In China, several large state-owned and private enterprises produce HV/EHV power transformers, autotransformers, and HVDC converter transformers. They serve State Grid, Southern Grid, railways, and export markets. These companies operate large-scale factories with UHV testing capability, supplying 110-1100 kV class transformers, as well as medium-power and distribution units. Exact rankings shift over time, so market overviews usually refer to them collectively as “leading Chinese transformer OEMs.”