Travelling Wave Capture with Optical Sensing
Installation
Optical sensors installed at ground potential
Safe design - no electronics or conductive wires at/to the high voltage
Electric field (voltage) based approach - minimizes need for sensors (1 per substation bus) and can also be integrated with magnetic field sensors
High sampling rate - optical electric field sensors sample at 1 million samples per second
User selectable triggers to detect events
1 microsecond GPS time tagging accuracy allows fault location within 500 feet and enables disturbance propagation monitoring (stability analysis) across the grid
Low cost installation - no possible adverse effect on relays, instrument transformers or other HV equipment
NGFS sensors can be mounted on a variety of structures
Operation
Events trigger waveform capture at one or more measurement nodes
High resolution events are sent wirelessly (or via fiber) to data repository
System notifies user (via email or text) of event(s) with initial characterization (fault, energization, etc.) and location estimate
Signal processing unit at ground potential
Connects via fiber (all dielectric) to the passive optical sensors
Accessible for maintenance
Event Analysis
User utility allows visualization for waveform analysis
Events are easily sorted and uploaded from data repository for analysis
Triggered events from any nodes can be compared
Easy zoom and cursor placement enables refined timing/distance estimates
Single ended or double ended analysis is supported
Software calculates distance to fault within 1000 feet
Mapping module pinpoints location and outputs latitude and longitude information
Asset management is facilitated by microsecond resolution for assessment of relay/breaker/protection operation
Incipient faults can be targeted for mitigation (eg occasional arcing in defective polluted insulator etc)
