- Product Specs at a Glance
- NDL - Network Digital Link
- OPV - Optimised Protection Variant
- MDL - Multi-Point Digital Link
- Antenna Range
- CCMS - Configuration Control & Monitoring Services
- Background Technology
Optimised Protection Variant (OPV)
The OPV (Optimised Protection Variant) is designed to support a pair of power line protection relays (eg General Electric L90). The relays typically use the radio link to exchange data packets at 64 kb/s containing power system voltage, current magnitude and phase angle information. This information is used to determine whether there is an unexpected event or power loss on the line, and to transmit information used to trip circuit breakers when a fault on the line is detected. Up to three OPV protection circuit links may be cascaded in order to handle longer ranges and difficult terrain.
The interface required for the protection relays is typically a synchronous serial interface using V.11 (RS422) signalling, at a 64 kb/s transmission rate. However other interfaces can also be accommodated.
The total link latency must not be greater than 2 power system cycles (i.e. 40 ms in each direction) and the jitter must not be greater than 130 microseconds. Since up to three protection circuit links may be cascaded, the latency of each link must therefore be less than 13 ms. Similarly the combined jitter of these links must not exceed 130 microseconds.