CN111162559A - Flexible direct current transmission system energy consumption device - Google Patents
Flexible direct current transmission system energy consumption device Download PDFInfo
- Publication number
- CN111162559A CN111162559A CN202010125869.4A CN202010125869A CN111162559A CN 111162559 A CN111162559 A CN 111162559A CN 202010125869 A CN202010125869 A CN 202010125869A CN 111162559 A CN111162559 A CN 111162559A
- Authority
- CN
- China
- Prior art keywords
- current
- energy consumption
- power sub
- module
- flexible direct
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Classifications
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/36—Arrangements for transfer of electric power between ac networks via a high-tension dc link
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M1/00—Details of apparatus for conversion
- H02M1/32—Means for protecting converters other than automatic disconnection
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/60—Arrangements for transfer of electric power between AC networks or generators via a high voltage DC link [HVCD]
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Direct Current Feeding And Distribution (AREA)
Abstract
The invention discloses an energy consumption device of a flexible direct-current power transmission system, which is used for solving the problem that direct-current overvoltage is generated on a direct-current side due to surplus direct-current power when an alternating-current system fails, and consists of a plurality of cascaded power sub-modules M1-Mn, a centralized energy consumption resistor R1, current-limiting inductors L1-L2 and isolating switches S1-S2; the power sub-module topology is composed of a capacitor C, a full-control type switching device T, an anti-parallel diode D, a voltage-sharing resistor R, a through-current diode D1, a bypass switch BRK and a thyristor VB. The energy consumption device is used for consuming surplus power on the direct current side of the flexible direct current power transmission system, is matched with the alternating current fault ride-through of the flexible direct current system, strives for action time for the fan when the fault cannot be cleared, and guarantees safety and reliability of the whole flexible direct current system.
Description
Technical Field
The invention belongs to the technical field of flexible direct current, and particularly relates to an energy consumption device of a flexible direct current power transmission system.
Background
The flexible direct-current transmission system is very suitable for the fields of new energy grid connection, island power supply, power grid interconnection and the like due to the obvious technical advantages, and is especially suitable for long-distance and high-capacity new energy occasions.
At present, the requirements of energy transformation and energy upgrading are increasingly urgent, and the development pace of new energy is remarkably improved. China is wide in breadth, offshore and open sea wind resources are rich, and the situation of power shortage in China can be well relieved by sending out the wind resources. Although flexible direct current transmission is the optimal solution for sending out new energy at present, the mechanical inertia of the fan is large, the reaction time is slow, when alternating current fault occurs in the onshore flexible direct current station, the fan cannot be cut off in time, the new energy is blocked from being sent out, energy accumulation of the converter valve is caused, the voltage of the module is increased, the direct current voltage is increased, and the whole system is damaged. Aiming at the problems, an energy consumption device is required to be added to the flexible and straight system to absorb surplus energy, the fan strives for action time, and the system safety is protected. At present, a scheme of a thyristor and an energy consumption resistor is generally adopted in engineering, an energy consumption device is connected to an alternating current side of a flexible direct station and needs to be switched in groups, but direct current flows through a converter valve, and the withstand pressure of the converter valve is increased.
Disclosure of Invention
The invention provides an energy consumption device of a flexible direct-current transmission system, which adopts a power sub-module series connection centralized energy consumption scheme to limit surplus energy to flow to a receiving-end converter valve so as to cause the lifting of module voltage in the converter valve.
In order to achieve the purpose, the flexible direct current transmission system energy consumption device comprises n cascaded power sub-modules M1-Mn, a centralized energy consumption resistor R1, a current-limiting inductor L1, a current-limiting inductor L2, an isolating switch S1 and an isolating switch S2;
the positive end of an isolating switch S1 is connected with the positive electrode of a direct current bus, the negative end of an isolating switch S1 is connected with the positive end of a current-limiting inductor L1, the negative end of the current-limiting inductor L1 is connected with the positive end of a power submodule M1, power submodules M1-Mn are cascaded, the negative end of the power submodule Mn is connected with the positive end of a current-limiting inductor L2, the negative end of a current-limiting inductor L2 is connected with the positive end of a centralized energy-consuming resistor R1, the negative end of a centralized energy-consuming resistor R1 is connected with the positive end of an isolating switch S2, and the negative end of an isolating switch S2.
