Novel active load tracing controller for battery-based energy storage system for reducing sudden demand surges: A real case study in a factory

A novel active load tracing controller is designed for a Battery-based Energy Storage System (BESS) to overcome sudden demand surges which are hard to forecast even with large historical load data. A 100 kW/155kWh BESS using lithium-ion batteries is set up in Daikin factory together with all the necessary safety measures. Within the constraints of the maximum power rating and available energy of BESS, the controller performs maximum demand reductions (MDR) by tracing actively the latest available load pattern in real time without using any forecasted loads. The performance of the controller is monitored experimentally over 5 months. Daily peak demand reduction factor (Kdpr) and monthly maximum demand reduction factor (Kmdr) are used as a quantitative measure to determine the performance of the controller. A new measurement index, namely reduction efficiency (eta R), is proposed to measure MDR achieved by the controller with the use of 1kWh. The controller achieves the average K mdr of 0.82, hence providing a monthly saving of RM1,196. It also achieves eta R of 0.25 kW/kWh, on average, from the experimental studies. The performance of the active load tracing controller is compared against other controllers such as load-following, fuzzy logic, spontaneous self-adjusting controller, and adaptive- threshold controllers, through simulation studies. The controller can provide the average K dpr of 0.53, K mdr of 0.77, and eta R of 0.24 kW/kWh from the simulation, which are higher than that of other controllers. In conclusion, the active tracing load controller can reduce peak demands effectively and is suitable for industries with unpredictable demand profiles.