Industrial Consultancy & Sponsored Research (IC&SR) , IIT Madras
Online Assessment of Moisture in Power Transformer Insulations
Technology Category/Market
Technology: System & method for measuring moisture in power transformer;
Industry: Energy, Power transformers, Instrument transformers, OIP insulation;
Applications: Power transformers, Instrument transformers, OIP insulation;
Market: The global power transformer market is projected to reach $61.95B by 2030, growing at a CAGR of 7.9% during the forecast period (2021-2030).
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Problem Statement
- The insulation in a power transformer must be clean & non contaminated, without any moisture or gases. Assessing the moisture content in insulation is thus a key factor to ensure transformer reliability & longevity.
- In the prior art, it is noted that moisture is measured using offline methods which required taking the transformer off the power line, which may not be desirable.
- The drawbacks encountered in the prior arts are listed herein: 1. The transformer needs to be taken off the power line during measurement and then the measurement may be done at periodic intervals say during servicing of the transformer. 2. Such periodic measurements may miss spikes in the moisture content of the insulation caused by weather conditions including others.
- Hence, there is a need to address above issues.
Technology
- Present patent claimed a method and system for online moisture assessment in the insulation of a transformer, accessible for external monitoring (Refer FIG.1).
- Further the patent describes power transformers and more particularly to measure moisture in insulations of power transfer.
- The system comprises a current transformer, a moisture sensing apparatus placed in proximity to the current transformer comprises alternating layers of insulation & foil, a voltage source connected to the moisture sensing apparatus, a frequency domain spectrometer connected to said moisture sensing apparatus & the power transformer.
Key Features/Value Proposition
Technical Perspective:
- The frequency domain spectrometer connected to the moisture sensing apparatus configured to determine a current across the moisture sensing apparatus against a frequency of the voltage signal based on a loss component in the moisture sensing apparatus and the power transformer.
- The frequency domain spectrometer applies frequencies from 0.1mHz to 1kHz across said alternating layers of insulation and foil, and plots current in said alternating layers of insulation and foil as a function of applied frequency. (Refer Figs. 2 and 3)
- The moisture may be monitored by monitoring tanδ in the moisture sensing apparatus and the transformer, which provides a signal proportional to tanδ.
Industrial Perspective:
- Provides a cost-effective system in simple design, reliable, & mitigate other issues in efficient manner.
Questions about this Technology?
Contact for Licensing
Research Lab
Prof. Jayashankar V
Department of Electrical Engineering.
Intellectual Property
- IITM IDF Ref. 808;
- Patent No: 416718 (Granted)
Technology Readiness Level
TRL- 2/3
Proof of Concept ready & validated