Lightning trip-out risk evaluation of a 220kV transmission line in Shiyan
The lightning trip-out accidents of Shiyan transmission lines occur frequently. The lightning parameters, lightning faults and geography of 220kV shi-xuan transmission line have been collected. The lightning striking simulation model has been built by using electromagnetic transient calculation software ATP-EMTP and multi-wave impedance model. The lightning withstanding level of tower and the lightning trip-out rate have been calculated. The actual operation of the transmission line has been considered in order to evaluate the risk of lightning trip-out. The results can provide guidance for the lightning protection of transmission linewhich locates in mountains.
Novel approach for determining spots of critical lightning performance along transmission lines
A novel approach is proposed for determining critical spots along transmission lines, concerning lightning performance. It takes into account two localized factors: stroke density and response of line structures to lightning currents. The methodology employs data supplied by lightning location systems and also information about line parameters in order to rank, by means of a severity index, the specific towers along line, which deserve protective actions. The procedure was applied to a real 230 kV line. The results, in terms of first ranked towers, were compared to the history of line outages, as indicated by a fault locator. The results were in very good agreement. This denotes the potential of the proposed approach for general application.
DISTRIBUTION LIGHTNING FAULT CORRELATION & ADVANCED APPLICATIONS OF LIGHTNING DATA
Advances in the accurate detection of lightning location and magnitude are fostering the capability for high-quality power system impact assessments. These impact assessments can support highly cost/benefit effective decisions in diverse applications across the spectrum of transmission and distribution operations. Case study examples are provided to further illustrate the role of Impact assessment that can be considered by integrating high-quality lightning data with sophisticated power system impact data monitoring systems and/or models of power system assets and it's behavior when impacted by lightning. A case study involving applications related to predictive design of transmission systems where performance forecasts are derived from integrating forensic stroke data are discussed.. In this case, comparisons will be discussed on the lightning performance and the cost between 69 kV transmission lines with a shielded and unshielded design, which utilizes lightning arresters. Utilizing lightning stroke data in a forensic application to target performance problems specific to maintenance construction programs for sub-transmission and transmission systems is reviewed. This allows deterministic performance indicators of specific line sections or even structures to be derived which can be applied in a cost and time effective maintenance function (i.e., Location-Centered Maintenance TM ) . Further this technology can target a performance problem early on and boost asset performance goals by identification of problems before recurrent event tracking systems would normally allow for this problem identification. The successful application of lightning data at the transmission level allows for the potential application in comparable fashion to distribution levels. Finally application of high quality lightning data holds significant potential for application on distribution systems where the potential exists to integrate observed lightning Systems to allow faster and more efficient restoration to impacted utility customers. Providing reduced crew and data with observed distribution disturbances. This application holds the potential to provide high quality damage location information to Outage Management Systems to allow faster and more efficient restoration to impacted utility customers, while also providing reduced crew and operational costs and better customer service. A Metatech/NRECA pilot program is discussed. Exploiting Emerging Technologies from Transmission Applications