The application of adaptive digital filter for the internal state estimation of batteries

We proposed an innovative estimation method for internal states of a rechargeable battery. First, we described the charge-discharge characteristic of a battery as a linear parameter varying model, and applied an adaptive-digital-filter theory to it. Finally, we estimated the state of charge and the usable input/output power accurately, which are necessary to fully utilize the battery power on the vehicle. The relationship between the current and terminal voltage of a storage battery is described using a linear parameter varying model. That made it possible to reduce the problem of recursively estimating the model parameters with an adaptive digital filter.