Instrumental Research on the Voltage Harmonic Distortion Coefficient in the Modern 110 kV Urban Electric Network

The article deals with assessing the level of voltage non-sinusoidality in the electric network with voltage of 110 - 220 kV. By carrying out direct measurements at a fixed number of connections of urban substations on the high voltage side, the materials were collected for analyzing higher harmonic voltage components. The measurements were carried out in accordance with the requirements of this procedure and with participation of employees of the energy supply company as part of the planned energy audit activities. Based on the results of the analysis, it is stated that the permissible, and in some cases limiting values of the higher harmonic components of the voltage are exceeded. During the analysis, the practice of assessing the harmonic composition in foreign countries, such as the United States of America, was studied, where harmonics were taken into account not only in voltage but also in current. Based on the results obtained, the authors consider that the current standard that regulates the quality of electrical energy in the Republic of Kazakhstan and in the territory of the CIS countries does not fully meet the requirements of the current situation in the electric networks. The reason is the rapid growth of types of electrical receivers based on semiconductors, which is not fully taken into account in the current standard. The authors state the further growth of power receivers with a non-linear consumption characteristic, which will worsen the situation regarding the non-sinusoidal voltage.