Systems and methods for power conversion are described. For example, a system may include a transformer including a plurality of secondary windings; a first set of switches connecting respective taps of the plurality of secondary windings to a first terminal; a second set of switches connecting the respective taps of the plurality of secondary windings to a second terminal; and an electrical load connected between the first terminal and the second terminal.

Systems and methods for power conversion are described. For example, a system may include a transformer including a plurality of secondary windings; a first set of switches connecting respective taps of the plurality of secondary windings to a first terminal; a second set of switches connecting the respective taps of the plurality of secondary windings to a second terminal; and an electrical load connected between the first terminal and the second terminal.

There is provided methods and apparatus configured to provide electrical converter control parameters, the apparatus comprising: a Structured H-infinity tuning module configured to determine one or more control parameters, for a model of an electrical converter control system and grid, based on variation of one or more grid parameters; and an output module configured to provide the one or more control parameters for implementation in the electrical converter control system.

There is provided methods and apparatus configured to provide electrical converter control parameters, the apparatus comprising: a Structured H-infinity tuning module configured to determine one or more control parameters, for a model of an electrical converter control system and grid, based on variation of one or more grid parameters; and an output module configured to provide the one or more control parameters for implementation in the electrical converter control system.

A power conversion device that performs power conversion between a DC circuit and an AC circuit includes a power conversion circuit including a plurality of sub-modules, a failure detection device that detects an internal failure of the power conversion circuit, and a control device that generates an operation command controlling operation of each of the plurality of sub-modules. The control device acquires a voltage value of a capacitor included in each sub-module, calculates a deviation between a variance value indicating a variation in the voltage value of the capacitor included in the sub-module in a reference period and a reference variance value in the sub-module for each of a plurality of sub-modules, determines a failure section of an internal failure based on the deviation in each sub-module when the internal failure is detected, and outputs an operation command based on a determination result to each sub-module.

A power module (2) including a molded package (4), three power terminals (6, 8, 10) protruding from a first side (40) of the molded package (4) is disclosed. The power terminals (6, 8, 10) include a positive DC terminal (6), a neutral terminal (8) and a negative terminal (10). The power module (2) includes a phase output power terminal (12) protruding from a second side (42) of the molded package (4). The power module (2) is a three-level power module including a plurality of control pins (14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36) protruding from the second side (42) of the molded package (4).

A switching bridge for the DC-DC stage of a power converter, the switching bridge having one or more sets of upper and lower series-connected switches (S1, S2) connected across a DC bus and arranged to be switched to provide an output AC voltage, the switching bridge further comprising a voltage divider (C1) arranged to vary the output AC voltage level according to the switching state of the switches.

The present invention has steps of determining a minimum number of levels (L_duty) required to output a target modulation ratio (d_ref) (S2), determining the total number (N_volt) of voltage orders to be controlled among a voltage fundamental wave and harmonics of power converter (S3), comparing the minimum number of levels (L_duty) and the total number (N_volt) of voltage orders to be controlled and fixing a larger one as the number of switching times N in a quarter cycle for the target modulation ratio (S4-S6); when (N_volt) is fixed, determining shape of an output voltage (S7), and based on the target modulation ratio and the number of switching times N in the quarter cycle, determining switching phases for N times, and deriving the pulse pattern for one cycle by which each output voltage level according to the target modulation ratio, the output voltage shape and the phase is determined (S8, S9).

The present invention has steps of determining a minimum number of levels (L_duty) required to output a target modulation ratio (d_ref) (S2), determining the total number (N_volt) of voltage orders to be controlled among a voltage fundamental wave and harmonics of power converter (S3), comparing the minimum number of levels (L_duty) and the total number (N_volt) of voltage orders to be controlled and fixing a larger one as the number of switching times N in a quarter cycle for the target modulation ratio (S4-S6); when (N_volt) is fixed, determining shape of an output voltage (S7), and based on the target modulation ratio and the number of switching times N in the quarter cycle, determining switching phases for N times, and deriving the pulse pattern for one cycle by which each output voltage level according to the target modulation ratio, the output voltage shape and the phase is determined (S8, S9).

Examples of the disclosure include a UPS comprising an output to be coupled to a load, a first converter leg to provide a first voltage to the output and including at least one of a first relay or fuse, a second converter leg in parallel with the first converter leg including at least one of a second relay or fuse and configured to provide a second voltage to the output out of phase with the first converter leg providing the first voltage signal, current sensors coupled to the first and second converter legs, respectively, and configured to provide a first signal indicative of a current in the first converter leg and a second signal indicative of a current in the second converter leg, respectively, and at least one controller to receive the signals, determine a current difference between the converter legs based on the signals, and decrease the current difference.