String The type of EHV swicthgear & 132kV CB
Options: ehv_asset_category = c(
"33kV CB (Air Insulated Busbars)(ID)(GM)",
"33kV CB (Air Insulated Busbars)(OD)(GM)",
"33kV CB (Gas Insulated Busbars)(ID)(GM)",
"33kV CB (Gas Insulated Busbars)(OD)(GM)",
"33kV RMU",
"33kV Switch (GM)",
"66kV CB (Air Insulated Busbars)(ID)(GM)",
"66kV CB (Air Insulated Busbars)(OD)(GM)",
"66kV CB (Gas Insulated Busbars)(ID)(GM)",
"66kV CB (Gas Insulated Busbars)(OD)(GM)")