Generator maintenance scheduling based on the risk of power generating unit failure

A power utility's ability to satisfy energy demand can be influenced significantly by unexpected breakdowns of power generating units. In most cases, such unexpected failures are also much more expensive to repair than taking planned preventative maintenance action. It has been found, especially in developing countries, that maintenance of often ageing power generating units is neglected due to high energy demand and low system capacity. The typical objectives pursued in the design of power generating unit maintenance schedules do not take these difficulties into account. A new scheduling criterion is therefore proposed in this paper. The occurrences of power generating unit failures may be estimated using methods from reliability theory in which the aim is typically to quantify the probability of a system completing its intended function for a specific duration of time. Based on this theory, our new scheduling objective seeks to maximise the probability of no power generating units in the power system failing during the scheduling window, weighted by the rated power generating capacity of each unit. The feasibility and effectiveness of this new objective is analysed by applying it, in conjunction with an exact solution approach, to two well-known generating maintenance scheduling test systems.