Experimental study on high voltage dielectric loss and capacitance increment of generator stator winding

High voltage dielectric loss and capacitance increment test can be considered as an indirect partial discharge test, which can be used to find out whether there are defects in generator stator winding. Especially for the long-running units, insulation aging test should be carried out in order to make a correct judgment of the stator insulation state. The dielectric loss and capacitance increment of stator windings of a 22-year-old unit in a factory are analyzed and studied Dielectric loss and capacitance of generator are measured by using series resonance test device and precision dielectric loss bridge. By comparing and analyzing the test data, the results show that the overall insulation condition of the generator unit is normal and it can continue to operate.