CN113517707B - MMC converter station surplus power consumption control method and system - Google Patents
MMC converter station surplus power consumption control method and system Download PDFInfo
- Publication number
- CN113517707B CN113517707B CN202110535886.XA CN202110535886A CN113517707B CN 113517707 B CN113517707 B CN 113517707B CN 202110535886 A CN202110535886 A CN 202110535886A CN 113517707 B CN113517707 B CN 113517707B
- Authority
- CN
- China
- Prior art keywords
- mmc
- voltage
- capacitance
- submodule
- energy storage
- 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
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
- H02J3/28—Arrangements for balancing of the load in a network by storage of energy
-
- 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
- H02J3/12—Circuit arrangements for ac mains or ac distribution networks for adjusting voltage in ac networks by changing a characteristic of the network load
-
- 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
-
- 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)
- Inverter Devices (AREA)
- Supply And Distribution Of Alternating Current (AREA)
Abstract
The invention discloses a surplus power consumption control method and system for an MMC converter station, comprising the following steps: when the direct-current voltage of the MMC converter station at the transmitting end exceeds the direct-current upper limit value, judging that surplus power appears, starting an energy storage strategy, and obtaining an MMC submodule capacitor reference voltage in NLM modulation according to an energy storage power instruction value; after the energy storage strategy is started, when the capacitance reference voltage of the MMC submodule exceeds the upper limit value of the capacitance voltage or the direct current voltage is lower than the lower limit value of the direct current voltage, the energy storage strategy is suspended, and the energy storage power instruction value is adjusted to be zero; after receiving the receiving end fault clearing signal, starting an energy release strategy, and obtaining an MMC submodule capacitor reference voltage in NLM modulation according to an energy release power instruction value; after the capacitance voltage of the MMC submodule is restored to the rated capacitance voltage, the reference capacitance voltage of the MMC submodule in NLM modulation is set to be the rated capacitance voltage value of the submodule. The invention realizes the consumption and the reuse of surplus power and inhibits the voltage rise of the direct current side.
Description
Technical Field
The invention relates to the technical field of MMC control, in particular to a surplus power consumption control method and system for an MMC converter station.
Background
The statements in this section merely provide background information related to the present disclosure and may not necessarily constitute prior art.
The Modular Multilevel Converter (MMC) applied to the flexible direct current transmission system adopts a nearest level approximation modulation (NLM) technology, and voltage modulation waves of each phase (or modulation waves of each bridge arm) need to be divided by capacitance voltage of the sub-module to obtain the number of sub-modules input by each bridge arm. MMC has no commutation failure problem, and is increasingly applied to projects such as Zhang Bei four-terminal flexible and straight offshore wind power grid connection and the like in new energy power generation and transmission systems. The MMC converter station of the transmitting end is connected with a new energy base such as photovoltaic, wind power and the like, and the voltage of the fixed alternating current side and the frequency of the fixed alternating current side are adopted to control, so that reliable grid-connected voltage is provided for new energy grid connection, but the power flowing into the converter station cannot be controlled, and the power flowing into the MMC of the transmitting end is determined by the new energy base. When the receiving end fails (including the AC power grid fault connected with the receiving end or the blocking of the receiving end converter station), the power sent by the receiving end is reduced, the new energy base at the sending end cannot timely reduce the sent power, the power flowing into the DC system is larger than the power flowing out of the DC system, surplus power can lead to the rising of the DC voltage, and the DC power transmission system is stopped when serious.
The current engineering method is that a plurality of groups of energy consumption resistors are arranged on the alternating current side of the transmitting end converter station, surplus power is dissipated by the energy consumption resistors, the method is quick in response, surplus power can be timely dissipated, direct current overvoltage is restrained, but the occupied area of the energy consumption device is large, the heat dissipation problem cannot be ignored, power impact in switching is large, and voltage on the alternating current side of the stable MMC is unfavorable.
Disclosure of Invention
In order to solve the problems, the invention provides a surplus power consumption control method and system for an MMC converter station, which comprises an energy storage strategy and an energy release strategy, wherein the energy storage power instruction and the energy release power instruction are set according to the capacity of the converter station and the actual energy storage capacity of a capacitor, so that surplus power is consumed and reused, and the voltage rise of a direct current side is restrained.
