CN113300620B - Starting method and system of modular multilevel matrix converter - Google Patents
Starting method and system of modular multilevel matrix converter Download PDFInfo
- Publication number
- CN113300620B CN113300620B CN202110500700.7A CN202110500700A CN113300620B CN 113300620 B CN113300620 B CN 113300620B CN 202110500700 A CN202110500700 A CN 202110500700A CN 113300620 B CN113300620 B CN 113300620B
- Authority
- CN
- China
- Prior art keywords
- matrix converter
- module
- voltage
- modular multilevel
- charging
- 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.)
- Active
Links
Images
Classifications
-
- 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
- H02M7/42—Conversion of dc power input into ac power output without possibility of reversal
- H02M7/44—Conversion of dc power input into ac power output without possibility of reversal by static converters
- H02M7/48—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
- H02M7/483—Converters with outputs that each can have more than two voltages levels
-
- 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
- H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
- H02M7/42—Conversion of dc power input into ac power output without possibility of reversal
- H02M7/44—Conversion of dc power input into ac power output without possibility of reversal by static converters
- H02M7/48—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
- H02M7/53—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal
- H02M7/537—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only, e.g. single switched pulse inverters
- H02M7/5375—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only, e.g. single switched pulse inverters with special starting equipment
-
- 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
- H02M7/42—Conversion of dc power input into ac power output without possibility of reversal
- H02M7/44—Conversion of dc power input into ac power output without possibility of reversal by static converters
- H02M7/48—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
- H02M7/53—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal
- H02M7/537—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only, e.g. single switched pulse inverters
- H02M7/5387—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only, e.g. single switched pulse inverters in a bridge configuration
-
- 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]
Abstract
The invention discloses a starting method and a system of a modular multilevel matrix converter, wherein the method comprises the following steps: initializing the modular multilevel matrix converter; uncontrolled charging is carried out on the modular multi-level matrix converter; according to a voltage-sharing strategy of real-time sequencing, voltage of the sub-modules is charged to a rated value Vsm in a balanced manner; when the average voltage of the bridge arm branch module reaches a preset rated value U 1 Then, completing sub-module charging, locking all bridge arm branch modules, and closing the alternating current breaker KM on the other side; and unlocking the modular multilevel matrix converter, and keeping the initial pulse output by the converter consistent with the alternating current voltage difference at two sides of the converter. The system comprises a modular multilevel matrix converter, an initialization module, an uncontrolled charging module, a sub-module charging module and an unlocking module. The invention can reduce the electric impact from the switching-on starting to the unlocking of the modular matrix converter, protect the safety of the modular matrix converter equipment and improve the stability of an accessed system.
Description
Technical Field
The invention relates to the technical field of alternating current transmission, in particular to a starting method and a starting system of a modular multilevel matrix converter.
Background
Because the outgoing line corridor has short resources and huge investment, the improvement of the transmission capability of the power transmission line is always an important research field of power engineering. The main factors limiting the transmission power of the alternating current transmission system are thermal limit, stable power limit and the like, and since the transformer is invented, the improvement of the voltage level becomes an important means for improving the transmission capability. In modern power systems, however, the problem of optimizing the frequency, another important parameter of the ac transmission, has also received attention. When a coal gas turbine power generation unit is used as the main power of a power supply, the unit requires higher rotating speed (frequency) to ensure the economical efficiency, so 50/60Hz becomes the standard frequency of a power grid. In recent years, renewable energy sources such as wind power generation and hydroelectric power generation have been rapidly developed, and therefore, because the rotational speed of a prime mover is low, and the prime mover is suitable for generating low-frequency power, and low-frequency power transmission has advantages such as reduced reactance and improved transmission capacity, the problem of frequency selection of power generation and power transmission related to renewable energy sources should be reviewed again.
Particularly for the wind power transmission in the medium and far seas, the existing transmission modes mainly comprise alternating current transmission and flexible direct current transmission, the alternating current transmission mode is influenced by the problem of cable capacitance and current and is not suitable for long-distance transmission, the construction cost of the flexible direct current transmission offshore converter station is high, and the low-frequency power transmission system can realize the long-distance transmission of the offshore wind power without the offshore converter station. A modular multilevel matrix converter (M3C) is a novel AC/AC conversion device, two sides of the device can be respectively used for connecting two three-phase alternating current systems, conversion of different voltage amplitudes and different frequencies at two sides is achieved, and the device is a low-frequency power transmission scheme with research and application potentials.
