Application of the Acoustic Emission Method for Diagnosis of On-Load Tap Changer

Abstract

This paper provides an example of the application of the acoustic emission (AE) method for the diagnosis of technical conditions of a three-phase on-load tap-changer (OLTC) G III type. The measurements were performed for an amount of 10 items of OLTCs, installed in power transformers with a capacity of 250 MVA. The study was conducted in two different OLTC operating conditions during the tapping process: under load and free running conditions. The analysis of the measurement results was made in both time domain and time-frequency domain. The description of the AE signals generated by the OLTC in the time domain was performed using the analysis of waveforms and determined characteristic times. Within the time-frequency domain the measured signals were described by short-time Fourier transform spectrograms.

Measurements on partial discharge in on‐site operating power transformer: a case study

“…AE method is usually applied for the PD localisation rather than for the PD intensity estimation. Generally, there are two main methods for localisation of the PD source using the AE method: triangular method (based on the differences in arrival times of the AE signals of each sensor) and highest volume method (based on the differences in amplitudes of the signals registered by every sensor) [8,[22][23][24].…”

Measurements on partial discharge in on‐site operating power transformer: a case study

“…AE method is usually applied for the PD localisation rather than for the PD intensity estimation. Generally, there are two main methods for localisation of the PD source using the AE method: triangular method (based on the differences in arrival times of the AE signals of each sensor) and highest volume method (based on the differences in amplitudes of the signals registered by every sensor) [8,[22][23][24].…”

A Review of Fault Diagnosis Research on On-Load Tap-Changers

“…The theory of phase space reconstruction was first proposed by Packard [13] and Takens [14] to study the chaotic characteristics of nonlinear signals. Through theoretical analysis and numerical calculation, it is proved that the phase space reconstruction can keep the geometric invariance of the original nonlinear dynamic system, which lays the foundation for the study of high-order nonlinear dynamic system by experimental method.…”

Vibro-Acoustic Methods in the Condition Assessment of Power Transformers: A Survey

“…These methods were used to tackle the problems of highly non-stationary nature of the signals and to improve the precision of the diagnostics. CWT, DWT and STFT have also been used in [20], [21], [71], and [72] for the extraction of the diagnostic material. Li et al [73] reported the shortcomings of the existing vibro-acoustic diagnostic methods when electrical faults without obvious mechanical vibration are being diagnosed, such as contact terminals fault and contact resistance anomaly.…”

Measurements on partial discharge in on‐site operating power transformer: a case study

“…AE method is usually applied for the PD localisation rather than for the PD intensity estimation. Generally, there are two main methods for localisation of the PD source using the AE method: triangular method (based on the differences in arrival times of the AE signals of each sensor) and highest volume method (based on the differences in amplitudes of the signals registered by every sensor) [8,[22][23][24].…”

A Review of Fault Diagnosis Research on On-Load Tap-Changers

“…The theory of phase space reconstruction was first proposed by Packard [13] and Takens [14] to study the chaotic characteristics of nonlinear signals. Through theoretical analysis and numerical calculation, it is proved that the phase space reconstruction can keep the geometric invariance of the original nonlinear dynamic system, which lays the foundation for the study of high-order nonlinear dynamic system by experimental method.…”

Vibro-Acoustic Methods in the Condition Assessment of Power Transformers: A Survey

“…These methods were used to tackle the problems of highly non-stationary nature of the signals and to improve the precision of the diagnostics. CWT, DWT and STFT have also been used in [20], [21], [71], and [72] for the extraction of the diagnostic material. Li et al [73] reported the shortcomings of the existing vibro-acoustic diagnostic methods when electrical faults without obvious mechanical vibration are being diagnosed, such as contact terminals fault and contact resistance anomaly.…”

Measurements on partial discharge in on‐site operating power transformer: a case study

“…AE method is usually applied for the PD localisation rather than for the PD intensity estimation. Generally, there are two main methods for localisation of the PD source using the AE method: triangular method (based on the differences in arrival times of the AE signals of each sensor) and highest volume method (based on the differences in amplitudes of the signals registered by every sensor) [8,[22][23][24].…”

A Review of Fault Diagnosis Research on On-Load Tap-Changers

“…The theory of phase space reconstruction was first proposed by Packard [13] and Takens [14] to study the chaotic characteristics of nonlinear signals. Through theoretical analysis and numerical calculation, it is proved that the phase space reconstruction can keep the geometric invariance of the original nonlinear dynamic system, which lays the foundation for the study of high-order nonlinear dynamic system by experimental method.…”

Vibro-Acoustic Methods in the Condition Assessment of Power Transformers: A Survey

“…These methods were used to tackle the problems of highly non-stationary nature of the signals and to improve the precision of the diagnostics. CWT, DWT and STFT have also been used in [20], [21], [71], and [72] for the extraction of the diagnostic material. Li et al [73] reported the shortcomings of the existing vibro-acoustic diagnostic methods when electrical faults without obvious mechanical vibration are being diagnosed, such as contact terminals fault and contact resistance anomaly.…”