Power direction method cannot be used for harmonic source detection

Power direction method has been widely used to identify the locations of harmonic sources in a power system. A number of utility-customer disputes over who is responsible for harmonic distortions have been settled with the help of the method. A closer examination of the method, however, reveals that the method is incorrect theoretically. A number of case studies show that the method can give incorrect results. In this paper, problems associated with the method are presented and analyzed