The 300 kW range extender can be applied to large-tonnage new energy mine cards. Through the 150 kW dual-motor series connection, each motor is independently controlled by a dual 800 A module dual-drive controller. The control mode is diversified, and the power generation can be reasonably matched according to the running state of the vehicle. The system always runs in an efficient and economical area, and the power generation efficiency reaches 4.25 kWh / L.