CN-121984308-A - Modularized energy-taking power supply, submodule and modularized multi-level converter

CN121984308ACN 121984308 ACN121984308 ACN 121984308ACN-121984308-A

Abstract

The application provides a modularized energy-taking power supply, a submodule and a modularized multi-level converter. The modular energy harvesting power supply may include a control module, a plurality of isolation modules, and a plurality of voltage sharing modules. The plurality of isolation modules are connected with the plurality of voltage equalizing modules in a one-to-one correspondence. The control module is used for sending control signals to each isolation module. The isolation module is used for reducing the input voltage and providing the output voltage to the control system. The voltage equalizing module is used for providing input voltage for the isolation module. The application greatly reduces the volume of the energy-taking power supply, increases the power density of the energy-taking power supply and accelerates the heat dissipation speed. According to the application, the voltage equalizing modules are connected in series for voltage division, so that the normal operation of the sub-module can be maintained under the condition of single power supply loop fault, the modularized energy-taking power supply can adapt to higher working voltage, the sub-module is prevented from using expensive power devices, and the cost of the sub-module is reduced.

Inventors

Su Zhekan
CAI HANQI
LIU CHAO
LIU LI
GAO JIANJIAN
ZHANG XIAOLIN
LI JIANDONG
GONG LINGYUN
LIU ZHUO
Tai Gu
WEI YIMING
ZHANG GUOHUA
HU RONG
YANG FAN
TANG RUBIN
LI FENGQI
Liu Zhuogun
LIU HONGEN
CHEN XIAOLI

Assignees

中国电力科学研究院有限公司
国家电网有限公司直流技术中心
国网浙江省电力有限公司超高压分公司
国网浙江省电力有限公司
国家电网有限公司

Dates

Publication Date: 20260505
Application Date: 20251229

Claims (11)

1. The modularized energy-taking power supply is characterized by comprising a control module, a plurality of isolation modules and a plurality of voltage equalizing modules, wherein the isolation modules are connected with the voltage equalizing modules in a one-to-one correspondence manner; The control module is used for sending control signals to each isolation module according to the acquired input voltage, output voltage and output current of each isolation module; The isolation module is used for reducing the input voltage according to the control signal and providing the output voltage for a control system; the voltage equalizing module is used for providing the input voltage for the isolation module according to the voltage of the submodule capacitor.
2. The modular power supply of claim 1, wherein the control module is connected to the input of each of the isolation modules, the control module further connected to the output of each of the isolation modules; the voltage equalizing modules are connected in series and then connected with the submodule capacitor in parallel, the voltage equalizing modules are connected with the input end of the isolation module, and the output end of the isolation module is connected with the control system.
3. The modular power supply of claim 2, wherein the voltage balancing module comprises a voltage balancing capacitor and a voltage balancing resistor in parallel.
4. The modular power supply of claim 1, wherein the isolation module comprises an overvoltage protection unit, a bypass unit, an isolation unit, and an anti-reflection unit; the overvoltage protection unit is used for performing overvoltage protection on the isolation unit under the condition that the input voltage exceeds a preset voltage threshold value; the bypass unit is used for bypassing the isolation module under the condition that the isolation module fails; The isolation unit is used for reducing the input voltage according to the control signal and providing the output voltage for the control system; The anti-reflection unit is used for preventing output power of other isolation modules in the plurality of isolation modules from being reversely injected into the isolation module where the anti-reflection unit is located.
5. The modular power supply of claim 4, wherein the overvoltage protection unit, the bypass unit, and the isolation unit are connected in parallel, the isolation unit being connected to the control system through the anti-reflection unit.
6. The modular power supply of claim 4 or 5, wherein the overvoltage protection unit employs a transient suppression diode or a varistor; the bypass unit adopts a breaker or a relay.
7. The modular power supply of claim 4 or 5, wherein the anti-reflection unit employs a diode; The anode of the diode is connected with the isolation unit, and the cathode of the diode is connected with the control system.
8. The modular power supply of claim 4 or 5, wherein the isolation unit employs a flyback circuit, a forward circuit, a full bridge circuit, a half bridge circuit, or a push-pull circuit.
9. A sub-module comprising a sub-module capacitor, a control system and a sub-module power supply according to any one of claims 1 to 8; The energy taking power supply of the submodule is connected with the submodule capacitor, and the energy taking power supply of the submodule is also connected with the control system.
10. A modular multilevel converter comprising a plurality of sub-modules according to claim 9, the plurality of sub-modules being cascaded.
11. The modular multilevel converter of claim 10, wherein the plurality of sub-modules includes a first sub-module and a second sub-module; the energy-taking power supply of the submodule of the first submodule is connected with the control system of the first submodule and also connected with the control system of the second submodule and is used for supplying power to the control system of the first submodule and the control system of the second submodule; The sub-module energy-taking power supply of the second sub-module is connected with the control system of the first sub-module and is also connected with the control system of the second sub-module and used for supplying power to the control system of the first sub-module and the control system of the second sub-module.

