Quality of supply in a hydro plant

By Y Harary, Elspec


Published in:

Electricity+Control, August 2013 (pages 26 - 27)

Enquiries: Email Wayne Bromfield, Impact Energy. Tel. 031 201 7191 or email wayne@impactenergy.co.za


The full article on Quality of supply in a hydro plant  can be downloaded in PDF format.


The Thomson hydro plant, located at the dam site, comprises an 11 kV induction generator. It is connected to an SP AusNet 22 kV distribution feeder, via a 22/ 11 kV, 7,8 MVA transformer. When the Melbourne Water Cooperation’s (MWC) network agreement expired, the plant’s impact on the SP AusNet distribution network (based on the Victorian Electricity Distribution Code had to be reviewed.

A study, conducted by Entura (Australian energy and water consultants) evaluated the effect of Thomson’s 7,45 MW power generation on the SP AusNet network. It recommended the use of a combined power quality solution, made up of the world’s fastest dynamic compensation systems, enabling MWC to comply with the distribution code.

The installation of Equalizer (EQ) and Equalizer-ST (EQ-ST) systems at the Thomson Reservoir hydro plant in Melbourne, Australia, achieved the necessary reactive support and code compliance.


Take note

  • Coupling a hydro system into a network requires careful engineering.
  • Voltage fluctuations and general quality of supply issues must be understood and accounted for in such a system.
  • Modern state-of-the-art systems introduce optimal compensation based on the network needs of any given time.