Impact of Distributed Wind Generators Reactive Power Behavior on Flicker Severity

When wind farms are connected to weak distribution networks, significant flicker emission can be expected, and it might not comply with the enforced grid code limits. This paper investigates and analyzes the impact of the possible wind generator reactive power control modes on the produced flicker levels. A frequency-selective reactive power control scheme is also proposed that makes it possible to mitigate the wind generator flicker emission under any reactive power exchange mode of the machine with the grid while respecting the grid code power factor restrictions. A realistic short-term wind profile is used and simulations are conducted on a 2 MW DFIG unit. Flicker measurement is carried out per IEC Standard 61000-4-15.