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Dry-type transformers and oil-immersed transformers have different working environments and heat dissipation conditions. Their selection standards for electrical steel show obvious targeted differences.

Oil-immersed transformers adopt conventional low-loss oriented electrical steel. Oil immersion provides good heat dissipation and stable temperature environment. Ordinary 30Q120, 30Q110 steel grades meet operational needs. Cost performance is the core selection priority.

Oil-immersed equipment allows relatively wider steel specification range. Sufficient oil circulation takes away core heat. It tolerates slight loss fluctuation of electrical steel. Ordinary grain-oriented steel can fully adapt to oil-immersed working conditions.

Dry-type transformers require higher-grade low-loss electrical steel. Dry-type equipment relies on air natural cooling. Its heat dissipation efficiency is far lower than oil immersion. High-loss steel easily causes overheating failure.

Dry-type transformers prefer laser scribed and HiB high-performance steel. Ultra-low core loss reduces core heat generation fundamentally. It avoids temperature overrun under air cooling conditions. It guarantees long-term stable operation.

Insulating coating requirements differ greatly for the two types. Dry-type transformers need high-temperature resistant C6 or C7 coatings. It adapts frequent temperature changes of air cooling. Oil-immersed transformers can adopt conventional C5 coatings.

Thickness selection also has obvious differences. Dry-type transformers prioritize 0.27mm and 0.23mm thin steel. Thin steel reduces loss and heat generation. Oil-immersed transformers commonly use 0.30mm economical steel.

In short, dry-type transformers have stricter electrical steel selection standards. They pursue ultra-low loss and high thermal stability. Oil-immersed transformers focus more on cost and basic performance balance.