Siemens Aktiengesellschaft

Siemens Energy Global Gmbh & Co. Kg

Mike Dommaschk

Klaus Würflinger

Jörg Lang

Jörg Dorn

Martin Pieschel

Joerg Dorn

Ingo Euler

Quoc-Buu Tu

Franz Karlecik-Maier

Carsten Wittstock

John-William Strauss

Joerg Lang

Tobias Bernhard

Herbert Gambach

Christoph Armschat

Klaus Wuerflinger

Volker Hussennether

Andreas Zenkner

Johann Holweg

Jürgen Rittiger

Guenter Ebner

Thomas Westerweller

Christian Siegl

Axel Preidel

Mark Davies

Wolfgang Goblirsch

Klaus Wurflinger

Dag Sörangr

Oliver Venjakob

Tobias Wieners-Rehrmann

Alfred Habermeier

Gunter Ebner

Wilhelm Wellmann

Günter Ebner

Sascha Kubera

Kraus WÜRFLINGER

A converter for symmetrical reactive power compensation has phase legs whose associated phases of a three-phase AC voltage network can be connected and are interconnected in an insulated star connection. The first phase leg is devoid of sub modules. The second and third phase legs each has a phase module with series-connected bipolar sub modules. A control device controls phase module currents and determines voltages to be set at each phase module. A decoupling unit calculates correction voltages for each phase module as a function of a first connection voltage between the first and second phase legs, a second connection voltage between the second and third phase legs and a first and/or a second control voltage each derived from target currents and the phase module currents of the second or third phase legs. The voltages to be set are derived from the control voltages and correction voltages.

Converter for symmetrical reactive power compensation, and a method for controlling same

A converter configuration has at least one series circuit with at least two series-connected sub-modules which in each case have at least one switch and are installed in each case at a predefined electrical installation position the converter configuration. The converter configuration further has a central unit connected to the sub-modules to control the sub-modules. The sub-modules in each case have a memory in which an identifier, in particular a serial number, uniquely identifying the respective sub-module is stored. The sub-modules in each case have a control device which can forward the stored identifier to the central unit via a communication connection connecting the respective sub-module and the central unit.

Converter arrangement and method for the operation thereof

A matrix inverter is connected to a first and a second multi-phase A.C. voltage network. First inductive elements are connected to the first A.C. voltage network and second inductive elements are connected to the second A.C. voltage network. A switch matrix connects the ends of the first inductive elements, to the ends of the second inductive elements. The switch matrix has inverter units. A regulation arrangement is connected to control inputs of the inverter units. The matrix inverter has a first inverter unit, which is arranged between the ends of the first inductive circuit elements and earth potential. The matrix inverter has a second inverter unit, connected between the ends of the first inductive circuit elements and the ends of the second inductive circuit elements. The regulation arrangement insures that the electrical power flowing to the matrix inverter is equal to the electrical power flowing out of the matrix inverter.

Matrix converter and method for generating an AC voltage in a second AC voltage grid from an AC voltage in a first AC voltage grid by means of a matrix converter

Electric power is transferred between an AC voltage grid and a DC voltage grid in the high-voltage range. Phase modules have at least one common DC voltage connection and separate AC voltage connections. A phase module branch between the DC voltage connection and each AC voltage connection has a series circuit of two-pole sub-modules, each with an energy storage device and a power semiconductor circuit in parallel with the energy storage device. The power semiconductor circuit is driven to generate either the voltage drop across the energy storage device or else a zero voltage at the two sub-module connection terminals. A converter transformer has a primary side on an AC voltage grid and a secondary side connected to the AC voltage connections. Improved protection against overloading is provided by at least one surge arrester between the or one of the common DC voltage connections and the inverter neutral point.

Modular multi-stage inverter comprising surge arrester

A device for inverting an electric parameter in the field of power transmission and distribution has a converter that can be connected between an alternating current grid and a DC circuit and having power semiconductor valves extending between an alternating current connection and a DC voltage connection. Each power semiconductor valve has a series circuit of bipolar submodules, each with an energy storage device and a power semiconductor circuit in parallel with the energy storage device, and a grid connection unit connected to the alternating current connection for connecting to the alternating current grid. Simple, effective, and inexpensive symmetrization of the voltages in the DC voltage circuit relative to ground potential is brought about. A star point reactor is connected between the grid connection unit and the inverter with a potential node, including throttle coils connected to a grounded star point. The throttle coils are implemented so that said coils implement a current path with a high impedance to ground potential for alternating current at the base frequency of the alternating current grid, and with low impedance to ground potential for DC current.

Star-point reactor

A method for the closed-loop control of current converters for adjusting the counter-voltage in a multi-phase electric energy transmission network having a multi-phase connection line. In order to be parameterize in various operating states, phase currents are registered on the connection line and transformed into system current components by way of transformation, voltages are registered on the phases of the connection line, and counter-system voltage components are formed therefrom by way of transformation, which are supplied to a voltage controller. Counter-system current components serving to reduce the counter-system are formed in the voltage controller, which are supplied to a target value input of a current controller. System current components are connected to an actual value input of the current controller, the output parameters thereof serving after retransformation as switching currents for switching units of the current converter.

