Dry type transformer is an important electrical appliance. During operation, attention should be paid to various operations, among which drying of dry-type transformer is more common. The main treatment method of dry transformer is water or moisture when it is in operation. To prevent short circuit, dry the dry type transformer. Whether ordinary dry-type transformers need to be dried depends on the following conditions:
Dry transformer plant
(1) For the newly installed dry oil transfer transformer, a comprehensive analysis shall be conducted to determine whether drying is necessary to determine the following conditions:
1) Qualified strength of electrical insulating oil and trace water;
2) Insulation resistance and absorption ratio (or polarization index) comply with the relevant provisions of the current national standard "Electrical Equipment Handover Test Standard for Electrical Installation Engineering" (GB 50150-2006).
3) The tangent value of tangent tan (%) of dielectric loss conforms to the requirements (the voltage level is lower than 35 kV, and the capacity is less than 4000 kV). A/No requirements are required).
(2) For newly installed dry transformer and reactor pneumatic conveying, comprehensive analysis response shall be conducted under the following conditions to determine whether it is dry or not:
1) Maintain positive internal pressure from factory to installation.
(2) The trace water in the residual oil shall not be greater than 30ppm;
3) After the dry type transformer and reactor pass through the insulation oil, insulation oil and trace water of insulation resistance, they shall meet the electrical strength of national standard and then be injected into the relevant provisions of "Installing electrical Engineering Equipment to test electrical equipment" (GB 50150-2006).
(3) When the body cannot maintain positive pressure and there is no obvious damage to the seal, a comprehensive judgment should be made on whether drying is needed based on the comprehensive analysis of installation and test records.
Dry transformers do not always need to be dried. It is necessary to see if drying is needed. It is necessary to improve the drying process of dry transformers, so that dry transformers can operate safely and smoothly and achieve continuous improvement in efficiency.
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