The invention relates to a modular multilevel matrix converter starting method with protection property (application number 201910904838.6), which mainly has the technical problems that firstly, the voltage of a submodule needs to be raised to a rated value in an unlocking control mode after uncontrolled charging is finished, and the voltage of the submodule is lower during unlocking, so that the control capability is poorer; secondly, in order to prevent the current from being too large in the starting process, the soft-start current-limiting resistor is always driven in the whole starting process (including uncontrolled charging and unlocked boosting), so that higher design requirements on the heat dissipation capacity of the soft-start current-limiting resistor are required, and the realization of the soft-start resistor is difficult.
The invention discloses an M3C pre-charging method based on staggered grouping (application No. 201910904839.0), which mainly has the following defects that firstly, a sub-module which is already charged is powered down due to loss during a bypass period, secondly, current impact exists in a grouping switching process, the voltage of the sub-module is inconsistent, and thirdly, the operation is relatively complicated. Therefore, there is a large limitation in this method in practical use.
Disclosure of Invention
In view of this, an object of the embodiments of the present invention is to provide a method and a system for starting a modular multilevel matrix converter, which are simple in starting implementation process, capable of reducing electrical impact from switching on to unlocking of the modular matrix converter, protecting the safety of a modular matrix converter device, and improving the stability of an accessed system.
In a first aspect, an embodiment of the present invention provides a method for starting a modular multilevel matrix converter, where the method includes:
and initializing the modular multilevel matrix converter.
And carrying out uncontrolled charging on the modular multi-level matrix converter.
And according to a voltage-sharing strategy of real-time sequencing, uniformly charging the voltage of the submodule to a rated value Vsm.
When the average voltage of the bridge arm branch module reaches a preset rated value U 1 And then, charging the sub-modules, locking all bridge arm branch modules, and closing the alternating current breaker KM at the other side to avoid overcurrent and sub-module overvoltage caused by sudden loading of alternating current voltage difference at two sides on the bridge arms.
And unlocking the modular multilevel matrix converter, keeping the initial pulse output by the converter consistent with the alternating current voltage difference at two sides of the converter, and avoiding electrical impact after unlocking.
With reference to the first aspect, an embodiment of the present invention provides a first possible implementation manner of the first aspect, where initializing the modular multilevel matrix converter includes:
and disconnecting the AC breakers Ks and KM at two sides of the modularized multi-level matrix converter.
The soft start resistive bypass switch Kr of the modular multilevel matrix converter is turned off.
With reference to the first aspect, a second possible implementation manner of the first aspect is provided by an embodiment of the present invention, where the performing uncontrolled charging on the modular multilevel matrix converter includes:
the input side ac breaker Ks is closed.
And an alternating current system Vs connected with the input side of the modular multi-level matrix converter carries out uncontrolled charging on the modular multi-level matrix converter through a soft start resistor Rs.
And when the uncontrolled charging time reaches the initial charging standard time t of the soft start resistor Rs, closing the soft start resistor bypass switch Kr.
With reference to the first aspect, an embodiment of the present invention provides a third possible implementation manner of the first aspect, where the equalizing charging the sub-module voltage to the rated value Vsm according to a real-time sorting voltage-equalizing strategy includes:
when the voltage of each sub-converter reaches the preset power-on voltage U 0 And then sequencing the voltage of each bridge arm branch module in each subconverter by the valve controller.
And cutting off the bridge arm branch modules with higher voltage, and locking the rest bridge arm branch modules, wherein the cut-off number is gradually increased from zero until reaching a preset fixed number n, and then keeping the cut-off number unchanged.
With reference to the first aspect, an embodiment of the present invention provides a fourth possible implementation manner of the first aspect, where the preset fixed number N is obtained by calculation according to a peak ac line voltage value Vs _ peak at the input side, a rated voltage Vsm of a submodule, and a number N of bridge arm modules, where N is N-Vs _ peak/(2 × Vsm).
In a second aspect, an embodiment of the present invention further provides a modular multilevel matrix converter starting system, where the system includes: the device comprises a modular multilevel matrix converter, an initialization module, an uncontrolled charging module, a sub-module charging module and an unlocking module.
The initialization module is used for initializing the modular multilevel matrix converter.
