Mar 30, 2026 (International Electrical Equipment Journal) — While dry-type transformers are favored in indoor scenarios, oil-immersed transformers, relying on their excellent heat dissipation performance, high reliability and cost advantages, still occupy a dominant position in the global power transformer market, especially in high-voltage and large-capacity power transmission and distribution scenarios. Statistics show that in 2024, the domestic transformer market in China reached 120 billion yuan, of which oil-immersed power transformers accounted for more than 50% – and a large proportion of these are exported to global markets, winning wide recognition from overseas buyers .
The most prominent advantage of Chinese oil-immersed transformers is their strong heat dissipation capacity and overload resistance, which adapt to the harsh operating conditions of global power grids. Taking mineral insulating oil as the cooling medium, the heat generated during operation can be quickly dissipated through oil convection circulation, and the heat dissipation efficiency is 30% higher than that of dry-type transformers [5]. Its overload capacity can reach 150% of the rated capacity, which is particularly suitable for power transmission scenarios with fluctuating loads such as rural power grids and industrial parks – a key demand in emerging markets. For example, the S22 series oil-immersed transformers produced by Qing
Cost-effectiveness and long-term stability are also important reasons why global buyers prefer Chinese oil-immersed transformers. In medium and high-capacity (25-500kVA) applications, the unit capacity cost of Chinese oil-immersed transformers is 25% lower than that of similar products in Europe and the United States, and the maintenance cycle is as long as 10 years, which is much longer than the 5-7 years of dry-type transformers [5]. In addition, the fully sealed structure and corrugated oil tank design make Chinese oil-immersed transformers able to adapt to extreme environments from -30℃
With the global energy transition, Chinese oil-immersed transformers are also moving towards environmental protection and intelligence, keeping pace with global trends. Natural ester insulating oil (such as soybean oil and coconut oil) is gradually replacing mineral oil, with a biodegradation rate of more than 98% and a flash point of 360℃, which is much higher than 160℃ of mineral oil, fully complying with EU CBAM and green transition strategies. At the same time, the integration of intelligent online monitoring systems enables real-time monitoring of oil temperature and partial discharge, improving operation and maintenance efficiency by 4
