Combined In-Oil Sensor for Vibration Measurement and Partial Discharge Detection using Acoustic and Electromagnetic Emissions SEBASTIAN COENEN Siemens AG Germany
نویسندگان
چکیده
Common acoustic partial discharge (PD) and vibration measurements use sensors attached on the outside tank wall of (power) transformers. Hereby, tank structure can lead to severe signal damping which in practice often leads to acoustic PD signals below noise level. Scope of the work is an acoustic and ultra-high frequency (UHF) detection of PD and additional recording of transformer vibrations during service without tank influences. For in-oil measurements a combined sensor is developed which is sensitive in a wide frequency range. The requirements of a combined in-oil sensor are defined including mechanical demands and signal processing. A diplexer integrated into the combined sensor is introduced to separate frequency spectra of vibrations PD acoustics and UHF waves. Prototype tests at laboratory conditions determine sensor qualities. Therefore, the setup uses reproducible, synthesized PD signals generated by an acoustic signal generator. UHF signals come from a RF pulser. In step with actual practice, a second setup uses a needle-sphere electrode emitting both, real UHF and acoustic signals. Vibration measurements are performed with a small winding, which is mechanically excited. The combined sensor is compared to common acoustic accelerometers and UHF antennas. Finally, the influence of the electric field strength being unavoidable at inside-tank measurements is evaluated.
منابع مشابه
Investigations of In-oil Methods for Pd Detection and Vibration Measurement
Usually, acoustic partial discharge (PD) and vibration measurements take place on the outside tank wall of power transformers. This contribution determines new approaches for acoustic PD measurements within the oil volume of the transformer combined with electromagnetic in-oil measurements. Scope of the work is an acoustic and ultra-high frequency (UHF) detection of PD and additional recording ...
متن کاملUhf and Acoustic Partial Discharge Localisation in Power Transformers
The reliability of electrical energy networks depends on the quality and availability of electrical equipment like power transformers. Local failures inside their insulation may lead to catastrophic breakdowns and can cause high outage and penalty costs. Beside the strength and type of a PD, the geometric PD position is of major interest concerning risk evaluation of the flaw. Conventional PD m...
متن کاملDetection of Partial Discharges in Power Transformers using UHF PD Measurements and Acoustic Measurements
For examination and diagnostics of the insulation quality of high voltage devices the measurement of partial discharge (PD) is accomplished. The conventional PD measurement according to IEC60270 is in some situations not sensitive enough because of the high interference level in field. The development of an unconventional measuring method using electromagnetic probes is presented. These probes ...
متن کاملCorrelation of Dga, Uhf Pd Measurement and Vibration Data for Power Transformer Monitoring
Reliability of electrical energy networks depends on quality and availability of electrical equipment like power transformers. Local failures inside their insulation may lead to catastrophic breakdowns. To prevent destroying events power transformers are e.g. tested on partial discharge (PD) activity. As testing is just snapshot information about transformers condition, permanent online monitor...
متن کاملFiber Optic Sensor for Acoustic Detection of Partial Discharges in Oil-Paper Insulated Electrical Systems
A fiber optic interferometric sensor with an intrinsic transducer along a length of the fiber is presented for ultrasound measurements of the acoustic emission from partial discharges inside oil-filled power apparatus. The sensor is designed for high sensitivity measurements in a harsh electromagnetic field environment, with wide temperature changes and immersion in oil. It allows enough sensit...
متن کامل