Harmonic Standards :

Considering that the harmonic problems will increase in the future, precautions should be taken to produce low level harmonics in the establishment stage of the facilities containing nonlinear loads. The system must be measured accurately and continuously and these standards must be ensured.
Necessary definitions, indices and limitations are made in harmonic standards of IEEE and IEC. In the logic of the standards stipulated by IEC, there is a limitation of the harmonics resulting from each load connected to the system. Thus, the total effect of the harmonics is thought to be limited. Therefore, the method proposed by IEC is applied at the point where any nonlinear load is connected. The standards set by IEEE are applied to both current and voltage harmonics and to the central busbars where more than one nonlinear load is connected. IEEE, IEC and EN standards of harmonics are summarized in Table 1. Dugan, R. C.,
McGranagan, M. F. and Beaty, H. W .; , Electrical Power Systems Quality ”, Mc Graw-Hill, 1996.
Table 1. IEEE, IEC and EN standards on harmonics