In order to achieve the above purpose, the present invention adopts the following technical scheme:
in a first aspect, the present invention provides a method for controlling surplus power consumption of an MMC converter station, including:
when the direct-current voltage of the MMC converter station at the transmitting end exceeds the direct-current upper limit value, judging that surplus power appears, starting an energy storage strategy, and obtaining an MMC submodule capacitor reference voltage in NLM modulation according to an energy storage power instruction value;
after the energy storage strategy is started, when the capacitance reference voltage of the MMC submodule exceeds the upper limit value of the capacitance voltage or the direct current voltage is lower than the lower limit value of the direct current voltage, the energy storage strategy is suspended, and the energy storage power instruction value is adjusted to be zero;
after receiving the receiving end fault clearing signal, starting an energy release strategy, and obtaining an MMC submodule capacitor reference voltage in NLM modulation according to an energy release power instruction value;
after the capacitance voltage of the MMC submodule is restored to the rated capacitance voltage, the reference capacitance voltage of the MMC submodule in NLM modulation is set to be the rated capacitance voltage value of the submodule.
In a second aspect, the present invention provides an MMC converter station surplus power consumption control system, comprising:
the energy storage strategy starting module is configured to judge surplus power when the direct-current voltage of the transmitting-end MMC converter station exceeds the direct-current upper limit value, start the energy storage strategy and obtain the capacitance reference voltage of the MMC submodule in NLM modulation according to the energy storage power instruction value;
the energy storage strategy suspending module is configured to suspend the energy storage strategy when the capacitance reference voltage of the MMC submodule exceeds the upper limit value of the capacitance voltage or the direct-current voltage is lower than the lower limit value of the direct-current voltage after the energy storage strategy is started, and adjust the instruction value of the energy storage power to zero;
the energy release strategy starting module is configured to start an energy release strategy after receiving a receiving end fault clearing signal, and obtain an MMC submodule capacitor reference voltage in NLM modulation according to an energy release power instruction value;
and the energy release strategy stopping module is configured to set the capacitance reference voltage of the MMC submodule in NLM modulation as the capacitance rated voltage value of the submodule after the capacitance voltage of the MMC submodule is recovered to the capacitance rated voltage.
In a third aspect, the invention provides an electronic device comprising a memory and a processor and computer instructions stored on the memory and running on the processor, which when executed by the processor, perform the method of the first aspect.
In a fourth aspect, the present invention provides a computer readable storage medium storing computer instructions which, when executed by a processor, perform the method of the first aspect.
Compared with the prior art, the invention has the beneficial effects that:
compared with the method for switching the energy consumption device, the method provided by the invention fully plays the capacity of the MMC for absorbing surplus power, utilizes a large number of sub-module capacitors contained in the MMC to absorb and release the surplus power, inhibits the voltage rise of the direct current side, does not need to increase hardware equipment, reduces the occupied area of the equipment, saves energy, reduces energy loss and strives for time for reducing the power generation of a new energy electric field.
Additional aspects of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.
Drawings
The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the invention.
Fig. 1 is a block diagram of a classical NLM algorithm provided in embodiment 1 of the present invention;
fig. 2 is a flowchart of a surplus power consumption control method of an MMC converter station provided in embodiment 1 of the present invention;
fig. 3 is a switching flowchart of the energy storage strategy and the energy release strategy provided in embodiment 1 of the present invention.
The specific embodiment is as follows:
the invention is further described below with reference to the drawings and examples.
It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the invention. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.
It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular forms also are intended to include the plural forms, and furthermore, it is to be understood that the terms "comprises" and "comprising" and any variations thereof are intended to cover non-exclusive inclusions, such as, for example, processes, methods, systems, products or devices that comprise a series of steps or units, are not necessarily limited to those steps or units that are expressly listed, but may include other steps or units that are not expressly listed or inherent to such processes, methods, products or devices.
Embodiments of the invention and features of the embodiments may be combined with each other without conflict.