Further, the power sub-module comprises at least one basic unit, and when the number of the basic units is larger than 1, the second port of the basic unit is connected with the first port of the second basic unit adjacent to the second port of the basic unit.
Further, the basic unit comprises a capacitor C, a fully-controlled switch device T, an anti-parallel diode D and a voltage-sharing resistor R, the positive end of the capacitor C, the collector of the fully-controlled switch device T, the cathode of the anti-parallel diode D and the positive end of the voltage-sharing resistor R are connected to the positive end of the port of the power submodule, and the negative end of the capacitor C, the negative end of the voltage-sharing resistor R, the emitter of the fully-controlled switch device T and the cathode of the anti-parallel diode D are connected to the negative end of the power submodule.
Furthermore, the positive end of the port of the power sub-module is connected with the positive end of the conduction bypass switch BRK, and the negative end of the conduction bypass switch BRK is connected with the negative end of the power sub-module.
Furthermore, the positive end of the port of the power sub-module is connected with the anode of the thyristor VB, and the cathode of the thyristor VB is connected with the negative end of the power sub-module.
Further, the negative terminal of the capacitor C is connected to the anode of the current diode D1, and the cathode of the current diode D1 is connected to the negative terminal of the power sub-module.
Further, the centralized energy dissipation resistor R1 is a metal resistor.
The invention has at least the following beneficial technical effects:
the energy dissipation device is bridged on positive and negative bus bars on the direct current side of the flexible direct current system, when an alternating current power grid fault occurs, the energy dissipation device conducts the fully-controlled switch devices T of all power sub-modules, surplus energy is discharged to the centralized energy dissipation resistor R1, direct current voltage is limited to be lifted, surplus energy is limited to flow to the receiving end converter valve, module voltage in the converter valve is limited to be lifted, and safety of the flexible direct current converter valve is guaranteed. After the flexible direct-current system is shut down, a large amount of electric energy is stored in the direct-current cable, and the characteristic that energy consumption resistors in the energy consumption devices consume energy is utilized, so that the direct-current cable can be rapidly discharged, and favorable conditions are created for restarting the system.
The centralized energy consumption resistor R1 has certain energy tolerance capability, can provide favorable conditions for the smooth ride-through of the alternating current fault, and strives for action time for the fan when the alternating current fault cannot be eliminated.
Furthermore, the energy consumption device is influenced by the voltage-sharing resistor R, when the voltage of the capacitor C of a certain power submodule is higher, the system stops charging the capacitor C by triggering the fully-controlled switch device T of the power submodule, the capacitor C discharges the voltage-sharing resistor R to reduce the voltage, when the voltage is lower than a set value, the fully-controlled switch device T of the power submodule is closed, the charging of the capacitor C of the power submodule of the system is recovered, and the capacitor voltage of each power submodule in the energy consumption device is controlled within a certain range.
Furthermore, the energy consumption device is beneficially influenced by the capacitor C, and the energy taking power supply of the power sub-module takes electricity from the capacitor C without additionally configuring a power supply.
Furthermore, the centralized energy consumption resistor R1 can be a metal resistor with mature technology and low price, adopts natural cooling, and can be placed outdoors to reduce the heating and ventilation requirements of a valve hall, thereby reducing the cost of an energy consumption device.
Furthermore, the energy consumption device is beneficially influenced by the bypass switch BRK, and the power sub-module can be isolated when in fault.
Furthermore, the energy consumption device is beneficially influenced by the thyristor VB, when the power submodule is in overvoltage and the bypass switch BRK fails to isolate the power submodule, the thyristor VB is broken down and short-circuited by the overvoltage of the power submodule, and the purpose of isolating the fault submodule is achieved.
Furthermore, the energy consumption device is beneficially influenced by the through-current diode D1, and when the bypass switch BRK is switched on, the capacitor C is prevented from discharging to the bypass switch BRK to cause damage to the bypass switch.
Drawings
FIG. 1 is a topology of an energy consuming device of a flexible DC power transmission system;
FIG. 2 is a power sub-module topology in embodiment 1;
FIG. 3 is a second power sub-module topology in example 2;
in fig. 1, 9-first base unit, 10-second base unit, 91-first base unit first port, 92-first base unit second port, 101-second base unit first port, 102-second base unit second port.
