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ProPoSed deSIgN of hIgh-voLtage toWer theft deteCtIoN aNd MoNItorINg devICe
yengopal, j.L.
University of KwaZulu Natal, Durban, South Africa Orcid: 0009-0007-7409-626X
Khan, M.f.*
University of KwaZulu Natal, Durban, South Africa Orcid: 0000-0003-1395-8608 www.linkedin.com/in/mohamed-fayaz-khan-36939324 *Correspondence: KhanM@ukzn.ac.za
abstract
The theft of steel members and tower footing electrodes from high-voltage (HV) transmission towers poses a significant risk to South Africa’s electrical infrastructure. These thefts degrade the structural integrity of the towers, potentially causing power outages, financial losses, and safety hazards. Existing measures, such as physical barriers, regular inspections, and specialised bolts, have proven inadequate, as they are reactive, costly, and only partially effective. These methods are reactive deterrents, rather than proactive, as theft can only be identified by line patrols conducted by utility workers. This study aims to develop and test a novel device for detecting theft in real-time, providing a proactive and cost-effective solution to protect HV transmission towers. The device uses a dual- sensor system – comprising vibration and audio sensors – integrated with an ESP32 microcontroller to detect the unique signatures of tools like angle grinders used in theft. A solar-powered, self-sustained design enables continuous operation in remote locations without external power sources. The device also monitors the condition of the tower footing electrode using a voltage divider circuit to detect degradation or theft. Real-time alerts are sent to control room operators via wireless communication when theft or tampering is detected, significantly reducing response times. Software simulations and hardware- based experiments were conducted to calibrate the device to function as described. Controlled experiments demonstrated the device’s effectiveness in detecting both steel member and electrode theft with minimal false alarms. The prototype met the criteria for low-cost production and sustainability, suggesting it is a viable solution for large- scale deployment. The next step involves refining the design for durability and compactness and conducting a long-term pilot study to further evaluate its real-world
performance. Despite the promising results, the adoption of such innovative solutions faces barriers, including regulatory hurdles, lengthy approval processes, and a risk- averse culture within the utility sector. Addressing these challenges is essential to ensure that novel technologies can be effectively implemented to safeguard critical infrastructure.
Keywords: condition monitoring, smart grid, theft detection
Introduction
In South Africa and internationally, high-voltage (HV) towers play a crucial role in energy transmission. These towers are, commonly, made of steel (Punse 2014). The most common HV tower type is the‘steel-lattice design’, due to its mechanical strength and cost efficiency. The strength of the tower is created through the interconnection of steel members to form a lattice (Punse 2014; Kamarudin et al. 2018). While this HV tower design has its advantages, there are also disadvantages in the form of theft and vandalism. The steel members which form the lattice are noted for being stolen, as many of these HV towers are in remote areas, with some in urban areas. This leaves them unmonitored and an easy target for theft. The stolen steel members can be sold as scrap metal (Vosloo and Mhaule 2016). There are consequences to the theft of the steel members, such as degradation of the overall structural integrity of the HV tower (Johnpaul et al. 2024). The decrease in structural strength can cause the tower to collapse. If this happens many issues can arise, such as power outages, electrical hazards, increased financial costs (replacement of the towers), and revenue loss.
Eskom’s work regarding the mitigation of HV tower theft began in earnest after an incident where a tension tower connecting two major substations collapsed due to vandalism. This resulted in “100% system disturbance for about 0.08 seconds and a loss of 110 MW to 15 transmission voltage customers”. This event affected the main manufacturing plant for Toyota as well as King Shaka International Airport. The estimated revenue loss was “approximately $80,000” (Vosloo and Mhaule 2016). A typical HV lattice-type tower can be seen in Figure 1.
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