A voltage source converter has a half bridge (18) with two current valves (19, 20) connected in series and an arrangement configured to carry out voltage measurements for determining a value of the DC voltage between opposite poles (21, 22) of a DC side of the converter. Each current valve comprises a semiconductor device (23, 24) controlled by an associated gate drive member (29, 30), each forming gate drive parts of one gate drive unit (28) in common to both current valves. The gate drive unit (28) comprises an isolated two-way communication link (33) between the gate drive members. The arrangement is included in the gate drive unit and configured to measure the entire DC voltage between said opposite poles (21, 22). A converter control device (31) calculates and sends control signals to the gate drive unit based on the result of the voltage measurement.

A voltage source converter has a half bridge (18) with two current valves (19, 20) connected in series and an arrangement configured to carry out voltage measurements for determining a value of the DC voltage between opposite poles (21, 22) of a DC side of the converter. Each current valve comprises a semiconductor device (23, 24) controlled by an associated gate drive member (29, 30), each forming gate drive parts of one gate drive unit (28) in common to both current valves. The gate drive unit (28) comprises an isolated two-way communication link (33) between the gate drive members. The arrangement is included in the gate drive unit and configured to measure the entire DC voltage between said opposite poles (21, 22). A converter control device (31) calculates and sends control signals to the gate drive unit based on the result of the voltage measurement.

Power conversion systems and methods to control a multiphase multilevel regenerative power converter with multilevel phase circuits that individually include multiple regenerative power stages with respective power stage outputs connected in series, each of the multiple regenerative power stages comprising a DC link circuit a switching rectifier coupled between a respective transformer secondary circuit and the DC link circuit, and a switching inverter coupled between the DC link circuit and the respective power stage output, including a controller that provides inverter switching control signals to control the respective switching inverters, provides rectifier switching control signals to control the respective switching rectifiers, and controls a non-zero phase relationship between the rectifier switching control signals of the respective switching rectifiers.

A multi-port recharge system. In some embodiments, the multi-port recharge system includes a transformer having one or more secondary windings, each of which connects to a non-isolated AC to DC converter. The primary of the transformer may connect to medium voltage utility power.

A three-phase autotransformer including three output groups and three inputs each connected to each of the outputs of a respective output group by windings, the windings being configured so that, when each input has a respective input voltage applied thereto, the three input voltages having the same input amplitude, being 120° out of phase with each other and defining a neutral point: for each output group, a main output voltage, taken between a main output of said output group and the neutral point, has an amplitude greater than the input amplitude; and output voltages of the autotransformer belong to a same Reuleaux polygon, each output voltage being associated with a respective output and being equal to a voltage between said output and the neutral point.

A three-phase autotransformer including three output groups and three inputs each connected to each of the outputs of a respective output group by windings, the windings being configured so that, when each input has a respective input voltage applied thereto, the three input voltages having the same input amplitude, being 120° out of phase with each other and defining a neutral point: for each output group, a main output voltage, taken between a main output of said output group and the neutral point, has an amplitude greater than the input amplitude; and output voltages of the autotransformer belong to a same Reuleaux polygon, each output voltage being associated with a respective output and being equal to a voltage between said output and the neutral point.

An apparatus for supplying power to a high-capacity load includes a three-to-two phase transformer including an input side three-phase transformer terminal for connection to a three-phase supply grid and output side first and second output-side single-phase transformer terminals. A converter arrangement has a first partial converter including a first input-side, single-phase AC voltage terminal for the first output-side transformer terminal and a first single-phase output terminal. A second partial converter has a second input-side single-phase AC voltage terminal for the second output-side transformer terminal and a second single-phase output connector. The partial converters are mutually connectable by the output terminals in an output-side series and/or parallel circuit and form a single-phase load terminal for the high-capacity load. A method for supplying power to a high-capacity load is also provided.

An apparatus for supplying power to a high-capacity load includes a three-to-two phase transformer including an input side three-phase transformer terminal for connection to a three-phase supply grid and output side first and second output-side single-phase transformer terminals. A converter arrangement has a first partial converter including a first input-side, single-phase AC voltage terminal for the first output-side transformer terminal and a first single-phase output terminal. A second partial converter has a second input-side single-phase AC voltage terminal for the second output-side transformer terminal and a second single-phase output connector. The partial converters are mutually connectable by the output terminals in an output-side series and/or parallel circuit and form a single-phase load terminal for the high-capacity load. A method for supplying power to a high-capacity load is also provided.

A method and line interface filter apparatus to couple a drive or group of drives to a shared multiphase AC bus, including individual phase circuits having an inductor coupled between a respective bus and drive phase lines, a resistor coupled to the respective drive phase line, and a capacitor coupled between the resistor and a common connection of the capacitors of the individual phase circuits, where the capacitance of the capacitors is 5 to 15 times a per-phase equivalent capacitance of the drive or group of drives, and the resistance of the resistors is two times a damping ratio times a square root of a ratio of the filter inductance to the filter capacitance, where the damping ratio is greater than or equal to 1.0 and less than or equal to 2.0.

A method and apparatus include a primary transformer coil, a secondary transformer coil, and a center tapped inductor coupled to the secondary transformer coil. A first switch may be in electrical communication with the center tapped inductor and may be configured to affect the first output voltage. A second switch may be in electrical communication with the center tapped inductor and may be configured to affect the second output voltage. In a particular example with an analog current (AC) output voltage, the two output voltages are out of phase to each other. In a direct current (DC) implementation, the transformer may be operated to output a positive and a negative output voltage. The apparatus may function as a resonant converter, or may operate in non-resonant mode. In one implementation, an H bridge may provide reactive power support. An inductor filter may be in electrical communication with the secondary transformer coil. Where desired, a diode bridge may be in electrical communication with the primary transformer coil.