SECONDARY BATTERY REMAINING CAPACITY ESTIMATION METHOD AND SECONDARY BATTERY REMAINING CAPACITY ESTIMATION APPARATUS

摘要

PROBLEM TO BE SOLVED: To provide a secondary battery remaining capacity estimation method and a secondary battery remaining capacity estimation apparatus using a Kalman filter, capable of achieving high accuracy SOC estimation using a simple equivalent circuit model and improving profitability and reliability.SOLUTION: An arithmetic processing unit integrates current values for a determination period, the determination period being defined as a period of latest three minutes. If a current integrated value is not less than 2.5% in a SOC change width, the arithmetic processing unit sets a Kalman gain Gk to "0" to invalidate a Kalman filter. At this time, the arithmetic processing unit calculates a current SOC estimation value by adding a previous SOC estimation value to a SOC change width. If the current integrated value is less than 2.5% in SOC change width, the arithmetic processing unit sets the Kalman gain Gk to "1" to perform SOC estimation based on Kalman filter scheme.