference source to obtain a busbar current value, a bus voltage value and an insulation resistance value, and finally, the data interaction between the monitoring device and equipment connected with a CAN bus is realized through the CAN bus. The monitoring device and the monitoring method provided by the invention have the benefits that the current, voltage and insulation resistance values of the high-voltage busbar of a battery can be simultaneously, quickly and accurately measured, battery key parameters is provided for a battery management system in real time, and the battery safety protection capability and the remaining electric quantity estimation accuracy are improved.

Description

technical field [0001] The invention relates to the technical field of electric vehicle battery management, in particular to a monitoring device and a monitoring method for a high-voltage bus of an electric vehicle. Background technique [0002] The power of an electric vehicle comes from its high-voltage battery pack, and the measurement of the voltage, current and insulation resistance of the power battery pack is crucial to the battery management system. On the one hand, the measurement of these parameters is used as the basic parameters for calculating the remaining power of the battery to ensure the reliability and accuracy of the calculation; Affect driving safety. [0003] The existing high-voltage bus monitoring devices are classified according to the functions of measuring current, voltage, and insulation resistance, and mainly include Hall current sensors, voltage sensors, resistance-dividing insulation detectors, and bridge-balanced insulation detectors. The pri...

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Problems solved by technology

[0004] In the above-mentioned high-voltage bus monitoring device, the measurement accuracy of the Hall current sensor is relatively low, especially for the case of small current, the accuracy is poor; the independent voltage measurement module set by the voltage sensor increases the cost of the battery management system, and also requires Occupies the space of the battery, thereby reducing the energy density of the battery, and in general, the voltage measurement module only measures the output voltage of the battery pack, and does not pay enough attention to the load end; resistance divider insulation monitors often need to introduce resistance, resulting in artificial insulation reduction In addition, the hardware will be more complicated and not convenient enough; the bridge balance insulation detector cannot detect the situation when the positive and negative insulation of the power battery system are equally reduced

[0005] In addition, in the above-mentioned monitoring device, the independent measurement modules cannot guarantee the synchronization of the current and voltage insulation resistance values, that is, the measurement of the parameters is not completed in the same time period, which will bring the original error in the estimation of the remaining power of the battery management system

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