Smart Substation Voltage Transformer (VT) Digital Interface Solution

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.

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 &plusmn;1&mu;s (based on IRIG-B/PTP), guaranteeing timestamp consistency for system-wide data.

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.

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: &plusmn;6kV/&plusmn;4kV, suitable for complex electromagnetic environments.

Protocol Support & Core Specifications

Category

Parameter

Performance Indicator

Communication Protocol

IEC 61850-9-2LE

Supported

Sampled Value (SV)

Sampling Rate

4000Hz

GOOSE Performance

Trip Command Delay

<3ms

Time Synchronization

Real-time Clock Accuracy

&plusmn;1&mu;s (IRIG-B/PTP)

Measurement Accuracy

Phase Angle Error

<&plusmn;0.2&deg;

EMC Level

RF Immunity

Class IV (10V/m, 80MHz-1GHz)

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).