Settle Hydro Diary - August 2015

Tuesday, 1 September 2015  |  Admin



The new Hydro Control Panel
During August there has been much activity in the powerhouse installing the new variable speed control system. During this time no generation was possible and we missed a few days of heavy rain and one spate event in what has been an otherwise very dry period. However the new system was commissioned on Monday 24th August and has been running satisfactorily since. With the old fixed speed system the screw's rotational speed remained constant to allow the generator output to match grid voltage and frequency, upstream river level being controlled by the hydraulically operated sluice gate. This meant that at low river levels, output from the generator was too low to feed the grid and the plant would shut down. With the new system the screw itself controls the rate of flow through the turbine with the sluice gate fixed fully open allowing the screw to operate under pressure of the full river level or "head". This method produces higher output at lower flows as well as allowing greater precision in controlling river levels to maintain flow through the fish pass, with the generator running.
The new monitoring screen which enables
the remote monitoring and control of the Hydro

Visually, observers will notice the screw turning a lot slower than it used to at lower river levels. It is still generating electricity at a reduced rate. An increase in river level will result in a corresponding speeding up of the screw and an increase in electrical output.