Reliability Evaluation for HV Substation Using Variable Failure Rate Affected by Preventive Maintenance

Summary

This paper proposes the methods to evaluate reliability of HV substation by using variable failure rate affected by preventive maintenance (PM) of HV equipment such as power circuit breakers, lines and busbars. The subcomponents of individual HV equipment are firstly classified according to its function. Secondly, the Weibull distribution technique is used to determine the mean time between failure (MTBF) and time-dependent failure rate of subcomponents calculated from the 20 years historical failure record. Next, the known time-dependent failure rate and MTBF are subsequently used to setup the schedule for PM in order to calculate variable failure rate influenced by the proposed PM schedule. The subcomponents with nearly similar MTBF are grouped together and will be replaced by the new one at the same time schedule. This scheduled replacement of such subcomponents usually decreases the total failure rate designated as variable failure rate of HV equipment. Finally, the variable failure rate of HV equipment is further applied to calculate the reliability of substation in term of probability of power outage of substation using the minimum cut-set method of possible failure events. A 230 kV breaker and a half bus arrangement substation in Thailand's transmission network is used for the evaluation. The results can be utilized for considering reliability of substation and applied as maintenance guideline to renovate HV equipment in substation.

Additional informations

Authors

Sidenvall Peter Hans Wilhelm, Gutman Igor, Zhao Changhao