Contents 1. Introduction
Harmonic distortion on the voltage and current waveforms significantly concerns present day's power systems due to the large proliferation of the harmonic producing loads. The most important effect of the harmonic distortion can be underlined as the increased losses and decreased life time of the power system equipments. Therefore, the limitation of harmonic pollution has been an imperative issue to decrease the failures depending on harmonic distortion. Accordingly, guidelines, recommended practices and standards have been prepared by several organizations and institutes [1]–[7]. In IEEE std. 519 [1], the total harmonic distortion of voltage and current measured at pcc (point of common coupling) is taken under limitation. In addition, current harmonics are individually limited in IEC 61000–3-2 [2], 3–4 [3] and 3–6 [4] standards, and the restrictions for the wave shape and distortion of the pcc voltage is determined in EN 50160 [5]. On the other hand, in IEC Std. 61000–4-7 [6] and 61000–4-30 [7], the methods are defined to measure harmonic distortion. However, in these standards, there is no method and/or index defined for the detection of dominant harmonic sources. Therefore, in the literature, these standards are accompanied by the research leading to the methods and indices for the detection of the harmonic producing loads and the sharing harmonic contributions between utility and consumer [8]–[20]. The methods and indices for the sharing harmonic responsibility can be classified into two groups according to their measurement strategies, which are single-point and distributed (or multi-point) measurements methods and indices [8]. The multi-point measurements method or index is implemented by using synchronous measurements performed in different metering sections. As a result, the harmonic source detection works based on multi-point measurements strategy are more reliable than the works based on single-point measurements strategy; however, they have higher costs and also are hindered by its requirement for the precise time synchronization.
