Abstract: The present invention relates to a secondary battery in which a first region and a second region of an insulation sheet are made of different materials, and thus thermal conduction between an electrode assembly and a cap plate can be blocked, light reflection that may occur during welding can be prevented, and static electricity and alignment can be maintained.

Abstract: A regenerative electric power storage system installed onboard a DC electric rail car comprises: a filter unit which removes high frequency components from the DC power supplied through the catenary of a pantograph; a storage unit for storing power; a bidirectional DC/DC converter which is electrically connected between the filter unit and the storage unit; a DC/DC filter unit to remove high frequency noise; a voltage detection unit and a control unit which controls the switching of the bidirectional DC/DC converter. Instability is presented in the remaining systems of the electric rail car.

Abstract: A regenerative electric power storage system installed onboard a DC electric rail car comprises: a filter unit which removes high frequency components from the DC power supplied through the catenary of a pantograph; a storage unit for storing power; a bidirectional DC/DC converter which is electrically connected between the filter unit and the storage unit; a DC/DC filter unit to remove high frequency noise; a voltage detection unit and a control unit which controls the switching of the bidirectional DC/DC converter. Instability is presented in the remaining systems of the electric rail car.