Transformers play a crucial role in the power network by handling electrical loads that fluctuate throughout the day. However, when a transformer fails, it causes severe disruptions in the power distribution system, leading to power outages, financial losses in repair and replacement, revenue loss, and reduced power quality and reliability. Internet of things (IoT)-driven solutions are helping utilities enhance the monitoring of transformers and reduce the probability of failure. This helps improve operational efficiency and reduce costs, this assisting utilities in building smarter grids. A look at innovative IoT use cases for transitioning to smart transformers and substations…
IoT solutions for transformers
Transformers generally encounter several problems, such as overheating and insulation failures, which complicate things by causing early ageing in transformers. This is where modern IoT can be adopted to prevent the wear and tear of transformer infrastructure.
For example, a cooling fan can be installed for additional cooling of transformers through smart devices, triggered based on temperature rise. This would be backed by a specialised algorithm fed into the controller to monitor the temperature rise of distribution transformers, activating the first cooling fan at 65 °C and the second cooling fan at 70 °C. This data is stored in the local memory and alerts are generated based on fluctuations in temperature. Additionally, IoT-based solutions are also being used to monitor and transform parameters such as oil levels and lug temperature.
IoT-based distribution transformer monitoring unit (DTMU) solutions help track important transformer conditions and send this data to a control centre using communication technology. It continuously monitors oil temperature, oil humidity and oil level to detect early warning signs of potential failures, allowing utilities to take preventive measures and protect assets. These units are easy to install on both new and existing transformers, providing a cost-effective and efficient solution for monitoring.
According to recent Central Electricity Authority guidelines on benchmarking operations and maintenance practices for distribution utilities, a well-designed DTMU should be simple, durable and capable of tracking all key parameters. It should also have the ability to generate alerts based on preset limits, ensuring quick action when needed. Additionally, the system should include a built-in GPS, GPRS, IoT or radio frequency (RF) modem, or be adaptable to existing communication systems for seamless data transfer. The DTMU should be able to detect sensor failures or disconnections, which may indicate theft or tampering. Further, a tracking module can be installed to locate stolen transformers, enhancing security. For reliability, the unit should be designed to withstand extreme temperatures, ranging from -10 °C to 50 °C, ensuring continuous operations even during harsh conditions. Additionally, all sensors, such as those for temperature and oil level measurement, should be pre-fabricated harnesses, making installation and maintenance easier and more efficient.
Meanwhile, a smart substation is an upgraded version of a self-protected transformer, designed with built-in protection systems, monitoring tools and automated controls to enable unmanned operation and real-time tracking of transformers and other substation equipment. These substations play a key role in improving power reliability and reducing system losses. Smart substations are equipped with various sensors to monitor important parameters such as voltage, current, load conditions, power factor, oil temperature, internal temperature, oil level, humidity and protection device status. Additionally, dissolved gas analysis sensors and smart breathers help detect internal transformer faults and moisture build-up, preventing early failures. These substations support remote monitoring and control using GPRS, IoT and RF-based communication technologies, ensuring smooth integration with existing systems. They also include automatic protection mechanisms that protect transformers from overloads, high voltage, short circuits and internal faults. To further enhance efficiency, smart substations are equipped with energy metering systems for energy audits and automatic theft detection, allowing utilities to track power usage, prevent unauthorised connections and optimise
electricity distribution.
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The remote monitoring of transformers is another focus area. In urban areas, a large number of distribution transformers have been equipped with communicable meters featuring automated meter reading (AMR) capabilities under government programmes such as R-APDRP and the Integrated Power Development Scheme. These meters are read remotely at data centres for seamless energy accounting and auditing. However, distribution transformers in rural areas generally do not have any metering facility (AMR/advanced metering infrastructure). Under the Revamped Distribution Sector Scheme, launched in July 2021, the installation of 250 million smart meters across the country is planned, along with smart system meters on all feeders and distribution transformers within a specified timeline for accurate energy audit and accounting. This is expected to enable transformer failure analysis and identify the cause of transformer failure by using artificial intelligence/machine learning, aiding in decision-making for repairs and replacement.