Changing the stator windings

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Rewinding the stator winding of a hydro-generator

Eltra MG carries out demanding rewinding of stator windings of large electrical machines, including self-excited brushless hydro-generators of high power and voltage.

As part of the project, the rewinding of the stator winding of a self-excited brushless hydro-generator with the following technical characteristics was performed:

• Rated power: 1130 kVA
• Rated voltage: 10.5 kV

Description of the works performed

The works comprised a complete renewal of the stator winding, using modern technologies and materials in accordance with the applicable standards:

• Dismantling of the existing stator winding and detailed inspection of the stator core
• Testing of the core condition and detection of possible local overheating
• Manufacturing and installation of a new stator winding from materials suited to high-voltage machines
• Application of a high-reliability insulation system in the appropriate thermal class
• Impregnation of the winding by the vacuum pressure process (VPI) or an equivalent impregnation technology
• Final electrical tests, including insulation resistance, absorption factor, inter-turn test and high-voltage test
• Preparation of the machine for safe and reliable commissioning

Benefits of the work performed

• Complete renewal of the stator insulation system
• Increased electrical and mechanical reliability of the hydro-generator
• Extended service life of the machine and reduced risk of trips
• Safe and stable operation at rated loads

Eltra MG has the expertise and technical capacity for rewinding the stators of large generators, hydro-generators and industrial electrical machines, ensuring high quality of work and long-term operating reliability.