| Title |
Distance Relaying Algorithm for Intertie Protection of a Wind Farm Considering the Fault Ride-through Requirement |
| Authors |
강용철(Kang, Yong-Cheol) ; 강해권(Kang, Hae-Gweon) ; 정태영(Zheng, Tai-Ying) ; 김연희(Kim, Yeon-Hee) ; 이영귀(Lee, Young-Gui) |
| Keywords |
Wind farm ; Distance relay ; Voltage blokcing ; Fault ride-through ; Differential equation ; Least square |
| Abstract |
A large modern wind farm should satisfy the requirements for a grid and accomplish the optimization of the wind farm system. The wind farm intertie protection system should consider a Fault Ride-Through (FRT) requirement for more reliable protection. The wind farm should keep connected to the grid in the case of a grid fault whilst it should be isolated for an intertie fault. This paper proposes a distance relaying algorithm suitable for wind farm intertie protection considering the FRT requirement. The proposed algorithm estimates the impedance based on a differential equation method because the frequency of the voltage and current deviates the nominal frequency. The algorithm extends the reach of Zone 1 up to 100 % of the length of the intertie to implement the FRT requirement. To discriminate an intertie fault from a grid fault, the algorithm uses a voltage blocking scheme because the magnitude of the voltage at the relaying point for an intertie fault becomes less than that for a grid fault. The performance of the algorithm is verified using a PSCAD/EMTDC simulator under various fault conditions. The algorithm can discriminate successfully the intertie fault from grid fault and thus helps to implement the FRT requirement of a wind farm. |