High-voltage transformers are the "heart" of the power grid, and vacuum oil injection is the "lifeline" that determines their insulation performance and service life. For power enterprises pursuing high reliability, mastering and applying advanced vacuum oil injection technology is the key to ensuring grid safety and reducing life-cycle costs.
Why is Vacuum Oil Injection Essential for High-Voltage Transformers?
The internal structure of a transformer is highly complex. Under normal atmospheric pressure, oil injection easily leaves trapped air bubbles within insulation gaps. Under strong electric fields, these bubbles can trigger partial discharges, eventually leading to insulation breakdown.
The core logic of vacuum oil injection is "evacuate first, inject second." By establishing an extremely high vacuum environment (typically requiring an ultimate vacuum degree of ≤5Pa), moisture and gases within the core and insulation micropores are thoroughly extracted. While maintaining this high vacuum, insulating oil is smoothly injected from the bottom, using the negative pressure differential to "draw" the oil deep into the insulation layers. This process not only eliminates the formation of air bubbles but also prevents oil oxidation. Industry standards explicitly mandate vacuum oil injection for transformers rated at 220kV and above, and strongly recommend it as the best practice for 110kV transformers.
An Integrated "Purification + Injection" Solution
Modern advanced vacuum oil injection has evolved into an integrated "double-stage vacuum oil purification + vacuum injection" mode. Take our high-efficiency double-stage vacuum system as an example:
Ultimate Vacuum: Integrating Roots booster pumps and rotary vane vacuum pumps, it easily establishes and maintains an ultimate vacuum of ≤5Pa.
Deep Purification: Utilizing three-dimensional, multi-level flash evaporation technology, it deeply removes free water, dissolved water, and fault characteristic gases from the oil.
Oil Quality Assurance: Ensuring that every drop of injected oil has a breakdown voltage of ≥75kV and a moisture content of <3ppm, cutting off the pathway for moisture and impurities to enter the transformer at the source.
Smart Control for Worry-Free Safety
Vacuum oil injection for high-voltage transformers has extremely strict requirements for time, temperature, and vacuum degree. Our equipment fully incorporates PLC smart control and infrared liquid level auto-detection:
One-Touch Start: After setting the parameters, the system runs fully automatically, adjusting the oil inlet/outlet balance in real-time.
Multi-Level Protection: Automatically shuts down and triggers audible/visual alarms in case of overpressure, oil shortage, or heating abnormalities, enabling unattended operation.
Precise Metering: Equipped with high-precision flowmeters, it ensures precise and controllable oil injection volumes, meeting the demands of lean management.
There is no "close enough" when it comes to safety—only "absolute reliability." We are committed to providing transformer vacuum oil injection and oil treatment solutions for all voltage levels, from 110kV to 1000kV. Whether it is for the commissioning of a new substation or the insulation restoration of an aging transformer, our double-stage vacuum system will deliver a "healthy" transformer with perfect insulation and long-term, maintenance-free operation.
If you would like to learn more about how our vacuum oil injection equipment can reduce costs and increase efficiency for your project, please contact our technical experts immediately. We will provide a free operational analysis and customized solutions, ensuring that every oil injection serves as a solid commitment to grid safety.