Pengubah kuasa dikelaskan mengikut aplikasi: langkah-naik (6.3kV/10.5kV atau 10.5kV/110kV, dsb. untuk loji kuasa), sambungan (220kV/110kV atau 110kV/10.5kV antara pencawang) dan langkah{{10}atau/}turun (35kV) 10.5kV/0.4kV untuk pengagihan).
Pengubah kuasa dikelaskan mengikut bilangan fasa: fasa-satu dan tiga-fasa.
Power transformers are classified by winding type: two-winding (each phase is mounted on the same core, primary and secondary windings are wound separately and insulated from each other), three-winding (each phase has three windings, primary and secondary windings are wound separately and insulated from each other), and autotransformer (one set of windings with a tap in the middle serves as the primary or secondary output). Three-winding transformers require the capacity of the primary winding to be greater than or equal to the capacity of the secondary and tertiary windings. The percentage of capacity for three-winding transformers, in the order of high voltage, medium voltage, and low voltage, is: 100/100/100, 100/50/100, 100/100/50. It is required that neither the second nor third windings operate at full load. Generally, the third winding voltage is lower and is mostly used for near-field power supply or connecting compensation equipment, connecting three voltage levels. Autotransformers: Available in step-up or step-down types, they are widely used in ultra-high voltage power grids due to their low losses, light weight, and economical operation. Commonly used small autotransformers are 400V/36V (24V) models, used for powering safety lighting and other equipment.
Pengubah kuasa dikelaskan mengikut medium penebat: pengubah terendam minyak (jenis kalis-api dan bukan{3}}api-nyala-minyak), pengubah jenis-kering dan pengubah terlindung gas SF6 110kV-.
Teras pengubah kuasa ialah semua struktur jenis-teras.
Tiga-pengubah kuasa fasa yang dikonfigurasikan dalam kejuruteraan komunikasi am ialah dua-pengubah penggulungan.
