Provided is a power conversion device which can be configured inexpensively and in which initial charging can be performed quickly. Accordingly, the power conversion device is provided with: a power conversion device cell having a first converter for converting a first AC voltage to a first DC voltage, a second converter for converting the first DC voltage to another voltage, and a first capacitor charged by the first DC voltage; and a control circuit for allowing charging of the first capacitor while changing the operational state of the first converter in accordance with the first DC voltage.

A modular multi-level converter including modules each having switching elements and at least one electrical energy storage element, wherein a first number of modules are interconnected to form a closed ring, and at least two taps are arranged between respective adjacent individual modules of the closed ring. Wherein at at least two taps respectively a second number of modules are provided as a phase module branching off from the closed ring and forming a star string comprising at least two modules, the phase module connected to the respective tap on one end and forming a phase terminal at an other end. Wherein the switching elements enable interconnection of energy storage elements of adjacent modules, as a result of which between two adjacent phase terminals a voltage difference is provideable, which is regulatable by a control unit in accordance with a polyphase rotating field profile. Furthermore, the present invention relates to a polyphase system and a method for efficient power exchange between modules.

Provided is a power conversion device which can be configured inexpensively and in which initial charging can be performed quickly. Accordingly, the power conversion device is provided with: a power conversion device cell having a first converter for converting a first AC voltage to a first DC voltage, a second converter for converting the first DC voltage to another voltage, and a first capacitor charged by the first DC voltage; and a control circuit for allowing charging of the first capacitor while changing the operational state of the first converter in accordance with the first DC voltage.

Reduced-power dynamic data circuits with wide-band energy recovery are described herein. In one embodiment, a circuit system comprises at least one sub-circuit in which at least one of the sub-circuits includes a capacitive output node that is driven between low and high states in a random manner for a time period and an inductive circuit path coupled to the capacitive output node. The inductive circuit path includes a transistor switch and an inductor connected in series to discharge and recharge the output node to a bias supply. A pulse generator circuit generates a pulse width that corresponds to a timing for driving the output node.

A resonant converter and a manufacturing method of a transformer thereof are provided. The resonant converter includes a full bridge circuit, an element, a first branch circuit, a second branch circuit and a secondary winding. The full bridge circuit includes a first node and a second node. The element includes an inductor or a capacitor. The first branch circuit includes a first primary winding. The second branch circuit includes a second primary winding, and the first and second primary windings have the same turn number. The transformer is constructed by the first and second primary windings and the secondary winding. The first branch circuit, the element and the second branch circuit are sequentially coupled in series between the first and second nodes. The first branch circuit and the second branch circuit are symmetrically located with respect to the element. The first and second branch circuits have the same impedance.

Control unit for controlling an inverter with a plurality of half bridges each having a first switching element connected to a potential of a DC link and a second switching element connected to another potential of the DC link. The control unit provides first signals to the first switching elements such that they are turned off upon receiving a request signal, and second signals to the second switching elements such that they are turned on upon receiving the request signal and to perform a comparison of a measured electric parameter of the inverter with a predefined threshold value. The control unit provides a second signal such that the second switching element controlled by the second signal is turned off for a predefined time span, if a switching criterion comprising a condition that the comparison results in that the measured electric parameter reaches or crosses the threshold value is fulfilled.

A drive circuit for an electromagnetic brake is used in a circuit including a motor, a converter converting a DC voltage into an AC voltage to be generated between a pair of DC link buses, and an inverter converting the DC voltage into an AC voltage and driving the motor. A full-bridge circuit has a pair of power supply terminals connected to the pair of DC link buses, and a pair of output terminals connected to the electromagnetic brake.

A multi-output power supply device includes an inductor, a first output terminal, a second output terminal, an FET, an FET, a chopper circuit, and a controller. The FET adjusts a current output from the inductor to the first output terminal. The FET adjusts a current output from the inductor to the second output terminal. The chopper circuit has the FET and the inductor. The FET is connected in parallel with the FET, and conducts or cuts off a current. The inductor is provided between the FET and the second output terminal. For example, the controller lowers a potential from the first output terminal by turning on the FET and sets a potential difference between a drain terminal and a source terminal of the FET to zero to suppress a switching loss when the FET is turned on.

An arrangement for controlling a power flow in an AC voltage grid includes a converter arrangement having a first converter and a second converter. The converters are connectable to one another on the DC voltage side through a DC voltage link and are each connectable to the AC voltage grid on the AC voltage side. During the operation of the arrangement, the converters are correspondingly connected to the AC voltage grid. A switching branch is provided in the DC voltage link in parallel with the converters and at least one controllable switching element is provided in the switching branch. A method for protecting the arrangement in the case of an overload is also provided.

A power conversion device of an embodiment includes a power conversion unit, a first capacitor, a gate circuit, a bypass circuit, and a discharging circuit. The power conversion unit includes a plurality of switching elements each having a gate and generates alternating current (AC) power from direct current (DC) power supplied to a provided DC input terminal. The first capacitor is provided on a DC input side of the power conversion unit. The gate circuit includes a drive circuit configured to output a gate drive signal to be supplied to gates of one or more switching elements among the plurality of switching elements and a second capacitor configured to smooth a power supply voltage of power to be supplied to the drive circuit. The bypass circuit causes the second capacitor to be charged with a part of power stored in the first capacitor at the time of power supply loss of a control system circuit and enables the gate drive signal to be maintained in a negative bias by power stored in the second capacitor.