AVO NZ and Lord Power Equipment is planning to market Distribution Fault Anticipation (DFA) technology and has requested Terry Krieg, a Senior Affiliate of Lord Consulting to undertake an evaluation and an assessment of the suitability of the technology for Australasia using publicly available information sources.
The DFA technology is based on 30 years of research initially via EPRI1 in the US and more than 10 years of practical field trials involving more than 10 US power utilities. In that time, an extensive database of experience in distribution faults has been collected.
The DFA technology uses waveform analysis and pattern recognition of system events to determine precursor indications of hardware failure or interference with the distribution line from flora and fauna. The aim is that these indications of early contact with plants and animals may be detectable before the fault can result in damage to line hardware resulting in a protection operation (line outage), equipment damage or a fire start.
The field trial experience has enabled the development of the largest database of waveform signatures and the development of a comprehensive set of algorithms to assess line condition.
In extensive trials the DFA device has been able to successfully detect and provide warning of problems with:
- Clamps and connections
- Clashing conductors
- Arcing and tracking of insulation due to pollution and/or humidity that may lead to pole-top fires
- Tap changers and voltage regulators
- Lightning arrestor failures
- Switching issues in reclosers and line switches
- Cable and bushing failures (applicable for ABC)
- Overhead conductor failures and downed conductors
- Tree and other vegetation issues such as contact with phase conductors
- Pole top transformer bushing failures
- Pad-mount transformer failures
- Bus capacitor bushing failures
- Capacitor bank problems such as failed cans, controller mal-operation, blown fuses, switch restrike etc.
The DFA technology consists of a single-ended monitoring device (no distributed line electronics) assembled as a 19" rack and fitted to standard (existing) CT and VTs at the substation. One unit is required per feeder and there appear to be no major issues in adapting the technology to typical Australian and New Zealand applications.
This technology provides the ability to reduce risk of fire starts and equipment damage, improving reliability, safety and efficiency by:
- Providing early warning of problems that might lead to line hardware or surrounding area damage including pole top fires, clashing conductors or downed conductors. A significant benefit is the ability to monitor and analyse intermittent line faults enabling correlation with weather
- Increasing work crew efficiency and effectiveness by providing information to localise faults that may be permanent or intermittent.
- Improving safety by early detection of problems that may result in downed conductors or similar damage that might be a risk to public safety and network reliability.
The technology will be marketed by AVO NZ and Lord Power Equipment who will provide local support for the product.
The assessment has concluded that this technology is suitable for the Australian and New Zealand market and typical local substation and feeder design and based on results from extensive field trials will provide significant benefit and reduced risk for utility owners.