CN111934572B - Super-large-scale energy storage MMC converter device and energy storage control method - Google Patents
Super-large-scale energy storage MMC converter device and energy storage control method Download PDFInfo
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- 238000004146 energy storage Methods 0.000 title claims abstract description 86
- 238000000034 method Methods 0.000 title claims abstract description 29
- 239000003990 capacitor Substances 0.000 claims abstract description 51
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 claims abstract description 22
- 229910052744 lithium Inorganic materials 0.000 claims abstract description 22
- 238000010248 power generation Methods 0.000 claims abstract description 14
- 239000000126 substance Substances 0.000 claims description 10
- 238000006243 chemical reaction Methods 0.000 claims description 9
- 238000001514 detection method Methods 0.000 claims description 6
- 238000009826 distribution Methods 0.000 claims description 6
- 230000009466 transformation Effects 0.000 claims description 6
- 238000010586 diagram Methods 0.000 description 11
- 238000004590 computer program Methods 0.000 description 7
- 238000012986 modification Methods 0.000 description 5
- 230000004048 modification Effects 0.000 description 5
- 238000005520 cutting process Methods 0.000 description 4
- 230000006870 function Effects 0.000 description 4
- 238000003860 storage Methods 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 2
- 230000004075 alteration Effects 0.000 description 1
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- 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
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- 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
- H02J3/32—Arrangements for balancing of the load in a network by storage of energy using batteries with converting means
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- 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
- Y02E10/00—Energy generation through renewable energy sources
- Y02E10/50—Photovoltaic [PV] energy
- Y02E10/56—Power conversion systems, e.g. maximum power point trackers
Abstract
The invention discloses a super-large-scale energy storage MMC converter device and an energy storage control method, and belongs to the technical field of modular multilevel converters. The device of the invention comprises: the bridge arms comprise a plurality of energy storage sub-modules and an inductor; the plurality of energy storage sub-modules are connected in series and connected with an inductor; each two bridge arms are connected through cables of the bridge arms to serve as a group of one-phase sub-converters; the one-phase sub-converters comprise three groups, and the three groups of the one-phase sub-converters are connected in parallel; the energy storage sub-module comprises: the photovoltaic power generation system comprises an energy storage submodule anode, an energy storage submodule cathode, a first IGBT, a second IGBT, a third capacitor, an inductor L1, a photovoltaic power generation unit, a lithium battery pack and a diode. The invention can effectively reduce the terminal voltage required by the battery pack, and the number of batteries connected in series with the battery pack is reduced, thereby improving the reliability of the batteries.
Description
Technical Field
The invention relates to the technical field of modular multilevel converters, in particular to a super-large-scale energy storage MMC converter device and an energy storage control method.
Background
Nowadays, with the rise of ultra-large scale energy storage technology, the requirements on the energy storage converter are more and more strict. The super-large-scale energy storage station has the characteristics of high voltage and large capacity, and a multi-level structure is required to be adopted for a converter. The Modular Multilevel Converter (MMC) is a novel multilevel converter, is widely applied to the fields of high-voltage direct-current transmission, energy storage converters and the like, and has the advantages of low manufacturing difficulty, good waveform quality, strong troubleshooting capability and the like. Therefore, the super-large-scale energy storage power station adopts the multi-level converter as a better choice. However, the problems of capacitor voltage balance of the sub-modules and circulating current of each bridge arm are caused, which brings great difficulty to the use of the MMC.
