INTEGRATION OF MEASUREMENT DATA INTO CONDITION ASSESSMENT: A THEORETICAL CONSIDERATION

The basis for optimization in asset management of electrical equipment is the availability of condition information. This condition information can be derived by utilizing measurement systems. For an economical viable use in secondary substations, the measurement systems need to have low investment and operating costs. The use of low-cost measurement electronics from the consumer sector results in favourable investment costs for the sensors itself. However, the time and thus costs of installing the sensors need to be considered as well for an economic integration of these measurement systems. In this paper, we analyse cause-effect relationships between component condition and measured variables to identify a minimum set of required measurement variables, which can be measured via non-invasive and easily retrofittable hardware. This analysis shows that condition information for all key components of the secondary substation can be derived from only four measured variables: station temperature, load current, air humidity, and transformer top-tank temperature. Furthermore, a method how to translate measurements to a condition indication utilizing the cause-effect relationships is presented. The condition indications can be used to support maintenance and renewal planning.