Variable two stage rate-limit control for battery energy storage system

The present work deals with a new energy management control scheme to regulate the battery discharge/charge rates (rate-limit) for a hybrid energy storage system (HESS), consisting of battery and supercapacitor. In general, batteries are used to supply slow transient (or steady state) load demand, due to its inherent properties of low power density and high energy density. The state of charge (SOC) of the battery will depend on the load demand value, rate limit, the settling time and path followed by the battery (trajectory) to fulfill the load demand. In the proposed control scheme, trajectory of the battery is controlled such that, the rate limit and the SOC are kept within the limits, while getting optimized. This scheme is adaptable for different power requirements and features variable rate limit control. Furthermore, the scheme proposes two stage rate-limit control. The control scheme is described in detail and demonstrated using MATLAB simulation results.