Disclosure of Invention
In order to solve the above problems, the present invention provides a very large scale energy storage MMC converter device, comprising:
the bridge arms comprise a plurality of energy storage sub-modules and an inductor;
the energy storage sub-modules are connected in series and connected with an inductor;
each two bridge arms are connected through cables of the bridge arms to serve as a group of one-phase sub-converters; the one-phase sub-converters comprise three groups, and the three groups of the one-phase sub-converters are connected in parallel;
the energy storage sub-module comprises: the photovoltaic power generation system comprises first to sixth IGBTs, first to third capacitors, a lithium battery pack, an energy storage submodule anode, an energy storage submodule cathode, an inductor L1, a photovoltaic power generation unit and a diode;
the input of current is controlled by controlling the turn-off of control switches of the first IGBT, the second IGBT, the third IGBT and the lithium battery pack;
the positive electrode of the energy storage sub-module is connected with the emitter of the first IGBT and the collector of the second IGBT;
the negative electrode of the energy storage sub-module is connected with the emitting electrode of the second IGBT;
the first capacitor is connected with the second capacitor in series, and the anode of the first capacitor is connected with the collector of the first IGBT;
the negative electrode of the second capacitor is connected with the emitter of the second IGBT;
an emitter of the third IGBT is connected with a collector of the fourth IGBT, and the collector of the third IGBT and the emitter of the fourth IGBT are respectively connected with the anode and the cathode of the first capacitor;
the emitter of the fifth IGBT is connected with the collector of the sixth IGBT, and the fifth IGBT
The collector of the second IGBT is connected with the emitter of the fourth IGBT and the anode of the second capacitor; an emitter of the sixth IGBT is connected with a cathode of the second capacitor;
the positive electrode of the third capacitor is connected with the emitter of the third IGBT, and the negative electrode of the third capacitor is connected with the emitter of the fifth IGBT;
one end of the inductor L1 is connected with the negative electrode of the third capacitor, and the other end of the inductor L1 is connected with the positive electrode of the lithium battery pack;
the negative electrode of the lithium battery pack is connected with the emitting electrode of the sixth IGBT;
and the positive electrode of the photovoltaic power generation unit is connected with the collector electrode of the third IGBT through a diode, and the negative electrode of the photovoltaic power generation unit is connected with the emitter electrode of the sixth IGBT.
Furthermore, the capacitance values of the first capacitor, the second capacitor and the third capacitor are the same and meet a preset range.
Further, the device is externally connected with a transformer, an alternating current power supply and a load.
The invention also provides an energy storage control method using the super-large scale energy storage MMC converter device, which comprises the following steps:
before the super-large-scale energy storage MMC converter is put into operation, SOC pre-detection is carried out on a lithium battery pack in an energy storage sub-module;
determining an alternating current end current reference value and a direct current end voltage reference value of the super-large-scale energy storage MMC converter;
detecting the circulating current power of each phase of sub-device, converting the circulating current power to obtain conversion data, and determining a circulating current reference value according to the conversion data and a direct-current terminal voltage reference value;
determining a current reference value of each bridge arm according to the circulating current reference value and the alternating-current end current reference value;
and carrying out dq coordinate transformation on the current reference value of each bridge arm, outputting dq voltage, carrying out abc coordinate transformation and SPWM modulation on the dq voltage, obtaining an output result, switching off the first IGBT to the sixth IGBT of the energy storage sub-module according to the output result, and carrying out energy storage control through switching off the first IGBT to the sixth IGBT.
Optionally, the SOC pre-detection includes:
checking whether the SOC of each battery of each branch in each lithium battery pack meets a battery input standard or not;
if each battery meets the battery input standard, the branch circuit is not broken;
and if a plurality of batteries do not meet the battery input standard, the branch circuit is broken, and the capacity and the SOC of the lithium battery pack of the broken branch circuit are calculated.
Optionally, the determination formula of the reference value of the alternating-current end current is as follows:
wherein the content of the first and second substances,
is the reference power, U, of any phase sub-device ac Is a voltage of an Alternating Current (AC) voltage,
is an ac power angle.
