Working Principle
Power transformers, reactors, bushings, and other oil-filled high-voltage electrical equipment typically use an insulation system composed of oil and paper/paperboard. When internal thermal faults, discharge faults, or oil/paper aging occur, various fault gases are generated and dissolved in the oil. Different types of faults produce different gas compositions and concentrations, so the fault gas composition can reflect the type of fault. Gas chromatography analysis is used to perform qualitative and quantitative analysis of fault gas components, obtaining the gas components and their contents, thereby achieving fault diagnosis of transformers.
3.1.23 Workflow
1. Transformer oil enters the oil-gas separation chamber through a closed circuit, and under vacuum conditions and ultrasonic electromagnetic excitation, oil-gas separation is achieved.
2. After oil removal by cold trap, the separated fault characteristic gases are introduced into the gas metering chamber, and then flow through the chromatographic column under the action of carrier gas. Utilizing the different adsorption and desorption effects of the chromatographic column on each gas component, the fault characteristic gases are separated in sequence.
3. The gas sensor detects the fault characteristic gases one by one according to the peak elution order, and converts the concentration characteristics of the fault gases into electrical signals.
4. The data processing unit analyzes and processes the electrical signals, calculating the concentrations of each fault gas component.
5. The communication module transmits data information such as gas component concentrations, carrier gas pressure status, and two-dimensional chromatograms to the process layer network according to TCP/IP and IEC61850 communication protocols. The main IED fault diagnosis system of the transformer condition monitoring performs comprehensive analysis and diagnosis of the chromatographic data, and alarms when the set attention value is exceeded, achieving online monitoring of transformer faults.
3.1.34 System Structure
