Abstract: Frequent charging/discharging to an electric energy storage element is suppressed for energy saving and longer lifetime. A transmission-line-side power converter device converts power from a transmission line, and supplies DC power to a feeder line connected to an electric energy storage element. An output current controller connected with a line voltage detector detects the feeder line voltage, and a charging rate detector detects a charging rate of the electric energy storage element. A control table sets charging/discharging start voltages and current saturated voltages based on the detected line voltage and charging rate. The output current controller controls the electric energy storage element to discharge at a high line voltage as the charging rate increase, to suppress charging the electric energy storage element at the low line voltage, and makes discharging difficult at the low line voltage to facilitate charging at the low line voltage as the charging rate decreases.

Abstract: Frequent charging/discharging to an electric energy storage element is suppressed for energy saving and longer lifetime. A transmission-line-side power converter device converts power from a transmission line, and supplies DC power to a feeder line connected to an electric energy storage element. An output current controller connected with a line voltage detector detects the feeder line voltage, and a charging rate detector detects a charging rate of the electric energy storage element. A control table sets charging/discharging start voltages and current saturated voltages based on the detected line voltage and charging rate. The output current controller controls the electric energy storage element to discharge at a high line voltage as the charging rate increase, to suppress charging the electric energy storage element at the low line voltage, and makes discharging difficult at the low line voltage to facilitate charging at the low line voltage as the charging rate decreases.

Abstract: A solid electrolyte type carbon dioxide gas sensor element has a solid electrolyte layer, a work electrode layer formed on one side of the solid electrolyte layer and containing an electron conducting material and an auxiliary electrode material, and a reference electrode layer formed on the same side or the other side of the solid electrolyte layer and containing an electron conducting material. The work electrode layer further contains a rare earth metal oxide or at least part of the auxiliary electrode material of the work electrode layer is a rare metal oxide carbonate.