Sharif Digital Repository

This paper presents a new method to determine the optimal number and locations of autorecloser and sectionalizer switches (AR/S) in distribution networks. The costs of AR/S investment, switch maintenance, and undistributed energy as well as reliability coefficients are considered in the objective function. Reliability parameters such as SAIFI, SADI, MAIFI, and ENS are evaluated in the case study system. As a new method, the weights of the reliability parameters are obtained by decision-makers using the analytical hierarchy process (AHP). The optimal size, type, and location of automatic switches are determined by minimizing the objective function using the particle swarm optimization (PSO)... 

To avoid saturation of a protective current transformer (CT) operating under an autoreclosing scheme, the CT size should be chosen much higher than a similar CT operating under a single-step fault clearing scheme. The main reason for this significant difference is that the residual flux (caused by the first stage of the fault) cannot be noticeably reduced during the deadtime interval of the reclosing process and, therefore, the occurrence of a subsequent fault can extremely saturate the CT. In this paper, a low-cost, low-power electronic device is developed and introduced to demagnetize the CT under the reclosing deadtime interval. It will be shown that by using this device, the required...