OPTIMAL CLEAR WIDTH CALCULATOR (OCWC) AND LINE STRIKE PROBABILITY CHART SERVICES (LSPC)
At long last, a quantitative means of reducing the risk of tree-conductor contacts. If you want significant (50% to 80%) improvements in reliability you need to identify where tree outages originate from. Unless your pruning program is very seriously behind, it is not likely that shorter maintenance cycles will substantially improve reliability. Generally, about 85% of tree-related outages arise from tree failure. Thus significant reliability improvements require a focus on reducing the risks inherent to tree failure.
Most utilities choose to handle the tree failure risk through a hazard tree identification and removal program. This approach has very limited success. Read the technical paper to get the details on how natural tree mortality absolutely swamps the hazard tree removal efforts. Even a hazard tree program that approaches a commercial logging operation in the number of tree removals will not provide enduring reliability improvements. (Find out why.)
The suggested use of the Optimal Clear Width Calculator is to use it to reduce tree line strike risks to about 20%. Such a residual risk can be readily handled by the hazard tree program.
The Optimal Clear Width Calculator allows you forecast the impact on line security for various proposed actions. This VM decision tool brings a new, clearer focus to the risk reduction benefit thereby improving the cost/benefit analysis process. (Click on the Examples bar at the left.)
How can you use the Optimal Clear Width Calculator and Line Strike Probability Chart Services? See examples for two different applications.
To get the details of this quantitative approach to risk reduction read the technical paper,Managing Tree-Conductor Conflicts by Risk Assessment.
HOW TO IMPROVE LINE SECURITY 50%
An illustration of integrating the Optimal Clear Width Calculator and Line Strike Probability Charts into a VM program and reducing tree-related outages by 50% on a system wide basis.
(Requires a familiarity with Line Strike Probability Charts and associated spreadsheets. Follow the examples provided above and/or read Managing Tree-Conductor Conflicts by Risk Assessment to familiarize yourself with them.)
Having read Managing Tree-Conductor Conflicts by Risk Assessment, get more details on why hazard tree programs provide only short term improvements in reliability. Then read on to see economic modeling of various widening scenarios. Depending on the average annual storm restoration costs, it may be possible to substantially decrease tree-related outages (including during severe storms) and save money.
You can get started on making substantial, quantified reliability improvements by subscribing to the Optimal Clear Width Calculator services.
If you’re interested in a broader determination of system risk or require assistance with economic analysis, contact Ecosync. We’ll custom design a project to meet your needs.
TREE DENSITY DETERMINATION
For help with stand density determination follow the link on the left.
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