And the uncontrolled charging module is used for carrying out uncontrolled charging on the modular multilevel matrix converter.
And the submodule charging module is used for charging the submodule voltage to a rated value Vsm in a balanced manner according to a voltage-sharing strategy of real-time sequencing.
The unlocking module is used for unlocking the bridge arm branch circuit when the average voltage of the bridge arm branch circuit module reaches a preset rated value U 1 And then, completing sub-module charging, locking all bridge arm branch modules, closing the alternating current breaker KM on the other side, unlocking the modular multilevel matrix converter, and keeping the initial pulse output by the converter consistent with the alternating current voltage difference on the two sides of the converter.
In combination with the second aspect, an embodiment of the present invention provides a first possible implementation manner of the second aspect, where the modular multilevel matrix converter includes: the soft start circuit comprises a soft start resistor Rs, a bypass switch Kr of the soft start resistor Rs, an isolation transformer TM, a grounding system and 9 bridge arm branches.
Each bridge arm branch comprises a plurality of cascaded full-bridge submodules and a branch inductor.
Two sides of the modularized multi-level matrix converter are connected with two alternating current systems Vs and VM.
With reference to the second aspect, an embodiment of the present invention provides a second possible implementation manner of the second aspect, where the initializing module includes:
and the alternating current breaker breaking unit is used for breaking the alternating current breakers Ks and KM at two sides of the modular multilevel matrix converter.
And the soft start resistance bypass switch disconnecting unit is used for disconnecting a soft start resistance bypass switch Kr of the modular multilevel matrix converter.
With reference to the second aspect, an embodiment of the present invention provides a third possible implementation manner of the second aspect, where the uncontrolled charging module includes:
and an alternating current breaker Ks closing unit for closing the input side alternating current breaker Ks.
And the soft start resistor charging unit is used for carrying out uncontrolled charging on the modular multi-level matrix converter through a soft start resistor Rs by an alternating current system Vs connected to the input side of the modular multi-level matrix converter.
And the soft-start resistor bypass switch closing unit is used for closing the soft-start resistor bypass switch Kr when the uncontrolled charging time reaches the preliminary charging standard time t of the soft-start resistor Rs.
With reference to the second aspect, an embodiment of the present invention provides a fourth possible implementation manner of the second aspect, where the sub-module charging module includes:
a sub-module voltage sequencing unit for sequencing the voltage of each sub-converter to a preset power-on voltage U 0 And then sequencing the voltage of each bridge arm branch module in each subconverter by the valve controller.
And the cutting unit is used for cutting off the bridge arm branch modules with higher voltage and locking the rest bridge arm branch modules, wherein the cutting-off number is gradually increased from zero until reaching a preset fixed number n, and then the cutting-off number is kept unchanged.
The embodiment of the invention has the beneficial effects that:
the invention can charge all the submodule voltages to the rated value under smaller current impact, the submodule voltages are kept balanced in real time in the whole process, and the submodule voltages can be maintained in a state of waiting for unlocking after charging is finished for a long time, and the unlocking process has no impact, thereby improving the safety and reliability of the whole system and being suitable for the engineering application of the modular multilevel matrix converter.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and those skilled in the art can also obtain other related drawings based on the drawings without inventive efforts.
Fig. 1 is a flow chart of a starting method of a modular multilevel matrix converter according to the invention;
fig. 2 is a schematic full-flow diagram of a starting method of the modular multilevel matrix converter according to the present invention;
fig. 3 is a schematic structural diagram of the modular multilevel matrix converter of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all embodiments of the present invention. The components of embodiments of the present invention generally described and illustrated in the figures herein can be arranged and designed in a wide variety of different configurations.
Referring to fig. 1 to 2, a first embodiment of the invention provides a method for starting a modular multilevel matrix converter, including:
and initializing the modular multilevel matrix converter.
And carrying out uncontrolled charging on the modular multi-level matrix converter.
And according to a voltage-sharing strategy of real-time sequencing, uniformly charging the voltage of the submodule to a rated value Vsm.
When the average voltage of the bridge arm branch module reaches a preset rated value U 1 And then, charging the sub-modules, locking all bridge arm branch modules, and closing the alternating current breaker KM at the other side to avoid overcurrent and sub-module overvoltage caused by sudden loading of alternating current voltage difference at two sides on the bridge arms.
