Investigation of the current harmonic parameters of wind energy converters

Current harmonic parameters of six grid connected wind energy converters (WECs) with a power of 1.5 MW and 1.8 MW were investigated. The evaluation was done according to the basic guidelines for harmonic limits EN 61000-3-2 and IEC 1000-3-3. Focus was on the definition and explanation of a typical shape of the standard parameters total harmonic distortion (THD), partial weighted harmonic distortion (PWHD) and the self-defined parameter total harmonic distortion with consideration of interharmonics (THDz) over the relative power of the WECs. Caused by the working principle of the power electronic voltage-source-inverters (VSI) used, the harmonic parameters show a clearly definable pattern, depending on the relative power of the WECs. The context between the power electronic converter operation and the format of the power quality curves over the relative power is given.