Investigation for variable ambient conditions effect on the insulation parameters of synchronous generators

Nowadays, it is known that synchronous generator stator winding insulations, which are used in the field of hydroelectric power production have various deformations depending on the amount of ambient humidity in both working environment conditions and storage conditions. For this reason, it can be concluded that the ratio of operational costs of these equipments with high investment cost is decreased according to the operation and storage environment of the equipment. In this study, it is aimed to analyze the negative effect of the insulation resistance parameters of the windings by examining the reactions of the insulation resistances of the windings depending on the high relative humidity and exposure time. For this purpose, an experimental set-up was developed and the winding of the synchronous generator was exposed to humidity and the insulation resistance values in the winding were measured. The results of the DC Insulation Resistance tests applied at different relative humidity exposure times were evaluated by taking into consideration the relevant standards. As a result, studies and measures to be taken in order to prevent or minimize the malfunctions resulting from the inability of the equipment to be maintained under appropriate ambient humidity conditions and the planning of DC insulation resistance tests within the scope of preventive maintenance studies are presented.