SOC estimation method

Abstract

The invention discloses an SOC estimation method. The method comprises the following steps: acquiring a current voltage V and a current A in real time; setting a voltage threshold Vh of an integral section; setting a table look-up section interval, an integral section interval and an interval threshold value P0 of the SOC; if the value P of the SOC is in the integral section interval, calculating the residual capacity Ct of the battery pack and the value P of the SOC by using an integral method; if the value P of the SOC is close to the threshold value P0, judging whether a difference value Vc delta exists between the current voltage V and the voltage threshold value Vh or not; if the value P of the SOC is located in the interval of the table look-up section, calculating the voltage VXCT after the display table is compensated according to the difference value Vc delta, comparing the voltage V with the voltage VXCT after the display table is compensated, and obtaining the corresponding SOC value PT.

Description

Technical field [0001] The present invention relates to the field of battery management, in particular a SOC estimation method. Background technique [0002] Now today's new energy market mainly uses two power storage batteries, one is a ternary battery, a lithium iron phosphate battery. The ternary battery is high, the unit power is large, and the battery is strong, but the stability is poor, the ignition point is low when he is impacted and high. Lithium iron phosphate batteries compared to ternary batteries, after constant improvement, safety is more stable, and the cycle life can reach more than 2,000 times, high temperature, and do not cause environmental pollution. In recent years, the Chinese government has a clear goal for energy-saving emissions and strong support, so the lithium phosphate battery is the most ideal power battery so far. Not only can the power battery of electric vehicles, but also with secondary energy such as solar energy, wind energy as electric reserv...

AI Technical Summary

Problems solved by technology

Ternary batteries have high density, large unit electric energy, and strong battery life, but poor stability and low ignition point when subjected to impact and high temperature.

[0005] like Figure 1-2 As shown, in the existing SOC estimation method, the reference voltage of the charge and discharge table lookup section is not accurate, and there are problems near the transition voltage threshold of the integration section and the table lookup section

If the voltage of the integration section is too low, the SOC will be integrated to the percentage corresponding to the voltage threshold, but the voltage does not reach the voltage threshold, which will give the user a feeling of being stuck at a certain percentage and reduce the user experience.

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