Optimal distribution network switch planning considering malfunction of switches

Sectionalising switches play a crucial role in the post-fault reconfiguration of distribution networks. In this paper, we propose a
mathematical model for the switch placement problem, through which the optimal configuration of manual and remote-controlled
switches (MSs and RCSs) as well as field circuit breakers (FCBs) can be determined. The objective is to minimise the installation
and operation costs of switches together with the reliability-oriented costs, which include the distribution company’s lost revenue
due to the undelivered energy and the regulatory incentives (or penalties) associated with service reliability indices. To determine
the regulatory incentives (or penalties), two reward-penalty mechanisms are applied to the system average interruption frequency
index (SAIFI) and system average interruption duration index (SAIDI). Also, a new reliability assessment model is developed in
this paper to quantify SAIFI, SAIDI, and expected energy not supplied. In this model, we consider the possibility of malfunction-
ing in RCSs and FCBs, which has a high occurrence probability, especially in severe weather conditions. The proposed switch
optimisation model is implemented on a test network to validate its applicability. The results reveal the importance of considering
the placement of FCBs and the possibility of switch malfunctions in switch placement models.