Ripple plant upgrades are not a particularly common occurrence within an electricity network because the equipment typically lasts 30 to 40 years. Such upgrades have, however, become common within Powerco’s network as its ripple plant equipment draws towards the end of its working life.
Ergo worked with Edison engineering consultants to upgrade ripple plants in 15 substations.
Powerco is New Zealand’s second largest electricity and gas distributor. It services around 400,000 North Island consumers, who represent 46 per cent of New Zealand’s gas connections and 16 per cent of electricity connections.
Ergo developed detailed three-dimensional design drawings for each upgrade, which enabled contractors to correctly install jumper bus bars and other equipment. Although there were common elements to all upgrades, each needed to be individually customised.
Powerco ripple plant upgrade tech specs A ripple plant consists of a ripple transmitter and a coupling cell that provides a high frequency signal (272, 283 or 317Hz) injected on the existing 33kV network. This signal propagates along the network to residential houses where a ripple relay is either switched on or off to control the load on the network.
Ergo have undertaken electrical design on the following ripple plant upgrades: Kaitimako Ripple Plant – 33kV 283Hz ripple transmitter, commissioned July 2009. Matapihi Rippe Plant – 33kV 283Hz ripple transmitter, commissioned February 2010. Waikino Ripple Plant – 33kV 217Hz ripple transmitter, commissioned August 2009. Brooklands, Huirangi, Brunswick, Stratford and Mikkelsen Road ripple plants are currently under construction and will be commissioned later this year. Masterton Ripple Plant – 33kV 217Hz ripple transmitter, currently being designed.