Risk assessment of rural diesel generation stations

The effect of aging assets on reliability has become an important area of study for BC hydro non-integrated area (NIA), due to the fact that many of the assets are approaching the age of retirement. System reliability assessment methods that incorporate the increasing probability of end-of-life failures for these assets are required. This paper outlines one risk assessment method for diesel generation stations based on RISK_A, a probabilistic analysis tool to simulate the effect of equipment aging and usage on reliability. A model was developed for assessing station reliability through assigning failure probabilities to all equipment and modeling their relationships. The adequacy of the current station facilities in term of supply reliability can be obtained and compared to the required reliability performance index or reliability performance curve which was defined in term of outage frequency and duration. End-of-life failure probability for diesel generation unit has been derived based on its actual maintenance history and age profile. The proposed method was implemented on an existing diesel generating station and the results show that not only can it demonstrate the reliability performance level the current station can achieve, but also provide an clear indication whether any aging unit can be retired or need to be replaced in order to maintain the adequate supply reliability of the station