Design of Light-Load Regenerative Brake Control System with Load Power Estimation for DC Electrified Railways

In DC-electrified railway systems, light-load regenerative brake control prevents the occurrence of overvoltage at the filter capacitor (FC) of the traction inverter of the regenerative vehicle. However, such control can restrict regenerative power more than necessary when the distance between the powering train and regenerative train is increased, although a sufficient load exists in the electric traction system. This study clarifies the principle of the method to restrict torque current of the regenerative train based on the load power. Subsequently, a method is proposed to design the load power estimation controller.