scholarly journals On the use of electromagnetic time reversal to locate faults in series-compensated transmission lines

Author(s):  
R. Razzaghi ◽  
G. Lugrin ◽  
M. Paolone ◽  
F. Rachidi
Electricity ◽  
2021 ◽  
Vol 2 (2) ◽  
pp. 168-186
Author(s):  
Md Tanbhir Hoq ◽  
Nathaniel Taylor

The introduction of series capacitors in transmission lines causes problems in terms of reliability and the security of distance protection relays. As distance protection is widely used in the transmission network, the challenge of applying it to series compensated lines has been taken up by utilities and relay manufacturers in various ways. In the field of power system protection, developments are largely driven by relay manufacturers, and are often not published in the academic literature; the status and trend of the relay manufacturer’s development are better found in their product manuals and patent activity. Further insight into specific implementations by transmission utilities can be found from publications in industry-led forums and some academic journals. This article surveys the status and development of distance protection for series compensated lines, with a focus on industrial implementation and practical considerations. Factors that influence the protection of series compensated lines are presented. Implementation examples reported by utilities are summarized as examples of the different situations encountered and the methods used to deal with them. It is observed that many utilities use communication-aided protection in series compensated lines, and distance protection is used with reduced reach. Solutions described in relay manuals are presented to demonstrate the manufacturers’ approaches to problems associated with series capacitor protection. While there are methods to counter voltage inversion, current inversion seems to represent a more serious challenge. A patent overview indicates the trends in this domain to be moving towards time-domain-based faster protection methods.


2011 ◽  
Vol 2011 (DPC) ◽  
pp. 000555-000579
Author(s):  
Jonathan Richard ◽  
Robert Dean

Metamaterials have a wide range of potential uses in areas such as optics, transmission lines, and RF design. The simplest metamaterial structures are Split-Ring Resonators (SRR) and Complementary Split-Ring Resonators (CSSR). Through the combination of various forms of these structures, different applications in the areas previously stated can be achieved. Under this investigation, a metamaterials transmission line was realized through micromachining a Liquid Crystal Polymer (LCP) substrate. Not only does LCP possess useful RF properties, it can also be easily micromachined. This transmission line consisted of several CSSRs in series, which performed as a high-order, high-frequency high-pass filter. This structure was unique to most metamaterial structures because LCP is a flexible substrate. It was observed that the resonant frequency of the filter did not change when the LCP transmission line was flexed in various ways. Next, micromachined vias were etched through the LCP substrate to demonstrate that these features do not affect the filter's response. Through utilization of these vias, the metamaterial structures can be physically conformed to nearly any shape or mounted onto another object without affecting the filter's response. As demonstrated in a simple filter structure, the shape manipulation has very little effect. Theoretically, extrapolating these methods to the development of metamaterials 3D RF invisibility cloaks, that are easily realizable and mountable onto an object, could prove useful.


Author(s):  
Zeynab Zandi ◽  
Keyhan Sheshyekani ◽  
Ebrahim Afjei

Abstract This paper investigates the effect of different bypassing schemes and grounding methods on the secondary arc current and the transient recovery voltage (TRV) of series compensated transmission lines. It is known that in series compensated lines, the peak value of the TRV may exceed the insulation strength. Furthermore, a secondary arc current is generated during a single line to ground fault mainly affected by the capacitive coupling between the healthy lines and the faulted line and can persist for seconds. The steadiness of secondary arc current prevents line reclosers from having a prompt closing to fulfill the system stability. This paper discusses different scenarios that can be employed to limit the secondary arc current consistency and to suppress a severe TRV during a single line to ground fault. A frequency domain analysis is conducted to better understand the nature of the secondary arc current. It is noted that an accurate arc model based upon the Kiziclay’s arc model is used in the simulations.


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