Optimum in-service time periods of MV/LV transformer–distribution substations

This is an analysis of cost-effective in-service time periods of indoor and outdoor MV/LV transformer/distribution substations operating in Poland. It addresses specific components of the overall operating costs, along with the variable average annual operating costs of substations versus in-service time periods depending on a specific accumulation rate, average repair costs and average value of energy not supplied to electricity users following power outage. Based on the estimations, cost-effective in-service time periods are calculated for specific construction types of substations. The analysis also includes a discount calculus.