Three-Phase Adaptive Auto-Reclosing for Single Outgoing Line of Wind Farm Based on Active Detection from STATCOM

Difficulties in identification of the fault property, for a fault on a single outgoing line of windfarm, arise due to rapid decrease in the electromagnetic energy of the transmission line after the tripping of three-phase breaker. An active solution to such problem is proposed based on low current injection from parallel connected static synchronous compensator (STATCOM). In the reclose sequence after wind turbines' cut off, the circuit breaker near wind farm and grid-connected circuit breaker of STATCOM are reclosed first. Therefore, based on selected switching operation of power electronic devices of STATCOM converter, a short duration discharge of dc capacitance to the faulty ac line is suggested. Correlation coefficient of resulting current waveform is utilized as an identification criterion for fault presence. Finally, a three-phase adaptive auto-reclosing scheme is proposed for the single outgoing line of 110 kV wind farm. The effectiveness and robustness of the proposed scheme are verified by PSCAD/EMTDC simulation.