TY - JOUR
T1 - Instability of Wind Turbine Converters during Current Injection to Low Voltage Grid Faults and PLL Frequency Based Stability Solution
AU - Göksu, Ömer
AU - Teodorescu, Remus
AU - Bak, Claus Leth
AU - Iov, Florin
AU - Kjær, Philip Carne
PY - 2014/1/9
Y1 - 2014/1/9
N2 - In recent grid codes for wind power integration, wind turbines are required to stay connected during grid faults even when the grid voltage drops down to zero; and also to inject reactive current in proportion to the voltage drop. However, a physical fact, instability of grid-connected converters during current injection to very low (close to zero) voltage faults, has been omitted, i.e., failed to be noticed in the previous wind power studies and grid code revisions. In this paper, the instability of grid side converters of wind turbines defined as loss of synchronism (LOS), where the wind turbines lose synchronism with the grid fundamental frequency (e.g., 50 Hz) during very deep voltage sags, is explored with its theory, analyzed and a novel stability solution based on PLL frequency is proposed; and both are verified with power system simulations and by experiments on a grid-connected converter setup.
AB - In recent grid codes for wind power integration, wind turbines are required to stay connected during grid faults even when the grid voltage drops down to zero; and also to inject reactive current in proportion to the voltage drop. However, a physical fact, instability of grid-connected converters during current injection to very low (close to zero) voltage faults, has been omitted, i.e., failed to be noticed in the previous wind power studies and grid code revisions. In this paper, the instability of grid side converters of wind turbines defined as loss of synchronism (LOS), where the wind turbines lose synchronism with the grid fundamental frequency (e.g., 50 Hz) during very deep voltage sags, is explored with its theory, analyzed and a novel stability solution based on PLL frequency is proposed; and both are verified with power system simulations and by experiments on a grid-connected converter setup.
KW - Converters
KW - Current control
KW - Power system faults
KW - Power system stability
KW - Wind power generation
U2 - 10.1109/TPWRS.2013.2295261
DO - 10.1109/TPWRS.2013.2295261
M3 - Journal article
SN - 0885-8950
VL - 29
SP - 1683
EP - 1691
JO - I E E E Transactions on Power Systems
JF - I E E E Transactions on Power Systems
IS - 4
ER -