And unlocking the modular multilevel matrix converter, keeping the initial pulse output by the converter consistent with the alternating current voltage difference at two sides of the converter, and avoiding electrical impact after unlocking.
With reference to the first aspect, an embodiment of the present invention provides a first possible implementation manner of the first aspect, where initializing the modular multilevel matrix converter includes:
and disconnecting the alternating current breakers Ks and KM at two sides of the modular multilevel matrix converter.
The soft start resistive bypass switch Kr of the modular multilevel matrix converter is turned off.
With reference to the first aspect, an embodiment of the present invention provides a second possible implementation manner of the first aspect, where the performing uncontrolled charging on the modular multilevel matrix converter includes:
the input side ac breaker Ks is closed.
And an alternating current system Vs connected with the input side of the modular multi-level matrix converter carries out uncontrolled charging on the modular multi-level matrix converter through a soft start resistor Rs.
And when the uncontrolled charging time reaches the initial charging standard time t of the soft start resistor Rs, closing the soft start resistor bypass switch Kr.
With reference to the first aspect, an embodiment of the present invention provides a third possible implementation manner of the first aspect, where the equalizing charging the voltage of the sub-module to the rated value Vsm according to a real-time sorting equalizing strategy includes:
when the voltage of each sub-converter reaches the preset power-on voltage U 0 And then sequencing the voltage of each bridge arm branch module in each subconverter by the valve controller.
And cutting off the bridge arm branch modules with higher voltage, and locking the rest bridge arm branch modules, wherein the cutting-off number is gradually increased from zero until reaching a preset fixed number n, and then keeping the cutting-off number unchanged.
The invention aims at the problem that the starting process of the device of the modular multilevel matrix converter is required to be completed before the modular multilevel matrix converter is put into operation from shutdown, the voltage of the module is smoothly raised to a rated value, and the electrical impact during unlocking is reduced.
With reference to the first aspect, an embodiment of the present invention provides a fourth possible implementation manner of the first aspect, where the preset fixed number N is calculated according to the input-side ac line voltage peak value Vs _ peak, the sub-module rated voltage Vsm, and the number N of the bridge arm branch modules, where N is N — Vs _ peak/(2 × Vsm).
Referring to fig. 3, a second embodiment of the invention provides a modular multilevel matrix converter start-up system, which includes: the device comprises a modular multilevel matrix converter, an initialization module, an uncontrolled charging module, a sub-module charging module and an unlocking module.
The initialization module is used for initializing the modular multilevel matrix converter.
And the uncontrolled charging module is used for carrying out uncontrolled charging on the modular multilevel matrix converter.
And the submodule charging module is used for charging the submodule voltage to a rated value Vsm in a balanced manner according to a voltage-sharing strategy of real-time sequencing.
The unlocking module is used for unlocking the bridge arm branch circuit when the average voltage of the bridge arm branch circuit module reaches a preset rated value U 1 And then, completing sub-module charging, locking all bridge arm branch modules, closing the alternating current breaker KM on the other side, unlocking the modular multilevel matrix converter, and keeping the initial pulse output by the converter consistent with the alternating current voltage difference on the two sides of the converter.
In combination with the second aspect, an embodiment of the present invention provides a first possible implementation manner of the second aspect, where the modular multilevel matrix converter includes: the soft start circuit comprises a soft start resistor Rs, a bypass switch Kr of the soft start resistor Rs, an isolation transformer TM, a grounding system and 9 bridge arm branches.
Each bridge arm branch comprises a plurality of cascaded full-bridge submodules and a branch inductor.
Two sides of the modularized multi-level matrix converter are connected with two alternating current systems Vs and VM.
With reference to the second aspect, an embodiment of the present invention provides a second possible implementation manner of the second aspect, where the initialization module includes:
and the alternating current breaker breaking unit is used for breaking the alternating current breakers Ks and KM at two sides of the modular multilevel matrix converter.
And the soft start resistance bypass switch disconnecting unit is used for disconnecting a soft start resistance bypass switch Kr of the modular multilevel matrix converter.
With reference to the second aspect, an embodiment of the present invention provides a third possible implementation manner of the second aspect, where the uncontrolled charging module includes:
and an alternating current breaker Ks closing unit for closing the input side alternating current breaker Ks.
And the soft start resistance charging unit is used for carrying out uncontrolled charging on the modular multi-level matrix converter through a soft start resistance Rs by an alternating current system Vs connected to the input side of the modular multi-level matrix converter.
