Battery charge state detecting method

A battery state of charge and detection method technology, applied in the direction of measuring electricity, measuring devices, measuring electrical variables, etc., can solve problems such as difficult to determine the initial SOC of the battery, estimation errors, and problems that cannot be solved well

CN105277898AInactive Publication Date: 2016-01-27ZHEJIANG UNIV
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Patent Information

Authority / Receiving Office
CN · China
Current Assignee / Owner
Publication Date
2016-01-27
Estimated Expiration
Not applicable · inactive patent

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Abstract

The invention discloses a battery charge state detecting method. The method comprises the steps that the initial SOC of a battery is determined; the self-discharge effect of the battery is considered; a table look-up method is used to accurately estimate the SOC of the battery; an ampere-hour integral method is used to acquire the SOC estimation value of the battery of a next moment; a battery Thevenin model is combined, and an extended Kalman filter algorithm is used to correct the SOC of the battery; and finally, low power, over-current, over-temperature and the like of the battery are judged to carry out early warning and protection. According to the method provided by the invention, the influence of self-discharge of the battery on the battery capacity and the influence of temperature, the number of times of cycle charge and discharge and charge and discharge current on the rated capacity of battery are comprehensively considered, wherein self-discharge of the battery is caused by first time of running and downtime of the battery; error correcting is carried out on the SOC of the battery; and the accuracy is improved.
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Description

technical field

[0001] The invention belongs to the field of electrical engineering, and relates to a battery management system, in particular to a method for detecting the state of charge of a battery. Background technique

[0002] With the continuous consumption of fossil energy, electric vehicles will become a new means of transportation and gradually replace traditional vehicles that rely on fossil energy. However, battery is the energy source of electric vehicles, and its correct management will directly affect the safety and stable operation of electric vehicles. Therefore, it is very important to estimate the state of charge (SOC) of the battery in the battery management system, that is, the remaining power of the battery. Inaccurate battery SOC estimation will lead to incorrect grasp of the real-time state of the battery, which may lead to excessive battery life. Charging and over-discharging, even overheating and other phenomena. These hazards will cause permanent...

Examples

Embodiment Construction

[0092] The present invention will be further described below in conjunction with the accompanying drawings.

[0093] The detection method of battery state of charge of the present invention comprises the following steps:

[0094] 1) According to the Thevenin model of the battery, its equivalent circuit is as follows figure 2 As shown, determine the parameters: battery polarization internal resistance R1, polarization capacitance C1 and battery internal resistance R0;

[0095] At present, most studies believe that the battery model can be integrated by the Shepherd model, the Unnewehniversal model and the Nernst model to obtain a composite model. The relationship between the open circuit voltage and the battery SOC can be expressed as:

[0096] E k = E 0 - Ri k - K 0 SOC...