Results using Different Reactive Power Definitions for Wind Turbines Submitted to Voltage Dips: Application to the Spanish Grid Code

Characterization of Measured Voltage Dips in Wind Farms in the Light of the New Grid Codes

“…Figures 3 and 4 show the three-phase voltage waveforms, the amplitude and the angle of the voltage space vector, [9], of two measured voltage dips. The voltage space vector is a complex magnitude obtained by combining the threephase instantaneous voltages -v a , v b and v c -, representing therefore the voltage dip uniquely through an instantaneous complex vector,V (t).…”

“…On the other hand, the rating of large wind farms reaches rating of conventional generating units and this development has carried out to requirements of how to connect wind farms to the grid. Until now, these grid codes -specified by the transmission system operators-mainly dealed with how a wind farm should operate in steady state while requirements recently imposed in some countries dealed with how a wind installation response to grid faults must be addressed, [9]. These are commonly referred to as the fault ride-through specifications.…”

“…Specifically, national grid codes are requiring uninterrupted generation throughout power system disturbances supporting the network voltage and frequency, and therefore, extending characteristics such as low voltage ride through, or reactive and active power capabilities, [9], [10]. In [9]- [13] grid connection requirements in Spain, Denmark, Germany, Ireland, Sweden and Scotland are studied. When the wind power penetration level is high, the protective disconnection of a large amount of wind power is an unacceptable consequence that may threaten the power system stability.…”

Power operating domain of a cascaded doubly fed induction machine

“…Indeed, during steady state performance, generating plants should be able to operate at different power factors (leading or lagging) depending on the voltage level at the point of common coupling. Besides, following voltage dips, wind turbines should remain connected to the grid and must supply reactive power and participate to the voltage regulation [3], [15]. Much research effort has focused on the stability and development of new control schemes for the CDFIG [4,8,12,13], yet no consideration has been given to define the safe operating domain of the generator, with regards to its ratings, and its contribution to reactive power generation required by grid codes.…”

Characterization and Visualization of Voltage Dips in Wind Power Installations

“…Therefore, some national grid codeswhich are specified by the Transmission System Operators (TSOs)-have additional requirements for integrating wind power installations with conventional types of generation, since premature tripping of wind generators due to power system disturbances can put system stability at risk, contributing to amplifying the disturbance [11], [14]. Specifically, national grid codes require uninterrupted generation throughout power system disturbances, support of the network voltage and frequency, and, therefore, extending characteristics, such as lowvoltage ridethrough and reactive and active power capabilities [15], [16]. Therefore, national grid codes demand, or impose, low-voltage ridethrough capability on wind farms and wind turbines.…”