Abstract
How to effectively manage large-scale battery systems has received a lot of attention recently. There are several design issues, such as reliability, efficiency and sustainability, that have been previously addressed in early works. However, the exibility issue and the complexity (scalability) issue are rarely addressed. To address these ve design issues, we design and analyze a multistage battery switching network constructed by a concatenation of various rectangular \shapes" of battery packs. The shape of each battery pack is speci ed by its voltage and its capacity. We show that our multistage battery switching network can support a maximum number of Lmax loads under the constraint that the total voltages of these loads do not exceed a design constant Vmax. Moreover, the voltage of each battery pack can be determined optimally by solving a Simultaneous Integer Representation (SIR) problem. To determine the capacity of each battery pack, we propose a max-min fairness battery allocation algorithm, and show by computer simulations that such an algorithm outperforms the uniform allocation scheme. We also propose a fault tolerant battery switching network that can still be operated properly even after Fmax battery packs fail. Such a fault tolerant battery switching network enables a battery system to implement the Largest Remaining Capacity First (LRCF) policy that does not require the knowledge of the load pro le.