On-line Insulation Monitoring Research Articles

Study on Measurement Error Test Method of On-Line Insulation Monitoring Device for Capacitive Equipment

The dielectric characteristic parameter, such as capacitance value, the dielectric loss tangent and leakage current values will change when insulation degradation occurs in capacitive equipment, thus the insulation on-line monitoring devices were used for the insulation state monitoring. At present, the monitoring mode, functional requirements, stability requirement, reliability requirement, and the access security impact has not been fully unified among different manufacturers. For the purpose of standardization of the design, production, testing and operation management of the device, studies were carried out in field of technical parameters and test methodology. Considering the structure and working principle of this kind device, key technical parameters of functional and technical requirements were put forward, and the measurement error performance testing method, as well as the detection circuit was also given under the laboratory conditions.

The Study of Capacitive Equipment Fault Location Based on the Relative Measurement Method

There is insufficient that get PT secondary voltage signal as a phase reference in capacitive device insulation online monitoring, in order to monitor the insulation accurately, this paper analyzes the advantages of using the relative measurement method for insulation monitoring, and determined the normal range of the dielectric loss by historical monitoring data and the number of failure equipment, furthermore positioned single or multiple faulty equipment by fault diagnosis matrix accurately. Finally, verified the effectiveness of the method by artificial simulation experiments in the laboratory.

On-Line Monitoring System for Transformer Partial Discharge

On-line insulation monitoring of transformer and the fault diagnosis are effective means to avoid sudden accidents happening on the transformer, which are necessary to perform the condition based maintenance (CBM) of transformer. Partial discharge is often accompanied by the external signals of sound, light and electricity as well as some detectable physical phenomena such as characteristic gas and dielectric loss. The partial discharge defects inside the transformer can be found by detecting the external signals. The principle of electro-acoustic monitoring, its monitoring systems and the related judgment technologies are expounded, on the basis of which an outline design of the monitoring system is presented.

Results of installation of 330 kV current transformers main insulation on-line monitoring system at «Dnepr-Donbass 330» substation

The article describes the results of implementing the current transformers (CT) main insulation on-line monitoring system, based on the developed measurement algorithms and the model of residual life prediction. The obtained results have been analyzed; conclusions have been drawn by the results of diagnostics and effectiveness of the existing methods and models implemented in the system.

Advancements during the past quarter century in on-line monitoring of motor and generator winding insulation

Electrical insulation plays a critical role in the operation of motor and generator rotor and stator windings. Premature failure of the insulation can cost millions of dollars per day. With advancements in electronics, sensors, computers and software, tremendous progress has been made in the past 25 yr which has transformed on-line insulation monitoring from a rarely used and expensive tool, to the point where 50% of large utility generators in North America are now equipped for such monitoring. This review paper outlines the motivation for online monitoring, discusses the transition to today's technology, and describes the variety of methods now in use for rotor winding and stator winding monitoring.