Voltage determination method and device for SOC initial value calculation

Abstract

The invention provides a voltage determination method and device for SOC initial value calculation. The method comprises steps that after a BMS is powered on, battery core sampling voltage values at multiple continuous sampling moments are obtained; a sampling average voltage value of the battery core is obtained through a plurality of battery core sampling voltage values; a voltage value of the battery pack is obtained within the sampling time, and a calculated average voltage value of the battery core is obtained through the voltage value of the battery pack; whether a difference value between the sampling average voltage value and the calculation average voltage value is within a first voltage threshold range or not is determined; if yes, whether the standing time before the BMS is powered on is within a first time threshold range or not is determined; if not, an SOC initial value is calculated through the sampling average voltage value. The method is advantaged in that the batterypack voltage is utilized to verify the core voltage, and further determination is carried out through the standing duration of the BMS, so the situation that the SOC initial value is wrong when the voltage is abnormal is avoided, and estimation accuracy of the SOC initial value is improved.

Description

technical field [0001] The present invention relates to the field of electric vehicles, in particular to a battery cell voltage determination method and device for calculating an SOC initial value. Background technique [0002] Battery SOC (State of Charge, state of charge) is the core parameter in the battery management system (BMS, Battery Management System). SOC estimation is to obtain the available power of the battery and the evaluation of battery life. The SOC parameter is used to prevent the battery from appearing during charging and discharging. Abnormal phenomena such as overcharge, overdischarge, overvoltage and undervoltage. SOC parameters are the premise of providing pure electric cruising range for electric vehicles, and accurate SOC estimation provides a guarantee for the safe cruising range of vehicles. [0003] Usually, the algorithm for SOC estimation mostly adopts the ampere-hour integration method or the extended Kalman filter recursive algorithm based on...

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Problems solved by technology

[0004] For the above estimation algorithm, if the voltage sampling is abnormal, the SOC value cannot be corrected, resulting in inaccurate SOC parameters. In the process of BMS power-on initialization, the voltage jump will affect the initial value of SOC, which will lead to SOC Estimates are biased

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