A method for determining the complex value of technical losses of full power in power three-phase two-winding transformers with account of additional losses from higher harmonic components

Introduction. In recent years, there has been a significant deterioration in the quality of electrical energy in the networks of industrial and non-industrial consumers as more and more electric receivers with nonlinear volt-ampere characteristics generating higher harmonic current components in the network are connected to them. The higher harmonic components of the current create additional losses in the transformer windings and additional losses on eddy currents in the magnetic circuit. All this leads to a decrease in the efficiency of electricity transmission processes and a reduction in the estimated service life of electrical equipment and electrical networks.

Goal. The study develops and test a methodology for determining the complex value of technical losses of full power in power three-phase two-winding transformers, taking into account additional losses from higher harmonic components.

Materials and methods. To implement the technique, a T-shaped replacement circuit of a three-phase two-winding power transformer is used, which is assumed to be symmetrical. To perform calculations using the proposed technique, passport data of a three-phase two-winding power transformer are required. Along with the study requires the data (active power, current and voltage) measured for each of the three phases and for each harmonic component starting from the 1st to the 40th using measuring instruments installed in the input cell supplying low-voltage busbars of a transformer substation, to which the final consumer of electrical energy is connected.

Results and discussion. The approbation of the developed methodology was carried out by the example of an existing power supply system supplying a metal galvanizing workshop, which includes a three-phase two-winding power transformer of the TMZ brand with a nominal capacity of 1000 kV •A. The measured data on the magnitude and harmonic composition of the current strength, active power and supply voltage were obtained using an electric energy quality analyzer Energomonitor 3.3 T installed in the input cell feeding the low-voltage busbars of a transformer substation. Based on the results of the approbation, the complex value of the technical losses of full power in a power three-phase two-winding transformer is calculated, taking into account additional losses from higher harmonic components.

Conclusion. The developed technique makes it possible to increase the accuracy of determining the complex value of technical losses of full power in power three-phase double-winding transformers operated in urban and industrial power supply systems by taking into account additional losses associated with the presence of higher harmonic components in the power supply system due to the presence of a nonlinear electrical load.

1. Chernysheva DV. The Effect of Non-sinusoidal Voltage and Current on the Elements of the Power Supply System. Proceedings of the Southwestern State University. Engineering and Technology. 2012;2-1:100-105. (In Russ.).

2. Prishchepa DN, Zagrutdinov YuA. Negative Impact of Non-linear Load on the Power Supply System. Proceedings of the Military Space Academy Named After AF. Mozhaisky. 2014;(644):199-203. (In Russ.).

3. Boyarskaya NP, Temerbaev SA, Dovgun VP, Kabak AL, Kolmakov VO. Analysis of the Spectral Composition of Currents and Voltages of LED and Gas-discharge Light Sources. Bulletin of the Krasnoyarsk State Agrarian University. 2013;(8):180-184. (In Russ.).

4. Leshchinskaya TB, Taranov MM. Investigation of the Emission Currents of Household Electric Receivers. Bulletin of the VP. Goryachkin Moscow State Agroengineering University. 2009;(2):54-61. (In Russ.).

5. Guzhov S, Polishchuk A, Turkin A. Street Lighting Networks with Semiconductor Control Devices and Light Sources: Control and Calculation of Modes. Semiconductor Lighting Engineering. 2009;(1):42-46. (In Russ.).

6. A Method for Determining Technological Losses of Electric Power for Traction at DC Traction Substations of Railway Transport. Patent RF No. 2573098 МПК B60M 3/00, G01R 21/133 / Kashtanov AL, Nezevak VL, Nikiforov MM, Ushakov SYu, Cheremisin VT. 2016. (In Russ.).

7. A method for Determining the Complex Value of Total Power Losses in Urban and Industrial Power Supply Systems // Patent RF, No. 2815674 МПК G01R 21/133 / Kostinskiy SS, Liventsov VS. 2024. (In Russ.).

8. Bruskin DE, Zorokhovich AE, Khvostov VS. Electric Machines and Micromachines: Studies. for Electrical Engineering Special Universities. 3-rd ed., reprint and add. Moscow: Higher School; 1987. 528 p. (In Russ.)

9. Singh GK. Power system harmonics research: a survey. European Transactions on Electrical Power. 2009;19(2):151-172.

10. Jaisiva S, Neelan S, Ilansezhian T. Harmonic analysis in non-linear loads of power system. International Research Journal of Engineering and Technology. 2016;3(5):1474-1478.