Detailed Description
In order to make the objects and technical solutions of the present invention clearer and easier to understand. The present invention will be described in further detail with reference to the following drawings and examples, wherein the specific examples are provided for illustrative purposes only and are not intended to limit the present invention.
Example 1
In fig. 1, the topology of the flexible dc power transmission system energy consumption device is composed of a plurality of cascaded power sub-modules M1-Mn, a centralized energy consumption resistor R1, a current-limiting inductor L1, a current-limiting inductor L2, an isolation switch S1, and an isolation switch S2. Assuming that the positive pole of each device in the energy consumption device close to the direct current bus is a positive end, the negative pole of each device close to the direct current bus is a negative end, the positive end of an isolating switch S1 of the device is connected with the positive pole of the direct current bus, the negative end of an isolating switch S1 is connected with the positive end of a current-limiting inductor L1, the negative end of the current-limiting inductor L1 is connected with the positive end of a power submodule M1, the power submodule M1-the power submodule Mn are cascaded, and n is more than or equal to 2; the negative end of the power sub-module Mn is connected to the positive end of the current-limiting inductor L2, the negative end of the current-limiting inductor L2 is connected to the positive end of the centralized energy-consuming resistor R1, the negative end of the centralized energy-consuming resistor R1 is connected to the positive end of the isolating switch S2, and the negative end of the isolating switch S2 is connected to the negative end of the dc bus.
Fig. 2 is a power sub-module topology of an energy consumption device of a flexible direct current transmission system, the power sub-module topology comprising a capacitor C, a fully-controlled switch device T, an anti-parallel diode D, a voltage-sharing resistor R, a current-passing diode D1, a bypass switch BRK, and a thyristor VB; the positive end of the capacitor C, the collector of the fully-controlled switch device T, the cathode of the anti-parallel diode D, the positive end of the voltage-sharing resistor R, the positive end of the bypass switch BRK and the anode of the thyristor VB are all connected to the positive end of the port of the power submodule, the negative end of the capacitor C and the negative end of the voltage-sharing resistor R are connected to the anode of the through-current diode D1, and the emitter of the fully-controlled switch device T, the cathode of the anti-parallel diode D, the negative end of the bypass switch BRK, the cathode of the thyristor VB and the cathode of the through-current diode D1 are connected to the negative end of the power submodule.
When the voltage of the direct-current bus is higher than a set value Uset1, the fully-controlled switching devices T of all the power sub-modules are switched on, the impedance of the energy consumption device is mainly energy consumption resistor R1, the direct-current side part or all current flows through the centralized energy consumption resistor R1, and the voltage of the direct-current bus is reduced; when the voltage of the direct current bus is lower than a set value Uset2, the fully-controlled switching devices T of all the power sub-modules are turned off, and because the sum of the capacitor voltages of all the power sub-modules is approximately equal to the set value Uset1, and Uset1> Uset2, the reverse blocking action of the through-current diodes D1 of the power sub-modules is achieved, no current flows to the direct current side of the energy consumption device, all the current on the direct current side flows to the receiving end converter valve, the voltage of the direct current bus is increased, and when the voltage of the direct current bus reaches Uset1 again, the energy consumption device is conducted. At the moment when all power sub-module fully-controlled switching devices T of the energy consumption device are conducted, the current limiting inductors L1 and L2 limit the current change rate of the energy consumption device R1, so that the current flowing through the energy consumption device has certain buffering. When the voltage of a direct current side is lower than Uset1 for a long time, the energy consumption device works in a steady-state voltage-sharing state, when the voltage of a capacitor C of a certain power submodule is higher, the system stops charging the capacitor C by triggering a fully-controlled switch device T of the power submodule, the capacitor C discharges a voltage-sharing resistor R to reduce the voltage, when the voltage is lower than a set value, the fully-controlled switch device T of the power submodule is closed, the system is recovered to charge the capacitor C of the power submodule, the voltage of the capacitor of each power submodule in the energy consumption device is controlled within a set range, and the set range is generally within +/-10% of rated voltage. When the power sub-module fails, the bypass switch BRK can be triggered to isolate the fault, when the bypass switch BRK fails, the power sub-module cannot be isolated, the voltage of the power sub-module further rises, and when the breakdown voltage of the thyristor VB is reached, the thyristor VB breaks down and is short-circuited, so that the purpose of isolating the failed power sub-module is achieved. When the system stops running, a large amount of electric energy is stored in the direct current cable, the direct current voltage drops slowly, the set values Uset1 and Uset2 can be reduced, the electric energy in the cable is quickly released through the centralized energy consumption resistor R1, and favorable conditions are created for restarting the system. When the energy consumption device needs to be overhauled, the isolating switch S1 and the isolating switch S2 are disconnected, and overhauling safety is guaranteed. The device designs the energy tolerance of the centralized energy consumption resistor through the rated power discharge time of the flexible direct system, strives for certain action time for the fan when an alternating current fault cannot pass through smoothly, and guarantees the safety of the system.
