Partial discharge. VII. Practical techniques for measuring PD in operating equipment

For pt.VI see ibid., vol.7, no.3, p.9 (1991) Online partial-discharge (PD) tests for monitoring the condition of the solid dielectric insulation in high-voltage equipment are discussed. Sources of external electrical noise are identified, as are attributes of PD and noise that are helpful in drawing distinctions between them. Methods for distinguishing between PD and noise are described. They are based on pattern recognition, time and frequency domain characteristics, or pulse time-of-flight analysis. Several online PD measuring systems for rotating machines, substation equipment, and high-voltage cables are presented.< >