TROPICAL LIGHTNING PEAK CURRENT CHARACTERISTIC MEASUREMENT USING INSTRUMENTED TOWER

• Main Author: Denov, Bryan
• Format: Dissertations
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/81262
• Institution: Institut Teknologi Bandung

Lightning is a growing concern in modern society, in line with technological advancements. Present-day society requires infrastructure such as various facilities, electrical systems, telecommunication systems, data processing systems, and instrumentation and control systems. All of these infrastructures are highly vulnerable to weather disturbances. The most influential weather condition is generated by Cumulonimbus (CB) clouds. CB clouds can produce lightning because their vertical growth allows for charge separation within the cloud. Subsequently, electrification occurs within the cloud, leading to lightning. Indonesia is known as a maritime continent and is located in a tropical region, making this geographical condition highly conducive to the formation of numerous CB clouds. The formation conditions of CB clouds include updraft (air rising due to surface heating or orographic characteristics of the land surface), aerosols (hygroscopic particles from sea salt and industry), and humid air. Indonesia has many islands, resulting in numerous updrafts. It also has tropical forests with high humidity and many industries and sea salt, leading to high aerosol content. Indonesia is also influenced by monsoon winds that support the formation of thunderclouds. Monsoon winds are caused by temperature differences between the land and sea that change every season. Monsoon winds blow from the Asian continent during the rainy season, passing through southern Sumatra, the mountainous regions of West Java, to the Australian continent. December to January is the rainy season, while March, April, and May are transition periods with more lightning occurrences than the rainy season. Monsoon winds blow from Australia, bringing high pressure in June, July, and August, bringing dry air. September, October, and November are transition periods with many lightning occurrences. During the monsoon winds blowing from Australia to Asia through Indonesia, they carry a large amount of water when passing over the ocean. This makes Indonesia the country with the highest density of lightning in the world. Lightning strikes can cause damage to building structures, equipment, fires, and even claim human lives. The threat of lightning strikes can be categorized into direct strikes and indirect strikes. Direct strikes can cause effects such as destruction, death, explosions, and fires. Indirect strikes can lead to conduction problems, voltage elevation, and voltage induction. To prevent the dangers of lightning strikes, it is necessary to study the characteristics of lightning, known as lightning parameters. Lightning parameters consist of peak current, current steepness, current charge, and impulse force. One of the lightning parameters significantly affecting its influence is the peak current of lightning. The peak current parameter of lightning influences the design of lightning protection systems chosen. To minimize the danger of lightning strikes, a well-designed lightning protection system is needed, utilizing lightning parameters according to the characteristics of lightning in the area to be protected. Measuring the peak current of lightning is one important way to obtain the characteristics of lightning at a specific location. This dissertation presents innovations in measuring the peak current of lightning using tower networks and structures equipped with magnetic tape measurement instruments, known as instrumented towers. The magnetic tape measurement instruments are calibrated using high current generator surjas with various variations such as tape position, frequency, and tape type. Furthermore, this dissertation provides an analysis of the characteristics of peak lightning currents influenced by several factors including geography, location altitude, distance from the coast, latitude, and garis bujur. This dissertation also presents new peak lightning current statistics in the tropics, particularly in Indonesia. In the study, a total of 166 peak lightning current data points were obtained from various locations in Indonesia. The research results indicate that low-lying areas have the highest peak lightning current values, while hilly areas have the lowest peak lightning currents. The results obtained show a correlation between peak lightning current and latitude. The correlation coefficient indicates that higher peak lightning currents tend to occur in areas with low latitudes and areas close to the equator. This dissertation demonstrates that each region has different statistics; therefore, promising statistics can be used in designing the appropriate lightning protection system for a specific area.