'Alstom Hydro & Scottish Power go for
‘Varley Skid' to operate MIV & Guide Vanes
Cruachan power station is Scotland’s largest
pumped-storage scheme and is located beneath Ben Cruachan 18 miles east of the town of Oban. The
station has four 100MW pump/turbine-generator units
supplying power to the National Grid, 2 of these
units were to be refurbished and upgraded over the
course of 2005.
Varley Hydraulics Ltd was awarded the contract
by Alstom Power Hydro to design and manufacture 2
No. high pressure Hydraulic Turbine Governor and
Main Inlet Valve (MIV) systems for Units 3 & 4 at
Provide a high pressure system utilising the
latest hydraulic technology incorporating
electronic proportional control.
New system to mechanically interface with
Design a fully integrated hydraulic power
unit incorporating all directional control and
An Accumulator system to be capable of responding very rapidly
to generating mode changes and to changes in demand.
Hydraulic cylinders to be of the ‘multi-stage’
type to give a 3 stage closing characteristic, 1 of
each pair of cylinders to incorporate a mechanical
Incorporate a position monitoring system for
precise feedback of Guide Vane movement.
A fully integrated control system using the latest
technology in electronic proportional hydraulic
- System designed using a bespoke 18 tonne
Accumulator support and reservoir fabrication
accommodating 2400 Litres of hydraulic fluid.
- Accumulator system with the capability of storing
in excess of 400 Litres of fluid under pressure to respond to system demand.
- Bespoke designed hydraulic control Manifolds to
minimise pipework and maximise ease of maintenance.
- Hydraulic cylinders designed using the latest
sealing technology and incorporating all the system
requirements including position monitoring using
LVDT’s and proximity switches.