The present disclosure relates to semiconductors. Some embodiments may include a series circuit arrangement of power semiconductors comprising: cooling-water boxes arranged on the semiconductors and electrically connected to them; two cooling-water distributor lines; respective branchings on the cooling-water distributor lines for the cooling chambers; and a control electrode arranged on the cooling-water distributor lines. The cooling chambers are connected in parallel between the cooling-water distributor lines with respect to a cooling-water stream. The cooling chambers are connected to the branchings via a respective connecting line. For at least some of the cooling chambers, the branchings on the cooling-water distributor lines are arrayed relative to the position of the respective cooling chamber in offset manner in relation to a geometrically shortest possible link to the cooling-water distributor lines, so that a difference of potential between the cooling chambers and the branchings is minimized.

The present disclosure relates to semiconductors. Some embodiments may include a series circuit arrangement of power semiconductors comprising: cooling-water boxes arranged on the semiconductors and electrically connected to them; two cooling-water distributor lines; respective branchings on the cooling-water distributor lines for the cooling chambers; and a control electrode arranged on the cooling-water distributor lines. The cooling chambers are connected in parallel between the cooling-water distributor lines with respect to a cooling-water stream. The cooling chambers are connected to the branchings via a respective connecting line. For at least some of the cooling chambers, the branchings on the cooling-water distributor lines are arrayed relative to the position of the respective cooling chamber in offset manner in relation to a geometrically shortest possible link to the cooling-water distributor lines, so that a difference of potential between the cooling chambers and the branchings is minimized.

According to an embodiment of the invention, a power conversion device that includes a power converter, a direct current capacitor, a voltage sensor, a rectifying element, an electromagnetic contactor, and a control circuit is provided. The power converter includes a pair of direct current terminals connected to a direct current power supply, includes multiple alternating current terminals connected to an electric power system of alternating current, converts direct current power input from the direct current power supply into alternating current power, and supplies the alternating current power to the electric power system. The direct current capacitor is connected between the pair of direct current terminals. The voltage sensor detects a voltage value of the direct current capacitor. The rectifying element is provided between the direct current capacitor and the direct current power supply and suppresses a reverse flow of electrical power from the power converter and the direct current capacitor into the direct current power supply. The electromagnetic contactor is connected in parallel with the rectifying element. The control circuit controls operations of the power converter and the electromagnetic contactor. In the case where the voltage value of the direct current capacitor detected by the voltage sensor is a prescribed value or more, the control circuit engages the electromagnetic contactor and supplies active power from the power converter to the electric power system; and in the case where the voltage value of the direct current capacitor detected by the voltage sensor is less than the prescribed value, the control circuit opens the electromagnetic contactor and supplies a reactive power from the power converter to the electric power system.

According to an embodiment of the invention, a power conversion device that includes a power converter, a direct current capacitor, a voltage sensor, a rectifying element, an electromagnetic contactor, and a control circuit is provided. The power converter includes a pair of direct current terminals connected to a direct current power supply, includes multiple alternating current terminals connected to an electric power system of alternating current, converts direct current power input from the direct current power supply into alternating current power, and supplies the alternating current power to the electric power system. The direct current capacitor is connected between the pair of direct current terminals. The voltage sensor detects a voltage value of the direct current capacitor. The rectifying element is provided between the direct current capacitor and the direct current power supply and suppresses a reverse flow of electrical power from the power converter and the direct current capacitor into the direct current power supply. The electromagnetic contactor is connected in parallel with the rectifying element. The control circuit controls operations of the power converter and the electromagnetic contactor. In the case where the voltage value of the direct current capacitor detected by the voltage sensor is a prescribed value or more, the control circuit engages the electromagnetic contactor and supplies active power from the power converter to the electric power system; and in the case where the voltage value of the direct current capacitor detected by the voltage sensor is less than the prescribed value, the control circuit opens the electromagnetic contactor and supplies a reactive power from the power converter to the electric power system.

A method and device is disclosed for charging and/or maintenance of lead-acid and alkaline accumulator batteries, allowing a charge, discharge, or recovery in control-conditioning cycles of these batteries. To increase efficiency of the battery recovery process, its charge is created by a reversible current in consecutive stages. Correction of the charging mode is provided based on voltage and temperature of the accumulator battery.

A method and device is disclosed for charging and/or maintenance of lead-acid and alkaline accumulator batteries, allowing a charge, discharge, or recovery in control-conditioning cycles of these batteries. To increase efficiency of the battery recovery process, its charge is created by a reversible current in consecutive stages. Correction of the charging mode is provided based on voltage and temperature of the accumulator battery.

A gate-drive system according to the present invention which transmits a drive signal to a semiconductor switching device, includes: an inverter circuit to supply high-frequency power including a fundamental wave component and plural harmonic components each having different frequencies; a power transmission circuit which is connected to the inverter circuit and transmits the high-frequency power outputted from the inverter circuit; power receiving circuits to individually receive the fundamental wave component and plural harmonic components of the high-frequency power transmitted from the power transmission circuit; and a control circuit to generate the drive signal for the semiconductor switching device on the basis of the plural harmonic components of the high-frequency power received by the power receiving circuits.

A gate-drive system according to the present invention which transmits a drive signal to a semiconductor switching device, includes: an inverter circuit to supply high-frequency power including a fundamental wave component and plural harmonic components each having different frequencies; a power transmission circuit which is connected to the inverter circuit and transmits the high-frequency power outputted from the inverter circuit; power receiving circuits to individually receive the fundamental wave component and plural harmonic components of the high-frequency power transmitted from the power transmission circuit; and a control circuit to generate the drive signal for the semiconductor switching device on the basis of the plural harmonic components of the high-frequency power received by the power receiving circuits.

A commutation cell for a flying capacitor module, to a flying capacitor module having the commutation cell and to a multi-level converter having the flying capacitor module is disclosed. The commutation cell includes a circuit board, two semiconductors mounted either on the same side or on opposite sides of the circuit board, four capacitors arranged in pairs on opposite sides of the circuit board, and flying capacitors connected to the input and output sides of the commutation cell, respectively. The capacitors located on opposite sides are connected to one another by way of via holes. Different commutation paths between the various capacitors extend on the first side and on the second side of the circuit board and along the vias, with currents flowing through the respective adjacent capacitors in opposing directions for an overall reduction in the parasitic inductances.

A commutation cell for a flying capacitor module, to a flying capacitor module having the commutation cell and to a multi-level converter having the flying capacitor module is disclosed. The commutation cell includes a circuit board, two semiconductors mounted either on the same side or on opposite sides of the circuit board, four capacitors arranged in pairs on opposite sides of the circuit board, and flying capacitors connected to the input and output sides of the commutation cell, respectively. The capacitors located on opposite sides are connected to one another by way of via holes. Different commutation paths between the various capacitors extend on the first side and on the second side of the circuit board and along the vias, with currents flowing through the respective adjacent capacitors in opposing directions for an overall reduction in the parasitic inductances.