From the experts
Evaluator Guide for Line Sensors
Line sensors for overhead and underground electric distribution circuits are a proven technology. Powerful sensing and long-range communications enable increased visibility of distribution system data for grid operators. But solutions vary, so when evaluating line sensing solutions be sure to consider the following criteria.
| Evaluation Criteria | Questions to Consider |
| 1. Fault Detection Technology | Are current thresholds sufficient for fault detection, or are additional remotely configurable algorithms such as di/dt or % change important? |
| 2. Accuracy | What accuracy is needed for both load data and fault magnitude? Fault magnitude may be used for “Distance to Fault” calculations. |
| 3. Fault Magnitude Range | Sensors vary greatly on fault magnitude range. What is your upper limit required for fault magnitude range? |
| 4. GPS Location and Timing | GPS is an important capability for verifying location and time stamping for sequence of events. Are these requirements? |
| 5. Sampling Rate | Sampling rates for waveforms vary from 20/cycle to 256/cycle. What resolution of waveform data is adequate for your fault analysis? |
| 6. Disturbance Capture | Can sensors can report disturbances in addition to faults with outages? Disturbances can identify precursors to faults. |
| 7. Load Unbalance Analysis | Most sensor systems report load data. Can the system also identify and quantify phase unbalance on 3-phase feeders? |
| 8. LED Visibility | The visibility of LEDs indicating faults can vary greatly.What LED visibility is required for your distances and lighting conditions? |
| 9. Wireless Communications | Which wireless technologies are supported (cellular, mesh)? Are separate gateways and RTUs needed in addition to sensors? |
| 10. Power Requirements | Is the system fully line-powered (at what amperage?), or does it require AC power and use of batteries? |
| 11. Conductor and Equipment Types | Overhead: what is maximum conductor size and voltage? Underground: can you install in livefront and deadfront cabinets? |
| 12. Environmental Ruggedness | Has the system been qualified to operate in harsh environments in terms of temperature, humidity, salt spray, ingress etc.? |
| 13. Field Proven Solution | Has the solution been deployed successfully in the field? What size (number of sensors) are the largest deployments? |
| 14. Product Roadmap | Does the solution provider have a long-term product development plan including updates and enhancements? |
To learn more about best practices and use cases for line sensing visit sentientstage.wpengine.com or email info@sentient-energy.com.
