Description
ABB RET650
Technical Specifications:
- Protection Functions: Differential protection, restricted earth fault, overcurrent, and thermal overload.
- Communication: IEC 61850, IEC 60870-5-103, Modbus, and DNP3.
- Inputs: Multiple current and voltage channels for comprehensive transformer monitoring.
Functional Features:
- Advanced Differential Protection: Harmonic restraint and blocking to prevent false tripping during transformer energization (inrush) and overexcitation.
- Thermal Modeling: Built-in transformer thermal replica to monitor winding and oil temperatures based on load.
- Tap Changer Monitoring: Interfaces with on-load tap changer (OLTC) controllers for integrated control.
Application Scenarios:
Power transformers in transmission and distribution substations, generator step-up (GSU) transformers, and large industrial power transformers.
Performance Parameters:
- Sensitivity: Highly sensitive differential protection for detecting low-level internal winding faults.
- Reliability: Continuous self-monitoring of hardware and software to ensure operational readiness.
Material Composition:
Ruggedized metal enclosure with advanced EMC shielding to operate reliably in high-noise substation environments.
Structural Features:
Features a large graphical HMI, intuitive navigation keys, and a withdrawable plug-in design for easy maintenance.
Working Principle:
Continuously compares the current entering and leaving the transformer. Any discrepancy indicates an internal fault, triggering a high-speed trip. It also monitors thermal and electrical parameters to predict maintenance needs.
Installation Requirements:
Strict adherence to CT polarity and wiring diagrams is mandatory. Ensure proper grounding of the relay chassis and secondary circuits.
Usage Precautions:
Perform comprehensive secondary injection testing to verify differential characteristics and harmonic blocking before commissioning. Never bypass differential protection during normal operation.