Example 2
The difference between this embodiment and embodiment 1 lies in that the power sub-module topology is different, in this embodiment, the power sub-module topology is as shown in fig. 3, the power sub-module topology is formed by cascading two identical basic units, a basic unit is the power sub-module topology in embodiment 1, a second end 92 of a first basic unit 9 of a power sub-module is connected to a first port 101 of a second basic unit 10, a first port 91 of the first basic unit of the power sub-module is connected to a second port of a second basic unit of a previous power sub-module, and a second port 102 of the second basic unit of the power sub-module is connected to a first port of a first basic unit of a next power sub-module; in this embodiment, the power sub-module topology is the same as the control method and function of the power sub-module topology in embodiment 1, but the power sub-module topology in this embodiment uses fewer structural components (packaged plates, some structural members inside the module) than the power sub-module topology 1, and the cost of the energy consumption device can be reduced to a certain extent.
Finally, it should be noted that: the technical solutions of the present invention are only illustrated in conjunction with the above-mentioned embodiments, and not limited thereto. Those of ordinary skill in the art will understand that: modifications and equivalents may be made to the embodiments of the invention by those skilled in the art, which modifications and equivalents are within the scope of the claims appended hereto.
Claims (7)
1. The flexible direct-current transmission system energy consumption device is characterized by comprising n cascaded power sub-modules M1-Mn, a centralized energy consumption resistor R1, a current-limiting inductor L1, a current-limiting inductor L2, an isolating switch S1 and an isolating switch S2;
the positive end of the isolating switch S1 is connected with the positive electrode of the direct current bus, the negative end of the isolating switch S1 is connected with the positive end of a current-limiting inductor L1, the negative end of the current-limiting inductor L1 is connected with the positive end of a power sub-module M1, the power sub-modules M1-Mn are cascaded, the negative end of the power sub-module Mn is connected with the positive end of a current-limiting inductor L2, the negative end of a current-limiting inductor L2 is connected with the positive end of a centralized energy-consuming resistor R1, the negative end of the centralized energy-consuming resistor R1 is connected with the positive end of an isolating switch S2, and the negative end of an isolating.
2. The flexible direct current transmission system energy consumption device of claim 1, wherein the power sub-module comprises at least one basic unit, and when the number of the basic units is greater than 1, the second port of the basic unit is connected with the first port of a second basic unit adjacent to the second port of the basic unit.
3. The flexible direct-current transmission system energy consumption device according to claim 2, wherein the base unit comprises a capacitor C, a fully-controlled switching device T, an anti-parallel diode D and a voltage-sharing resistor R, wherein a positive terminal of the capacitor C, a collector of the fully-controlled switching device T, a cathode of the anti-parallel diode D and a positive terminal of the voltage-sharing resistor R are connected to a positive terminal of a port of the power sub-module, and a negative terminal of the capacitor C, a negative terminal of the voltage-sharing resistor R, an emitter of the fully-controlled switching device T and a cathode of the anti-parallel diode D are connected to a negative terminal of the power sub-module.
4. The flexible direct current transmission system energy consumption device as claimed in claim 3, wherein a positive end of the power sub-module port is connected with a positive end of a conduction bypass switch BRK, and a negative end of the conduction bypass switch BRK is connected with a negative end of the power sub-module.
5. The flexible direct current transmission system energy consumption device of claim 3, wherein a positive end of the power sub-module port is connected with an anode of a thyristor VB, and a cathode of the thyristor VB is connected with a negative end of the power sub-module.
