1. Introduction
The efficient operation and maintenance of electrical substations are crucial to ensuring reliable energy supply. In recent years, the increasing complexity and demands on electrical infrastructure have highlighted several challenges in substation monitoring and maintenance. Traditional methods often fall short in providing the necessary real-time insights and early warnings needed to prevent failures and ensure continuous operation. The implementation of advanced monitoring technologies, such as automated visual and thermal systems, represents a significant advancement in addressing these challenges.
The focus substation is located in Santa Marta, Colombia, and plays a vital role in the regional power distribution network. The company is a leading Colombian organization dedicated to the transmission of electricity, ensuring reliable and efficient energy supply across the country.
This project focuses on an extra high voltage substation, where an automated system integrating high-resolution PTZ, thermographic and IoT cameras were deployed. The system's objective is to enhance the remote monitoring capabilities, allowing for timely detection of thermal anomalies and other failure modes through advanced analytics. This paper details the system components, their installation and observed benefits, including specific instances where early detection of anomalies prevented potential failures and significant financial losses. The integration of these technologies into the existing SCADA system further supports remote decision-making and operational efficiency.
2. Challenges in substation monitoring
The operation and maintenance of electrical substations are essential to ensure reliable energy conditions. Over the years, various challenges have emerged, driving the need to seek more advanced solutions. The following are some of the challenges experienced in monitoring electrical substations:
2.1. Challenges in early detection of thermal anomalies
Electrical substations are subject to a variety of failure modes and abnormal conditions that can jeopardize operation and safety. Identifying these anomalies early is challenging but crucial to avoid unplanned interruptions and equipment damage. Thermal anomalies can result from issues such as contact problems, irregular loads, insulation cracks defective relays. These issues increase the internal temperature of electrical equipment, leading to shortened life expectancy of the asset, unexpected disturbances and potential damage to power systems.
Specific examples of where these issues can occur include:
- Transformers: Overheating in transformers can be caused by insulation failures or issues with the cooling system. Identifying hotspots early is critical to prevent transformer fires and extensive damage.
- Circuit Breakers: Contact problems in circuit breakers can lead to localized heating. If left undetected, this can cause the breaker to malfunction, resulting in outages or equipment damage.
- Busbars: Irregular loads and poor connections at busbars can create thermal anomalies. Ensuring even load distribution and secure connections are essential to avoid overheating.
- Cables and Connectors: Defective relays or improper connections in cables and connectors can cause significant temperature rises. Regular monitoring is required to prevent cable insulation damage and potential failures.
- Switchgear: Insulation cracks in switchgear can lead to partial discharge and thermal anomalies. Early detection helps in maintaining the integrity and functionality of the switchgear.
Two factors make early detection of thermal anomalies particularly challenging:
- Manual Inspection Limitations: Manual inspection of infrared images requires experienced engineers to check and judge the collected images one by one. This process is not only time-consuming but also prone to human error, making it difficult to consistently identify thermal anomalies1.
- Complexity of Equipment: Substations contain a variety of equipment with different thermal characteristics. The complexity and diversity of these components make it challenging to set uniform criteria for anomaly detection and require tailored approaches for different types of equipment2.
Early detection using infrared thermography is essential to prevent equipment failure and ensure the reliability of the power grid. However, these challenges must be addressed to improve the accuracy and effectiveness of thermal monitoring in substations.
2.2. Inaccessibility to critical areas
Some areas of electrical substations can be difficult or even dangerous for personnel to access. This inaccessibility can hinder the inspection and maintenance of equipment in critical areas, leading to poor supervision. Specific examples of inaccessibility challenges include:
- High-Voltage Areas: Areas near high-voltage equipment, such as transformers and circuit breakers, can be hazardous to access without appropriate safety measures. Personnel must navigate around energized components, increasing the risk of electrical hazards3.
- Confined Spaces: Substations often have confined spaces where equipment like switchgear is installed. These areas are challenging to access and require specialized training and equipment to ensure safe entry and exit.