Example 1
As shown in FIG. 1, which is a classical NLM algorithm block diagram, the capacitance voltage of the MMC submodule is given as the rated capacitance voltage V CN Phase voltage modulation wave v of j (j=a, b, c) * mj The number n of sub-modules of the j-phase upper bridge arm input is obtained through NLM algorithm uj Number n of submodules put into j-phase lower bridge arm lj Wherein round is a rounding operation; the surplus power control method of the MMC converter station is applied to the MMC converter station at the transmitting end connected with the new energy base, comprises an energy storage strategy and an energy release strategy, and adopts the capacitance of the MMC submodule to set the voltage value V * C Substitute V CN The control block diagram of the NLM modulation link directly acting on the MMC is shown in fig. 2, and the switching flow of the strategy change-over switch S is shown in fig. 3;
the method specifically comprises the following steps:
1) Setting an energy storage power instruction value P according to the actual engineering parameters of the MMC converter station * C Instruction value P of energy release power * C DC voltage upper limit V for energy storage strategy starting criterion * dc_max DC voltage limit V for energy storage strategy pause criterion * dc_min Upper limit value V of capacitance voltage of submodule with MMC * C_max MMC submodule capacitor rated voltage value V CN ；
2) When the MMC DC voltage at the transmitting end is higher than V * dc_max When the surplus power of the power transmission system is judged to occur, an energy storage strategy is started, and the surplus power is judged to occur according to an energy storage power instruction P * C Calculating the submodule capacitor reference voltage in NLM modulation by the following formula (5) to reduce the input quantity of MMC submodules, improve the submodule capacitor voltage, absorb surplus power, store the surplus power in the MMC submodule capacitor and inhibit the rise of direct-current voltage;
3) During the starting period of the energy storage strategy, if the capacitance voltage of the MMC submodule exceeds the upper limit value V of the capacitance voltage of the MMC submodule * C_max Or the DC voltage is lower than the DC voltage limit value V * dc_min Suspending the energy storage strategy and indicating the energy storage powerChanging the value to zero;
4) After receiving the fault clearing signal of the receiving end, starting an energy release strategy according to an energy release power instruction value P * C Calculating MMC submodule capacitor reference voltage in NLM modulation by a formula (9) to increase the input quantity of MMC submodules, so that the MMC submodule capacitor voltage is reduced, and the stored surplus power is released stably;
5) In the energy release process, after the capacitance voltage of the MMC submodule is restored to the rated capacitance voltage, the reference capacitance voltage of the submodule is given as the rated capacitance voltage value V of the submodule CN The MMC is restored to the normal operation state.
During normal operation of the soft-direct system, the direct-current voltage V dc At a set threshold value V * dc_max The strategy switch s=1, the reference value V of the submodule capacitor voltage * C Rated voltage value V for submodule capacitor CN The number of submodules of each phase of MMC participating in direct-current voltage support is the rated value N;
after surplus power occurs due to the fault of the receiving end, the direct current voltage V dc Exceeding a set threshold value V * dc_max When the energy storage strategy is started, the strategy change-over switch S=2, and the energy storage power command value P is used for controlling the energy storage power * C V calculated from the following formula (5) C The value of (t) is taken as a voltage reference value V of the capacitance of the sub-module * C The number of submodules of each phase participating in direct-current voltage support is gradually reduced in an NLM algorithm; during this period, if the submodule capacitor voltage V C Rising to the upper limit value V of the capacitance voltage of the submodule * C_max Suspending energy storage, and storing energy power command value P * C Given 0, prevent the sub-module capacitance from being damaged by overvoltage, V * C_max The value of (2) is recommended to be 1.5 times the rated voltage of the capacitance of the submodule, namely 1.5V CN The method comprises the steps of carrying out a first treatment on the surface of the If the direct current voltage V dc Below a set threshold value V * dc_min The direct current voltage is controlled within a reasonable range, and the energy storage is also suspended at the moment, P * C Taking 0;
if t 0 When receiving the cleared signal of the receiving end fault at any time, starting the energy release strategySlightly, the strategy change-over switch s=3, and the submodule capacitor is controlled according to the energy release power instruction value P * C Discharging, and calculating V from the following formula (9) C The value of (t) is taken as V * C In NLM algorithm, the number of submodules participating in direct-current voltage support of each phase is gradually increased, wherein V C (t 0 ) At t 0 The average voltage of the submodule capacitor which is latched at the moment is recovered to the rated value V CN And after that, the strategy change-over switch S=1, and the MMC converter station resumes normal operation.
