Dynamic evaluation method of SOC of power cell

Abstract

The invention relates to the technology of management of power cells, and discloses a dynamic evaluation method of an SOC of a power cell. Thus, dynamic evaluation of the SOC of the power cell can be simply and precisely achieved. According to the invention, if an open circuit voltage method is used for evaluating the SOC value, certain compensation will be made according to temperature features; the SOC and the Volume after the compensation are used as initial values of the electrification of this time; if the open circuit voltage method is not used, the SOC and the Volume read from the EPPROM are directly used as the initial values of the electrification of this time; then, in the normal charging and discharging states, the current cell volume Volume is acquired according the charging and discharging current Ic, Id based on the ampere hour integration method; in the charging state, the cell volume Volume and the SOC are corrected according to the SOC of the charging curve and the corresponding cell voltage point CVn; and in the discharging state, the cell volume Volume and the SOC are corrected according to the magnitude of the discharging current and the SOC of the discharging curve and the corresponding cell voltage point DVn in the discharging current condition.

Description

Technical field [0001] The invention relates to a management technology of a power battery, in particular to a dynamic estimation method of the SOC (remaining power) of a power battery. Background technique [0002] With the popularity of automobiles and the continuous deterioration of air quality, energy-saving and environmentally friendly new energy vehicles, especially electric vehicles, have become an important direction for technological innovation in the world's automobile industry, which is also an inevitable choice for sustainable development. At present, the power battery related technology as the power source of new energy vehicles or electric vehicles has become one of the key technologies restricting the development of electric vehicles. In order to ensure the safe and reliable operation of power batteries, ensure battery safety, and extend battery life, battery Effective management of the charging and discharging process of the battery, the most important of which is...

AI Technical Summary

Problems solved by technology

[0005] At present, the SOC algorithm of the battery management system mainly includes the ampere-hour integration method, the open-circuit voltage method, the internal resistance method, the Kalman filter method, and the neural network model algorithm. The ampere-hour integration method is widely used because of its simplicity, but it is prone to Accumulated errors make the SOC judgment more and more inaccurate; the open circuit voltage method can accurately predict its SOC as long as the battery model is accurate, but it is only used in static state, that is, when the circuit is open, and it is mostly used as an auxiliary measurement in actual use; internal resistance The method can also judge the battery SOC more accurately, but because there are many factors affecting the battery content, it is difficult to use the internal resistance method for the SOC measurement of the battery; the Kalman filter algorithm and the neural network algorithm are also popular algorithms in recent years, but the principle More complex, more difficult to implement

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