And the soft-start resistor bypass switch closing unit is used for closing the soft-start resistor bypass switch Kr when the uncontrolled charging time reaches the preliminary charging standard time t of the soft-start resistor Rs.
With reference to the second aspect, an embodiment of the present invention provides a fourth possible implementation manner of the second aspect, where the sub-module charging module includes:
a sub-module voltage sequencing unit for sequencing the voltage of each sub-converter to a preset power-on voltage U 0 The valve controller then adjusts the voltage to each leg branch module in each subconverterAnd (6) sorting.
And the cutting unit is used for cutting off the bridge arm branch modules with higher voltage and locking the rest bridge arm branch modules, wherein the cutting-off number is gradually increased from zero until reaching a preset fixed number n, and then the cutting-off number is kept unchanged.
The embodiment of the invention aims to protect a starting method and a system of a modular multilevel matrix converter, and has the following effects:
the invention provides a starting method and a system of a modular multilevel matrix converter, which are characterized in that a submodule is charged through a single-side alternating-current line voltage and a soft start resistor, the soft start resistor is cut off after the submodule is charged to a certain stage, a submodule with higher voltage is cut off based on the real-time sequencing of submodule voltage, and the rest submodules are locked, wherein the cut-off number is gradually increased to a fixed number from zero and is kept unchanged until the submodule voltage reaches a rated value, all submodules are locked, then an alternating-current switch on the other side is closed, the modular multilevel matrix converter is unlocked, and the first pulse during unlocking needs to be matched with alternating-current voltages on two sides. The method is simple in implementation process, can reduce the electric impact from switching on to unlocking of the modular matrix converter, protects the safety of the modular matrix converter equipment, and improves the stability of an accessed system.
The computer program product of the method and the apparatus for starting a modular multilevel matrix converter provided in the embodiments of the present invention includes a computer-readable storage medium storing a program code, and instructions included in the program code may be used to execute the method in the foregoing method embodiments.
Specifically, the storage medium can be a general storage medium, such as a mobile disk, a hard disk, and the like, and when a computer program on the storage medium is executed, the method for starting the modular multilevel matrix converter can be executed, so that the electrical impact from switching on to unlocking of the modular matrix converter can be reduced, the safety of the modular matrix converter equipment is protected, and the stability of an accessed system is improved.
The functions, if implemented in software functional units and sold or used as a stand-alone product, may be stored in a non-transitory computer-readable storage medium executable by a processor. Based on such understanding, the technical solution of the present invention may be embodied in the form of a software product, which is stored in a storage medium and includes instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the method according to the embodiments of the present invention. And the aforementioned storage medium includes: various media capable of storing program codes, such as a usb disk, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk, or an optical disk.
Finally, it should be noted that: the above-mentioned embodiments are only specific embodiments of the present invention, which are used for illustrating the technical solutions of the present invention and not for limiting the same, and the protection scope of the present invention is not limited thereto, although the present invention is described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: any person skilled in the art can modify or easily conceive the technical solutions described in the foregoing embodiments or equivalent substitutes for some technical features within the technical scope of the present disclosure; such modifications, changes or substitutions do not depart from the spirit and scope of the embodiments of the present invention, and they should be construed as being included therein. Therefore, the protection scope of the present invention shall be subject to the protection scope of the appended claims.
Claims (7)
1. A starting method of a modular multilevel matrix converter is characterized by comprising the following steps:
initializing the modular multilevel matrix converter;
uncontrolled charging is carried out on the modular multi-level matrix converter;
according to a voltage-sharing strategy of real-time sequencing, voltage of the sub-modules is charged to a rated value Vsm in a balanced manner;
when the average voltage of the bridge arm branch module reaches a preset rated value U 1 Then, completing sub-module charging, locking all bridge arm branch modules, and closing the alternating current breaker KM on the other side;
unlocking the modular multilevel matrix converter, and keeping the initial pulse output by the converter consistent with the alternating current voltage difference at two sides of the converter;
according to the voltage-sharing strategy of real-time sequencing, sub-module voltage is charged to a rated value Vsm in a balanced mode, and the method comprises the following steps:
when the voltage of each sub-converter reaches the preset power-on voltage U 0 Then, sequencing the voltage of each bridge arm branch module in each subconverter by the valve controller;
cutting off the bridge arm branch modules with higher voltage, locking the rest bridge arm branch modules, wherein the cut-off number is gradually increased from zero until reaching a preset fixed number n, and then keeping unchanged;
the preset fixed number N is calculated according to the input side alternating line voltage peak value Vs _ peak, the submodule rated voltage Vsm and the number N of the bridge arm branch modules, and N is N-Vs _ peak/(2 × Vsm).
