Modeling of power batteries based on subspace identification method

The research on modeling of power battery based on the subspace identification method was conducted. Firstly, an equivalent circuit model of the battery was set up. To identify the parameters of the model, through the acquisition data of the battery's current and voltage, a general state-space model was developed by the subspace identification method. Then by the method of equivalent transformation, the system matrices of the general model were transformed to be identical to the equivalent circuit model structurally. The parameters of the equivalent circuit model were then calculated. Experiments and simulations under the driving conditions were conducted, it is showed that the model indentified by these methods simulates the battery's behavior effectively. And the parameters with physical meaning were acquired.