Description

Modularized energy-taking power supply, submodule and modularized multi-level converter Technical Field The application relates to the technical field of power electronics, in particular to a modularized energy-taking power supply, a submodule and a modularized multi-level converter. Background The soft direct current converter valve (which can be a modularized multi-level converter MMC) is used as a core component of the soft direct current transmission system, and the performance and reliability of the soft direct current converter valve directly influence the safety, stability and economy of the soft direct current transmission system. MMC has become flexible direct current transmission engineering's preferred topology because of possessing advantages such as high modularization, easy extension, output waveform quality. MMCs typically include six legs, each leg being cascaded from a large number of sub-modules. The submodules generally comprise submodule capacitors, a control system, an energy taking power supply and the like. The energy-taking power supply can provide stable and reliable electric energy for other parts in the sub-module. In actual operation, the energy-taking power supply is in a high-voltage and high-current electromagnetic environment for a long time, bears multiple functions such as electric stress, thermal stress and mechanical stress, and is extremely easy to age, fatigue and even damage. The related art generally takes energy directly from the submodule capacitor, and converts the voltage of the submodule capacitor of several kilovolts into the voltage (e.g., 15V) required by the control system through a DC/DC converter. With the development of flexible direct current transmission technology, a single power device is difficult to directly bear the working voltage with higher voltage level, and a plurality of power devices are often required to be connected in series for use, so that the complexity of control is increased, and the problems of large energy taking power supply volume, low power density, difficult heat dissipation and the like caused by too small modulation duty ratio due to too high voltage transformation ratio are also caused. Once the energy-taking power supply fails, the whole sub-module loses control capability, and the sub-module bypass state detection is possibly failed when serious faults occur, so that the MMC is stopped. Disclosure of Invention In order to solve the problems of large volume, low power density and difficult heat dissipation in the prior art, the application provides a modularized energy-taking power supply, a submodule and a modularized multi-level converter. In a first aspect, the present application provides a modular power supply that may include a control module, a plurality of isolation modules, and a plurality of voltage sharing modules. The plurality of isolation modules are connected with the plurality of voltage equalizing modules in a one-to-one correspondence. The control module is used for sending control signals to each isolation module according to the collected input voltage, output voltage and output current of each isolation module. The isolation module is used for reducing the input voltage according to the control signal and providing the output voltage for the control system. The voltage equalizing module is used for providing input voltage for the isolation module according to the voltage of the sub-module capacitor. Optionally, the control module is connected with the input end of each isolation module, and the control module is also connected with the output end of each isolation module. And after the voltage equalizing modules are connected in series, the voltage equalizing modules are connected with the submodule capacitors in parallel. The voltage equalizing module is connected with the input end of the isolation module, and the output end of the isolation module is connected with the control system. In some possible implementations, the voltage balancing module includes a voltage balancing capacitor and a voltage balancing resistor connected in parallel. In other possible implementations, the isolation module includes an overvoltage protection unit, a bypass unit, an isolation unit, and an anti-reflection unit. The overvoltage protection unit is used for performing overvoltage protection on the isolation unit under the condition that the input voltage exceeds a preset voltage threshold value. The bypass unit is used for bypassing the isolation module under the condition that the isolation module fails. The isolation unit is used for reducing the input voltage according to the control signal and providing the output voltage for the control system. The anti-reflection unit is used for preventing output power of other isolation modules in the plurality of isolation modules from being reversely injected into the isolation module where the anti-reflection unit is located. The overvoltage protection unit, the bypass unit