How Utilities Can Achieve Automated, Condition-Based Grid Maintenance to Boost Safety and Grid Reliability
Site safety, equipment reliability, and a balanced budget from smooth operations are the cornerstones of a successful power grid. Today’s utility companies face immense challenges with current equipment monitoring practices, such as failures from aging electrical equipment, the need to extend the life of critical assets, and carrying out ongoing lifecycle management that is essential to having a reliable grid.
Today, more than ever, power utilities want to increase grid reliability while reducing costs. A typical electrical grid in America is made up of thousands of geographically dispersed substations that require visual and thermal inspections to ensure the health of critical assets. In the U.S., much of the equipment is 25 years or older and requires constant monitoring and condition-based maintenance to retain reliability.
A major obstacle for U.S. utilities is having limited manpower for maintenance, as many workers have reached retirement without a pool of adequate replacement workers. The shortage of personnel resources means a lack of availability to perform the required calendar-based maintenance practices of the past to protect assets. Visiting sites to manually inspect and see what’s happening at the remote substation is now positioned as a large concern, as there is limited manpower available to carry out in-person checks. Current and future needs of the utility industry include around-the-clock critical asset monitoring and a condition-based maintenance program.
Another daunting challenge within the utility industry is keeping a handle on equipment failure science. That can mean missing critical warnings and impending failure signs ahead of catastrophic breakdowns by using only manual thermal inspection personnel, who need to be in the right place at the right time to catch the fault. The benefit of moving to a touchless monitoring system is the ability to have a timely response to conditions in a substation or vault.
Utilities Turning to Automation
Intelligent sensors provide continuous thermal monitoring and analytics, allowing utilities to safely prevent failures and schedule condition-based maintenance. These intelligent systems increase grid reliability while reducing operating and maintenance (O&M) costs. An intelligent system, featuring a utility-grade touchless monitoring solution, enables remote substation inspections that can cut travel costs significantly while extending more strategic duties of staff. This is compared to manual inspections that require a significant amount of travel time with costs taking up to 20% of all O&M budgets.
The system consists of monitoring software, automated thermal cameras, and advance analytics that together help utilities to improve grid reliability. Advanced visualization with machine learning provides live streaming snapshots (Figure 1) and alarms that integrate with supervisory control and data acquisition (SCADA) and asset management systems.
Prioritizing maintenance based on asset health data rather than time is key to meeting the challenge. The use of real-time data to prioritize asset maintenance will reduce potential outages and helps with the planning of replacement of key equipment. Utilities can expect up to a 20% decrease in breakdowns due to real-time alarms that identify potential issues before they occur.
Touchless and Timeless
At a typical substation, sensors can be mounted on any A-frame or post that’s available within the yard, and because they use infrared technology, they are both non-invasive and non-intrusive. Expert staff works with the utility to ensure they have the best field of view of all the key components with a minimal number of sensors to reduce cost and improve return on investment (ROI). The automated system monitors all key components within a yard to provide real-time thermal data that is necessary to move from time-based maintenance to condition-based maintenance.
A huge benefit to utilities is the increase in safety for personnel and security at the site. The monitoring system will allow the utility to see who is at the substation at all times. It can ensure that safety protocols are being followed and that only authorized personnel and vehicles are at the site. It ensures that the conditions at the site are safe before personnel are allowed to enter.
A 2011 industry study revealed that transformer bushings lead up to 17% of catastrophic failures within transformers. The thermal analytics integrated with the touchless monitoring system allows the system to monitor multiple areas within the transformer, including the high-failure-rate components such as bushings, the cooling system, and the load-tap changer. Analytics can then be set, and alarming performed in real-time. The same sensor can be utilized to monitor multiple key components within the transformer for early warning signs of impending failure.
The intelligent thermal sensor has been designed to meet and exceed utility grade specifications and has the capability to integrate the thermal data and real-time alarms into SCADA systems and asset management applications. With programmable pan-tilt-zoom features, it can monitor up to 192 points of interest from a single sensor.
Early warning detection is a key component to moving to condition-based maintenance. In a typical substation, thermal and visual sensors are deployed in the yard and situated for optimal monitoring of the assets (Figure 2). The digital video server (DVS) is a gateway that sits inside the substation and manages the sensors, the recordings, and analytics. The DVS communicates with DNP, Modbus, or IEC 61850 protocol, allowing for the seamless integration into SCADA or asset management systems. In this way, the maintenance team is immediately made aware of any conditions at the substation that need attention. This could be anything from an overheating bushing or arrestor to an intruder at the substation.
Raw data gathered from the monitoring system sensors is stored inside the gateway and sent to the asset management system. This allows the utility’s staff to trend the data that then goes into an asset performance management (APM) system or customized asset performance maintenance software, allowing the utility to gracefully make the move from time-based maintenance to a condition-based maintenance approach.
Receiving early warning detection is key, and the gateway performs all necessary actions to provide this information to the utility. Depending on the utility, not all substations have high-speed network connectivity, so the gateway allows each instance to choose to either stream video in real-time or to send snapshots to preserve bandwidth. Having a distributed architecture where the processing is done at the network edge, allows utilities to control the monitoring of specific assets as they deploy these types of solutions.
With a touchless thermal sensor, a commonly deployed scenario consists of a simple run circle sequence that is programmed into the unit to patrol various assets in the substation to monitor and gather temperature data. The patrol sequence incorporates specific equipment targets to populate and trend the temperature data into the APM system. The flexibility of the system allows utilities to collect asset health data in real-time without having to go to the site. The primary purpose of collecting data and storing it in a secure gateway is to build actionable maintenance items and to help the utility keep the grid running reliably.
Visualizing the Data
Analytics are central to providing early warnings, well before accidents and failures happen. A role-based asset health dashboard is vital to track these warnings and establish a condition-based maintenance program. It collects alarms and data in real-time and helps to prioritize maintenance scheduling.
The dashboard acts as a single pane of glass, collecting and managing data from the enterprise systems that are already in existence within the utility, then allowing the O&M team and the asset management team to prioritize and develop mutual key performance indicators (KPIs) that are needed to run the business. The result is an operations dashboard system view that can integrate multiple areas of information into one. The team can then drill into specific assets to prioritize which asset needs maintenance, while considering multiple data points, whether it’s online oil sample data, bushing temperature information, visual and thermal sensor views, as well as aging information, all within a single pane of glass.
The utility can then prioritize maintenance and move to condition-based maintenance approaches. The system provides a unique maintenance dashboard of alarm details. It allows operators to prioritize which assets need maintenance and how much time they have before they could potentially fail.
Achieving the Benefits of Condition-Based Maintenance
A condition-based maintenance program offers utilities numerous advantages over a time-based approach. By reducing the need for costly truck rolls and physical inspections, utilities can reduce overall maintenance costs, improve reliability and safety, and allocate scarce resources in response to known issues. Effectively transitioning doesn’t happen overnight, but by starting small, collecting the right data, and verifying the accuracy of the data, utilities can successfully implement the new approach and achieve the full benefits of a condition-based maintenance strategy.
—Jason Howarth is director, Teledyne FLIR / Automated & Integrated Solutions + Optical Gas Imaging, and Angelo Rizzo is president and CEO of Systems With Intelligence (SWI).