ELECTRIC SUPERCHARGER USING WASTE HEAT FROM INTERNAL COMBUSTION ENGINE AND POWER SUPPLY METHOD THEREOF

An object is to improve fuel consumption, drivability and exhaust gas purification by efficiently converting waste heat of the engine into electrical power and storing the electrical power in a dedicated electric storage so that the boost pressure from the electric air compressor can be flexibly outputted. The electric supercharging device includes a steam cycle device 2 configured to expand the steam generated by waste heat of an engine 1 to rotate an expander 25, a first generator 5 connected to the expander 25 and configured to generate an electrical power by torque of the expander 25, a dedicated battery 8 which stores the electrical power generated by the first generator 5, and an electric supercharger 9 configured to drive a compressor 11 with a motor 14 driven by the electrical power of the dedicated battery 9 to generate compressed air.