In the framework of the first contract, Axpo Power AG has commissioned Alstom to upgrade the exciters and discharges of the 37.5 MWA hydro generators units 1 and 2 in the Löntsch power plant.
The scope of the order includes the conversion of the excitation system for brushless regulators, the replacement of voltage transformers and circuit breakers with enclosed switchgears and the installation of fully insulated shockproof busbars for the discharges. The contract provides for sequential processing of machinery, and should be completed respectively during the summer 2015 and 2016.
The Löntsch power plant is one of the oldest power plants of Axpo Power Ltd and has formed the first Swiss power plant network together with the Aare power Plant in Beznau at the beginning of the 20th century. The power plant has an average annual power generation of 120 million kWh and uses the water of Lake Klöntal fed by a catchment basin in the Glarus Alps (central Switzerland).
For the second contract, Grande Dixence Ltd and Hydro Exploitation Ltd have commissioned Alstom to replace the four rotors and poles on the Sécheron machines at the Nendaz power plant in Valais. Replacing rotors on existing equipment is a technically demanding task as there are significant restrictions on the interfaces with shafts, bearings and the stator. The Nendaz power plant stators will be gradually replaced by Alstom.