Power System Harmonics and Unbalance Distribution Calculation Based on Measurement

The modeling of harmonic source based on harmonic measurement is put forward for the first time. Three-phase fundamental and harmonic models of the whole power system are built in the paper. Then, the power system harmonics penetration (PSHP) software package is developed on VC++ circumstance. Zhengzhou, Luoyang and Sanmengxia electric power system in Henan grid are studied, and the harmonics and unbalance of railway traction substations are measured. At last, the distributions of harmonics and unbalance in three areas grid are calculated using PSHP and compared with the measured results. On basis of calculated results and measured results, setting parameter values of relays of sensitive nodes and lines are checked. Some rules of the harmonics and unbalance distributions have been summarized and some advices have been put forward.