In the electrical power system, the coordination of directional overcurrent protection relays (DOPR) plays a preeminent role in protecting the electrical power system with the help of primary and back up protection to keep the system vigorous and to avoid unnecessary interruption. The coordination between these relays should be pursued at optimal value to minimize the total operating time of all main relays. The coordination of directional overcurrent relay is a highly constrained optimization problem. The DOPR problem has been solved by using a hybridized version of particle swarm optimization (HPSO). The hybridization is achieved by introducing simulated annealing (SA) in original PSO to avoid being trapped in local optima and successfully searching for a global optimum solution. The HPSO has been successfully applied to five case studies. Furthermore, the obtained results outperform the other traditional and state of the art techniques in terms of minimizing the total operating of DOPR and convergence characteristics, and require less computational time to achieve the global optimum solution.
<p>・Table 1 shows the evaluation results of four types (05-</p><p>T125, (05-T-40), (05-L125A), (05-L-40A)) in a 500V power supply. Table 2 shows the evaluation results of four types (10-T125, (10-T-40), (10-L125A), (10-L-40A)) in a 1000V power supply.<br></p><p>・Figure 5 and Table 3 show the waveform and data of 05-T125. Fig. 6 and Table 4 show the waveform and data of 10-L-40A.</p><p>・ All eight types of waveforms, including those with (), are attached together in a separate document.</p><p><br></p>
<p>・Table 1 shows the evaluation results of four types (05-</p><p>T125, (05-T-40), (05-L125A), (05-L-40A)) in a 500V power supply. Table 2 shows the evaluation results of four types (10-T125, (10-T-40), (10-L125A), (10-L-40A)) in a 1000V power supply.<br></p><p>・Figure 5 and Table 3 show the waveform and data of 05-T125. Fig. 6 and Table 4 show the waveform and data of 10-L-40A.</p><p>・ All eight types of waveforms, including those with (), are attached together in a separate document.</p><p><br></p>
A new scheme of zero-sequence overcurrent protection of converter transformer based on zero-mode inrush current characteristics in station area