Accurate coordination method based on the dynamic model of overcurrent relay for industrial power networks taking contribution of induction motors into account. Issue 4 (14th January 2020)

• Record Type: Journal Article
• Authors: Ghotbi Maleki, Mahdi; Mohammadi Chabanloo, Reza; Farrokhifar, Meisam
• Is Part Of: IET generation, transmission & distribution. Volume 14:Issue 4(2020)
• Page Start: 645
• Page End: 655
• Publication Date: 2020-01-14
• Subjects: relay protection -- fault location -- power distribution protection -- power distribution faults -- short‐circuit currents -- overcurrent protection -- genetic algorithms -- induction motors; conventional coordination constraints -- false trip issue -- nondirectional OC relays -- power network -- accurate coordination method -- dynamic model -- overcurrent relay -- industrial power networks -- induction motors -- short‐circuit currents -- SCC -- transient currents -- transient component -- miscoordination -- backup relays -- conventional relay coordination methods -- specific fault location -- relays coordination; Electric power production -- Periodicals; Electric power transmission -- Periodicals; Electric power distribution -- Periodicals; 621.3105
• DOI: 10.1049/iet-gtd.2019.0325
• Languages: English
• ISSNs: 1751-8687

Abstract

Abstract : Induction motors are widely used in the industry. These motors contribute to short‐circuit currents (SCCs) by generating transient currents. The transient component in the SCC causes a change in the operating times of the overcurrent (OC) relays and miscoordination between the main and the backup relays. Therefore, the conventional relay coordination methods that use fixed SCCs for a specific fault location are not suitable for industrial power networks. In addition, the contribution of induction motors may cause a false trip in non‐directional OC relays at healthy feeder. Here, a method based on the dynamic model of the OC relay is proposed to take the effect of transient component of SCC into account in relays coordination. A new set of constraints is added to the conventional coordination constraints in order to solve the false trip issue. In this case, an optimisation algorithm is needed to coordinate non‐directional OC relays. The proposed method is implemented in a power network of cement factory and the results indicate the effectiveness of the proposed method. Here the genetic optimisation algorithm has been used and the simulation has been achieved using DIgSILENT and MATLAB software.