Reliability estimation of paper insulated components

In view of the coming major asset replacement wave of power grid components, new lifetime prediction tools are developed to assist asset managers in making technically and economically sound decisions. This paper discusses the modeling technique based on the concept of quality parameters applied to paper insulated systems. The concept of quality parameters was recently introduced for power transformers to obtain a measurable quantity which relates the actual degradation process to an observable quantity. The present paper discusses a general approach for modeling other power components along the same lines. In case of a power transformer, oil samples can be taken and analyzed in order to estimate the DP (degree of polymerization) value, which is linked to the mechanical strength of the insulation material. This quantity then serves as quality parameter. Using a probabilistic approach based on the physical degradation mechanism a remaining lifetime model was developed. This resulted in a scheme, which is flexible in the sense that any new available data can be included to enhance the prediction reliability. The question addressed here is whether a similar approach can be applied to other power components as well. In particular we have investigated the possible use of quality parameters which are not directly correlated to one degradation mechanism. We will define different kinds of quality parameters and propose a component reliability model that incorporates all of these.