Regenerative power storage system mounted on DC electric railway car

A regenerative power storage system for a Direct Current (DC) electric railway car, the regenerative power storage system comprising:

• an inverter converting a DC power supplied through a pantograph into an AC power in order to drive at least one motor;
• a first filter unit connected between the pantograph and the inverter in series with the inverter and removing high frequency components of the DC power, the first filter unit including an first inductor and a first capacitor;
• a charging unit connected between the first filter unit and the inverter in parallel with the inverter, and preventing an over current from passing therethrough;
• a second filter unit connected to the charging unit in series, and configured to remove high frequency components of the DC power supplied through the charging unit, the second filter unit including a second inductor and a second capacitor;
• a storage unit connected to the second filter unit and configured to store the DC power which passed through the second filter unit;
• a bidirectional DC/DC converter electrically connected between the second filter unit and the storage unit in series, and controlled such that the bidirectional DC/DC converter is open or closed in charging mode or electricity mode in response to a control signal;
• a DC/DC filter electrically connected between the bidirectional DC/DC converter and the storage unit in series, and configured to remove high frequency noise;
• a voltage detection unit configured to detect applied voltage of the second filter unit;
• and
• a control unit configured to determine the applied voltage detected by the voltage detection unit, and configured to perform control such that the bidirectional DC/DC converter is open or closed.