ABB REL 356

ABB REL 356 Current Differential Protection
1-2
Product Overview and Specifications
For an internal fault, the currents are essentially in phase at the terminals of the transmission line. For an external fault,
the currents are 180° out of phase. Figure 1-1 illustrates the concept.
Figure 1-1. Fault Recognition
Standard Features
· Current differential protection algorithm
· Numerical processing
· Multiple microprocessor design
· Current change detectors and selectable voltage change detectors
· Direct transfer trip
· Channel independent high set phase and ground overcurrent units, directional or non-directional
· Fault locator
· High speed operation, typical 1½ cycle
· Close into fault detection
· Open breaker and stub bus trip
· Contact outputs for
· Breaker trip
· General start
· Breaker failure initiation
· Reclose initiate and block
· System failure alarm
· Channel failure alarm
· Trip alarm
· RS232C series communications port
· Adaptive protection communication channel delay compensation
· Digital fault recording
· 10 analog waveforms from local and remote measurements
· 64 digital channels
· 12 samples per cycle
· Local HMI interface
· 19” rack mounting
Communication Channel Options
REL 356 is available with eight different communication interfaces:
· 9600 bps audiotone
· British Telecom audiotone
· 56/64 kbps direct digital
· 56/64 kbps 820 nm multi-mode fiber
· 56/64 kbps 1300 nm single mode fiber, short reach
· 56/64 kbps 1300 nm single mode fiber, medium reach
· 56/64 kbps 1300 nm single mode fiber, long reach
· 56/64 kbps direct digital with G.703 interface