Current inverter trains rely on air brakes for most of the braking force in high velocity zones due to restrictions on traction motor and inverter capacities. If the electric braking force in high velocity zones can be increased, maintenance costs can be reduced due to the decrease in frequency of brake shoe and lining replacement. The Railway Technical Research Institute (RTRI) has developed a method to significantly increase electric braking force in high velocity zones by inserting a low-cost resistor between the inverter and traction motor (i.e. induction motor). The increase in electric braking force in high velocity zones is achieved by raising the terminal voltage of traction motors through insertion of a resistor R (Fig. 1) between the inverter and traction motor for a regenerative brake. In a stationary test simulating an ordinary suburban motor car train, it was verified that the electric braking force in constant torque zones is extended to high velocity zones when a resistor of 1.37 is inserted (Fig. 2). According to the simulation, the constant torque zone is expected to extend up to the maximum speed after inserting a resistor of 3, making the auxiliary air brake in high velocity zones unnecessary. It was also shown that the handling capacity of brake energy (deceleration: 3 km/h/s when the train is full) increases by about 1.7 times the current capacity for a 3M5T set motor car train (Fig. 3).