Optionally, the dc terminal voltage reference value is determined by the following formula:
wherein, the first and the second end of the pipe are connected with each other,
for any phase sub-unit current DC component reference value, alpha k For distributing coefficient, U, of current dc Is a direct-current voltage, and the voltage is,
is a reference value k of the voltage at the DC terminal dc-pk And k dc-ik Proportional and integral coefficients of the kth phase direct current component are respectively;
the current distribution coefficient is determined by the following formula:
wherein Q k For any phase sub-deviceTotal capacity and Q of energy sub-module battery pack all The determination formula for the total capacity current distribution coefficient is as follows:
optionally, the conversion formula of the commutation power is as follows:
wherein, the first and the second end of the pipe are connected with each other,
is an alternating component of the first phase circulating current, P diffa The circulating current power of the first phase is, similarly,
is an alternating component, P, of the second phase circulating current diffb Is the circulating power of the second phase,
is the AC component, P, of the third phase circulating current diffc Circulating power of the third phase.
Optionally, the current reference value of each bridge arm is determined by the following formula:
wherein the content of the first and second substances,
the reference current of the upper bridge arm of any phase sub-device,
The reference current of the lower bridge arm of any phase sub-device and the circulating current reference value of any phase sub-device,
the reference value is the current reference value of the alternating current end of the current of any phase of the electronic device.
The invention can effectively reduce the terminal voltage required by the battery pack, and the number of batteries connected in series with the battery pack is reduced, thereby improving the reliability of the batteries.
Drawings
FIG. 1 is a diagram of a very large scale energy storage MMC converter device of the present invention;
FIG. 2 is a diagram of an energy storage submodule of a very large scale energy storage MMC converter device according to the present invention; FIG. 3 is a flow chart of a method for cutting off a very large scale energy storage MMC converter device according to the present invention; FIG. 4 is a flow chart of a method for putting a very large scale energy storage MMC converter device into operation according to the present invention;
FIG. 5 is a flow chart of an energy storage control method using a very large scale energy storage MMC converter device according to the present invention;
FIG. 6 is a control block diagram of an energy storage control method using a very large scale energy storage MMC converter device according to the present invention;
FIG. 7 is a voltage waveform diagram of the capacitor terminal and the battery terminal of the energy storage submodule of the energy storage control method using the ultra-large scale energy storage MMC converter device according to the present invention;
FIG. 8 is a waveform diagram of three phase voltages on the AC side of an energy storage control method using a very large scale energy storage MMC converter apparatus according to the present invention;
fig. 9 is a dc side voltage waveform of an energy storage control method using a very large scale energy storage MMC converter device according to the present invention.
Detailed Description
Example embodiments of the present invention will now be described with reference to the accompanying drawings, however, the invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein, which are provided for a complete and complete disclosure of the invention and to fully convey the scope of the invention to those skilled in the art. The terminology used in the exemplary embodiments illustrated in the accompanying drawings is not intended to be limiting of the invention. In the drawings, the same unit/element is denoted by the same reference numeral.
Unless otherwise defined, terms (including 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. Further, it will be understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense.
The invention provides a very large scale energy storage MMC converter device, as shown in figure 1, comprising:
the bridge arms comprise a plurality of energy storage sub-modules and an inductor; the plurality of energy storage sub-modules are connected in series and connected with an inductor;
each two bridge arms are connected through cables of the bridge arms to serve as a group of one-phase sub-converters; the one-phase sub-converters comprise three groups, and the three groups of the one-phase sub-converters are connected in parallel;
the device is externally connected with a transformer, an alternating current power supply and a load.
