Device and method for controlling a load flow in an alternating-voltage network

Patent metadata

Field	Value
Publication number	US-10468884-B2
Application number	US-201515780653-A
Country	US
Kind code	B2
Filing date	Dec 14, 2015
Priority date	Dec 14, 2015
Publication date	Nov 5, 2019
Grant date	Nov 5, 2019

Abstract

A device controls a load flow in an alternating-voltage network. The device is distinguished by a module series circuit of two-pole switching modules that can be inserted in series into a phase line of the alternating-voltage network. Each switching module has an energy store and controllable power semiconductors that can be switched on an off and each switching module can be controlled in such a way that a switching-module voltage can be produced at the poles thereof, which switching-module voltage corresponds to a positive or negative energy-store voltage or a voltage having the value of zero. A control apparatus for controlling the switching modules is provided, which control apparatus is configured to control the switching modules in such a way that a periodic longitudinal voltage can be produced at the module series circuit. A method for controlling a load flow in an alternating-voltage network is performed by the device.

First claim

The invention claimed is:

1. A device for controlling a load flow in an alternating-voltage network, the device comprising:
a first modular series connection of bipolar switching modules serially inserted into a phase line of the alternating-voltage network, each of said bipolar switching modules having pole connectors, an energy-storage device and power semiconductors capable of being driven and capable of being switched on and off, and capable of being driven in such a manner that a switching-module voltage that corresponds to a positive or negative energy-storage voltage or to a voltage having a value zero can be generated at said pole connectors;
a control device for driving said bipolar switching modules and being set up to drive said bipolar switching modules in such a manner that a periodic longitudinal voltage is generated at said modular series connection;
a second modular series connection of said bipolar switching modules inserted into an outgoing line of the alternating-voltage network which is connected to the phase line, and by means of said second modular series connection a second longitudinal voltage can be generated;
an energy-exchange device connected to said first modular series connection and to said second modular series connection and set up for an exchange of electrical energy between the phase line and the outgoing line;
wherein said energy-exchange device includes a busbar and a first inverter connected on a direct-voltage side to said energy-storage device of one of said bipolar switching modules of said first modular series connection, and on an alternating-voltage side to said busbar, said energy-exchange device further includes a second inverter which is connected on a direct-voltage side to said energy-storage device of one of said bipolar switching modules of said second modular series connection, and on an alternating-voltage side to said busbar.

2. The device according to claim 1 , wherein said energy-exchange device has a transformer and said first and said second inverters are respectively connected to said busbar via said transformer.

3. The device according to claim 1 , wherein said energy-exchange device has an additional transformer and said busbar is connected to a further alternating-voltage network via said additional transformer.

4. The device according to claim 1 , wherein said energy-exchange device includes at least one energy-exchange branch in which a series connection of energy-exchange modules is disposed, each of said energy-exchange modules has poles, an energy-storage device and power semiconductors that are capable of being driven and capable of being switched on and off, and is capable of being driven in such a manner that at said poles an exchange-module voltage can be generated that corresponds to the positive or negative energy-storage voltage or to the voltage having the value zero.

5. The device according to claim 1 , wherein a plurality of additional modular series connections having said bipolar switching modules are disposed which can be respectively inserted into additional outgoing lines assigned to them and connected to the phase line, wherein said energy-exchange device is connected to said additional modular series connections and has been set up for an exchange of energy between the phase line, the outgoing line and the additional outgoing lines.

6. The device according to claim 5 , wherein said energy-exchange device includes energy-exchange branches disposed between the phase line, the outgoing line and the additional outgoing lines, which form a ring structure.

7. The device according to claim 5 , wherein said energy-exchange device includes energy-exchange branches between the phase line, the outgoing line and the additional outgoing lines, which form a star structure.

8. The device according to claim 1 , wherein the device has been set up for controlling a load flow in a polyphase alternating-voltage network.

9. The device according to claim 1 , wherein said bipolar switching modules take a form of full-bridge circuits.

10. The device according to claim 1 , wherein said bipolar switching modules each take a form of two oppositely-directed half-bridge circuits.

11. A method for controlling a load flow in an alternating-voltage network, which comprises the steps of:
providing a first modular series connection of bipolar switching modules which has been inserted into a phase line of the alternating-voltage network, wherein each of the bipolar switching modules has poles, an energy-storage device and power semiconductors that are capable of being driven and capable of being switched on and off, and capable of being driven in such a manner that at the poles a switching-module voltage can be generated that corresponds to a positive or negative energy-storage voltage or to a voltage having a value zero;
providing a control device driving the bipolar switching modules in such a manner that a periodic longitudinal voltage is generated at the first modular series connection;
providing a second modular series connection having the bipolar switching modules and which has been inserted into an outgoing line of the alternating-voltage network which is connected to the phase line, and generating a second longitudinal voltage by the second modular series connection;
exchanging electrical energy between the phase line and the outgoing line by way of an energy-exchange device connected to the first modular series connection and to the second modular series connection;
wherein the energy-exchange device is provided a busbar and a first inverter connected on a direct-voltage side to the energy-storage device of one of the bipolar switching modules of the first modular series connection, and on an alternating-voltage side to the busbar, the energy-exchange device further includes a second inverter which is connected on a direct-voltage side to the energy-storage device of one of the bipolar switching modules of the second modular series connection, and on an alternating-voltage side to the busbar.

12. The method according to claim 11 , which further comprises:
driving the bipolar switching modules of the second modular series connection by means of the control device in such a manner that a further longitudinal voltage is generated at the second modular series connection; and
exchanging electrical energy between the phase line and the outgoing line by means of an energy-exchange device connected to the first modular series connection and the second modular series connection.

Assignees

• Siemens Ag

Inventors

• Augsburger Friedemann
• Ergin Dominik
• Knaak Hans-Joachim
• Philipp Andreas
• Schaefer Jochen

Classifications

• Y02E40/50

  Arrangements for eliminating or reducing asymmetry in polyphase networks · CPC title

• H02M5/44

  using discharge tubes or semiconductor devices to convert the intermediate DC into AC · CPC title

• H02J3/26

  Arrangements for eliminating or reducing asymmetry in polyphase networks · CPC title

• H02J3/1814 Primary

  having reactive elements actively controlled by bridge converters, e.g. unified power flow controllers [UPFC] or controlled series voltage compensators · CPC title

• Y02E40/18

  Cross-Sectional Technologies · mapped topic