Description
ABB RET620E-1G
Technical Specifications:
- Protection Functions: Percentage biased differential, restricted earth fault, overcurrent, and thermal overload.
- Magnetizing Inrush Restraint: Advanced algorithms to prevent false tripping during transformer energization.
- Communication: IEC 61850, IEC 60870-5-103, Modbus.
Functional Features:
- Differential Protection: High-sensitivity internal fault detection.
- Thermal Modeling: Accurate representation of transformer winding and oil temperatures.
- Tap Changer Monitoring: Integration with on-load tap changer (OLTC) control.
Application Scenarios:
- Transmission and distribution substations.
- Industrial step-down transformers.
- Generator step-up (GSU) transformers.
Material Composition & Structural Characteristics:
- High-Speed Processing: Optimized hardware for ultra-fast differential tripping.
- Robust I/O: Sufficient inputs for Buchholz, sudden pressure, and temperature relays.
Working Principle:
Continuously compares the current entering and leaving the transformer. Any discrepancy beyond the set threshold indicates an internal fault, triggering an instantaneous trip. Thermal models simulate the internal temperature based on load current and ambient conditions.
Installation Requirements:
- Ensure correct CT polarity and ratio matching for all transformer windings.
- Connect non-electrical protection devices (e.g., Buchholz) to the designated binary inputs.
Usage Precautions:
- Carefully configure the inrush restraint settings to avoid nuisance trips during energization.
- Perform through-fault and differential tests during commissioning to validate CT circuits.
