Waveform and Location Analyses of Localis Lightning Locating System Zulkurnain Abdul-Malek, Z. Adzis Inst. of High Voltage & High Current Universiti Teknologi Malaysia Johor Bahru, Malaysia zulkurnain@utm.my Aulia + , Novizon Electrical Engineering Department Universitas Andalas Padang, Indonesia + aulia007@gmail.com N. Abdullah TNB Research Sdn Bhd Kuala Lumpur, Malaysia Abstract— Lightning mapping or locating systems are based on several working principles such as the Time of Arrival (ToA) and the Directional Finder (DF). The country wide lightning locatingsystem(LLS) owned by TNB Malaysiais able to determine the coordinate of the cloud-to-ground lightning strike within 500m accuracy. A new method is proposed to determine the coordinate of any cloud-to-ground lightning strike within a certain local region with a better accuracy. The localised LLS is based on the measurement of induced voltages due to lightning strikes in the vicinity of an existing overhead telephone lines. The localised lightning locating system (LLLS) is made up of three components: an overhead telephone line, a voltage surge measuring system, and a central processing station. The overhead telephone line was purposely constructed in such a way to simply form a Cartesian system suitable for lightning strike location mapping. The mapping of the lightning strike locations was successfully implemented using a LabView based program. Simulated lightning as well as real lightning data were used in this study. The induced voltage waveforms were compared with other previously published data. The location calculations were compared with those obtainedfrom the nationalLLS. Resultsshow that the LLLS captures more lightning strikes during the period of the study. I. I NTRODUCTION Lightning strike is a dangerous natural phenomenon that can cause various problems. Telecommunication subscriber lines (TSLs) and electrical power lines are two systems that are almost always affected by nearby lightning strikes. Better designs of lightning protection systems can be realised if data on lightning strike distribution in a given region is known. Commercial lightning mapping or locating systems are based on several technologies [1,2]. The two most popular methods are thosebased on the Time of Arrival(ToA) and the Directional Finder (DF) principles. An example of the lightning locating system (LLS) based on the ToA method is the country-wide LLS owned by the TNB, the power utility in Malaysia. The system is capable of determining the coordinates of cloud-to-ground lightning strikes within 500 m accuracy. For a localised distribution of lightning, say within 1 km 2 area, this accuracy is too large for the data to be meaningful. In this work, a new method to determine the coordinate of any cloud-to-ground lightning strike withina certain localised region is proposed. The localised LLS is suitable for determining lightning strike distributions for a small area. It is based on the measurement of induced voltages due to lightning strikes in the vicinity of existing overhead telephone lines [3-6]. Studies related to lightning induced voltages and the corresponding models to approximate lightning effects were carried out by sever researchers [7-9]. II. E XPERIMENTAL S ETUP LLLS Setup Figure 1 shows the simplified diagram of the localise lightning locating system (LLLS) installed at UTM Institute of High Voltage and High Current. If a lightning is to strike certain point in the measuring area, indicated as point S, th corresponding electromagnetic field of the lightning stri will induce travelling waves in the nearby overhead ca The closest points of inductionare those that are perpendicular to the strike location. These are shown a x and S y . At the point of induction, the induced current is separated into two signals that travel in an opposite directio 180 o phase in difference, toward the ground. The cables are terminated by 50 Ω resistors which act as the measuring transducers as well. A time difference of arrival (TDoA) method was used determine the lightning strike coordinate. Clearly, the arriv time of the induced voltage or surge is dependent on distance travelled. Hence, for the strike location (0,0), distance travelled along the (x,y) coordinates is (270/2, 210/2) or (135,105). For this case, the TDoA shall be ( since the induced voltages arrive at the same time on respective cable ends and hence no net time difference arrival. If the TDoA is positive in both cable X and Y, say (x,y), the strike location is in quadrant I (Figure 1), where x and y represent the S x and S y respectively. If for example, the TDoA is negative in cable X but positive in cable Y, that is (- x,y), the strike location is in quadrant II. LLLS Calibration with a Known Source A lightning current impulse generator was energised produce several kiloamperes into a tall conductor locat various locations. Due to some technical problem faced during the experiment, the calibration was done for Lin (Y-axis) only. The lightning impulse generator (Haefely PSurge 30.2) was placed at several positions along the axis. The injected surge current magnitude were also varied A 14-m length conductor connected to the PSurge ouput wa used to represent the lightning channel. Figure 2 show locations of the applied surge current during the experimen (locations 1, 2 and 3). C and D are the measuring points. 978-1-4244-8286-3/10/$26.00 ©2010 IEEE 132