2. The method for starting up a modular multilevel matrix converter according to claim 1, wherein initializing the modular multilevel matrix converter comprises:
disconnecting the alternating current breakers Ks and KM at two sides of the modular multilevel matrix converter;
and disconnecting a soft start resistance bypass switch Kr of the modular multilevel matrix converter.
3. The method for starting up a modular multilevel matrix converter according to claim 1, wherein the uncontrolled charging of the modular multilevel matrix converter comprises:
closing the input side alternating current breaker Ks;
an alternating current system Vs connected with the input side of the modular multi-level matrix converter carries out uncontrolled charging on the modular multi-level matrix converter through a soft start resistor Rs;
and when the uncontrolled charging time reaches the initial charging standard time t of the soft start resistor Rs, closing the soft start resistor bypass switch Kr.
4. A modular multilevel matrix converter startup system, comprising: the system comprises a modular multilevel matrix converter, an initialization module, an uncontrolled charging module, a sub-module charging module and an unlocking module;
the initialization module is used for initializing the modular multilevel matrix converter;
the uncontrolled charging module is used for carrying out uncontrolled charging on the modular multi-level matrix converter;
the submodule charging module is used for charging the submodule voltage to a rated value Vsm in a balanced manner according to a voltage-sharing strategy of real-time sequencing;
the unlocking module is used for enabling the average voltage of the bridge arm branch circuit module to reach a preset rated value U 1 Then, completing sub-module charging, locking all bridge arm branch modules, closing the alternating current breaker KM on the other side, unlocking the modular multilevel matrix converter, and keeping the initial pulse output by the converter consistent with the alternating current voltage difference on the two sides of the converter;
the sub-module charging module includes:
a sub-module voltage sequencing unit for sequencing the sub-modules when the voltage of each sub-converter reaches a preset power-on voltage U 0 Then, sequencing the voltage of each bridge arm branch module in each subconverter by a valve controller;
and the cutting unit is used for cutting off the bridge arm branch modules with higher voltage and locking the rest bridge arm branch modules, wherein the cutting-off number is gradually increased from zero until reaching a preset fixed number n, and then the cutting-off number is kept unchanged.
5. The modular multilevel matrix converter startup system of claim 4, wherein the modular multilevel matrix converter comprises: the system comprises a soft start resistor Rs, a bypass switch Kr of the soft start resistor Rs, an isolation transformer TM, a grounding system and a plurality of bridge arm branches;
each bridge arm branch comprises a plurality of cascaded full-bridge sub-modules and a branch inductor;
two sides of the modularized multi-level matrix converter are connected with two alternating current systems Vs and VM.
6. The modular multilevel matrix converter startup system of claim 4, wherein the initialization module comprises:
the alternating current breaker disconnecting unit is used for disconnecting the alternating current breakers Ks and KM at two sides of the modularized multi-level matrix converter;
and the soft start resistance bypass switch disconnecting unit is used for disconnecting the soft start resistance bypass switch Kr of the modular multilevel matrix converter.