The energy storage sub-module, as shown in fig. 2, includes: the energy storage module comprises an energy storage sub-module anode, an energy storage sub-module cathode, first to sixth IGBTs (S1-S6), first to third capacitors (C1-C3), an inductor L1, a photovoltaic power generation unit, a lithium battery pack and a diode;
the positive electrode of the energy storage sub-module is connected with the emitting electrode of the first IGBT and the collector electrode of the second IGBT; the negative electrode of the energy storage submodule is connected with the emitting electrode of the second IGBT;
the first capacitor is connected in series with the second capacitor, and the anode of the first capacitor is connected with the collector of the first IGBT;
the cathode of the second capacitor is connected with the emitter of the second IGBT;
the emitter of the third IGBT is connected with the collector of the fourth IGBT, and the emitter of the third IGBT and the emitter of the fourth IGBT are respectively connected with the anode and the cathode of the first capacitor;
an emitter of the fifth IGBT is connected with a collector of the sixth IGBT, and a collector of the fifth IGBT is connected with an emitter of the fourth IGBT and a positive electrode of the second capacitor;
an emitter of the sixth IGBT is connected with the negative electrode of the second capacitor;
the positive electrode of the third capacitor is connected with the emitter of the third IGBT, and the negative electrode of the third capacitor is connected with the fifth IGBT
The emitting electrodes of the IGBTs are connected;
one end of the inductor L1 is connected with the negative electrode of the third capacitor, and the other end of the inductor L1 is connected with the positive electrode of the lithium battery pack;
the negative electrode of the lithium battery pack is connected with the emitter of the sixth IGBT;
the positive electrode of the photovoltaic power generation unit is connected with the collector electrode of the third IGBT through a diode, and the negative electrode of the photovoltaic power generation unit is connected with the emitter electrode of the sixth IGBT.
The energy storage submodule controls the switching-off of the control switches of the first IGBT, the second IGBT, the third IGBT and the fourth IGBT, controls the cutting-off of current, and controls the switching-on of the control switches of the first IGBT, the second IGBT, the third IGBT and the lithium battery pack.
As shown in fig. 3, the working principle of the energy storage submodule in 2 cutting modes is shown; the first cutting method comprises the following steps:
the switch S1 is controlled to be kept off by a driving signal; controlling the switch S2 to be closed through a driving signal;
at the moment, current flows in from the positive pole of the submodule and flows out to the negative pole of the submodule through the S2 switching tube; the second cutting method comprises the following steps:
the driving signal controls the switch S1 to keep off; the driving signal controls the switch S2 to be turned off;
at this time, current flows from the negative pole of the submodule, passes through the backward diode T2 and flows out to the positive pole of the submodule.
As shown in fig. 4, the working principle of 2 input methods for the energy storage submodule; the first input method comprises the following steps:
the switch S2 is kept off, the switch S1 is kept on, the switches S3 and S5 are closed, the switches S4 and S6 are opened, current flows from the positive electrode, and the capacitors C1, C2 and C3 and the battery pack are charged through the T1 and the S3; the photovoltaic power generation unit charges the battery through the diode.
The second input method comprises the following steps:
switch S2 remains off, switch S1 remains on, switches S4 and S6 are on, switches S3 and S5 are off, capacitors C1, C2, C3 and the battery pack discharge, and current flows from the negative electrode, through S1, and out the positive electrode.
The capacitance values of the first capacitor, the second capacitor and the third capacitor are the same and meet a preset range.
Wherein fs is the switching frequency of the IGBT in the sub-module; ron is the conduction impedance of the IGBT in the sub-module; rc is the equivalent impedance of the capacitor.
The present invention also provides an energy storage control method using the ultra-large scale energy storage MMC converter device, as shown in fig. 5, including:
before the super-large scale energy storage MMC converter is put into operation, SOC pre-detection is carried out on a lithium battery pack in an energy storage submodule;
determining an alternating current end current reference value and a direct current end voltage reference value of the super-large-scale energy storage MMC converter;
detecting the circulating current power of each phase of sub-device, converting the circulating current power to obtain conversion data, and determining a circulating current reference value according to the conversion data and a direct-current terminal voltage reference value;
determining a current reference value of each bridge arm according to the circulating current reference value and the alternating-current end current reference value;
and carrying out dq coordinate transformation on the current reference value of each bridge arm, outputting dq voltage, carrying out abc coordinate transformation and SPWM modulation on the dq voltage, obtaining an output result, switching off the first IGBT to the sixth IGBT of the energy storage sub-module according to the output result, and carrying out energy storage control through switching off the first IGBT to the sixth IGBT.
