To address the engineering challenges of a 220 kV photovoltaic (PV) collection substation in Tibet

including high altitude

extreme low temperature

and limited land resources

this paper conducts research on the design of a high-altitude compact substation.First

based on relevant standards

the external insulation and air clearance of equipment under high-altitude conditions are corrected

and the corrected air clearance values for 35 kV and 220 kV switchgear are obtained.Second

equipment selection schemes are proposed considering low temperature

intense ultraviolet radiation

and sandstorms

including the adoption of KI50X low-temperature transformer oil

heat tracing for GIS tanks

tank-type circuit breakers

UV-resistant fluorocarbon paint and composite bushings

and sandstorm-proof double-sealed enclosures.Third

assembled shunt capacitors are selected instead of frame-type capacitors

reducing the footprint by approximately two-thirds.Finally

a double-layer elevated platform arrangement combining 220 kV GIS and 35 kV switchgear is proposed.The results show that the compact double-layer arrangement saves about 50% of land compared with conventional single-layer schemes while ensuring safe equipment operation under harsh environmental conditions.The findings of this paper can serve as a design reference for PV collection substations in high-altitude and extremely cold regions.