Battery state-of-charge estimator using robust H_∞ observer

摘要

A battery state-of-charge (SOC) estimator uses a robust H∞ filter design by taking into account the battery parameter uncertainties, which is due to battery age, variation, and operating conditions such as temperature and SOC level. Each of the time-varying battery parameter values and their variation rates are bounded. By utilizing the parameter variation bounds and parameter variation rate bounds into the design process and minimizing the H∞ gain from the measured current signal to the estimation error of Voc, the battery SOC estimator can achieve enhanced robustness to the variations of battery age, variation, and operating conditions that include temperature and SOC level.

主权项

1. A method of determining a state-of-charge for a battery while connected to a plurality of loads, the method comprising steps of:
measuring a terminal voltage of the battery; measuring a temperature of the battery coinciding with the measured terminal voltage; inputting the measured terminal voltage to a first linear time invariant infinity observer filter, the first linear time invariant infinity observer filter developed in an off-vehicle design process, wherein the first linear time invariant infinity observer filter minimizes a gain of an output energy signal to an input energy signal of the battery; estimating, by a control module, an open circuit voltage in response to the measured terminal voltage input to the first linear time invariant infinity observer filter; determining, by the control module, the state-of-charge of the battery as a function of the open circuit voltage; and regulating the battery in response to the state-of-charge.