Ultra-wideband Partial Discharge Research Articles

Continuous Monitoring of Smart Grid Devices Through Multi Protocol Label Switching

Data refreshment rate of a present power system is relatively slow and in some cases this slow refreshment rate may not be capable of providing information about dynamic state of power system devices. The use of multi protocol label switching based technique is one option to overcome this problem. A cost effective and simpler detection device is needed for condition monitoring and integrating the sensor signals into the smart grid monitoring system. Remote and on-line monitoring of ultra wide band partial discharge signal in a switch-yard is a new concept in smart grid technology that will help avoid damage of switchyard devices. It is possible to convert the radio frequency partial discharge signal into an equivalent milli-volt or milli-ampere output for remote or centralized monitoring of switchyard devices. Multi Protocol Label Switching based data transfer rate is faster than the conventional data transfer system of a power grid. In this paper a new and technically better method of on-line radio frequency partial discharge monitoring from a remote smart grid control room through multi protocol label switching is discussed.

A method for discriminating original pulses in online partial discharge measurement

Partial discharge (PD) measurement is a promising method for condition assessment of insulation systems in high voltage equipments. Conventional PD measuring systems have some difficulties in the measurements especially in online conditions and noisy environments. There is a growing tendency to use new measuring systems for separation of PD pulses from different sources and rejection of external noises. In this investigation a new ultra wideband PD measuring system and relevant methodology are discussed. The proposed system uses an efficient detection method for extracting PD pulses embedded in noisy signal, meanwhile, a wavelet multiresolution analysis is applied to reduce background and communication noise level. In this paper some new and modified features for pulse classification procedure have been proposed. The proposed system, methodology and features have been implemented on a hydrogenerator and also a power transformer. Finally performance of the system is discussed.

Diagnóstico en Línea de Motores de Gran Capacidad mediante la Detección de Descargas Parciales Utilizando Técnicas de Banda Ultra Ancha

A non-standardized and non invasive method for on-line diagnosis of high capacity motors is presented. The method is based on ultra wide band partial discharge measuring techniques. The signals measured by the sensor are stretched electronically, digitized and fed to a conventional partial discharge digital detector. The results obtained in thirteen motors of 2500 HP at 13.8 kV during operating in an oil pumping facility, are presented, and comparison with literature values is done. The results allow concluding that the technique used has the adequate sensitivity for on-line diagnosis of high capacity motors.

Aging assessment of large generator insulation based on PD measurements*

Abstract The statistical parameters of phase resolved partial discharge (PD) distribution and ultra-wideband (UWB) characteristics of PD pulse are proposed for aging assessment of large generator insulation. Multi-stress aging tests of the model generator stator bar specimens were performed and PD measurements were conducted using both digital PD detector with frequency ranging from 40 kHz to 400 kHz and UWB PD detector with bandwidth from 10 MHz to 3 GHz at different aging staged. The test results show that the skewness and UWB frequency characteristics of PD can be taken as the characterization parameters for aging assessment of generator insulation. Furthermore, the measurement results of real generator stator bars show that these methods based on statistical parameters and UWB characteristics of PD are prospective for aging assessment and residual lifetime estimation of large generator stator insulation. *Supported by National Natural Science Foundation of China (Grant No. 59837260), China Postdoctora...