As shown in fig. 6, the determination of the upper and lower bridge arm currents of each phase needs to be composed of an alternating current of each phase and a circulating current of each phase, and the circulating current of each phase is composed of a direct current part and an alternating current part. The method comprises the steps of stabilizing the voltage of a direct-current bus by determining a direct-current bus reference value, determining the input power of an MMC converter by setting an input active power reference value of an alternating-current part of the converter, introducing a current distribution coefficient, and distributing the magnitude of each phase of direct-current reference value according to the capacity of each phase of connected battery pack, so that the charging and discharging power of each battery pack is controlled.
SOC pre-detection, comprising:
checking whether the SOC of each battery of each branch in each lithium battery pack meets a battery input standard or not;
if each battery meets the battery input standard, the branch circuit is not broken;
and if a plurality of batteries do not meet the battery input standard, the branch circuit is broken, and the capacity and the SOC of the lithium battery pack of the broken branch circuit are calculated.
Optionally, the determination formula of the reference value of the alternating-current end current is as follows:
wherein the content of the first and second substances,
is the reference power, U, of any phase sub-device ac Is a voltage of an Alternating Current (AC) voltage,
is an ac power angle.
The determination formula of the reference value of the direct-current end voltage is as follows:
wherein the content of the first and second substances,
for any phase sub-device current DC component reference value, U dc Is a direct voltage, alpha k For the current distribution coefficient,
Is a reference value k of the voltage at the DC terminal dc-pk And k dc-ik Respectively are the proportion and integral coefficient of the kth phase direct current component;
the current distribution coefficient is determined by the following formula:
Q k total capacity and Q of energy storage submodule battery pack for any one-phase submodule all Is the total capacity.
The conversion formula of the commutation power is as follows:
wherein the content of the first and second substances,
is an alternating component of the first phase circulating current, P diffa The circulating current power of the first phase is, similarly,
is an alternating component of the second phase circulating current, P diffb Is the circulating current power of the second phase,
is the AC component, P, of the third phase circulating current diffc Circulating power of the third phase.
The current reference value of each bridge arm is determined according to the following formula:
wherein the content of the first and second substances,
is the reference current of the upper bridge arm of any phase sub-device,
The reference current of the lower bridge arm of any phase sub-device and the circulating current reference value of any phase sub-device,
the reference value is the current reference value of the alternating current end of the current of any phase of the electronic device.
As shown in fig. 7, the voltage at the capacitor of the energy storage sub-module is about 500V, the voltage at the battery pack end is about 125V, the voltage output is increased by 4 times, the capacitor voltage of the conventional half-bridge sub-module reaches 500V, and the 500V battery pack needs to be connected in parallel at the capacitor, while the topology of the energy storage sub-module of the invention can meet the requirement only by 125V, which greatly reduces the number of sub-batteries needing to be connected in series in the battery pack, thereby improving the operation reliability of the battery pack.
As shown in fig. 8, a waveform of an ac side phase voltage of 0 to 0.4 seconds is recorded, and a phase voltage is a sine wave with a peak value of about 54KV, because each bridge arm is connected with 50 sub-modules, the MMC converter is a 51-level converter, and the generated ac waveform tends to a sine wave, and the harmonic characteristics are good.
As shown in fig. 9, the voltage waveform of the load at the dc end of 0-2.5 seconds was recorded. The direct current voltage is stabilized at about 135KV after 0.7 second, and the voltage stability is good.
The invention can effectively reduce the terminal voltage required by the battery pack, and the number of batteries connected in series with the battery pack is reduced, thereby improving the reliability of the batteries.
As will be appreciated by one skilled in the art, embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and so forth) having computer-usable program code embodied therein. The solution in the embodiment of the present application may be implemented by using various computer languages, for example, object-oriented programming language Java and transliteration scripting language JavaScript, etc.
