Novel on-line partial discharge monitoring system for generator/motor stator insulations

Nowadays on-line monitoring scheme with trending technique is widely adopted in insulation diagnosis. In this paper, two types of online monitoring instrumentation for an insulation diagnosis are proposed. The first unit obtains the parameters such as partial discharge magnitude and dynamic stagnation voltage (DSV) in selected frequency bands. The partial discharge activities can be interpreted more precisely by these techniques. The second one indicates the partial discharge spectra in reduced time resolution with lower cost. Several online sensors for partial discharges monitoring are also introduced.