Numerical Protection Relays
Generator Protection Relay
The Siemens modular digital relay provide:
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Short-circuit protection, including overcurrent, impedance, and differential schemes
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Stator and rotor ground-fault detection (both directional and 100% coverage)
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Under-/over-excitation protection, reverse-power protection, and unbalanced load detection
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Over-/under-frequency and voltage protection, load decoupling, breaker failure, re‑closing, inadvertent energization prevention, and synchronization assistance
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Flexible hardware supports up to 16 current transformers and 8 voltage transformers.
- Ethernet (RJ45) interface with protocols including IEC 61850, Modbus, DNP3, Profinet, and redundancy features (PRP, HSR)
Transformer Protection Relay
Siemens transformer differential protection relay, designed specifically to safeguard two-winding transformers provides:
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Transformer Differential Protection
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Restricted Ground Fault (RGF) Protection
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Overcurrent Protection
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Over/Under Voltage Protection
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Over/Under Frequency Protection
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Overexcitation (V/Hz) Protection
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Unbalanced Load Protection
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Thermal Overload Protection
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Arc Flash Detection
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Breaker Failure Protection
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Features built-in Ethernet and supports IEC 61850 (with GOOSE), IEC 60870-5-103/104, Modbus TCP, DNP3, and PROFINET IO via optional pluggable modules.
Feeder/Motor Protection Relay
Siemens protection relay provides:
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Directional & Non-Directional Overcurrent
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Ground Fault Protection
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Fault Locator
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Arc Protection
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Voltage & Frequency Protection
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Capacitor Bank Protection
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Breaker Management & Control
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Fits a 1/3 × 19-inch module with I/O configurations ranging from 4 to 8 CT inputs and various binary I/O options.
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Built-in Ethernet interface supports IEC 61850 (with GOOSE), and optional modules for IEC 60870, Modbus TCP, DNP3, PROFINET IO.
Protection Relays with Cyber Security
Siemens Protection Relays provides:
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Phase Overcurrent (50/51)
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Earth Fault Overcurrent (50N/51N)
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Directional Overcurrent (67/67N)
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Transformer Differential (87T)
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Restricted Ground Fault (64R)
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Distance Protection (21)
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Overvoltage / Undervoltage (59/27)
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Rate of Change of Frequency (ROCOF) (81R)
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Breaker Failure (50BF)
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Synchrocheck / Synchronism Supervision (25)
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Encrypted Protocols – Supports TLS/HTTPS for web access and secure file transfers.
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Secure IEC 61850 (GOOSE & MMS) – With encryption and authentication for substation communication.
