Ahai power station receives self-closing electronic ring gate system

Alstom has delivered the world’s first self-closing electronic ring gate control system to the Ahai hydro power station in China.

This represents a major technical advance for the safety of the dam.

The system supplied by Alstom is a unique innovation that boasts the world’s first electronic ring gate control system with hydraulic synchronisation – meaning that in an emergency, the system can close by itself, cutting the flow of water to stop the turbine.


The Ahai dam, owned by Yunnan Jinsha River Hydropower Co. Ltd, is currently under construction and comprises 5×400 MW Francis hydro turbine generator units, for which the five turbines are being supplied by Alstom under a contract worth US$134.9 milliion. The first unit will be commissioned in spring 2012.

With a diameter of 10 metres, a height of 2.6 metres and weighing 110 tonnes, the Ahai ring gate is the biggest one in the world.