On 9 May 2011 12:38, Bob Ammerman wrote: > ----- Original Message ----- > From: "Justin Richards" > To: "Microcontroller discussion list - Public." > Sent: Sunday, May 08, 2011 10:25 AM > Subject: Re: [OT]:how are hydroelectric power stations synchronised > > >>> I once saw a generator being switched on line at a hydro power station = in >> >> I would like to see that. > > I used to develop control software for hydroelectric plants. The basic wa= y a > generator is synced in manually has been well described here: a device > called a synchroscope displays the phase relationship between the grid an= d > the generator. The 'scope looks something like a clock with a single hand= .. ...snip....... > > -- Bob Ammerman > RAm Systems > > > IIRC the earlier model of the "synchoscope" used two schyncronous motors - one driven from the grid and the other from the local plant. The motors were coupled to a differential gear (like a cars diff - but smaller) which driectly connected to the indicator. Frequency difference was indicated by a moving indicator and phase difference could be read directly as an offset from vertical provided the motors were near - identical. RP --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .