Recloser-fuse Miscoordination Research Articles

Comparison between saturated-iron core and shielded-iron core superconducting fault current limiters on recloser-fuse coordination of radial distribution systems connected with distributed generation

Abstract Recently, distributed generators (DGs) are being largely amalgamated with radial distribution systems because of their positive impacts on these systems such as voltage profile improvement and power loss minimization. However, if this integration is not well-planned, it can lead to serious problems in the protection devices. One of these problems is the recloser-fuse miscoordination. This paper presents an effective solution to the recloser-fuse miscoordination due to DGs integration with RDS. The proposed approach is based on suppressing the DG current during fault period so that the contribution of DG to the fault current becomes minimal. Two types of superconducting fault current limiters (SFCLs) namely, saturated iron-core and shielded iron-core SFCLs are studied and a comparison between their performance is presented. The proposed solution was implemented on IEEE 33-bus RDS. All simulation studies are performed on MATLAB script. The simulation results illustrated that saturated iron-core SFCL could not recover recloser-fuse coordination in some of the studied cases. However, shielded iron-core SFCL could successfully restore the recloser-fuse coordination in all the studied cases. This shows that shielded iron-core SFCL is preferred in solving recloser-fuse miscoordination.

Recloser-Fuse settings in distribution systems with optimizing multiple distributed generation considering technical aspects

<p><span>With the widespread of using distributed generation, the connection of DGs in the distribution system causes miscoordination between protective devices. This paper introduces the problems associated with recloser fuse miscoordination (RFM) in the presence of single and multiple DG in a radial distribution system. Two Multi objective optimization problems are presented. The first is based on technical impacts to determine the optimal size and location of DG considering system power loss reduction and enhancement the voltage profile with a certain constraints and the second is used for minimizing the operating time of all fuses and recloser with obtaining the optimum settings of fuse recloser coordination characteristics. Whale Optimizer algorithm (WOA) emulated RFM as an optimization problem. The performance of the proposed methodology is applied to the standard IEEE 33 node test system. The results show the robustness of the proposed algorithm for solving the RFM problem with achieving system power loss reduction and voltage profile enhancement.</span></p>

An Adaptive Relaying Scheme for Fuse Saving in Distribution Networks With Distributed Generation

In some situations, utilities may try to “save” the fuse of a circuit following temporary faults by de-energizing the line with the fast operation of an upstream recloser before the fuse is damaged. This fuse-saving practice is accomplished through proper time coordination between a recloser and a fuse. However, the installation of distributed generation (DG) into distribution networks may affect this coordination due to additional fault current contributions from the distributed resources. This phenomenon of recloser-fuse miscoordination is investigated in this paper with the help of a typical network that employs fuse saving. The limitations of a recloser equipped with time and instantaneous overcurrent elements with respect to fuse savings, in the presence of DG, are discussed. An adaptive relaying strategy is proposed to ensure fuse savings in the new scenario even in the worst fault conditions. The simulation results obtained by adaptively changing relay settings in response to changing DG configurations confirm that the settings selected theoretically in accordance with the proposed strategy hold well in operation.

Prevention of Reliability Degradation from Recloser–Fuse Miscoordination Due To Distributed Generation

Distributed generation (DG) may bring about reliability degradation, instead of reliability enhancement, due to recloser-fuse miscoordination. For the prevention of this reliability degradation, this paper proposes a method to find the threshold value of the DG capacity, beyond which recloser-fuse coordination is lost. Mathematical equations for protective devices are used to set up the protection settings and calculate the threshold value. Three reliability indices-SAIFI, SAIDI, and ENS-are evaluated and compared with the study cases in the reliability test system RBTS bus 2. The results show that the proposed method is effective to prevent the deterioration of system reliability. In addition, a simple modification to the protection system is presented as a preliminary solution.