Investigation of an Atypical Sixth Harmonic Current Level of a 5 MW Wind Turbine Configuration

Harmonic aspects of wind power integration

“…The harmonic emission from an individual wind turbine is discussed in the previous section. The impact of the wind farm on the propagation has not been studied, but harmonic resonances have been widely studied [1,3,[20][21][22][23]. The parallel resonance has the main impact on the emission of the farm, thus the emission into the grid is several times higher than that of the individual turbines.…”

Study of resonance in wind parks

“…These studies are mainly based on frequency scan simulations which allow the frequency range and peak impedance values of parallel resonances to be established. Some studies point out analytical expressions to determine the frequency of the first parallel resonance, which can be close to low-and high-order harmonic emissions of WT power electronic converters [13,15]. Studies [7,13] also present a summary of the most important WP harmonic and resonance issues.…”

“…Most research works model converters as harmonic current sources and analyze the influence of WP parameters on parallel resonance [1,7,8,[11][12][13][14][15][16][17][18]. These studies are mainly based on frequency scan simulations which allow the frequency range and peak impedance values of parallel resonances to be established.…”

“…1(a) shows a generic WP layout where WTs are supplied through low voltage (LV) underground cables and medium to low voltage (MV/LV) transformers and are interconnected with an N r × N c collection grid of medium voltage (MV) underground cables from the MV collector bus [7,8,[11][12][13][15][16][17]. Capacitor banks in onshore WPs can also be connected to this bus and harmonic filters are usually installed on the line side of WT converters to mitigate frequency switching harmonics [7,8].…”

Grid Integration of Wind Energy Systems

“…• Interharmonics due to generator pole switching, if generators with two pole pairs are applied; • Interharmonics due to the speed-depending frequency conversion between rotor and stator of DFIM [39]; • Harmonics due to the slot numbers of the generators, if one part of the generator is directly connected to the grid, depending on the speed; 1.5 MW-generators have, e.g., slot numbers of N s =72 on the stator and N r =60 on the rotor; • Harmonics due to resonance effects [40];…”