Key points are not available for this paper at this time.
The characteristics of partial discharge (PD) are the basis of generator PD monitoring and diagnosis. Based on the actual large generator stator bar, four typical defects were made, including a delamination defect between the conductor and insulation, a delamination defect between insulation and insulation, a defect in the slot, and a defect at the end. A voltage pressure test was carried out, and the dynamic characteristics of the four defects in the process of voltage step-up and step-down tests and voltage withstand test were obtained. The main findings of this paper are as follows: (1) For the first time, the PD pulse repetition rate of typical generator defects in the process of voltage step-up and step-down tests accord with the exponential law, and the goodness of fit R 2 is greater than 0.95. (2) The discharge magnitude of the delamination defect between the conductor and insulation shows a strong fluctuation during the voltage withstand test, and the standard deviation of discharge quantity for 13 h is 2203.01 pC, which is a typical characteristic differentiated from the other three discharges. (3) Although the discharge magnitude of each defect fluctuated, the phase resolved PD patterns of the same defect have high similarity, and the similarity hash values are all above 0.67. The PD uniqueness of different types of defects and the PD similarity of the same defects are the basis of pattern recognition and diagnosis of generator stator defects.
Li et al. (Wed,) studied this question.