Abstract: A lithium composite negative electrode which allows a hybrid capacitor to operate at room temperature by reducing interfacial resistance in the electrode, a hybrid capacitor comprising the composite negative electrode, and manufacturing methods thereof. The lithium composite negative electrode is a laminar electrode including a lithium ion conductive solid electrolyte, an alginate gel electrolyte, and lithium-doped carbon. Further, a hybrid capacitor includes a positive electrode including a carbon material and/or a metal oxide, the lithium composite negative electrode, and a neutral aqueous electrolyte filled between the positive electrode and the lithium composite negative electrode. The lithium composite negative electrode is configured as a laminar electrode including the lithium ion conductive solid electrolyte, the alginate gel electrolyte, and the lithium-doped carbon.

Abstract: A lithium composite negative electrode which allows a hybrid capacitor to operate at room temperature by reducing interfacial resistance in the electrode, a hybrid capacitor comprising the composite negative electrode, and manufacturing methods thereof. The lithium composite negative electrode is a laminar electrode including a lithium ion conductive solid electrolyte, an alginate gel electrolyte, and lithium-doped carbon. Further, a hybrid capacitor includes a positive electrode including a carbon material and/or a metal oxide, the lithium composite negative electrode, and a neutral aqueous electrolyte filled between the positive electrode and the lithium composite negative electrode. The lithium composite negative electrode is configured as a laminar electrode including the lithium ion conductive solid electrolyte, the alginate gel electrolyte, and the lithium-doped carbon.

Abstract: A ground fault current limiter, in which reactors are connected in series to a neutral point for compensating for capacitances to ground of a power switches capable of turning ON/OFF at a high speed are connected in parallel with respective reactors, occurrence of a ground fault is detected from a phase difference between a zero-phase sequence current and a zero-phase sequence voltage at time of sampling, an optimal compensation quantity of capacitances to ground is computed based on the zero-phase sequence current and the zero-phase sequence voltage at time of occurrence of a ground fault, and ON/OFF of the switches are controlled thereby to alter the reactor quantity so as to correspond to the compensation quantity.

Abstract: The voltage in a converter 20 is compared with a reference voltage to detect an input power failure, in response to which a motor driven by the converter is automatically decelerated in accordance with a stored signal pattern/speed reduction curve such that the energy regenerated by the motor is equal to its power consumption. The DC bus voltage of the converter is thus maintained substantially constant during the regenerative braking of the motor, and it is promptly halted without resort to any mechanical braking unit.