The energy storage strategy, the energy release strategy and the energy storage power instruction value P are as follows * C Is described in detail:
first, the symbol will be described:
c: a sub-module capacitance value;
n: the number of sub-modules equipped for each bridge arm of the MMC;
n uj : the number of submodules put into the j-phase upper bridge arm;
n lj : the number of sub-modules put into the j-phase lower bridge arm;
P * C : an energy storage power/energy release power instruction set in an energy storage strategy/energy release strategy;
v * mj : voltage modulated wave of j (j=a, b, c) phase;
V dc : DC side voltage of MMC converter station;
V dcN : rated dc side voltage of MMC converter station;
V * dc_max : starting an energy storage strategy when the direct current voltage is larger than the starting criterion of the energy storage strategy;
V * dc_min : a pause criterion of the energy storage strategy, a power instruction P in the energy storage strategy when the direct current voltage is smaller than the pause criterion * C Set to 0;
V C : capacitance voltage average value of all submodules of MMC;
V C (t): the capacitance voltage average value of all submodules of the MMC at the moment t;
V C (t 0 )：t 0 all submodules of MMC at the moment have average capacitance voltage;
V CN : a submodule capacitor voltage rating;
V * C : a sub-module capacitance voltage reference value;
V * C_max : the upper limit of the reference value of the capacitance voltage of the submodule, when the capacitance voltage of the submodule is larger than the upper limit, the energy storage strategy is suspended, and the power instruction P is stored * C Set to 0;
W C (0): when the MMC operates normally, all sub-modules store energy in a capacitor;
W C (t): and at the moment t, the energy stored by all the submodules of the MMC is stored in the capacitor.
(1) Energy storage strategy:
when the MMC operates normally, the capacitance voltage of the submodule is V CN ：
Energy W stored during normal operation of MMC C (0) The method comprises the following steps:
during the operation of the energy storage strategy, setting the power required to be absorbed by the MMC as P * C MMC submodule capacitance energy W C (t) satisfies both the formulas (3) and (4):
the P-based formula (1) -formula (4) can be obtained * C After power is absorbed, the capacitance voltage average value V of all submodules C (t) lifting to:
if the direct voltage can be maintained at the rated value V in the process dcN The number of sub-modules of each phase for DC voltage support is reduced to N ′ ：
The following is an energy storage power instruction P * C Is described by the selection of: ideally, P * C The control effect is optimal when the control effect is exactly equal to the surplus power of the direct current system, namely P * C The power difference value of the alternating current side at the two ends of the power transmission and reception is the best; however, the communication means is required to collect the alternating current side power of the receiving end in real time to calculate with the alternating current side power of the transmitting end, communication is delayed, transmitted data are all historical data, and comparison of real-time data cannot be achieved; if the ac side power of the receiving end varies greatly during the fault period, the error generated by the comparison will be great, and the control effect will be affected.
Therefore, when the energy storage strategy is applied to the transmitting-end MMC converter station, the energy storage capacity of the MMC can be considered, and P can be calculated by referring to the dissipation power of the configured energy dissipation resistor * C Taking a fixed value, and no communication support is needed at this time; for example, under north-opening engineering parameters, P * C It can be taken as 1/4 of the rated power of the converter station, i.e. 375MW, instead of a set of dissipation resistors.
(2) Energy release strategy:
when the receiving end fault is cleared, the surplus power situation disappears, and then the energy stored in the submodule capacitor is released smoothly by adopting an energy release strategy, so that the voltage of the submodule capacitor is reduced, and the submodule capacitor is restored to the rated running state.
Let t be 0 Starting the energy release strategy at any time, and releasing the submodule capacitorPower enable instruction P * C Discharge is carried out on t 0 Time submodule capacitor voltage V C Latching to obtain V C (t 0 ) At V C Reduced to V C In the process of (t), energy DeltaW emitted by the capacitance of the submodule C (t) is:
ΔW C (t)＝∫P * C dt (8)
v in the energy release process obtained by the formulas (7) and (8) C The variation of (t) is:
in the energy release process, the number of sub-modules playing the role of direct-current voltage support is gradually increased and restored to N, and the energy release power instruction P * C The value of (2) may take into account the power take-off capability of the converter station, so in this embodiment P * C Selecting 10% of rated power of the converter station to realize stable release of energy; for example, under north-opening engineering parameters, P * C It can be taken to be 10% of the rated power of the converter station, i.e. 150MW.
The MMC surplus power control strategy of the embodiment can be used in a transmitting-end MMC converter station connected with a new energy base, an energy storage power instruction and an energy release power instruction can be set according to the capacity of the converter station and the actual energy storage capacity of a capacitor, surplus power can be consumed and reused, the voltage rise of a direct current side is restrained, the arrangement of a part of energy consumption devices can be replaced, the occupied area of equipment is reduced, the energy loss is reduced, and the time for reducing the power emission of a new energy electric field is shortened.
