Rehabilitation of the second hydrogenerator of Devin Hydro Power Plant
During 2019-2020, CERB EAD engaged in the rehabilitation of the second hydrogenerator (HG2) of the Devin Hydro Power Plant.
The main activities in the rehabilitation of HG2 include:
- Preparation of workshop drawings, including technical construction file, electromagnetic, thermal, and mechanical calculations, technical operation instruction and other necessary prescriptions for the performance of rehabilitation activities
- Repair and restoration works on the stator body, including inspection of the geometrical dimensions of the active parts and inspection of the condition of the welding while retaining all overall and fitting dimensions
- Design, manufacturing, and laying out of a new magnetic core
- Design, manufacturing, and installation of a new stator winding
- Manufacturing of 36 spare rods (18 upper and 18 lower)
- Rehabilitation of the rotor, including replacement of the interwinding insulation of 16 polar coils and replacement of the poles’ insulation
- Manufacturing of a new spare polar coil
- Manufacturing of new wedges to tighten the poles on the rotor ring
- Transportation of the units and details, subject of the present rehabilitation, from the HPP to the CERB production base and back.
The Devin HPP is an energy facility within the Dospat-Vacha Hydro Power Cascade under the National Electricity Company (NEK EAD). The power plant has two turbo-generator groups with nominal output of 45 000 kVa. The generators’ voltage is 10.5 kV and their rotation speed is 375 rpm -1 . They were designed and manufactured during the 1980s.