METHODOLOGY FOR SELECTING PARAMETERS OF A PASSIVE FILTER TO IMPROVE THE QUALITY OF ELECTRICITY IN ELECTRIC NETWORKS WITH AN ACTIVE RECTIFIER
Authors:   Nosov Magnitogorsk State Technical University, Nikolaev Aleksandr , Afanasev Maksim Yu. ,   Nosov Magnitogorsk State Technical University, Maklakov Alexander S. ,   Nosov Magnitogorsk State Technical University, Bulanov Mikhail V. ,   Nosov Magnitogorsk State Technical University
Published: December 2023

The relevance Due to the wide spread of compact metallurgical plants, which use powerful drives with frequency converters with active rectifiers (FC-AR), an urgent task has become the fight against resonant phenomena in medium voltage electrical networks, since these converters, despite their significant advantages, have a disadvantage — the deterioration of the quality of electricity in the power supply system 6–35 kV. Existing methods of dealing with resonant phenomena in medium voltage electrical networks, in which non-linear elements are present, such as powerful drives of rolling mills with FC-AR used in power supply systems of metallurgical enterprises, do not always allow changing the situation for the better. One way to solve this problem is to use classic traditional filters. Often, the use of traditional filters to eliminate strong voltage distortions in sections of 6–35 kV does not have the desired effect. The installation of traditional filters is accompanied by additional parasitic current resonances, which amplify the intermediate harmonics. These harmonics multiply the oscillations and strongly distort the voltage shape when the frequency response of the distribution network is superimposed with the region of high-frequency harmonics generated by modern FC-AR. Aim of research The article is devoted to the issues of improving the electromagnetic compatibility (EMC) of FC-AR as part of electric drives of rolling mill stands with an internal power supply system for metallurgical plants in the presence of resonant phenomena through the use of specialized passive filters (SPF). Research methods Methods of theoretical and experimental researches are applied in the work. When studying the causes of the occurrence of resonant phenomena, experimental data obtained in the course of research work at the metallurgical plant JSC Metallurgical Plant Balakovo were used. For the processing of experimental data, mathematical modeling methods were used in the Matlab environment with the Simulink application. Results The significance of the results of the work lies in improving the quality of electricity in the distribution electrical networks of mini-plants with FC-AR in the presence of resonant phenomena in the frequency response of the network through the use of SPF. The implementation of the results of the work is an improvement in quality indicators and, as a result, an increase in the reliability of the operation of all power converters in the internal power supply system and a decrease in emergency situations associated with the failure of power elements. The results of the work were implemented at the metallurgical plant of JSC Metallurgical Plant Balakovo. The quantitative indicator of the technical effect of changing the level of the coefficient of the total harmonic components of the voltage in the general sections of the factory GPP КU is: 1) without the use of SPF КU = 10.26 %; 2) when using SPF КU = 1.42 % (relative change δ КU = –72 %). These results can be used at other compact metallurgical enterprises with extended cable lines of medium voltage 6–35 kV and powerful electric drives with FC-AR.