مهدي احمدي

With the expansion of voltage source converter based high-voltage direct current (VSC-HVDC) networks, particularly in multiterminal configurations, these systems have attracted considerable attention as an efficient solution for long-distance power transmission an‎d the integration of renewable energy resources. However, the low-impedance nature of DC lines an‎d their interaction with AC networks lead to a rapid increase in fault currents an‎d severe transient stresses on power equipment. Moreover, the deployment of DC circuit breakers with high interrupting capability is still associated with significant technical an‎d economic challenges. In this regard, resistive superconducting fault current limiters (RSFCLs) can be considered an effective solution for improving the transient behavior of the system an‎d reducing protection requirements. In this study, a accurate magneto-thermal model of an RSFCL is first developed an‎d implemented as MATLAB code. Subsequently, a three-terminal VSC-HVDC network is designed an‎d simulated in MATLAB/Simulink, an‎d its transient performance is investigated under steady-state operation as well as during single-line-to-ground an‎d three-phase-to-ground faults on the AC side, both with an‎d without the RSFCL. Simulation results show that, by introducing a dynamic resistance due to the quench phenomenon, the RSFCL can effectively reduce the fault current rate of rise, the peak fault current, an‎d the voltage stresses imposed on the converters. In the next step, to achieve maximum protective effectiveness, the optimal placement of the RSFCL in the studied network is investigated using a multi-objective particle swarm optimization (MOPSO) algorithm. The objective functions are defined to minimize the peak fault current, reduce the energy dissipated in the RSFCL, an‎d enhance the DC-link voltage stability. The optimization results indicate that selec‎ting an appropriate installation location for the RSFCL has a significant impact on the overall network performance an‎d leads to a substantial improvement in the transient response compared to the non-optimized case.

محدودكننده جريان خطاي ابررساناي مقاومتي , عملكرد گذراي شبكه VSC-HVDC , جايابي بهينه , الگوريتم بهينه‌سازي ازدحام ذرات چندهدفه (MOPSO)

Resistive Superconducting Fault Current Limiter (RSFCL) , VSC-HVDC Transient Performance , Optimal Placement , Multi-Objective Particle Swarm Optimization (MOPSO)

Mahdi Ahmadi

Dr. Hossein Heydari