TY - JOUR
T1 - Enhanced fault ride-through of power converters using hybrid grid synchronization
AU - Sahoo, Animesh
AU - Ravishankar, Jayashri
AU - Ciobotaru, Mihai
AU - Blaabjerg, Frede
PY - 2021/1/27
Y1 - 2021/1/27
N2 - Inaccurate phase-angle jump estimation of the grid voltage during faults is one of the major causes for poor fault ride-through performance of converters. To overcome this issue and make the converter’s current controller robust, this paper proposes a hybrid grid synchronization transition technique. In this concept, a synchronous reference frame based phase-locked loop (SRFPLL) grid synchronization method is used during normal grid operation and switched to an arctangent based phase-angle estimation during grid faults. Simultaneously frequency estimation is switched to the arctangent derived frequency. A common transition method, which depends on the phase-angle error between the two phase estimation techniques, is proposed to ensure a smooth transition between the hybrid phase-angle and frequencies. The transition technique is implemented using the current control of a three-phase voltage source converter in the synchronous reference frame. The performance of the converter during both symmetrical and asymmetrical grid faults along with the fault ride-through strategies is tested using real-time experiments. It is observed that the transition based hybrid grid synchronization technique reduces the loss of synchronism duration. Additionally, it offers a more robust converter current control performance compared to the SRFPLL technique over a wide range of voltage sags and phase-angle jumps.
AB - Inaccurate phase-angle jump estimation of the grid voltage during faults is one of the major causes for poor fault ride-through performance of converters. To overcome this issue and make the converter’s current controller robust, this paper proposes a hybrid grid synchronization transition technique. In this concept, a synchronous reference frame based phase-locked loop (SRFPLL) grid synchronization method is used during normal grid operation and switched to an arctangent based phase-angle estimation during grid faults. Simultaneously frequency estimation is switched to the arctangent derived frequency. A common transition method, which depends on the phase-angle error between the two phase estimation techniques, is proposed to ensure a smooth transition between the hybrid phase-angle and frequencies. The transition technique is implemented using the current control of a three-phase voltage source converter in the synchronous reference frame. The performance of the converter during both symmetrical and asymmetrical grid faults along with the fault ride-through strategies is tested using real-time experiments. It is observed that the transition based hybrid grid synchronization technique reduces the loss of synchronism duration. Additionally, it offers a more robust converter current control performance compared to the SRFPLL technique over a wide range of voltage sags and phase-angle jumps.
U2 - 10.1109/JESTPE.2021.3054851
DO - 10.1109/JESTPE.2021.3054851
M3 - Article
JO - IEEE Journal of Emerging and Selected Topics in Power Electronics
JF - IEEE Journal of Emerging and Selected Topics in Power Electronics
SN - 2168-6777
ER -