GWZC-9872 Loop Closing Protection Relay Introduction

          The GWZC-9872 Loop Closing Protection Relay is a smart protection device specifically designed for 33kV&66kV high-voltage power grids. It integrates loop synchronization detection and automatic reclosure functions, leveraging high-performance processors to achieve millisecond-level fault judgment. Supporting the optional IEC61850 communication protocol, it features a modular design for flexible configuration, making it suitable for substation loop protection and grid stability enhancement scenarios.

GWZC-9872 Loop Closing Protection Relay Functions and Characteristics​
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Primary Functions (ANSI Codes):​​

1. Inverse-Time Overcurrent Protection with Voltage Blocking (ANSI 51V)
2. Inverse-Time Overcurrent Protection (ANSI 51)
3. Loop Closing Overcurrent Protection (ANSI 51)
4. Loop Closing Zero-Sequence Overcurrent Protection (ANSI 51N)
5. Circuit Breaker Closing Protection (ANSI 67)
6. Zero-Sequence Overcurrent Protection Stage I (ANSI 50N)
7. Zero-Sequence Overcurrent Protection Stage II (ANSI 51N)
8. Inverse-Time Zero-Sequence Overcurrent Protection (ANSI 51N)
9. Overvoltage Protection (ANSI 59)​​
10. Undervoltage Protection (ANSI 27)
11. Potential Transformer Disconnection Protection (ANSI 47)
12. Control Circuit Breaker Protection (ANSI 74)

​Communication Functions:​​

1. Protocols: IEC 61850 (Optional), Modbus, DNP3.0, Ethernet RS485.
2. Interfaces: 2×RJ45 ports for high-speed data exchange (100Mbps), enabling seamless SCADA integration.

​Key Characteristics:​​

1. ​Processing and Memory: 32-bit DSP core with 512KB FRAM (ensures 10-year data retention for fault logs).
2. ​Measurement Accuracy: Monitors |Z|, Φ, I0, V0 with 0.2% precision for reliable fault discrimination.
3. ​Input/Output Flexibility: 7×CT/VT inputs and 10×programmable relays for customizable trip circuits.
4. ​Logic Configuration: LOGIC>EDIT™ graphical editor for easy protection logic programming.
5. ​Trip Circuit: 250V AC/DC rated with seal-in monitoring to prevent nuisance operati ns.
6. ​Time Synchronization: IRIG-B/PPS support (±1μs accuracy) for coordinated event recording.
7. ​Anti-Maloperation: Adaptive TV algorithm filters noise to avoid false triggering.
8. ​Communication: Dual Ethernet and fiber interfaces for redundant connectivity.
9. ​Data Recording: 32-cycle COMTRADE waveform capture for detailed fault analysis.
10. ​Low Power Design: <5W operation (compatible with 24-220V DC/AC supplies).
11. ​EMC Robustness: Class IV certification (IEC 60255-26) for electromagnetic compatibility.
12. ​Environmental Tolerance: Operates from -40°C to +85°C, ensuring reliability in extreme conditions.