Real-time hardware-in-the-loop approach for adaptive centralized protection schemes using clustering algorithms

The main objectives of adaptive protection are isolating only the faulty network section and operating with varying network topologies and levels of generation. To accomplish this, the settings of protective devices may need to modify if, for example, the network topology is changed. Protection relays can have several predefined setting groups (SGs) depending on the number of possible configurations. However, centralized protection and control devices can store a limited number of setting groups, in many cases by far less than the number of possible network topologies. Therefore, in adaptive centralized protection schemes where online setting calculation is not feasible, a proper method should be used to cluster the different possible configurations and reduce their number to match or be fewer than the number of available SGs in relays. The offline calculated settings for each cluster can be stored in the centralized protection and control devices, which continuously monitor the status of circuit breakers (CBs) online. Then, upon detecting a change in the CB status, the corresponding SG will be activated. This paper presents three new methods for clustering network topologies, considering N-1 contingency in adaptive relay coordination. These methods are compared to the one in the literature and each other in terms of operation time delay of relays. Moreover, to mitigate false operations of relays due to unavailability of communication networks, a setting group is dedicated to the robust setting group. Finally, a practical implementation of the proposed method using IEC 61850 standard is illustrated using two schemes step by step. IEEE 14-bus is selected as a test system to evaluate the applicability of the proposed methods. The results, obtained by using MATLAB, DIgSILENT Programming Language, and hardware-in-the-loop setup show the effectiveness of the proposed methods in minimizing operating time delays of overcurrent relays.