Harmonic Power Direction Method for Smart Grids

Active power flow direction is a common method used by most industries to determine the flow of harmonics in the distribution network and for data monitoring analysis. This method is integrated into most power quality analyzers and commercial software. Therefore, this paper seeks to examine the harmonic power flow direction method and quantify the size of the harmonic contribution of each harmonic source connected at the Point of Connection (PoC). A radial distribution network with harmonic loads is used and modelled in the DIgSILENT power factory. It was found that the harmonic power flow depends on the flow of harmonic current within the power system. It can be that the harmonic sources have negative power at a harmonic frequency which means it injects the harmonic current, but the dominant contribution is only from one or two harmonic sources. Thus, the load with the highest percentage of individual and total harmonic distortion is the dominant contributor to harmonics. DIgSILENT gives the contribution of each load connected at the PoC by indicating the percentage of total harmonic distortion. The active power flow direction method is the practical and commercial method to use in the industries. This gives a solution for the ongoing harmonic source detection research. It is recommended to use DIgSILENT, it shows the direction of harmonic current flow and quantifies the harmonic content within the network.