Abstract: In order to reduce the harmonic pollution on the public power grid, a pre-condition is to accurately detect harmonic sources. One of the methods to detect harmonic sources is based on Emanuel power theory. Firstly, according to the principle of segregation of the fundamental and non-fundamental apparent power, which is based on Emanuel power theory, values of h times harmonic apparent power can be calculated and used as the basis to locate the harmonic source. Simulation analysis on Matlab/Simulink and measurement results have proved the validity and rationality of this method.