The determination of power quality indicators in distribution networks of farmers’ and suburban farms

The increase of indicators of quality of electric energy (IQEE) in distributive networks (DN) of 0.38 kV at asymmetrical loading was carried out by ap-plication of various ways and technical means car-rying out balancing of operating modes of electric networks (EN). The tests of the shunt-symmetrizing devices (SSD) at installation in DN were carried out; their mathematical modeling on experimental physical models at various connections in EN was made. As objects of EN research Irkutsk, Chere-mkhovo and other regions of Eastern Siberia were used. As a result of researches it was revealed that in EN of low voltage not casual and probabilistic asymmetry of currents and tension could arise be-cause of large number of irrationally distributed asymmetrical and nonlinear loadings. The tempo-rary charts characterizing coefficients of the return K2U and zero sequences of K0U tension showed that the maximum value of coefficient of K2U in the stud-ied EN without SSD made 5.35 %, a population mean of M(K2U) - 3.86 %; for K0U coefficient re-spectively - 12.07 % and M(K0U) - 9.02 % at SSD included in loading knot. The population mean of coefficient of K2U increased by 0.32 % in compari-son with K2U, received at loading redistributed on phases. The value of population mean for coeffi-cient of K0U decreased to 2.6 7 % that was 6.35 % less for EN operating modes without SSD and was 3.63 % less at the situation of redistribution of elec-tric loading on phases. After studying the reason of emergence and influence of asymmetry on IQEE the analysis of methods of its compensation which revealed was carried out that for elimination of a probabilistic component of asymmetry expedient it is possible to consider use of the transformers hav-ing the scheme of connection "a star - a zigzag with zero", with the SSD installation in a zero wire.