IN-SITU REPAIR OF HYDRO GENERATOR STATOR WINDING

摘要

An in-situ process for repair of hydrogenerator stator winding bars in particular overhang stator winding bars, involving partial dismantling of the hydrogenerator, comprising the steps of: - identifying the failed winding zone and the fused copper conductor; - removing deposits from the affected zone in the identified copper conductors; - brazing the elementary conductors by making 45° joint; - grinding the brazed joints; - staggering the joints of the conductors; - bending manually the conductors" edge after brazing; - insulating the brazed joints of the elementary conductors; - carrying out tests for the brazed joints and tests for electrical parameters of the hydrogenerator stator winding; characterized in that - the step of brazing comprises scarf brazing of the identified conductors on overhang position, - the step of staggering comprises placing the joints in different tires to achieve the pre-repairing bar conductor stack height, - the step of bending comprises a step of annealing the copper conductors to make the conductors bendable such as to match the intricate profile of the overhang portion, and - the step of insulation comprises inter stand insulation of the brazed joints.