Determining maximum penetration level of distributed generation sources in distribution network considering harmonic limits and maintain protection coordination scheme

In addition to the advantages of distributed generation (DG) sources, also it would have disadvantages such as harmonic distortions generation and changing in short-circuit current. Harmonic distortion generation may exceed from permissible harmonic level and cause problem. Furthermore, the change in short-circuit current can cause performance of incorrect in the over-current relays. In first, this paper presents effects and problems of connecting DG sources to network and then by using Genetic Algorithm (GA) determines optimal sizing of DG sources so that remains network protection scheme without changes, also harmonic distortions stay in allowable limitation. Studies have been done on IEEE 14-bus radial network and results is shown finally.