Method and apparatus for differentiating contributions of harmonic pollution sources

摘要

A method of determining parameters of a harmonic pollution source connected to a power line at a connection point. The harmonic pollution source is a power customer and the power is supplied by an electric utility. The electric utility is also a source of harmonic pollution. Both the utility and customer can be modeled as a harmonic current source in parallel with an impedance. In the method of the present invention, a harmonic voltage and a harmonic current are measured at the connection point between the utility and customer. The voltage and current measurements are combined with the known reference impedances in a calculation to yield the magnitude of current produced by the customer or utility harmonic current sources. Also, the present invention provides a method for determining the relative harmonic pollution contributions from the utility and customer. Both the utility and customer can then know exactly how much harmonic pollution they are emitting into the power line to which they are connected. The pollution contribution calculation requires knowledge of both utility and customer reference impedances and the harmonic voltage and harmonic current measurements. The present invention includes a method of determining a pollution contribution from the customer where the pollution contribution measurement is not influenced by changes in utility impedance.