Enhancement Of Low-Voltage Ride Through Of Wind Energy Conversion System Using Superconducting Saturated Core Fault Current Limiter

For enhancing the fault ride through (FRT) capability of doubly fed induction generator (DFIG), the major concern is to remain connected with the grid for maintaining the grid code. For improving this entity, saturated core fault current limiter (SCFCL)-based protection system has been used in the DFIG system for protecting it from the fault current during fault conditions. The main features of transformer-type three-limb SCFCL is that the Alternating Current (AC) coils embedded across the two limbs, and the Direct Current (DC) coils embedded across the other remaining limb. The main features of SCFCL is that the core is saturated during normal operating condition, and during the fault condition, high current generates sufficient magnetic flux in the AC coil, which drives each core out of the saturation. Because of this, SCFCL operates in high-permeability zone and increases the impedance of the AC coil, which limits the fault current. In this paper, the above behaviour of SCFCL under normal and faulty condition has been analysed by simulated mathematical modelling and verifying it with the experimental setup. In addition to conserve good FRT performance, the fault consequences in DFIG system such as rotor current, DC link voltage, and torque fluctuations are analysed. Also, the simulation result justifies the efficacy of SCFCL compared with the other conventional schemes.