P37.105: Balance of Substations: Batteries, Arresters and Ratings
Objective
The project objective is to identify opportunities to extend the service life of select assets while evaluating technologies, systems, and methodologies that may impact overall substation performance. The research focuses on equipment and technologies that enhance substations reliability, safety, and longevity but may not align with the scope of other existing EPRI projects. Research topics are member driven and may vary annually based on evolving priorities and interests. Recent areas of interest include battery monitoring systems, surge arresters and surge arrester failure monitoring, station ampacity rating methodologies, and the use of robotics for substation inspection applications.
Research Value
- Maximize the service life of existing station assets by evaluating select technologies, including battery system monitoring and surge arrester condition monitoring
- Enable utilities to make informed decisions regarding substation robotics deployment by presenting empirical data and field-based case studies associated with robotics inspection and monitoring applications
- Provide thermal models and guidance to optimize power output when applying station ampacity rating methodologies to the transmission system
Approach
Evaluate commercial surge arrester monitors: This multi-year task evaluates several commercially available surge arrester monitors for performance and effectiveness, leveraging EPRI’s long standing research in surge arrester failures and associated metrics. The approach involves evaluating each monitor through a combination of lab-based unit testing and substation deployment assessments.
Assess the performance of battery monitoring systems: This multi-year task assesses battery monitoring systems from several different manufacturers. Use bench testing and battery emulators to develop repeatable test plans that enable comparison between systems that may otherwise require different battery chemistries or configurations.
De-risk robotic applications for substation inspections: This research quantifies the capabilities and limitations of commercially available autonomous mobile robots and autonomous data assessment for substation inspections. This task collects empirical data from extended durations of robotics deployment in EPRI’s 138kV research substation, from novel applications within EPRI’s broader research portfolio, and from case studies presented by utility members.
Update EPRI’s Increased Powerflow Guidebook and Calculator for 2027: This guidebook, updated annually with the latest standards and requirements, advises utilities on how to calculate and apply ampacity ratings to substation equipment pursuant to NERC requirements and FERC order 881. The web-based calculator implements the equations and methodologies described in the Increased Powerflow Guidebook in a user-friendly interface that partially automates compliance documentation for utility members.
Anticipated Deliverables
| Deliverable | Date |
|---|---|
| Surge Arrester Health Characterization Using Commercial Technology (Technical Update) | 12/31/2027 |
| EPRI Increased Power Flow Guidebook – 2027: Increasing Power Flow in Lines, Cables, and Substations (Technical Update) | 12/31/2027 |
| The Platinum Book Calculator (Software) | 12/31/2027 |
Past EPRI Work on Topic
| Product ID | Title | Description | Published Date |
|---|---|---|---|
| 3002030041 | Battery Monitoring Systems Procurement Guide for Substation Applications | This is a quick reference guide describing considerations when selecting and procuring a battery monitoring system for an existing battery bank installation to prevent unexpected project delays. | June 2024 |
| 3002032926 | Arrester Condition and Failure Monitoring | This report describes multi-year efforts by EPRI to evaluate the online metrics associated with surge arrester health. | December 2025 |
| 3002030040 | Robotics Assisting Electrical Substation Inspectors | This report documents the results of a quadruped robot deployment performed in EPRI’s 138kV research substation. Various tests evaluated the capabilities and limitations of the robot in a substation environment for navigation, data collection, and reporting, under varied environmental conditions. | November 2024 |
| 3002032786 | EPRI Increased Power Flow Guidebook – 2025: Increasing Power Flow in Lines, Cables, and Substations |
This guidebook is a best practice reference on increasing power flow capabilities of overhead transmission lines, underground cables, power transformers, and substation equipment. | December 2025 |
| 3002031149 | EPRI Facilitating Adoption of FERC Order 881 for Substation Equipment – 2024 Update | This document explores the intricacies of Advanced Line Ratings and their application at transmission utilities including Ambient Air Adjusted ratings of substation assets such as switches, breakers, and bus materials. | December 2024 |