I. Core Principle
The transformer winding deformation tester determines the deformation of the winding by measuring the frequency response characteristics (sweeping frequency impedance spectrum) of the winding. When the winding experiences displacement, distortion, or inter-turn short circuit, its distributed inductance and capacitance parameters will change, resulting in a significant deviation in the frequency response curve, thereby enabling the identification of winding deformation issues.
II. Key Evaluation Indicators
Frequency Range: Determines the detection sensitivity. A wide frequency band (10Hz – 2MHz) can comprehensively assess the winding deformation at different positions.
Scan Points: Affects the resolution of the curve. Typically, the scan points should be ≥ 200.
Dynamic Range: Determines the ability to identify minor deformations. It should be ≥ 100dB.
Repeatability Error: Reflects the stability of the instrument. The error should be < 0.5%.
Anti-interference Capacity: This is a key indicator for on-site testing. The instrument must have a good electromagnetic compatibility design.
III. Selection Method (Three-level Evaluation Method)
Level: Matching of basic technical parameters
1. Applicable Transformer Range
Voltage Level: Needs to cover 0.4kV – 1000kV
Capacity Range: Should cover 50kVA – 1000MVA
Winding Type: Can test windings in Y, D, Z, single-phase, autotransformer, and other connection forms
2. Core Hardware Requirements
Output Impedance: Uses 50Ω standard impedance, matching the common standards of the power industry
Injection Signal: Voltage 10Vpp, Current 20mA (typical value)
Frequency Response Measurement: Amplitude Accuracy ±0.5dB, Phase Accuracy ±0.5°
3. Test Efficiency Indicators
Single-phase Measurement Time: < 3 minutes (1kHz – 2MHz, 2000 points)
Data Storage: Can store ≥ 1000 sets of complete test data
Connection Method: Supports single-ended method, differential method, and other connection methods
Second Level: In-depth Evaluation of Function and Performance
1. Diagnostic Analysis Function
(1) Essential Functions
Correlation Coefficient Calculation (RLC Algorithm)
Spectrum Curve Overlap Comparison
Historical Data Trend Analysis
Automatically Generate Standard Format Report
(2) Advanced Functions (Recommended)
Three-dimensional Spectrum Analysis (Amplitude Frequency, Phase Frequency, Impedance)
Artificial Intelligence Assisted Diagnosis
Deformation Degree Quantitative Evaluation
Fault Type Automatic Identification
2. Field Adaptability
Operating Temperature: -20°C to + 50°C
Protection Grade: IP65 (Dust and Waterproof)
Power Supply Method: Built-in Lithium Battery (Battery Life ≥ 8 hours) + AC Adapter
Portability: Overall Machine Weight < 10kg, Integrated Design
3. Data Management and Compatibility
Support IEEE/CSV Standard Data Format
Compatible with DL/T 911 Historical Data
Wireless Data Transmission Function (Wi-Fi / Bluetooth)
Complementary Professional Analysis Software (Windows / Mobile)
Third Level: Reliability Verification Evaluation
1. Qualifications and Certifications
Have a third-party test report issued by a provincial-level or above power research institute
Contain Type Test Reports for EMC and Environmental Adaptability
Have a CNAS Accredited Metrological Calibration Certificate
2. Cases and Verification
Real Measurement Cases of Similar Transformers ≥ 50
Have a Verification Report Comparing with Short-circuit Test Results
Accurate Rate of Inspection Verification ≥ 90%
3. Technical Support System
Can Provide On-site Application Training
Equipped with Diagnostic Analysis Support Team
Promise Free Software Upgrade
Have a Typical Case Database
Post time: Dec-09-2025