Separation of customer and supply harmonics in electrical power distribution systems

This paper aimed towards the development of an adequate method dealing with the possibility of identification of harmonic sources and focusing the problem of interactions between supply distortion and load distortion. The developed research work is composed of two parts. The first part is concerned with detecting how each load in a power system network behaves under the influence of harmonics (determining the degree of the load nonlinearity). The second part is devoted to develop a suitable quantitative measure for the share of waveform distortion produced by a single customer (nonlinear load) when there are many customers (linear and nonlinear loads) sharing the same distribution network. An estimated degree of waveform nonlinearity is introduced and evaluated through the indication of a new harmonic factor that is known as the nonlinearity factor (NLF). This factor was useful to asses the responsibility share of the distortion level of each individual distorting load connected to the same feeding point The suggested technique has been successfully confirmed through real and practical on-site measurements at the 11 kV Alexandria Electricity Distribution systems