Abstract: A method of static reactive power compensation is disclosed wherein the system voltage is compensated by supplying advanced-phase or retarded phase reactive power in dependence upon the difference between the system voltage and a reference voltage. The difference is formed by a comparator which receives a variable reference voltage from a filter containing a time lag circuit and which receives the system voltage as an input. For transients, the output of the filter does not change and thus reactive power is applied. For smooth variations, the output of the filter follows that of the system voltage so that the output of the power compensation circuit is maintained at zero.

Abstract: In a generating system including a plurality of parallel-operated fuel cells possessing a plurality of stacks, each of the cells is provided with a control circuit comprising chopper means each composed of switching elements which are ignition-controlled and each of which is connected to the output terminal of the respective cells, and ignition circuits each generating an ignition signal for ignition-controlling the switching elements in such manner that output current of the chopper means is made to be a prescribed value in accordance with the output current, whereby output control is effected in respect of each stack of the fuel cells so that load in respect of the respective cells is equalized and parallel operation with a high efficiency is effectuated.

Abstract: A transmission line interconnecting system including an AC-DC converter connected to a first transmission line; and a forced-commutated type inverter connected to a second transmission line. DC terminals of the AC-DC converters and the forced commutated type inverter are connected and the output voltage of the forced commutated type inverter is varied by controlling DC voltage to feed a reactive power to the second transmission line in a normal state and to feed an active power from the first transmission line through the AC-DC converter and the forced excited type inverter to the second transmission line in an emergency state.

Abstract: A semiconductor device is immersed into a cooling medium in its liquid phase disposed in a vessel. The cooling medium changes to its vapor phase due to heat from the semiconductor device to enter a condenser located above the vessel. The cooling medium condensed in the condenser passes through a conduit connected to the lower portion of the vessel to be directly mixed with the liquid cooling medium within the vessel.