Abstract: An apparatus for transmitting energy to and from superconductive coils, via a unipolar capacitor having a large capacitance. The apparatus is characterized by the use of two on-off self-controllable switches which are turned on and off under instructions from a control circuit or the like. The control circuits assure that the capacitor voltage remains constant by operating the switches in response to detected voltage levels.

Abstract: A circuit for transmitting energy to and from coils is improved by connecting a coil to a bridge circuit composed of a diode and a switch such as a gate turn-off thyristor. An opposite polarity switch and diode construction may be used in addition to selectively allow the direction of current flow through the coil to be reversible.

Abstract: This invention relates to an apparatus for controlling a D.C. power transmission system having a line-commutated converter which is connected between a first A.C. system and D.C. power transmission lines and which performs power conversion between A.C. power and D.C. power, and a forced-commutated converter which is connected between the D.C. power transmission lines and having a second A.C. system and which performs power conversion between A.C. power and D.C. power. In order to control transmission power in the two-terminal D.C. power transmission system wherein the two A.C. systems are associated by direct current, a control apparatus for a D.C. power transmission system according to this invention includes a voltage detector which detects a D.C. voltage of the D.C.

Abstract: The disclosed inverter system comprises three three-phase inverters connected in parallel across a positive and a negative terminal of a DC source including a negative terminal, and two three-phase transformers each including star-connected primary windings connected at one end to three AC outputs of the mating inverter and at the other ends connected to the neutral source terminal. Three secondary windings of each transformer are serially connected to those of the other transformer across three star-connected phase windings of a synchronous motor and three AC output of that inverter not connected to the transformer. The motor includes a neutral terminal connected to the neutral source terminal.

Abstract: A commutation circuit for an inverter using an auxiliary source to accumulate the energy for commutation is simplified by assigning to the main diodes mounted in series with the main thyristor of the inverter the role of preventing partial discharge of the storage devices during the commutation process.