In 1999 PWCS commenced an expansion of their Kooragang facilities to become the largest and most efficient coal handling operation in the world. This expansion included installing a further three 10MVA 33/6.6kV onload tapchanging transformers. Following a review of available voltage regulating relays the local engineering consultants chose the a-eberle REGSys system for the new transformers.

Subsequently a further 3 relays were purchased to upgrade the original units. The voltage regulators were supplied by Protection and Monitoring Systems. A significant factor in this choice was the ability to simulate the voltage regulation environment prior to installation and commissioning via REGSim software. It was thus possible to pre-determine how the regulation system would behave in response to dynamic loading including surges, fault conditions, etc and therefore maximise system reliability before going on-line.