7. The modular multilevel matrix converter startup system of claim 6, wherein the uncontrolled charging module comprises:
an alternating current breaker Ks closing unit for closing the input side alternating current breaker Ks;
the soft start resistor charging unit is used for carrying out uncontrolled charging on the modular multi-level matrix converter through a soft start resistor Rs by an alternating current system Vs connected to the input side of the modular multi-level matrix converter;
and the soft-start resistor bypass switch closing unit is used for closing the soft-start resistor bypass switch Kr when the uncontrolled charging time reaches the preliminary charging standard time t of the soft-start resistor Rs.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110500700.7A CN113300620B (en) | 2021-05-08 | 2021-05-08 | Starting method and system of modular multilevel matrix converter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110500700.7A CN113300620B (en) | 2021-05-08 | 2021-05-08 | Starting method and system of modular multilevel matrix converter |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113300620A CN113300620A (en) | 2021-08-24 |
| CN113300620B true CN113300620B (en) | 2022-08-19 |
Family
ID=77321054
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110500700.7A Active CN113300620B (en) | 2021-05-08 | 2021-05-08 | Starting method and system of modular multilevel matrix converter |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113300620B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113937995B (en) * | 2021-09-17 | 2023-08-08 | 南京南瑞继保电气有限公司 | Soft start method and storage medium of low-frequency power transmission system |
| CN114301036B (en) * | 2021-12-28 | 2024-03-26 | 南瑞集团有限公司 | Cascaded multi-level converter and on-load and off-load starting method thereof |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104821711B (en) * | 2015-04-30 | 2017-11-21 | 许继集团有限公司 | A kind of modular multi-level flexible direct-current transmission converter starts method |
| CN105119508B (en) * | 2015-09-18 | 2017-09-22 | 山东建筑大学 | Full-bridge and the modularization multi-level converter and startup method of half-bridge submodule series-parallel connection |
| CN105515353B (en) * | 2016-01-27 | 2018-06-19 | 东南大学 | The four port electric power electric transformers based on mixed type module multi-level converter |
| CN108462197B (en) * | 2018-03-29 | 2021-05-18 | 许继集团有限公司 | Starting control method and device for flexible direct-current transmission converter valve |
| CN110739871B (en) * | 2019-09-23 | 2020-10-02 | 中国南方电网有限责任公司超高压输电公司广州局 | Alternating current charging control strategy suitable for hybrid MMC under two working conditions of short circuit and no short circuit on direct current side |
-
2021
- 2021-05-08 CN CN202110500700.7A patent/CN113300620B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN113300620A (en) | 2021-08-24 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Varma et al. | PV solar system control as STATCOM (PV-STATCOM) for power oscillation damping | |
| Peralta et al. | Detailed and averaged models for a 401-level MMC–HVDC system | |
| Barnes et al. | Voltage source converter HVDC links–the state of the art and issues going forward | |
| CN110350506B (en) | Direct-current wind turbine generator, medium-voltage direct-current direct grid-connected system and control and protection system | |
| CN107005151B (en) | Starting of HVDC converters | |
| CN113300620B (en) | Starting method and system of modular multilevel matrix converter | |
| CN110086198B (en) | Multi-terminal hybrid direct-current power transmission system control method for offshore wind power grid connection | |
| Jain et al. | Blackstart of power grids with inverter-based resources | |
| CN111541362B (en) | Switching control method and system for MMC redundancy sub-module | |
| Saleh et al. | Evaluating the performance of digital modular protection for grid-connected permanent-magnet-generator-based wind energy conversion systems with battery storage systems | |
| CN114825431B (en) | Grid-connected system and control and protection system for sending wind power plant out through diode rectification | |
| Lin et al. | Research on starting‐up control strategy of VSC‐HVDC system | |
| Shewarega et al. | Simplified modeling of VSC-HVDC in power system stability studies | |
| CN106936154B (en) | Series-parallel direct-current power grid starting method for large-scale long-distance offshore wind power grid connection | |
| Tanaka et al. | Reactive power compensation capability of a STATCOM based on two types of Modular Multilevel Cascade Converters for offshore wind application | |
| CN115967088A (en) | Power distribution fault self-healing method of flexible interconnection switch and related device | |
| Chen et al. | Adaptive thermal control for power fluctuation to improve lifetime of IGBTs in multi-MW medium voltage wind power converter | |
| Chen et al. | Coordination of mode switching control and SMES unit for low‐voltage ride‐through fulfillment of power electronic transformer | |
| Mustafa et al. | Mitigation of unbalanced voltage sags and voltage unbalance in cigre low voltage distribution network | |
| Hagh et al. | Improving fault ride-through of three phase voltage source inverter during symmetrical fault using DC link fault current limiter | |
| CN116722573B (en) | Offshore wind power monopole hybrid direct current transmission system capable of being started under direct current negative pressure | |
| CN116722575B (en) | Method and device for starting offshore wind power direct-current transmission system with direct-current bypass switch | |
| CN111711210B (en) | Energy storage system and offshore wind power device suitable for offshore wind power | |
| Xin-Nian et al. | Study on the impact of commutation failure on AC voltage of rectifier-side in UHVDC | |
| Kazi et al. | Control and Protection of Hybrid LCC-VSC HVDC Transmission System based on VDCOL Strategy. |
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 | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |