Current detection calibrating method

Abstract

The invention relates to a current detection calibrating method and relates to the technical field of electric cars. According to the mainly adopted technical scheme, the current detection calibratingmethod comprises the steps that present current data of a battery of an electric car are obtained through detection by a diverter; through a pre-stored function relational expression between the first current errors and the current data under the situation that the diverter is aged and the diverter resistance drifts, the current data are calibrated to obtain first calibrated current data; and through a pre-stored function relational expression between second current errors and the current data under the situation that the diverter temperature drifts, the first calibrated current data are calibrated to obtain final current data. Through the final current data obtained through the current detection calibrating method, the influences of the temperature and aging reasons on the diverter are removed, the final current data are closer to actual current data, thus the remaining electric quantity of the battery of the electric car is estimated through the calibrated final current data more precisely, and data such as the attenuation degree of the battery are estimated more precisely.

Description

technical field [0001] The invention relates to the technical field of electric vehicles, in particular to a current detection and calibration method. Background technique [0002] In the field of electric vehicle technology, the battery and its management technology of electric vehicles are the core technology of electric vehicles, the battery management system is the core component of the battery system, and the current detection function is one of the basic functions of the battery management system. The accuracy of current detection and Reliability has a direct impact on state estimation and fault diagnosis of electric vehicles. [0003] In the prior art, a shunt is generally used for current detection, that is, the shunt is set on the negative pole of the battery. At this time, the output current passes through the shunt to generate a corresponding voltage. The voltage value conforms to Ohm's law, and the high-precision digital / analog signal After the conversion, the v...

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Problems solved by technology

[0004] However, the shunt will age after being used for a long time, causing the resistance value of the shunt to drift, and in the case of temperature changes, the resistance value of the shunt will also drift, so the shunt measured after long-term use The accuracy of the current data is low, which will affect the estimation of the remaining power of the battery and the degree of power attenuation of the battery.

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