A single-phase power converter is disclosed for converting a direct current power source to an alternating current power across first and second output terminals, which may be connected to a split-phase system having a first-phase load connected between one phase and a second-phase load connected between the other phase. When the loads are not balanced, the single-phase power converter provides a differential current to compensate for the imbalance.

A DC/DC power converter converts voltage at an input of the DC/DC power converter to a voltage at an output of the DC/DC power converter, where the output voltage is a multiple of the input voltage. The DC/DC power converter comprises two switching circuits electrically connected in series, two capacitors electrically connected in series, and a resonant circuit comprising a resonant capacitor and a resonant inductor. The series connection of the two capacitors is electrically connected in parallel to the series connection of the two switching circuits. The resonant circuit is electrically connected to the two switching circuits. A first capacitor of the two capacitors is electrically connected in parallel to the input. Each switching circuit comprises two switching units electrically connected in series, wherein each switching unit comprises two or more switches electrically connected in series.

A method for controlling a hybrid switched capacitor (SC) converter includes (a) generating control signals for controlling switching devices of the hybrid SC converter, in a manner which regulates one or more parameters of the hybrid SC converter, (b) detecting flying capacitor voltage imbalance in the hybrid SC converter, and (c) in response to detecting flying capacitor voltage imbalance in the hybrid SC converter, generating the control signals in a manner which varies switching state duration of the hybrid SC converter, to move flying capacitor voltage towards balance.

A method for operating a multilevel converter in flycap topology, in which the multilevel converter has at least two semiconductor switches controlled by control pulses of variable pulse durations within a control period that recurs at a control frequency to selectively interconnect a voltage source connected to an input of the multilevel converter, an output of the multilevel converter, and at least one auxiliary capacitor arranged between the input and the output, for generating an output voltage. The method includes using at least one oscillation parameter that describes the oscillation behavior of at least one harmonic of an electrical measured variable, at least one correction pulse duration is determined for a future control pulse to reduce the amplitude of the at least one harmonic and at least one semiconductor switch is controlled with a control pulse of the determined correction pulse duration.

A power converter to be tested is supplied with arm current from a hysteresis converter in a state in which it is connected to an auxiliary converter through a line. In the power converter and the auxiliary converter, a circulation operation is performed in which a current path bypassing power storage elements is formed between an output terminal of the power converter and an output terminal of the auxiliary converter, after the start of output of arm current in accordance with a reference current command value in which an AC component and a DC component are superimposed, until a DC component of arm current reaches a predetermined level. After execution of the circulation operation, in the power converter and the auxiliary converter, voltage control of the power storage elements and the output terminals is started.

Described herein is a multi-level power convertor and a method for a multi-level power convertor. The multi-level power convertor includes a DC port; an AC port; a first power converting unit, a second power converting unit, a coupling inductor, and an inductive filtering unit. The first power converting unit is coupled to the DC port and includes a first AC terminal adapted to provide a first plurality of voltage levels. The second power converting unit is coupled to the DC port and includes a second AC terminal adapted to provide a second plurality of voltage levels, where the second plurality of voltage levels are phase-shifted by 90 degrees with respect to the first plurality of voltage levels. The coupling inductor includes first and second windings with a same number of turns. The inductive filtering unit is arranged between the AC port and ends of the first and second windings.

A method includes detecting a voltage signal of a three-level power converter, the voltage signal indicative of a capacitor voltage balancing in the three-level power converter, and dynamically adjusting an operating variable to adjust the voltage signal until the capacitor voltage balancing in the three-level power converter satisfies a criteria.

A voltage evaluation value generator receives voltage detection values of power storage elements of all of converter cells included in a power converter and generates a first voltage evaluation value of each power storage element of all of the converter cells and a second voltage evaluation value of each power storage element in a plurality of converter cells included in each of a plurality of groups obtained by classifying all of the converter cells in advance, without using a mean value of voltage detection values. A voltage macro controller uses the voltage evaluation value to calculate a control value set in common to at least the converter cells in the same group for controlling deficiency and excess of stored energy in all of the converter cells and the converter cells in each group.

A power converter includes a switched-capacitor circuit that forms different capacitor networks out of a set of capacitors. It does so in a way that avoids losses that can arise when capacitors are connected together.

A circuit arrangement for balancing a split DC link arranged between a first DC-voltage terminal and a second DC-voltage terminal is disclosed. The first DC-voltage terminal is connected via a first semiconductor switch to a first intermediate point that is connected via a second semiconductor switch to a bridge center point that is connected via a third semiconductor switch to a second intermediate point that is connected via a fourth semiconductor switch to the second DC-voltage terminal. A first terminal of a resonant capacitor is connected to the first intermediate point, and a second terminal of the resonant capacitor is connected to a DC-link center point via a connecting path, in which a resonant inductor is arranged in a series circuit with the third semiconductor switch, and which runs via the second intermediate point. An additional winding is magnetically coupled to the resonant inductor and a first terminal thereof is connected via a first diode to a first terminal of a countervoltage source, and a second terminal thereof is connected to a second terminal of the countervoltage source so that an energy coupled into the additional winding from the resonant inductor is discharged into the countervoltage source.