Risk-based planning of distribution substation considering technical and economic uncertainties

In this paper, a new risk-based planning method is proposed which pays more attention to low-probability and high consequences events in LV distribution network. The proposed approach is implemented for planning of LV distribution networks and for optimally determining the size, number, and placement of distribution transformers. In the proposed approach, three different risk strategies are defined for distribution system operator (DSO). They are named risk-seeker, risk-neutral, and risk-averse. While the probabilistic behavior of parameters is not considered by the first one, a risk-neutral DSO considers it and makes decisions based on the expected cost. The risk-averse DSO makes, instead, decision based on the worst possible case. An uncertainty model of the system's variables is based on discrete states, called scenarios. The cost of Distribution System Planning consists of investment cost, maintenance cost, power losses cost, and reliability cost. A transformer overload penalty function is also defined to consider the effect of possible transformers' overloads during their life time. The proposed approach, applied to a test system consisting of 42 electric load points, can properly reduce the cost of extreme event and therefore, DSO has less concern about these possible situations.