P37.117: Using Voltage and Current Measurements for Monitoring Asset Conditions
Objective
The project objective is to utilize existing data streams of voltage and current to assess the health of substation equipment. The focus of this project is on voltage and current signals already being measured for other functions (i.e., protection, control, metering) and readily available in many substations. Research interests include enhanced understanding of online voltage and current waveforms as indicators of asset health, evaluation of the effectiveness of commercial solutions (if available), and development of novel techniques. The overall, multi-year goal of this project is to create guidelines to inform member utilities on ways they may be able to monitor incipient asset failure in their substations using these data streams.
Research Value
- Increased reliability of power supply through early detection of asset failures
- Enhanced safety by reducing unexpected catastrophic equipment failure
- Improved risk assessment of substation assets using minimal quantities and types of data
- Lower operations and maintenance (O&M) costs for monitoring major substation equipment health
- Reduced replacement costs by avoiding collateral damage from catastrophic equipment failure
Approach
Capture coupling capacitive voltage transformers (CCVT)/voltage transformers (VT) signals during CCVT/VT degradation: This project aims to record voltage waveform signatures during instrument transformer failure to enable future creation of thresholds, algorithms, or methods that could detect similar failures in the future. Research may be performed on a combination of computer models and some quantity of physical assets, depending upon the level of member engagement. The project intends to stress CCVTs or VTs to accelerate their aging through thermal cycling, overvoltage stress, or other means. As the devices are pushed into failure modes, comparing online data readings to baseline may offer opportunities to identify voltage signatures indicative of failure. The forensic examination of failed devices may further identify
Evaluate capabilities of instrumentation used to capture secondary voltage signals: This project plans to enhance the industry’s understanding of how the selection of ancillary instruments used to capture CCVT/VT voltage signals may impact CCVT/VT health monitoring. Examples of instruments connected to voltage device secondaries may include power quality monitors, relays, phasor measurement units (PMUs), or other data recorders. The impact of built-in device filtering, sampling rate, and triggering capabilities are of particular interest as they relate to signal quality for CCVT/VT health monitoring. The goal of this task is to improve our understanding of the capabilities and limitations of repurposing specific pieces of ancillary equipment to monitor VT/CCVT signal health with data typically captured by these devices for other purposes.
Anticipated Deliverables
| Deliverable | Date |
|---|---|
| Voltage Transformer Accelerated Aging Tests (Technical Update) | 12/31/2026 |
| Voltage Transformer Condition Monitoring Implementation Guide (Guide) | 12/31/2026 |
Past EPRI Work on Topic
| Product ID | Title | Description | Published Date |
|---|---|---|---|
| 3002030062 | Evaluation of CCVT Secondary Voltage Recordings During Power System Phenomena | This is a report documenting the results of recording a healthy CCVT’s signals during the occurrence of imposed defects in nearby systems or equipment at EPRI’s 138-kV research substation. The planned 2025–2026 baseline testing and secondary signal recording associated with accelerated aging tests will build upon lessons learned from this effort. | December 2024 |
| 3002027138 | Using Voltages and Currents:Applicable Assets | This report is a review of literature to determine which substation assets are likely candidates for health monitoring using voltage and current signals. The selection of CCVTs/VTs for P37.117’s 2025-2026 evaluation is based in part on the outcomesof this report. | December 2023 |
| TR-100205 | Workshop Proceedings: Failed High-Voltage Instrument Transformers | These workshop proceedings describe utility field failures, identify failure modes, and identify possible mitigation measures associated with high voltage current and potential transformers. The field data from these proceedings may inform failure modes identified in upcoming P37.117 testing. | January 1992 |
| TR-113649 | Proceedings: High Voltage Current Transformers and Bushings: Failure Prediction and Prevention Symposium | These conference proceedings include several reports and papers documenting high voltage Current Transformer (CT) accelerated aging tests sponsored by EPRI, including approach, monitoring techniques, and analysis of failed units. The lessons learned from accelerated aging tests in this space inform approaches to accelerated aging test for other instrument transformers in 2025+ forP37.117. | December 1999 |