- Environmental Conditions: Adverse weather conditions, such as extreme heat, cold, or storms, impact the accessibility of outdoor substations. Dust and debris can also obstruct pathways and make it difficult to perform inspections and maintenance tasks.
- Complex Layouts: The intricate layout of substations, with multiple interconnected components, makes it challenging to reach certain areas. This complexity requires careful planning and execution of maintenance activities to avoid disrupting operations.
2.3. Need for continuous supervision
Substations operate 24/7 and require continuous supervision to ensure optimal functioning. The increasing complexity of electrical networks and the integration of distributed energy resources necessitate constant monitoring to maintain reliability and address any issues promptly. Continuous condition monitoring using sensors and advanced technologies provides real-time data on critical variables such as temperature, humidity and electrical parameters. This data helps in early detection of potential failures, enabling timely maintenance and reducing the risk of unplanned outages4-5.
Additionally, the growing demand for electrification, such as electric vehicles (EVs) and renewable energy sources, has increased the load on electrical substations. These changes in load over time can create new challenges for substation management. For example:
- Load Variability: The integration of renewable energy sources like solar and wind introduces variability in the power supply, requiring substations to manage fluctuating loads efficiently.
- Increased Demand: The adoption of electric vehicles and the expansion of EV charging infrastructure place additional demand on substations, necessitating upgrades and enhanced monitoring to handle the increased load.
- Grid Stability: The rise in distributed energy resources requires substations to maintain grid stability and ensure the seamless integration of various power sources, which can be complex and demand continuous oversight.
Overall, the need for continuous supervision is driven by the dynamic nature of modern electrical grids and the critical role of substations in maintaining reliable and efficient power distribution.
3. System description
The implementation of an automated visual and thermal monitoring system represents a significant technological advancement in substation monitoring. This system integrates a variety of advanced components and sensors that enable advanced, real-time supervision, detecting anomalies and generating automated responses. Below is a detailed description of the key aspects of the implemented system.
3.1. System components
The automated monitoring system comprises several essential components that work together to provide comprehensive and effective substation supervision:
3.1.1. Visual monitoring sensors: Visual monitoring sensors (Figure 1) are essential for capturing high-resolution images of equipment, connections critical areas within substations. These sensors provide detailed visual information for remote inspection and analysis problem detection. To ensure reliable operation in harsh substation environments, these sensors must comply with IEC61850-3 standards. Enhanced features such as smart infrared capabilities for night vision, automated patrolling presets multiple presets for video analytics with intelligent motion detection functions improve their functionality. These features enable real-time visualization and remote inspection, making them crucial for safety and security asset monitoring in challenging conditions.
3.1.2. Thermal infrared sensors: Thermal sensors (Figure 2) are essential for detecting temperature anomalies in electrical equipment and systems by capturing infrared light emitted by objects, which is invisible to the human eye. These sensors, equipped with mobility systems and communication capabilities via the IEC61850 protocol, are crucial for identifying hotspots and incipient failure modes. They facilitate the detection of overheating and hot spots by capturing temperature-based images and data. Additionally, thermal sensors offer multiple presets, allowing the configuration of different regions of interest per preset and generating temperature readings and thermal alarms associated with each analyzed object, enhancing their functionality and precision. These sensors must be able to operate reliably under harsh conditions, including high levels of EMI, ESD, voltage surges temperature extremes.
3.1.3. Onsite servers: Onsite servers (Figure 3) are crucial for substation monitoring and managing storing data from various sensors and cameras. Local analysis and storage of video and thermal data minimize the use of bandwidth on the operations network and improve system reliability in case of network failures, ensuring continuous, dependable monitoring and alarm notification under challenging conditions. These servers must be designed and built to withstand harsh substation conditions, with no fans or moving parts be equipped with industrial-rated power supplies and solid-state drives. Complying with IEC61850-3 and IEEE1613 standards ensures reliable operation in environments with high levels of EMI, ESD, voltage fluctuations extreme temperatures.