The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the application. It will be understood that each flow and/or block of the flowchart illustrations and/or block diagrams, and combinations of flows and/or blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
While the preferred embodiments of the present application have been described, additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. Therefore, it is intended that the appended claims be interpreted as including preferred embodiments and all alterations and modifications as fall within the scope of the application.
It will be apparent to those skilled in the art that various changes and modifications may be made in the present application without departing from the spirit and scope of the application. Thus, if such modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is intended to include such modifications and variations as well.
Claims (9)
1. A very large scale energy storage MMC converter apparatus, the apparatus comprising:
the bridge arms comprise a plurality of energy storage sub-modules and an inductor;
the energy storage sub-modules are connected in series and connected with an inductor;
each two bridge arms are connected through cables of the bridge arms to serve as a group of one-phase sub-converters; the one-phase sub-converters comprise three groups, and the three groups of the one-phase sub-converters are connected in parallel;
the energy storage sub-module comprises: the photovoltaic power generation system comprises first to sixth IGBTs, first to third capacitors, a lithium battery pack, an energy storage submodule anode, an energy storage submodule cathode, an inductor L1, a photovoltaic power generation unit and a diode;
by controlling the turn-off of the control switches of the first to sixth IGBTs, the charge and discharge of the first to third capacitors and the charge and discharge of the lithium battery pack, controlling the input of current;
the positive electrode of the energy storage sub-module is connected with the emitter of the first IGBT and the collector of the second IGBT;
the negative electrode of the energy storage sub-module is connected with the emitting electrode of the second IGBT;
the first capacitor is connected with the second capacitor in series, and the anode of the first capacitor is connected with the collector of the first IGBT;
the negative electrode of the second capacitor is connected with the emitter of the second IGBT;
the emitter of the third IGBT is connected with the collector of the fourth IGBT, and the collector of the third IGBT and the emitter of the fourth IGBT are respectively connected with the anode and the cathode of the first capacitor;
an emitter of the fifth IGBT is connected with a collector of the sixth IGBT, and the collector of the fifth IGBT is connected with an emitter of the fourth IGBT and a positive electrode of the second capacitor; an emitting electrode of the sixth IGBT is connected with a negative electrode of the second capacitor;
the positive electrode of the third capacitor is connected with the emitter of the third IGBT, and the negative electrode of the third capacitor is connected with the emitter of the fifth IGBT;
one end of the inductor L1 is connected with the negative electrode of the third capacitor, and the other end of the inductor L1 is connected with the positive electrode of the lithium battery pack;
the negative electrode of the lithium battery pack is connected with the emitter of the sixth IGBT;
and the positive electrode of the photovoltaic power generation unit is connected with the collector electrode of the third IGBT through a diode, and the negative electrode of the photovoltaic power generation unit is connected with the emitter electrode of the sixth IGBT.
2. The apparatus of claim 1, wherein the first to third capacitors have the same capacitance value and satisfy a predetermined range.
3. The apparatus of claim 1, externally connected to a transformer, an alternating current power source, and a load.
4. A method of energy storage control using the apparatus of any of claims 1-3, the method comprising:
before the super-large-scale energy storage MMC converter is put into operation, SOC pre-detection is carried out on a lithium battery pack in an energy storage sub-module;
determining an alternating current end current reference value and a direct current end voltage reference value of the super-large-scale energy storage MMC converter;
detecting the circulating current power of each phase of sub-device, converting the circulating current power to obtain conversion data, and determining a circulating current reference value according to the conversion data and a direct-current terminal voltage reference value;
determining a current reference value of each bridge arm according to the circulating current reference value and the alternating-current end current reference value;
and carrying out dq coordinate transformation on the current reference value of each bridge arm, outputting dq voltage, carrying out abc coordinate transformation and SPWM modulation on the dq voltage, obtaining an output result, switching off the first IGBT to the sixth IGBT of the energy storage sub-module according to the output result, and carrying out energy storage control through switching off the first IGBT to the sixth IGBT.
