Brian P Kelley, P.E. (IL), Vice President and Project Director, Sargent & Lundy
Utilities and consumers are increasingly focused on developing and utilizing a Smart Grid, from smart meters and smart lighting to self-healing networks and efficient utilization of distributed energy resources. But at the forefront of this grid transformation are smart substations. Utilities are turning to smart substations to better monitor and control substation equipment, thereby allowing them to improve the performance of existing and new assets. Smart substations contain smart devices installed on the power delivery system in order to provide enhanced substation protection, control, and monitoring. Key mechanisms of a smart substation include a smart dashboard and device monitoring systems. While installing the smart devices allows the substation to become data-rich, that doesn’t make it smart. What makes it smart is the transformation of smart device data into information that allows the utility to make informed decisions about system operations and preventative and corrective maintenance.
"The improved ability to monitor and control substation equipment using transformer monitoring, battery monitoring, and advanced relaying can increase efficiency and improve system operations"
With a smart substation, collecting and understanding data, then making decisions based on it are critical components to increasing overall efficiency and providing greater value. The utilization of modern microprocessor relaying with an IP over fiber interface to a SCADA network increases visibility and control. Utility IT groups are now responsible for transforming the substation data into information-rich dashboards and notifications that promote proactive control of systems and device conditions, thereby helping prevent outages and equipment damage. This smart substation dashboard can be designed to provide a color-coded system that quickly identifies abnormal conditions, as well as minor and major issues, and automatically alerts the utility via email or text. The dashboard also allows the utility to view historical trends related to energy use and system performance, furthering the utility’s efforts to plan for and manage long-range system capacity planning.
One of the significant ways utilities are improving system and equipment performance is through equipment monitoring. Using new monitoring systems in conjunction with a substation computer and associated diagnostic tools allows utilities to perform automated analysis on the health of substation components. The asset health monitoring software creates trending, analysis, and problem notification reports for substation equipment, including transformers and station batteries. Transformer monitoring includes automated gas alarms that produce email notifications, bushing monitoring, and fault counter and recorder data. When applied, this information can prolong the lifespan of new and existing transformers by monitoring oil sediment temperature, nitrogen levels, and dissolved gases that indicate internal arcing. The transformer monitoring systems can be specified and included in new transformers—direct from the factory—or can be field-added to existing transformers. The monitoring systems are then connected back to the control house and SCADA system via fiber. Battery monitoring systems operate in a similar fashion; they provide 24/7 monitoring of string voltage, cell voltage and float current, provide high-resolution ohmic measurement for each cell, ambient and pilot temperatures, and electrolyte monitoring. The overall goal of these monitoring systems is to improve visibility of equipment health and maintenance requirements.
Utilities are better able to predict and respond to system issues when they have a better understanding of equipment performance, maintenance requirements, and overall system operations. The improved ability to monitor and control substation equipment using transformer monitoring, battery monitoring, and advanced relaying can increase efficiency and improve system operations. Smart substations are still a relatively new concept, and their monitoring systems and capabilities are still being perfected, but no one can question the value they bring to a utility.