3.1.4. IoT sensors: These sensors (Figure 4) play an essential role in monitoring confined spaces within substations, such as inside switch gears or underground vaults. These sensors provide both thermal and visual data, enhancing situational awareness and asset health management in these challenging environments. These sensors must be designed for electric power applications and must be able to operate reliably under harsh conditions, like high levels of EMI and ESD voltage surges.
3.1.5. Communication systems: All cameras and sensors used in the system are equipped with communication systems that enable real-time data transmission based on the IEC61850 standard to a SCADA interface located in a control center. This facilitates remote supervision and decision-making.
3.1.6. Control platform: A software-based control center (Figure 5) provides the user interface for monitoring and controlling the sensors, visualizing data receiving alerts in case of anomalies.
3.2. System Architecture
The system was designed to deliver analytical signals to the substation's main controller for supervision across various operation levels. The video server not only delivers signals to the local system but also provides real-time video to the control center.
The primary goal of sensor placement is to efficiently supervise and analyze the maximum number of assets and equipment, thereby optimizing resource implementation. The system incorporates three thermal sensors with analytics, covering 576 thermal tracking positions, which monitor 96% of the substation's power equipment. Thermographic sensors for equipment supervision are strategically located to ensure their visual field includes the substation's transformers.
Additionally, six visual cameras with 1152 viewing positions have been installed. These cameras can be remotely accessed via SCADA for visualization or from the central monitoring station or the substation's HMI monitoring. This setup offers significant benefits, including estimated savings on night trips to the substation for verifying maneuvers in robotized metal-clad cells. The placement of these cameras was determined to support operations by providing the control center with a clear view of remotely executed maneuvers. Figure 6 shows the overall architecture of the solution.
4. Results.
Early detection of thermal anomalies in critical power system components was successfully achieved, leading to significant preventive measures and cost savings:
- 34.5 kV Bushing of a 220/110/34.5 kV 100 MVA Transformer: An initial thermal anomaly was identified in the internal part of the bushing. Failure to detect this early could have resulted in a potential fire risk to the transformer, with estimated costs of approximately US$2.5 million.
- 34.5 kV XLPE Power Cable Terminals: Early detection of thermal anomalies in these terminals allowed for scheduled normalization. This preventive action avoided potential failures or emergency de-energization, which could have led to unmet demand and operational disruption due to the outage of the 220/110/34.5 kV 100 MVA transformer.
- 13.8 kV Metalclad Cell at Circuit Exit in XLPE Cable Connection: A thermal anomaly was detected internally, preventing a failure with an estimated potential impact of US$70,000.
These anomalies were promptly reported through the substation's Supervision and Control System (SSC) and communicated via email to the designated engineers, ensuring timely intervention and mitigation of risks.
5. Conclusions and recommendations
The implementation of an automated visual and thermal monitoring system at the Substation has demonstrated substantial benefits in enhancing the reliability and efficiency of substation operations. By integrating high-resolution PTZ and IoT cameras with thermographic sensors, the system has significantly improved the early detection of thermal anomalies and other potential failure modes. The advanced analytics and real-time data transmission to the SCADA system have enabled rapid and informed decision-making, ultimately preventing costly failures and ensuring uninterrupted power supply.
Key achievements of the project include the successful identification of critical thermal anomalies, such as the initial thermal anomaly in the 34.5 kV bushing of a 100 MVA transformer, which averted a potential fire hazard and significant financial loss. The proactive detection and timely response to issues in power cable terminals and metal-clad cells further highlight the system's efficacy in maintaining operational integrity.
The integration of these advanced monitoring technologies offers a robust solution for remote substation supervision. The project's success underscores the importance of continuous innovation and the adoption of cutting-edge technologies in the energy sector to address evolving challenges and ensure the stability of power distribution networks.
Future recommendations include the expansion of such automated systems to other substations within the network, continuous improvement of the analytics algorithms for even more precise anomaly detection and the exploration of additional IoT-based solutions to further enhance the scope and depth of substation monitoring. These steps will contribute to the overarching goal of achieving a resilient and reliable electrical infrastructure capable of meeting the growing demands of modern energy consumption.
This article was originally published on Electric Energy Online: