YB series compact substation (YB□-12/0.4) — a factory-built, fully prefabricated power unit combining MV switchgear, transformer, and LV distribution in one engineered housing for 3.6–12 kV three-phase AC networks. Designed for municipal, civil, and industrial power distribution where fast deployment and a small footprint matter. Offers flexible integration of mainstream MV/LV switchgear, user-customized electrical configurations, and plug-and-play commissioning that minimizes site construction. Built to GB 17467, GB/T 11022, DL/T 537, IEC 62271-1, and IEC 62271-202.