Example 2
The embodiment provides an MMC converter station surplus power consumption control system, includes:
the energy storage strategy starting module is configured to judge surplus power when the direct-current voltage of the transmitting-end MMC converter station exceeds the direct-current upper limit value, start the energy storage strategy and obtain the capacitance reference voltage of the MMC submodule in NLM modulation according to the energy storage power instruction value;
the energy storage strategy suspending module is configured to suspend the energy storage strategy when the capacitance reference voltage of the MMC submodule exceeds the upper limit value of the capacitance voltage or the direct-current voltage is lower than the lower limit value of the direct-current voltage after the energy storage strategy is started, and adjust the instruction value of the energy storage power to zero;
the energy release strategy starting module is configured to start an energy release strategy after receiving a receiving end fault clearing signal, and obtain an MMC submodule capacitor reference voltage in NLM modulation according to an energy release power instruction value;
and the energy release strategy stopping module is configured to set the capacitance reference voltage of the MMC submodule in NLM modulation as the capacitance rated voltage value of the submodule after the capacitance voltage of the MMC submodule is recovered to the capacitance rated voltage.
It should be noted that the above modules correspond to the steps described in embodiment 1, and the above modules are the same as examples and application scenarios implemented by the corresponding steps, but are not limited to those disclosed in embodiment 1. It should be noted that the modules described above may be implemented as part of a system in a computer system, such as a set of computer-executable instructions.
In further embodiments, there is also provided:
an electronic device comprising a memory and a processor and computer instructions stored on the memory and running on the processor, which when executed by the processor, perform the method described in embodiment 1. For brevity, the description is omitted here.
It should be understood that in this embodiment, the processor may be a central processing unit CPU, and the processor may also be other general purpose processors, digital signal processors DSP, application specific integrated circuits ASIC, off-the-shelf programmable gate array FPGA or other programmable logic device, discrete gate or transistor logic devices, discrete hardware components, or the like. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like.
The memory may include read only memory and random access memory and provide instructions and data to the processor, and a portion of the memory may also include non-volatile random access memory. For example, the memory may also store information of the device type.
A computer readable storage medium storing computer instructions which, when executed by a processor, perform the method described in embodiment 1.
The method in embodiment 1 may be directly embodied as a hardware processor executing or executed with a combination of hardware and software modules in the processor. The software modules may be located in a random access memory, flash memory, read only memory, programmable read only memory, or electrically erasable programmable memory, registers, etc. as well known in the art. The storage medium is located in a memory, and the processor reads the information in the memory and, in combination with its hardware, performs the steps of the above method. To avoid repetition, a detailed description is not provided herein.
Those of ordinary skill in the art will appreciate that the elements of the various examples described in connection with the present embodiments, i.e., the algorithm steps, can be implemented as electronic hardware or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the solution. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.
The above is only a preferred embodiment of the present invention, and is not intended to limit the present invention, but various modifications and variations can be made to the present invention by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
While the foregoing description of the embodiments of the present invention has been presented in conjunction with the drawings, it should be understood that it is not intended to limit the scope of the invention, but rather, it is intended to cover all modifications or variations within the scope of the invention as defined by the claims of the present invention.
Claims (6)
1. An MMC converter station surplus power consumption control method, characterized by comprising:
when the direct-current voltage of the MMC converter station at the transmitting end exceeds the direct-current upper limit value, judging that surplus power appears, starting an energy storage strategy, and obtaining an MMC submodule capacitor reference voltage in NLM modulation according to an energy storage power instruction value;
after the energy storage strategy is started, when the capacitance reference voltage of the MMC submodule exceeds the upper limit value of the capacitance voltage or the direct current voltage is lower than the lower limit value of the direct current voltage, the energy storage strategy is suspended, and the energy storage power instruction value is adjusted to be zero;
after receiving the receiving end fault clearing signal, starting an energy release strategy, and obtaining an MMC submodule capacitor reference voltage in NLM modulation according to an energy release power instruction value;
after the capacitance voltage of the MMC submodule is restored to the rated capacitance voltage, setting the reference capacitance voltage of the MMC submodule in NLM modulation as the rated capacitance voltage value of the submodule;
in the energy release process, after the capacitance voltage of the MMC submodule is restored to the rated capacitance voltage, the reference capacitance voltage of the submodule is given as the rated capacitance voltage value VCN of the submodule, and the MMC is restored to the normal running state;
after the energy storage strategy is started, the input quantity of the MMC submodules is adjusted according to the capacitance reference voltage of the MMC submodules so as to reduce the input quantity of the MMC submodules and increase the capacitance voltage of the MMC submodules;
average value V after increasing capacitance voltage of MMC submodule C (t) is:
wherein V is CN Capacitor voltage rating for MMC submodules; c is the capacitance value of the MMC submodule; n is the number of sub-modules in each phase of bridge arm; p (P) * C An energy storage power instruction value set in an energy storage strategy;
the input quantity of each phase of submodule of MMC is reduced to N ′ ，N ′ For the average value V of rated direct-current voltage of MMC converter station and capacitance voltage of MMC submodule C A ratio of (t);
after the energy release strategy is started, the input quantity of the MMC submodules is adjusted according to the capacitance reference voltage of the MMC submodules so as to increase the input quantity of the MMC submodules, reduce the capacitance voltage of the MMC submodules and release surplus power;
in the surplus power release process, the capacitance voltage average value V of MMC submodule C The variation of (t) is:
wherein V is C (t 0 ) At t 0 All MMC submodules capacitor voltage average value at moment; c is the capacitance value of the MMC submodule; n is the number of bridge arm sub-modules of each phase; p (P) * C And the energy storage power command value is set in the energy storage strategy.
