transformer substation; electrical substation
A facility where voltage is transformed for power distribution. Common in technical and everyday contexts.
この地域には新しい変電所が建設された。
A new transformer substation was built in this area.
変電所の近くに住んでいるので、たまに低いブーンという音が聞こえる。
I live near a substation, so I sometimes hear a low humming sound.
発電所 generates electricity, whereas 変電所 only transforms or distributes voltage that has already been generated elsewhere.
Compound of 変 (hen, 'change') + 電 (den, 'electricity') + 所 (sho, 'place'). A straightforward technical term.