Using electrical energy storage to support customers under faulted network conditions

As load grows and demand on double circuit distribution networks increases, there is an increased probability that under (n-1) fault conditions it would no longer be possible to supply all customers at peak times without infringing the thermal ratings of components on the remaining single circuit. Under such circumstances, expensive network reinforcement could be required. One alternative could be to install an electrical energy storage (EES) system at a critical point on the network.. This could enable customers to continue to be supplied, even at peak times, for 1-2 hours, giving time for extensive lower voltage reconfiguration to take place. This paper describes how such a system would work, investigates optimum battery size, and evaluates the likely benefits that could occur, both for customers and for the DSO, as a result of its implementation.