Method for regulation of power converters and arrangement for carrying out the method

A device for converting an electric current includes at least one phase module having an AC terminal and at least one DC terminal. Phase module branches, each of which is equipped with serially connected submodules, are respectively provided between each DC terminal and each AC terminal. Each submodule is provided with at least one power semiconductor. Semiconductor protecting means are connected in parallel or in series to at least one of the power semiconductors to enable the device to withstand even high short-circuit currents for a sufficient period of time. A method for protecting the power semiconductors of the device, is also provided.

Semiconductor protection elements for controlling short circuits at the DC end of voltage source converters

A device has a converter which is connected to a direct voltage circuit through a short-circuit protection unit. The short-circuit protection unit is arranged at least partially in the direct voltage circuit and is provided in the direct voltage circuit to suppress short-circuit current flowing through the converter. The device contains one or more controllable power semiconductors, wherein a protection element is arranged in parallel to at least one of the controllable power semiconductors. The device prevents the negative effects of a short circuit occurring in the direct voltage network in a particularly reliable manner. For this purpose, the protection element is an energy store.

Apparatus having a converter

A device converts electrical energy into heat in the field of drive voltage technology and/or high voltage technology. The device contains a brake resistance and at least one controllable brake power semiconductor for controlling the conversion, enabling a rapid and economical transformation of effective power into heat as required. To this end, the brake resistance contains a plurality of individual brake resistances that are each part of a bipolar submodule. The submodules are connected in series, form a submodule series connection, and at least partially contain an energy accumulator respectively connected in parallel to an associated individual brake resistance and a controllable brake power semiconductor, which allows the current flow over the respectively associated individual brake resistance in a brake position, and interrupts the current flow over the brake resistance in a normal operating position.

Converter with distributed brake resistances

A device for converting an electric current has a phase module, which in turn has an alternating current connection and at least one direct current connection connected to an intermediate direct current circuit. The device further has an energy accumulator. A phase modulation path is formed between each direct current connection and each alternating current connection. Each phase modulation path has a series connection of submodules, which each have a power semiconductor. A semiconductor protective device is provided in parallel connection to power semiconductors of each submodule. A control unit actuates the semiconductor protective device, and energy accumulator(s) are equipped for supplying energy to the control unit. The device safely prevents damage from a short circuit on the direct-current side, even when the supply grid is connected, because a direct current connection of each phase module is connected to the intermediate direct current circuit via a direct-current switch.

Method for limiting damage to a converter having power semiconductors in the case of a short circuit in the DC voltage intermediate circuit

A device for inverting an electric current has at least one phase module which has an alternating current connection and at least one direct current connection. Semiconductor valves having semiconductor modules are connected in series and are provided for switching the electric current between the alternating current connection and each direct current connection. At least one power storage device is provided for storing electrical power. In order to provide such a device, with which the adverse effects of a bridging short circuit are reliably and effectively reduced, it is proposed that each semiconductor module has semiconductor groups connected in parallel to each other, wherein each semiconductor group of the semiconductor module is connected via its own separate semiconductor current path to at least one of the power storage devices.

Converter with short-circuit current limiting

A method for charging and/or discharging energy storage devices is performed in a multilevel converter including at least one phase module branch having a series circuit of submodules each with at least one power semiconductor circuit for connection or disconnection of an energy storage device in a circuit parallel to the power semiconductor circuit and a submodule sensor for detection of an energy storage actual value. An energy change state is obtained and a determination is made as to whether connected energy storage devices in a phase module branch can be charged or discharged. The next energy storage device to be switched in each phase module branch is selected by predetermined logic dependent on an energy change state, through which energy stored in energy storage devices is kept approximately at the same level. A high clock rate is simultaneously avoided for connection and disconnection of the selected energy storage device.

Driving of a phase module branch of a multilevel converter

In the method for closed-loop control of at least two converters in an energy transmission and/or distribution system, each rectifier regulator and each inverter regulator provides a differential DC voltage from the difference between a given set DC voltage and the relevant received measured DC voltage, and also provides a differential DC current from a differential DC current from the difference between a set DC current and the corresponding received measured DC current. Each converter is a self-commutated converter with power semiconductors. The rectifier regulation of the provided converter is regulated such that the sum of the product of the differential voltages and the value of given set DC current at the corresponding rectifier and the differential current is a minimum. The inverter regulation regulates the corresponding inverter such that the sum between the differential voltage and the differential current is a minimum.

Closed-loop control method for an HVDC transfer installation having a DC voltage intermediate circuit and self-commutated converters

A device for converting an electrical current includes at least one phase module with an AC voltage connection and at least one DC voltage connection, a phase module branch disposed between each DC voltage connection and the AC voltage connection and each phase module branch having a series circuit of submodules, each of which has an energy accumulator and at least one power semiconductor and closed-loop control means for regulating the device. The device can regulate circulating currents in a targeted manner by providing each phase module with at least one inductance and configuring the closed-loop control means to regulate a circulating current that flows through the phase modules.

Device for converting an electric current

A method and a device for converting an electrical current include at least one phase module having an AC voltage connection and at least one DC voltage connection. A phase module branch is disposed between each DC voltage connection and the AC voltage connection. Each phase module branch includes a series circuit of submodules, each having a capacitor and at least one power semiconductor. The apparatus can establish aging of an energy storage device in a simple manner by using a capacitor diagnosis device for a time-dependent determination of the capacitance of each capacitor.

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Guteborn, Germany

Mike Dommaschk