The technical system of a power transformer main transformer is quite extensive, but its core can be summarized into four aspects: electromagnetic design technology, insulation technology, cooling technology, and protection and monitoring technology. These technologies work together to ensure the long-term stable operation of the main transformer under high voltage and high capacity conditions.
Electromagnetic Design Technology: The focus is on optimizing the core structure and winding layout to reduce losses and improve efficiency. By rationally designing the turns ratio, leakage flux path, and short-circuit impedance, it is possible to improve short-circuit impact resistance and operational stability while ensuring voltage transformation capability. This part directly determines the upper limit of the main transformer's performance.
Insulation Technology and Materials Technology: The main transformer needs to withstand extremely high voltages, therefore, the requirements for the insulation system are extremely stringent. Oil-paper insulation systems or dry epoxy insulation structures are typically used, and processes such as vacuum drying and vacuum oil injection are employed to eliminate internal air bubbles and prevent partial discharge. The level of insulation technology directly affects the safe lifespan of the main transformer.
Cooling Technology and Operation Technology: The main transformer generates a large amount of heat during operation, requiring heat dissipation through methods such as oil-immersed self-cooling, forced oil circulation air cooling, or water cooling. With technological advancements, intelligent temperature control systems are also widely used, which can automatically adjust the cooling intensity according to the load, improving energy efficiency.
In terms of protection and monitoring technology, main transformers are typically equipped with relay protection systems such as differential protection, gas protection, and overcurrent protection, combined with online monitoring technology.