5. The method of claim 4, the SOC pre-detection, comprising:
checking whether the SOC of each battery of each branch in each lithium battery pack meets a battery input standard or not;
if each battery meets the battery input standard, the branch circuit is not broken;
and if a plurality of batteries do not meet the battery input standard, the branch circuit is broken, and the capacity and the SOC of the lithium battery pack of the broken branch circuit are calculated.
6. The method of claim 4, the AC end current reference value
The determination formula of (1) is as follows:
wherein the content of the first and second substances,
is the reference power, U, of any phase sub-device ac Is an alternating voltage of
Is an ac power angle.
7. The method of claim 4, wherein the dc terminal voltage reference is determined by the following equation:
wherein the content of the first and second substances,
for any phase sub-unit current DC component reference value, alpha k For distributing coefficient, U, of current dc Is a direct-current voltage, and the voltage is,
is a reference value k of the voltage at the DC terminal dc-pk And k dc-ik Respectively are the proportion and integral coefficient of the kth phase direct current component;
the current distribution coefficient is determined by the following formula:
wherein Q is k Total capacity and Q of energy storage submodule battery pack for any one-phase submodule all Is the total capacity.
8. The method of claim 6, wherein the circulating current power is converted again by the following conversion formula:
wherein the content of the first and second substances,
is an alternating component of the first phase circulating current, P diffa The circulating current power of the first phase is, similarly,
is an alternating component, P, of the second phase circulating current diffb Is the circulating current power of the second phase,
in a third phase of circulationOf alternating current component, P diffc Circulating power of the third phase.
9. The method of claim 4, wherein the current reference value of each bridge leg is determined according to the following formula:
wherein the content of the first and second substances,
the reference current of the upper bridge arm of any phase sub-device,
The reference current of the lower bridge arm of any phase sub-device and the circulating current reference value of any phase sub-device,
the reference value is the current reference value of the alternating current end of the current of any phase of the electronic device.
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2012024984A1 (en) * | 2010-07-22 | 2012-03-01 | 荣信电力电子股份有限公司 | Modular multilevel converter-based transformerless battery energy storage topology |
| CN103236706A (en) * | 2013-04-23 | 2013-08-07 | 中国科学院电工研究所 | Battery energy storage system based on modular multilevel AC-AC (Alternating Current-Alternating Current) converter topology |
| CN104113082A (en) * | 2014-07-17 | 2014-10-22 | 西安交通大学 | Modular full direct current photovoltaic system and control method thereof |
| CN204928610U (en) * | 2015-08-14 | 2015-12-30 | 国家电网公司 | Single -phase non - isolated form photovoltaic grid -connected inverter |
| CN106877371A (en) * | 2017-03-30 | 2017-06-20 | 上海交通大学 | A kind of control method of the modular multi-level converter with energy-storage function |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2012024984A1 (en) * | 2010-07-22 | 2012-03-01 | 荣信电力电子股份有限公司 | Modular multilevel converter-based transformerless battery energy storage topology |
| CN103236706A (en) * | 2013-04-23 | 2013-08-07 | 中国科学院电工研究所 | Battery energy storage system based on modular multilevel AC-AC (Alternating Current-Alternating Current) converter topology |
| CN104113082A (en) * | 2014-07-17 | 2014-10-22 | 西安交通大学 | Modular full direct current photovoltaic system and control method thereof |
| CN204928610U (en) * | 2015-08-14 | 2015-12-30 | 国家电网公司 | Single -phase non - isolated form photovoltaic grid -connected inverter |
| CN106877371A (en) * | 2017-03-30 | 2017-06-20 | 上海交通大学 | A kind of control method of the modular multi-level converter with energy-storage function |
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