A STRATEGY FOR LOW-COST UTILITY CONNECTION OF BATTERY ENERGY-STORAGE SYSTEMS

Battery energy storage is a well-known concept that has applications w ithin the electricity supply industry. In a battery energy storage sys tem (BESS), the d.c. energy in the batteries is exchanged with the d.c . utility using a power conversion system (PCS). The development of a generic low-cost PCS is identified as being critical to commercial via bility of battery energy storage. The paper presents commercial and fu nctional advantages of using a modular approach to power conversion in a BESS. Dynamic models are developed for both single and networked po wer converters. These are used to demonstrate the technical feasibilit y of the modular approach. The Wavedriver PCS is presented. This uses a modular network of generic power converters to provide higher functi onality. Each power converter incorporates a higher level of systems i ntegration than is usually. present in a traditional PCS. This approac h changes the balance on the commercial viability of energy storage sy stems. (C) 1997 Published by Elsevier Science S.A.