Seven considerations for transformer selection - Solutions - Huaqiang Electronic Network

inductance

(1) The transformer should use the products with proven high reliability to prevent the inferior products or the eliminated varieties from entering the power system. The preferred factory should be selected according to the failure rate and the repair rate. The product should be recognized by the national authorized institution. The type test report passed the product appraisal organized by the national authorized unit.

(2) Oil-immersed transformers of 110kV and above should be fully sealed with metal expanders. Manufacturers are required to strengthen the supervision and management of insulating oils. High-quality insulating oils should be selected according to national or industry standards. Oil sources should be selected according to the requirements of the ordering users. Oil and inferior oil injection equipment, at the same time should solve the problem that the current transformers generally appear after the operation of hydrogen and methane exceeding the standard.

(3) Capacitive voltage transformers, the manufacturer shall be required to list the ferromagnetic resonance test items as routine test. The test voltage shall be 0.8U and 1.2U (where U refers to the rated primary phase voltage, the same below), and the manufacturer is not suitable. The medium voltage end arrester is used to limit the resonant overvoltage.

(4) Porcelain outer insulation transformers should be selected from the size of the umbor skirts, to ensure sufficient umbrella distance and creepage distance, in order to meet the requirements of the installation site environmental conditions against rain and flash.

(5) The fixing of the SF gas insulated transformer head support and the fixing of the capacitive screen connector should be stable and reliable to prevent malfunction during transportation. When the outer insulation is made of Silicone Rubber, the quality of the casting should be ensured to avoid accidents.

(6) Solid insulation transformers, which require the manufacturer to ensure that the resin penetrates into the interior of the primary winding layer to prevent accidents. Indoor products should use products that pass the pollution condensation test to meet environmental conditions. Outdoor products should be subjected to various assessments such as rain, high and low temperature conditions, and ultraviolet radiation to meet the requirements of outdoor environmental conditions.

(7) The dynamic thermal stability multiple of the transformer should be proposed according to the power grid vision plan to meet the development needs. For the small current ratio transformer, special attention should be paid to the dynamic heat stability problem.