Happy Valley and Morphett Vale East (MVE) 275/66kv substations are located only 10km apart in the midst of Adelaide’s southern suburbs, a rapidly developing residential and commercial area. They are key installations in ElectraNet’s bulk supply of the region together sharing a demand of some 500MW.

Optimum load sharing between the substations has been difficult due to differing transformer sizes and impedances and close interconnection via a number of 66kV lines.

Application of the REGSYS voltage regulator system, manufactured by a-eberle GMBH of Nuremburg in Germany has provided a unique and flexible solution allowing the two substations’ Automatic Voltage Regulator Relay (AVR) systems to be operated in automatic mode and in parallel with reduced circulating currents. Optimising the secondary system in this way has improved primary asset utilisation.