Guide to Selecting and Deploying an Online Monitoring System for DC Bias in Transformers
Date: June 14, 2026, 02:12:02
- Prerequisites for Model Selection: First, assess whether there is a risk of DC magnetic field interference in your area—specifically, sites located near DC transmission grounding electrodes, areas with active geomagnetic induced currents, or sites where abnormal increases in transformer noise and vibration have been observed in the past.
- Monitoring Plan: A two-dimensional solution combining a neutral-point DC current sensor and vibration spectrum analysis, which not only directly measures the magnitude of DC bias but also verifies the extent of the bias’s impact on the transformer through vibration characteristics
- Deployment Priority: Substations near DC grounding electrodes → High-latitude regions with active geomagnetic induction → Main transformers rated at 220 kV and above
1. Selection of core indicators
| norm | fundamental requirement |
|---|---|
| DC current measurement range | Ranging from a few amperes to tens of amperes |
| Vibration Spectrum Analysis | Covers even-order harmonic frequency bands (50 Hz, 150 Hz, etc.) |
| communication protocols | Modbus RTU/TCP |
2. Frequently Asked Questions FAQ
2.1 Q: Can DC bias current monitoring and core ground current monitoring be combined?
Answer: The physical quantities being monitored are different (neutral-point DC vs. ground loop current), and the sensor installation locations are also different. The two types of data can be aggregated on the same backend platform, but they are independent at the sensor level.
2.2 Q: Does DC bias monitoring require calibration?
Answer: We recommend calibrating DC current sensors once a year. Vibration sensors are passive devices and do not require periodic calibration.
Additional Information
This content provides additional technical details and an analysis of application scenarios. For specific selection and configuration plans, please consult with your supplier and confirm the details based on your actual equipment to ensure the solution is tailored to your needs and feasible. Best practices may vary across different application scenarios; we recommend referring to engineering case studies in similar scenarios for comparative evaluation.
Disclaimer: The content of this article is for technical exchanges and reference only, and does not constitute any form of procurement commitment or contract offer. Product technical parameters, configuration programs and prices are subject to the actual signed contracts and technical agreements.
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