Real-time commercial availability index of a steam power plant: Graph theory and matrix method

Abstract

Worldwide, the structure of the power industry is changing to that of a market economy to ensure commercial accountability. Resources, therefore, are allocated for operation and maintenance from commerical considerations rather than technical alone, necessitating the introduction of a commercial approach to analysis of reliabilty, efficiency, and maintenance criticality for power plants. These requirements suggest the need to introduce performance monitoring systems in the form of a single composite index encompassing the consequences of non-performance with respect to all these parameters and which can effectively respond to market demands. Such performance monitoring system is developed in the current paper. Graph theory has been applied to the complex system of a steam power plant to consider its structure explicitly and to derive reliability/availability, efficiency, and maintenance indices. Its representation at system level is modeled by system structure graphs to study reliability/efficiency indices (viz. RTRI and RTEI). The approach has already been applied by the authors for the development of an efficiency index, i.e. RTEI, and a maintenance criticality index to optimize the maintenance cost. In the current paper, it is applied to develop a single composite index, i.e., a real-time commercial availability index (RTAI)com. The various attributes that affect commercial availability are identified as also the interactions among them. With these, a commercial availability attributes' digraph is developed and its corresponding variable permanent commercial availability attribute interaction matrix is written. The permanent function of this matrix is then analysed to study the various aspects of commercial availability as well as to evaluate (RTAI)com. A scheme for implementation of the procedure to develop a single composite index has also been proposed. This will monitor the health of the mechanical equipment of a steam power plant as Supervisory Control and Data Acquisition (SCADA)® monitors its electrical equipment.