scholarly journals Extending the Functionality of On-line PD Monitoring Equipment for MV Power Cables

2017 ◽  
Author(s):  
Y. Li ◽  
P.A.A.F. Wouters ◽  
P. Wagenaars
Keyword(s):  
Time Domain ◽  
Propagation Velocity ◽  
Characteristic Impedance ◽  
Signal Propagation ◽  
Time Domain Reflectometry ◽  
Monitoring Equipment ◽  
High Frequency Signal ◽  
Medium Voltage ◽  
On Line ◽  
Frequency Domain Approach

<p>An on-line partial discharge (PD) monitoring and location system for medium voltage cable circuits was developed previously. This paper explores ways to extend its range of application. The extension includes PD location method by time domain reflectometry (TDR) when reflections are not easily identifiable. The functionality of the PD monitoring equipment can also be widened by sensing other quantities related to the condition of the cable insulation using the same device. Dynamic cable temperature monitoring can be achieved by recording variation in the high frequency signal propagation velocity along the cable. Water ingress in paper-insulated lead-covered (PILC) cable decreases the cable’s characteristic impedance while it increases the permittivity of the insulation. It can be observed by changes in the reflection pattern from the cable or by a lowered propagation velocity. Instead of recording reflection patterns in time domain, a frequency domain approach based on an impedance scan is investigated to be applied for cables in service.</p>

Spread Spectrum Time Domain Reflectrometry Applied to Electrical Systems in Nuclear Power Plants

2010 ◽  
Author(s):  
Gary M. Sandquist ◽  
Carl J. Sandquist
Keyword(s):  
Time Domain ◽  
Integrated Circuit ◽  
Spread Spectrum ◽  
Power Plants ◽  
Short Circuit ◽  
Time Domain Reflectometry ◽  
Nuclear Plant ◽  
Current Time ◽  
Electrical Systems ◽  
On Line

A recently developed technique “Spread Spectrum Time Domain Reflectometry” (SSTDR), and supporting test devices will be adapted and tested to monitor and diagnose nuclear plant electrical systems. Current time domain reflectometry methods cannot detect or locate small faults after arc fault events, because their impedance discontinuity is too small and transient to create a measurable reflection. However, on-line, unobtrusive SSTDR can detect and locate arc and other electrical faults when the (∼msec) short circuit returns a strong reflected signal. These observations have led to development of SSTDR. If SSTDR can be successfully adapted to present and future nuclear plant electrical systems, it will be possible to monitor, on-line, the integrity of the electrical system continuously and with only minor equipment modification and no consequential safety issues. An integrated circuit (IC) is under development at the University of Utah for applications in the aircraft industry that will be adapted and used for this proposed development.

Sign in / Sign up

Export Citation Format

Share Document