Practical method to determine the harmonic contribution of a specific harmonic load

Quantitatively determining harmonic contribu-tion of the specific harmonic source at the particular bus of concern is an important task for power quality management. Compared with traditional methods where it's assumed that the background harmonics remain constant with time, the method proposed in the paper for calculating the equivalent harmonic impedance is also effective under the condition that the background harmonics fluctuate with time. The method is based on the complex least squares theory. And then the procedure for identifying harmonic contribution of the specific harmonic load on the bus of concern is presented. Case study based on the IEEE 14-bus test system shows that the proposed method is more practical for harmonic contribution determination when the background harmonics vary with time than the traditional methods.