REL551 1MRK002480-AE 电流差分函数是主控/主控设计

REL561

The current differential function is of master/ master design, evaluating each phase current separately at both ends, utilising both the current amplitude and phase angle (segregated vector comparison).
All currents are Fourier filtered in order to extract the sine and cosine components. The six components, two per phase, are included in a message that is transmitted every 5 ms to the remote terminal over a synchronous 56/64 kbit/s data channel. Also included in the message is information for differential function supervision, CT saturation detection, synchronisation of terminals, transfer trip signals etc.
The differential measurement is stabilised phase by phase with the current scalar sum, see Fig. 1. The degree of stabilisation is settable.
All currents are individually supervised by CT saturation detectors to minimise the requirements to the current transformers. In the event of CT saturation, the degree of stabilisation is increased in the affected phase in both ends, see Fig. 1.

• Line differential functionality comprises;
– phase segregated current differential measurement evaluating both magnitude and phase angle
– increased stabilisation through CT saturation detector
– continuous compensation of transmission delay, enabling use of route switched communication networks
– transfer trip within the digital communication channel
– master/master design
– interfaces for multiplexed connections, direct fibre or pilot wires
• Additional protection functionality such as;
– phase and residual current functions
– breaker failure protection
– fast interbay communication of binary signals
– current circuit supervision
– single- or multi-pole tripping
• Control;
– command control
– autoreclosing
• Monitoring;
– event recorder
– disturbance recorder
– trip value recorder
– status indication of all input and internal binary signals
– presentation of measured mean values of line current and frequency with accuracy up to 0.25%
• Metering;
– pulse counter logic
• Remote-end data communication alternatives;
– multiplexed, dedicated fibre and galvanic channel
– communication channel supervision
• Serial communication;
– SPA or IEC 870-5-103 port (monitoring)
– LON port (control)
• Extensive configuration possibilities by use of internal logical gates, timers and user configurable connections between different functions, binary inputs and outputs
• Several input/output module options including measuring mA input module (for transducers)
• Extensive software ’tool-box’ for monitoring, evaluation and user configuration of the terminal
• Flexible software and hardware