1. Problem In the pre-computer era, power outages did not have a significant impact on a person’s daily life. Today, however, even momentary power interruptions cause major inconveniences due to the widespread use of computers, clocks, and other electrical devices [1]. Most of these interruptions occur on overhead power lines. Power distribution systems are made up of a network of both overhead and underground wires. Unlike underground power systems, overhead systems are exposed to lightning, vegetation, and wildlife. These exposures create a variety of problems for the power distribution industry. Animal-related power outages account for a large percentage of electrical service interruptions [2]. Most of these animal-related interruptions are caused by squirrels or birds physically touching, contaminating, or nesting on high voltage equipment. Mississippi Power Company alone had 1133 reported animal- related outages last year, causing 565,000 customer minutes of interrupted electrical service [3]. This translates into millions of dollars lost due to reduced power use, man-hours paid for repair, and the cost of replacing damaged equipment. Today’s power companies are not only worried about collecting revenues and saving money on repairs; they are also concerned about providing reliable electric service to each and every customer. Customers expect a certain amount of reliability or assurance from anything they purchase; this causes power companies to work harder than ever to avoid even the smallest power outages [1]. Therefore, preventing even a small portion of animal-related outages would increase the quality of electric service to many customers. Many attempts have been made to guard high voltage equipment from animal-related power outages. Most of these attempts involve creating physical barriers or insulating equipment to prevent animals from coming in contact with energized components. However, there are still many situations where energized equipment cannot be protected because of the equipment size or function. For instance, the contacts of a gang operated air brake switch (GOAB), shown in Figure 1, cannot be totally insulated, because the contacts are designed to make an electrical connection. GOAB switches are used to divide power lines into different sections so that power can be rerouted in the event of a power outage. The term “air brake” is used because air physically separates the contacts of the switch in the open position. FIGURE 1: Gang Operated Air Brake SwitchFigure 2 shows a similar switch used in substations to separate or connect alternate power sources. This switch is referred to as a bus tie switch. The design of this type of switch makes it nearly impossible to barricade or insulate. FIGURE 2: Gang Operated Air Brake Bus Tie Switch Other devices in substations, such as high voltage structures, are also hard to insulate or barricade because of their physical size. Some substation high voltage equipment covers several hundred square feet. In these cases, an electronic animal deterrent that covers large areas would be most effective in preventing animal-related power outages. Currently several companies manufacture products that use traditional methods to protect high voltage equipment from animal damage. Traditional means of protection include contact insulation, pole barriers, and static-charge devices. Critter Guard Inc. manufactures wire and pole barriers that prevent ground animals from reaching high-voltage equipment. These designs are ineffective as a bird deterrent [4]. Nontraditional means of deterring animals include ultrasonic devices. The current devices are designed to constantly emit random frequencies at a set volume level. This is a problem, because animals eventually become accustomed to the constant noise, rendering these devices ineffective after a short period of time [1]. However, when operating an electronic device near power lines, its effectiveness is not the only consideration. These devices must be able to function in high levels of electromagnetic interference and capable of handling an over-current or over-voltage condition. The power supplies used in current electronic animal-deterrents are not designed to handle these power surges. The environment surrounding outdoor high-voltage equipment is susceptible to large transients and high field stresses due to the frequency of lightning. The proposed design will combine several features to better protect itself against these uncontrollable phenomenons. Transient voltage suppressers and specially placed diodes will be used to guard the internal electronics against voltage and current spikes that lightning can sometimes cause. Motion detectors will be used to trigger the device when an animal approaches. Once the device has been triggered, high-intensity strobe lights will flash and the speakers will emit a loud pattern of sonic and ultrasonic noise. The strobe light is another feature that no other animal deterrent designs incorporate. The motion detector coverage area can also be adjusted, which will allow flexibility in different mounting situations. Existing animal deterrents are not weatherproof and are made from plastic. Plastic will eventually breakdown under the sun’s ultraviolet rays, and it does not shield the circuitry from electromagnetic interference. The aluminum enclosure the proposed device will be in shields the internal electronics and will not be deteriorated by ultraviolet light. The proposed deviceincludes random sound and light patterns. As previously mentioned, most ultrasonic devices emit a constant sound, which animals easily become accustomed to [1]. The motion sensor will allow the device to remain silent until triggered, keeping the animals from becoming accustomed to the sound. The proposed design includes several other key features that make it more appealing to power companies. Maintainability is one of the characteristics that power companies look for when buying a new piece of equipment. The proposed design will be powered by 120VAC instead of batteries, reducing maintenance. The proposed design will also include an infrared (IR) link that will allow the device to be accessed by an IR remote control to determine operational status. This feature is important because the device could be located on a utility pole out of reach. If needed, the device can be reprogrammed through a common
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