Patent application number | Description | Published |
20100020577 | PRODUCTION OF A REAL POWER EQUILIBRIUM OF THE PHASE MODULES OF A CONVERTER - A converter has at least one phase module, an AC voltage terminal and a DC voltage terminal. A phase module branch is formed between each DC voltage terminal and each AC voltage terminal. Each phase module branch has a series circuit containing submodules which each have a capacitor, a power semiconductor, and submodule sensors for detecting energy stored in the capacitor and with a regulation device for regulating the apparatus in dependence on energy values and predetermined desired values. Therefore unbalanced loading of the energy storage units is avoided. The regulation device has a summation unit for summing the energy values while obtaining branch energy actual values and a device for calculating circuit current desired values in dependence on the branch energy actual values. The regulation device compensates for imbalances in the branch energy actual values in dependence on the circuit current desired values. | 01-28-2010 |
20100034001 | Converter with Short-Circuit Current Limiting - 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. | 02-11-2010 |
20100060235 | DRIVING OF A PHASE MODULE BRANCH OF A MULTILEVEL CONVERTER - 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. | 03-11-2010 |
20100085785 | 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 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. | 04-08-2010 |
20100118578 | DEVICE FOR CONVERTING AN ELECTRIC CURRENT - 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. | 05-13-2010 |
20100321038 | MONITORING OF THE AGING OF THE CAPACITORS IN A CONVERTER BY MEANS OF CAPACITANCE MEASUREMENT - 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. | 12-23-2010 |
20110205771 | CLOSED-LOOP CONTROL METHOD FOR AN HVDC TRANSFER INSTALLATION HAVING A DC VOLTAGE INTERMEDIATE CIRCUIT AND SELF-COMMUTATED CONVERTERS - A closed-loop control method for at least two converters in an energy transmission and/or distribution system. The converters may be controlled either as rectifier or inverter and they are connected to each other by a DC link. A measured DC voltage and a measured DC current is measured at each converter and transmitted to a rectifier regulator for regulating the corresponding rectifier or to an inverter regulator for regulating the corresponding inverter. Each rectifier regulator and each inverter regulator gives the difference between a given set DC voltage and the relevant received measured DC voltage to give a differential DC voltage and the difference between a set DC current and the corresponding received measured DC current to give a differential DC current. The measured DC current, the measured DC voltage, the set DC current and the set DC voltage are normalized with which a regulation of inverters formed of switchable power semiconductors connected by a DC link can be carried out, wherein the proviso of set currents being zero is possible. Each converter is a self-commutated converter with power semiconductors and 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 and the inverter regulation regulates the corresponding inverter such that the sum between the differential voltage and the differential current is a minimum. | 08-25-2011 |
20110235375 | APPARATUS HAVING A CONVERTER - 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. | 09-29-2011 |
20120187924 | METHOD FOR CONTROLLING CURRENT CONVERTERS AND ASSEMBLY FOR PERFORMING SAID METHOD - 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. | 07-26-2012 |