Scientific Journal of KubSAU

The importance of improving the quality of electrical energy was growing along with the development and wide implementation in the production of valve converters and various highperformance processing units, such as arc furnace, welding machines etc. The main causes of potential and existing non-compliances of non-sinusoidal voltages can be joining sources and non-sinusoidal reactive power sources, including resonant filters, to existing electric grids without taking into account their possible impact on the distortion of the sinusoidal voltage. Transformers are affected by the non-sinusoidal shapes of the curves of current and voltage. The effect is characterized by the fact that the harmonics of current and voltage increase transformer temperature, compared to purely sinusoidal current and voltage. The aim of this work is to study the influence of higher harmonics on power loss in power transformers. Experimental study of operation of power transformers was carried out on the developed model of the transformer substation. The experiments were conducted with different capacities of transformers that have variables in the range of 250-1000 kVA. By using programmable voltage source a sinusoidal voltage is formed containing the third, fifth, sixth, seventh, ninth and twelfth harmonics. The level of harmonics is changed in the range of 2-12 %

Both domestic and foreign experience have noted that the introduction of diagnostic tools was one of the most important factors in increasing the economic efficiency of the use of equipment in industry. The purpose of diagnostics is detection and prevention of failures and failures, maintenance of operational parameters within the specified limits, forecasting of the state for the purpose of full use of the resource. Today, more than ever, the assessment of the current state of the electric power is particularly acute. With one regulatory method of testing electric motors, it was necessary to make a sufficiently in-depth analysis of technical documentation for testing or diagnosis of new modern tests or diagnostics. The relevance of the transition to non-destructive methods of motor testing is increased in order to increase their service life. At present, there is a need to introduce more gentle methods of testing electric bodies, since the standardized test method has a negative impact on the condition of electric motors as a whole and on the integrity of the structure. In order to ensure the necessary level of reliability of electrical equipment at enterprises, it is necessary to use modern testing methods and diagnostic systems