Smart Substation Voltage Transformer (VT) Digital Interface Solution

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Smart Substation Digital Interface Scheme​
​Technical Focus:​​ Deep integration of the IEC 61850 protocol
This solution deeply integrates the IEC 61850 standard to build a future-oriented digital transformer system, achieving device interoperability, efficient data sharing, and intelligent system operation and maintenance.

​Key Innovations​

1. ​Composite Sensing Technology​
• ​Rogowski Coil + Capacitive Voltage Divider Composite Sensing:​​ Combines the Rogowski coil's wide frequency response (suitable for transient harmonics) with the high accuracy of capacitive voltage division, achieving non-saturated measurement of full-frequency signals (0.5Hz ~ 3kHz), eliminating ferroresonance risks inherent in traditional iron-core transformers.
2. ​Embedded High-Precision Merging Unit (MU)​​
• Supports IEC 61850-9-2LE Sampled Value (SV) transmission protocol.
• Sampling rate: 4000Hz, meeting transient process analysis requirements.
• GOOSE tripping delay <3ms, ensuring fast response of protection systems.
• Real-time clock synchronization accuracy ±1μs (based on IRIG-B/PTP), guaranteeing timestamp consistency for system-wide data.
3. ​Intelligent Self-Diagnosis System​
• ​Ferroresonance Online Early Warning:​​ Monitors characteristic resonance frequencies (30-300Hz) in real-time and actively triggers damping strategies.
• ​Winding Temperature Rise Warning:​​ Embeds temperature sensors to dynamically analyze temperature rise curves and predict insulation aging risks.
• ​Fault Location:​​ Achieves bay-level precision, supporting remote operation and maintenance decisions.
4. ​Industrial-Grade Electromagnetic Compatibility (EMC)​​
• EMC Immunity Level: Class IV (Complies with GB/T 17626):
• Radio Frequency Electromagnetic Field Immunity: 10V/m (80MHz~1GHz)
• Surge/EFT Immunity: ±6kV/±4kV, suitable for complex electromagnetic environments.

​Protocol Support & Core Specifications​

​Technical Value​

1. ​Fully Digital Architecture:​​
   Replaces analog signal cables with direct digital outputs (SV) from the MU, reducing system costs and operation & maintenance complexity.
2. ​Enhanced Safety & Reliability:​​
   Self-diagnosis functions detect 90% of potential faults in advance. Class IV EMC immunity withstands strong electromagnetic interference within substations.
3. ​System Compatibility:​​
   Deeply integrates the IEC 61850 protocol stack for seamless connection to various smart substation monitoring/protection systems (e.g., Siemens, ABB, NARI Group).