Systems and methods for estimating battery pack capacity

摘要

System and methods for estimating a capacity of a battery are presented. A measure of data skewness may be calculated from a battery system terminal voltage measurement. Inflection points in the data skewness of the terminal voltage measurement may align with transition points associated with a battery system. These transitions points may be associated with known SOCs determined from testing and/or characterization of the battery system. Using the detected transitions and associated SOCs and an indication of an accumulated charge provided to/from the battery between the transitions, an estimated capacity of the battery system may be determined.

主权项

1. A method of estimating a capacity of a battery pack, the method comprising:
receiving, by battery control electronics associated with the battery pack from a voltage sensor configured to measure a terminal voltage of the battery pack, battery pack terminal voltage measurement information; calculating, by the battery control electronics, skewness information based on the battery pack terminal voltage measurement information, the skewness information defining a relationship between the battery pack terminal voltage measurement information and a plurality of states of charge of the battery pack; identifying, by the battery control electronics, a first inflection point in the skewness information; determining, by the battery control electronics, a first state of charge of the battery pack associated with the first inflection point; determining, by the battery control electronics, a second state of charge of the battery pack; determining, by the battery control electronics, a net charge difference of the battery pack between the first state of charge and the second state of charge; determining, by the battery control electronics, an estimated capacity of the battery pack based on the net charge difference, the first state of charge, and the second state of charge; and controlling, by the battery control electronics, an operation of the battery pack based on the estimated capacity of the battery pack, wherein the operation comprises at least one of a charging operation, a discharging operation, and a balancing operation.