Energy storage power supply parallel operation

Battery systems with parallel-connected units can be set up with different connection structures.

I. INTRODUCTION Batteries have found promising applications to a variety of areas for energy storage and power supply, from portable electric devices, e.g., cellphones and laptop computers, to large-scale systems, such as electric vehicles (EVs) and power grid energy storage plants.

To predict the SoP of a battery pack system with parallel cells/strings, however, both and t need to be identified, which makes the problem more complicated than the SoP prediction for individual or series-connected battery cells. where Iq is the q-th row of the identity matrix of size Q, and these system matrices involved, i.e.,

Parallel operation of battery cells has been modeled for performance evaluation – as well as sensitivity analysis to hetero-geneous cell resistance,, –, charge capacity,,, –, number of parallel cells,, and system configuration .

To study the cell SoC evolution in a battery system in-cluding parallel connections, as compared to Coloumb Count-ing through the integral of time-varying cell current, it is computationally more efficient to alternatively track the cell OCV since it can be directly extracted from the state vec-tor x.

To ensure the safe and efficient operation, the maximum acceptable current or power of the battery system should, therefore, be dynamically updated on the fly according to the real-time system states and operating conditions.