6. The flexible direct current transmission system energy consumption device according to claim 3, wherein a negative terminal of the capacitor C is connected with an anode of a through-current diode D1, and a cathode of the through-current diode D1 is connected with a negative terminal of a power sub-module.
7. The flexible direct current transmission system energy consumption device according to claim 1, wherein the centralized energy consumption resistor R1 is a metal resistor.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010125869.4A CN111162559A (en) | 2020-02-27 | 2020-02-27 | Flexible direct current transmission system energy consumption device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010125869.4A CN111162559A (en) | 2020-02-27 | 2020-02-27 | Flexible direct current transmission system energy consumption device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN111162559A true CN111162559A (en) | 2020-05-15 |
Family
ID=70566620
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010125869.4A Pending CN111162559A (en) | 2020-02-27 | 2020-02-27 | Flexible direct current transmission system energy consumption device |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111162559A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112421669A (en) * | 2020-12-10 | 2021-02-26 | 南方电网科学研究院有限责任公司 | Alternating current fault ride-through method and system for offshore wind power through flexible direct current transmission |
| CN112834858A (en) * | 2021-01-29 | 2021-05-25 | 国网江苏省电力有限公司电力科学研究院 | On-site detection method for direct-current energy consumption device |
| CN116388282A (en) * | 2023-06-06 | 2023-07-04 | 清华大学 | DC energy consumption device and switch submodule |
-
2020
- 2020-02-27 CN CN202010125869.4A patent/CN111162559A/en active Pending
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112421669A (en) * | 2020-12-10 | 2021-02-26 | 南方电网科学研究院有限责任公司 | Alternating current fault ride-through method and system for offshore wind power through flexible direct current transmission |
| CN112834858A (en) * | 2021-01-29 | 2021-05-25 | 国网江苏省电力有限公司电力科学研究院 | On-site detection method for direct-current energy consumption device |
| CN116388282A (en) * | 2023-06-06 | 2023-07-04 | 清华大学 | DC energy consumption device and switch submodule |
| CN116388282B (en) * | 2023-06-06 | 2023-10-20 | 清华大学 | DC energy consumption device and switch submodule |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111162559A (en) | Flexible direct current transmission system energy consumption device | |
| CN106953305B (en) | A kind of combined high-voltage dc circuit breaker and its control strategy with DC power flow control ability | |
| CN108322056B (en) | Modular high-voltage direct-current conversion device and control method thereof | |
| WO2016107616A1 (en) | Apparatus for preventing capacitance overvoltage in voltage-source type inverter | |
| CN102549907A (en) | Converter with active fault current limitation | |
| CN109193625B (en) | Novel combined direct current breaker topology | |
| CN109873407A (en) | A kind of annular bridge-type multiport mixed DC breaker | |
| CN102904280A (en) | Device and method for traversing grid fault by double-fed wind power converter | |
| CN214314552U (en) | Multifunctional multiport hybrid direct current breaker | |
| CN111224421A (en) | Flexible direct current transmission system direct current side energy consumption device topology | |
| CN111030060A (en) | Clamp-on circuit breaker topology suitable for direct current fault removal | |
| CN114400670A (en) | Voltage sag treatment device and implementation method | |
| CN104779825A (en) | Cross type sub-module structure of modular multilevel converter (MMC) | |
| CN112865046A (en) | Multifunctional multiport hybrid direct current breaker and control method | |
| CN211530759U (en) | Flexible direct current transmission system energy consumption device | |
| CN106998151A (en) | Multilevel converter based on asymmetric Shuangzi module and half-bridge submodule | |
| CN111900703B (en) | Hybrid direct current breaker | |
| CN214959327U (en) | Energy storage circuit and modular multilevel converter | |
| CN114531050A (en) | Energy-consumption type modular multilevel converter and control method | |
| CN115133568A (en) | Active neutral point clamp switching sequence for parasitic inductance control of power conversion assembly | |
| CN211530758U (en) | Direct current side energy consumption device of flexible direct current transmission system | |
| CN113489359A (en) | Submodule topology with direct-current fault clearing capability | |
| CN108429244B (en) | Electronic switch and hybrid high-voltage direct-current circuit breaker | |
| CN114221318B (en) | MMC sub-module circuit topology structure, fault ride-through method and application thereof | |
| CN216489890U (en) | Flexible shore-based variable frequency power supply system based on movable energy storage equipment |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |