Calculation and correction device and method for state of charge (SOC) of marine power lithium ion battery

Abstract

The invention provides a calculation and correction device and a method for the state of charge (SOC) of a marine power lithium ion battery. An SOC calculation link is used for calculating the SOC of all groups of batteries based on an ampere hour metering method, an SOC error compensation link is used for carrying out compensation correction on an result measured by the SOC calculation link based on an alternating current internal resistance, and the SOC error compensation link operates for each certain time; when the SOC error compensation link operates, a compensated result is outward output as an SOC output signal; when the SOC error compensation link does not operate, the SOC of all the groups of batteries, measured by the SOC calculation link in real time based on the ampere hour metering method, are outward output as an SOC output signal. The calculation and correction device is simple in structure, fast in calculation speed, high in correction accuracy, and high in real-time property. The calculation and correction device and the method are applicable to a marine lithium battery pack which is large in battery power demand, and higher in voltage.

Description

technical field [0001] The invention relates to the field of lithium-ion batteries, in particular to a method for calculating and correcting the state of charge of a marine lithium-ion power battery. Background technique [0002] With the increasing requirements for energy saving and environmental protection worldwide, electric propulsion inland waterway ships using lithium-ion batteries as the main power source have emerged. Compared with electric vehicles, the power battery capacity of electric propulsion inland watercraft is large, the number of battery packs is large, and the battery life is long. Under normal navigation and propulsion conditions, it is required to be able to accurately detect the remaining power of the battery in real time to control the cruising range and speed of the ship. . Therefore, the measurement and calculation device of the remaining power of the marine lithium-ion battery should consider the overall measurement method of the multi-battery pac...

AI Technical Summary

Problems solved by technology

In the existing SOC (State of charge) measurement method, the error of the ampere-hour measurement method will accumulate with the increase of power consumption time, and the mathematical relationship between the open circuit voltage method and the internal resistance method is complicated and not suitable for real-time online multi-group batteries Measurement, intelligent algorithms require precise mathematical models and tedious intelligent calculations

[0003] Chinese invention patent 200510094755.3 discloses a modified ampere-hour measurement method, but the voltage value used for correction will fluctuate during online estimation, resulting in correction errors

Invention patent 201110180561.0 discloses an improved neural network method and realizes it with DSP. This method is cumbersome in calculation and relatively expensive in DSP

Invention patent 201210013565.4 discloses to correct the error produced by the ampere-hour measurement method according to the curve of the sharp change of SOC at the initial and final discharge, but this method cannot be corrected when the battery is in the middle of discharge

Invention patent 201210576793.2 discloses the method of estimating SOC using three-dimensional tables of open circuit voltage, current and temperature for electric vehicles, but it can only be measured when the vehicle is stopped, and the ship cannot stop sailing, so it is not suitable for marine use

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