Improvements in Fault Location Capability at CenterPoint Energy to Reduce Response Time and Improve Accuracy of Fault Reporting

摘要

In 2006, CenterPoint Energy was faced with two problems. The first was the lengthy response times to pinpoint the fault site after a sustained outage. This meant it took longer to get repairs underway and longer to ultimately restore the line. The second was the low accuracy of fault locations made it difficult on momentary faults to know exactly where the fault occurred. This meant that at times it was not possible to determine a true root cause for an outage. To address these issues a traveling wave system for fault location was first trialed and then deployed across the 345 kV and 138 kV networks to dramatically improve the locating accuracy. The TW installations have allowed for quick fault locations to be provided to the field patrols directly from the Control Center. The accuracy of the fault locations has been within one or two spans in many cases. A root cause is much easier to identify and is typically found by the patrols that can now take time to climb the one or two structures identified. For all voltage classes, the percentage of outages with an 'unknown' cause has reduced to an average outage rate of 20% compared to 40% before the TWS fault location method was available. Future work will involve implementing a direct link with SCADA and developing an algorithm to compensate for some errors noted on some lightning events due to fast leaders before the main strike.