2. The MMC converter station surplus power consumption control method of claim 1, wherein the stored power command value is set to a fixed value.
3. A surplus power consumption control method of an MMC converter station as claimed in claim 1, characterized in that the energy release power command value is set to 10% of the rated power of the MMC converter station.
4. An MMC converter station surplus power consumption control system, comprising:
the energy storage strategy starting module is configured to judge surplus power when the direct-current voltage of the transmitting-end MMC converter station exceeds the direct-current upper limit value, start the energy storage strategy and obtain the capacitance reference voltage of the MMC submodule in NLM modulation according to the energy storage power instruction value;
the energy storage strategy suspending module is configured to suspend the energy storage strategy when the capacitance reference voltage of the MMC submodule exceeds the upper limit value of the capacitance voltage or the direct-current voltage is lower than the lower limit value of the direct-current voltage after the energy storage strategy is started, and adjust the instruction value of the energy storage power to zero;
the energy release strategy starting module is configured to start an energy release strategy after receiving a receiving end fault clearing signal, and obtain an MMC submodule capacitor reference voltage in NLM modulation according to an energy release power instruction value;
the energy release strategy stopping module is configured to set the capacitance reference voltage of the MMC submodule in NLM modulation as the capacitance rated voltage value of the submodule after the capacitance voltage of the MMC submodule is recovered to the capacitance rated voltage;
in the energy release process, after the capacitance voltage of the MMC submodule is restored to the rated capacitance voltage, the reference capacitance voltage of the submodule is given as the rated capacitance voltage value VCN of the submodule, and the MMC is restored to the normal running state;
after an energy storage strategy is started, the input quantity of MMC submodules is adjusted according to the capacitance reference voltage of the MMC submodules so as to reduce the input quantity of the MMC submodules and increase the capacitance voltage of the MMC submodules;
average value V after increasing capacitance voltage of MMC submodule C (t) is:
wherein V is CN Capacitor voltage rating for MMC submodules; c is the capacitance value of the MMC submodule; n is the number of sub-modules in each phase of bridge arm; p (P) * C An energy storage power instruction value set in an energy storage strategy;
the input quantity of each phase of submodule of MMC is reduced to N ′ ，N ′ For the average value V of rated direct-current voltage of MMC converter station and capacitance voltage of MMC submodule C A ratio of (t);
after the energy release strategy is started, the input quantity of the MMC submodules is adjusted according to the capacitance reference voltage of the MMC submodules so as to increase the input quantity of the MMC submodules, reduce the capacitance voltage of the MMC submodules and release surplus power;
in the surplus power release process, capacitor voltage of MMC submoduleAverage V C The variation of (t) is:
wherein V is C (t 0 ) At t 0 All MMC submodules capacitor voltage average value at moment; c is the capacitance value of the MMC submodule; n is the number of bridge arm sub-modules of each phase; p (P) * C And the energy storage power command value is set in the energy storage strategy.
5. An electronic device comprising a memory and a processor and computer instructions stored on the memory and running on the processor, which when executed by the processor, perform the method of any one of claims 1-3.
