Investigation of Distribution Transformers Vibrations in Terms of Core and Winding Condition Assessment

Abstract

This work refers to the criterion values used to assess the state of the active part of the transformer based on the analysis of the effective value of the total vibration acceleration and the frequency spectrum. It was proved in the work that the criteria values should be differentiated for transformers of different rated power. Transformers with lower rated power are characterized by lower RMS values of vibration acceleration than units with higher rated power, which cannot remain without impact on the criteria values. Trend analysis of the total aRMS values may reveal increasing defects before the currently applicable criteria values are exceeded. In addition, the influence of the position of the sensor on the frequency spectrum of the obtained signals was analyzed. It was proved that the sensors should be mounted in the middle of the transformer tank, between its lower part and the cover. The dependence of RMS value of vibration acceleration on no-load losses was also determined for transformers of different types but the same rated power. This relationship will not have a large share in the total vibrations of the transformer, due to slight changes in the value of aRMS occurring for all analyzed units.

Distributed Vibration Monitoring System for 10 kV-400 kVA 3D Wound Core Transformer under Progressive Short-Circuit Impulses

“…Now we compare the presented distributed wireless sensors monitoring system with similar state-of-the-art technologies for status monitoring of the distribution transformers. The use of the vibroacoustic method using a piezoelectric accelerometer was reported for core and winding measurement and condition assessment, and two criteria were proposed for assessing the condition of transformers based on the results of vibroacoustic tests [31]. Among versatile monitoring methods for the transformer conditions, optical measurement methods seem attractive due to their high spatial resolution, wider monitoring range, and high stabilities, and thus the distributed fiber optic sensing system is suitable for transformer monitoring [32][33][34].…”

Techno-Economic Analysis of Alternative PV Orientations in Poland by Rescaling Real PV Profiles

“…However, the amount of energy produced depends on the time of production because the production of electricity at the same time causes serious technical issues-overloads of lines and violations of voltage level-which cause premature aging and increase the risk of a failure of the power system network elements [36]. As a result, there is a need to pay particular attention to the diagnostic and monitoring of elements of modern power systems [37,38]. Moreover, according to a typical contract between plant owner and operator, when the violation level is unacceptable and there is no other solution, the transmission or distribution system operator may order to reduce the power of power plants.…”

Research on vibration energy harvesting technology of power equipment based on alternating magnet array

“…For example, when the transformer works normally, the metal parts continue to vibrate under the action of the alternating magnetic field. These vibrations operate under the dominant frequency of 100 Hz, including a small amount of 200 Hz, 300 Hz and even higher frequency components [11][12][13]. The vibration acceleration of transformer shell fluctuates with the change of transformer capacity and working conditions, ranging from 3 to 10 m/s 2 [14][15][16].…”