Partial discharge recording & analysis

Partial Discharge (PD) has become an important tool in the assessment of electrical insulation. In particular, it appears to be one of the few methods that has any hope of predicting remnant life of any particular piece of equipment. Such predictions hinge on changes in the discharge pattern over the lifetime of the equipment. The present paper describes a method of recording the PD activity which measure individual discharges and the point-on-cycle (POC) at which they occur. The circuit involves a varying level of sensitivity rather than a set dead-time usually employed to separate discharges. This means that large pulses are not prevented from being registered by a prior smaller discharge