6. A computer readable storage medium storing computer instructions which, when executed by a processor, perform the method of any of claims 1-3.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2021105059406 | 2021-05-10 | ||
| CN202110505940 | 2021-05-10 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113517707A CN113517707A (en) | 2021-10-19 |
| CN113517707B true CN113517707B (en) | 2023-08-08 |
Family
ID=78064443
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110535886.XA Active CN113517707B (en) | 2021-05-10 | 2021-05-17 | MMC converter station surplus power consumption control method and system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113517707B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115102217B (en) * | 2022-08-23 | 2022-11-18 | 山东大学 | Method for determining stable operation domain of MMC at receiving end of LCC-MMC hybrid cascaded direct-current power grid |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107404130A (en) * | 2017-08-31 | 2017-11-28 | 天津大学 | MMC redundancy submodule DC voltage support and control methods |
| CN107769216A (en) * | 2016-08-18 | 2018-03-06 | 中国电力科学研究院 | A kind of voltage modulated method for the access of weak AC network |
| CN109787265A (en) * | 2019-01-31 | 2019-05-21 | 中国能源建设集团天津电力设计院有限公司 | A kind of flexible HVDC transmission system control method for coordinating stabilized new energy and go out fluctuation |
| CN111541362A (en) * | 2020-03-27 | 2020-08-14 | 山东大学 | Switching control method and system for MMC redundancy sub-module |
-
2021
- 2021-05-17 CN CN202110535886.XA patent/CN113517707B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107769216A (en) * | 2016-08-18 | 2018-03-06 | 中国电力科学研究院 | A kind of voltage modulated method for the access of weak AC network |
| CN107404130A (en) * | 2017-08-31 | 2017-11-28 | 天津大学 | MMC redundancy submodule DC voltage support and control methods |
| CN109787265A (en) * | 2019-01-31 | 2019-05-21 | 中国能源建设集团天津电力设计院有限公司 | A kind of flexible HVDC transmission system control method for coordinating stabilized new energy and go out fluctuation |
| CN111541362A (en) * | 2020-03-27 | 2020-08-14 | 山东大学 | Switching control method and system for MMC redundancy sub-module |
Non-Patent Citations (1)
| Title |
|---|
| Yang Xing等.An Improved NLM Strategy for MMC Emergency Power Control.《 2020 IEEE/IAS Industrial and Commercial Power System Asia (I&CPS Asia)》.2020,1251-1255. * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN113517707A (en) | 2021-10-19 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP6110884B2 (en) | Control circuit | |
| WO2017000925A1 (en) | Fault current-suppressing damper topology circuit and control method thereof and converter | |
| US20130334818A1 (en) | Dynamic Braking on a Wind Turbine During a Fault | |
| CN105656299B (en) | A kind of startup strategy suitable for full-bridge modules multilevel converter | |
| CN113517707B (en) | MMC converter station surplus power consumption control method and system | |
| ES2900730T3 (en) | Converter in triangular configuration | |
| JP2005278269A (en) | Drive controller for vehicle | |
| KR20160012381A (en) | Hybrid HVDC converter having modular multilevel converter | |
| US9847642B2 (en) | Control circuit | |
| ES2533471T3 (en) | Circuit layout for use in a wind turbine | |
| US20180013290A1 (en) | Control circuit | |
| CN117595349A (en) | Efficient medium-voltage alternating current interconnection device and control method thereof | |
| CN112054495A (en) | Energy absorption circuit for direct current system and control method thereof | |
| CN110729881A (en) | Modular energy discharge submodule for optimizing bypass scheme and control protection method thereof | |
| WO2021017337A1 (en) | Energy control circuit and control method therefor | |
| CN110571815B (en) | Controllable unloading module based on resistance-capacitance device, circuit and control method | |
| CN115395549A (en) | Modular multi-level hybrid energy storage system and implementation method, device and equipment thereof | |
| EP2834896A1 (en) | Control circuit | |
| CN111244999B (en) | Control method of hybrid energy consumption device | |
| CN114531050A (en) | Energy-consumption type modular multilevel converter and control method | |
| EP3935709A1 (en) | System and method for supplying electric power to a grid and for supporting the grid | |
| CN210745011U (en) | Modular energy discharge submodule for optimizing bypass scheme | |
| JP3261947B2 (en) | Self-excited DC power transmission controller | |
| CN110571814B (en) | Energy control circuit and method based on resistance-capacitance device | |
| CN113612222B (en) | Fault ride-through control method for hybrid direct current transmission system |
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 |