Wildlife-related incidents on power systems has been increasing year by year. These uncontrollable events cause massive impact in terms of cost. Single outages contribute to penalties, loss, repairs, and replacements. Annual outages are categorized as weather, wildlife, vegetation, accidents, and unknown cases. An article by INMR stated that 50% of wildlife-induced incidents are caused by birds.
Wildlife-related incidents on power system can be divided into two – electrocution and flashover. Electrocution often caused by making contact with either two energized component or one energized component and a ground component. Bird electrocution will determine the effectivity of auto-reclosers and record the downtime duration of outages if reclosers failed to function. Considering these reclosers will eventually operate the system normally, but successive incidents will lead to damages. Auto-reclosing system will not operate once the electrocuted bird will remain having contact to energized components without falling. Most electrocution incidents occur on MV systems where space between energized components is approximately 40 centimeters at substations and 1 meter for overhead lines. Birds having wide range of wingspan are the greatest threat of electrocution during landing and take-off. Aside from bridging on power lines, birds can also be electrocuted on cross-arms while perching.
Flashovers caused by birds are least likely to occur but can be as damaging as outages caused by electrocution. Bird droppings will be accumulated on insulators during dry season. During wet season, accumulation of bird droppings will cause soluble contamination to enter. The solution forms an electrolyte, a key factor in producing leakage current. When there is enough leakage current over the insulator, arcing begins to take place. As per electrical utilities, when the leakage current is approximately 70 percent of the creepage distance, flashover will automatically take place. Consequences of a flashover may extend to power outages, potentially causing disruptions to essential services and business operations, as well as equipment damage and much of a concern is the safety implication which may cause serious injury or death to personnel working nearby.
How can we avoid animal-related outages?
Considering the huge cost, loss of wildlife and interruption to consumers, power companies are leaning towards any solution offered to prevent such incidents. One of the criteria to be considered is the installation cost of a specific solution lower than the cost of a possible outage. Midsun IKM, based in Austria, specializes in distributing over 100 wildlife outage protection products. These are ready-made products for power companies, electrical substations, transmission, and distribution lines to show its commitment to protect power companies and mitigate risk to wildlife at any season.
Awareness to cost of wildlife-related outages is obviously increasing, leading to an increase in demand of dependable and effective solutions for safeguarding animals and power companies. Additionally, long term solution for power companies will be the adjustments to designs in terms of spacing and also the consideration of applying abovementioned solutions on early stages.
Reference:
INMR 2023, Protecting Overhead Lines & Substations from Wildlife Induced Outages, https://www.inmr.com/protecting-overhead-lines-substations-from-wildlife/