Perspective, J Electr Eng Electron Technol Vol: 12 Issue: 1
Condition Assessment of Power Transformers using Dissolved Gas Analysis
Jennifer Ayain*
Computer Science Department, School of Computer Science, Bina Nusantara University, Jakarta, Indonesia
*Corresponding Author:Jennifer Ayain
Computer Science Department
School of Computer Science, Bina Nusantara University
Jakarta, Indonesia
E-mail: ayainj@binus.edu
Received date: 14 February, 2023, Manuscript No. JEEET-23-96646;
Editor assigned date: 16 February, 2023, PreQC No. JEEET-23-96646(PQ);
Reviewed date: 03 March, 2023, QC No. JEEET-23-96646;
Revised date: 10 March, 2023, Manuscript No. JEEET-23-96646(R);
Published date: 20-March, 2023, DOI: 10.4172/2325-9838.1000942.
Citation: Ayain J (2023) Condition Assessment of Power Transformers using Dissolved Gas Analysis. J Electr Eng Electron Technol 12:2.
Abstract
Condition Assessment of Power Transformers using Dissolved Gas Analysis (DGA) is a widely used technique for detecting incipient faults in transformers. Power transformers are acute components of power systems and their failure can result in significant financial losses and even pose a threat to human life. DGA is a non-destructive, cost-effective and reliable method for assessing the condition of transformers. Dissolved gas analysis is based on the fact that when a transformer experiences a fault, gases are generated due to the breakdown of the insulating oil and solid insulation materials. These gases dissolve in the transformer oil and their presence can be used as an indicator of the type and severity of the fault. The most common gases generated in transformers during faults are Hydrogen (H2 ), Methane (CH4 ), Ethylene (C2H4 ), Acetylene (C2H2 ), Carbon Monoxide (CO), Carbon Dioxide (CO2 ), and Oxygen (O2 ). The concentrations of these gases can be measured in the oil sample and compared to the standard diagnostic ratios to identify the type of fault.
Keywords: power transformers
Description
Condition Assessment of Power Transformers using Dissolved Gas Analysis (DGA) is a widely used technique for detecting incipient faults in transformers. Power transformers are acute components of power systems and their failure can result in significant financial losses and even pose a threat to human life. DGA is a non-destructive, cost-effective and reliable method for assessing the condition of transformers.
Dissolved gas analysis is based on the fact that when a transformer experiences a fault, gases are generated due to the breakdown of the insulating oil and solid insulation materials. These gases dissolve in the transformer oil and their presence can be used as an indicator of the type and severity of the fault. The most common gases generated in transformers during faults are Hydrogen (H2), Methane (CH4), Ethylene (C2H4), Acetylene (C2H2), Carbon Monoxide (CO), Carbon Dioxide (CO2), and Oxygen (O2). The concentrations of these gases can be measured in the oil sample and compared to the standard diagnostic ratios to identify the type of fault.
DGA is a proactive approach to transformer maintenance as it allows early detection of incipient faults before they can cause major damage. It can also help in identifying the root cause of the fault and guide the maintenance team in planning the corrective actions. DGA is particularly useful for transformers operating in harsh environments, where the risk of faults is higher due to temperature and humidity variations, and exposure to contaminants.
The DGA test involves taking an oil sample from the transformer and analyzing the gases dissolved in it. The sampling interval depends on the type of transformer, its age, and the operating conditions. For example, large power transformers may require annual or bi-annual sampling, while smaller transformers may be sampled less frequently. The oil sample is analyzed in the laboratory using Gas Chromatography (GC) or Fourier Transform Infrared (FTIR) spectroscopy. These techniques allow the identification and quantification of the dissolved gases.
The interpretation of the DGA results is based on the diagnostic ratios, which are calculated using the concentrations of the different gases. The diagnostic ratios are specific to each type of fault and are based on the knowledge and experience of the transformer experts. For example, the most common diagnostic ratios used for detecting thermal faults are the key gases ratio (H2/CO), the Upper Tolerance Limit (UTL) ratio (C2H2/C2H4), and the Lower Tolerance Limit (LTL) ratio (CH4/H2). For detecting electrical faults, the most commonly used ratio is the Duval Triangle (D1, D2, and D3).
The DGA technique has several advantages over other transformer monitoring methods. It is non-intrusive, which means that the transformer does not have to be taken offline for testing. It is also a cost-effective method as it does not require specialized equipment or extensive training. Moreover, it provides valuable information on the condition of the transformer, which can help in planning the maintenance activities and prolonging the transformer's life.
However, DGA also has some limitations that should be considered. The interpretation of the results requires expertise and experience, and different laboratories may use different diagnostic ratios, which can lead to inconsistent results. The results can also be affected by factors such as the sampling technique, the oil temperature, and the storage conditions of the sample. Therefore, it is important to use a reputable laboratory and to follow the standard sampling procedures.
Conclusion
In conclusion, Dissolved Gas Analysis (DGA) is a powerful tool for the condition assessment of power transformers. By detecting incipient faults, it enables proactive maintenance and reduces the risk of costly failures. DGA is a non-intrusive and cost-effective method that provides valuable information on the condition of the transformer, enabling the maintenance team to take timely corrective actions. However, the interpretation of the results requires expertise, and the results can be affected by various factors. Therefore, it is essential to use a reputable laboratory and follow standard sampling procedures to ensure consistent and reliable results. Overall, DGA is an important technique in the maintenance of power transformers, contributing to the safety and reliability of the power system.
