CN112436739A - Modular combined direct-current transformer and control method thereof - Google Patents
Modular combined direct-current transformer and control method thereof Download PDFInfo
- Publication number
- CN112436739A CN112436739A CN202011454589.4A CN202011454589A CN112436739A CN 112436739 A CN112436739 A CN 112436739A CN 202011454589 A CN202011454589 A CN 202011454589A CN 112436739 A CN112436739 A CN 112436739A
- Authority
- CN
- China
- Prior art keywords
- voltage
- mmc
- direct
- direct current
- transformer
- 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.)
- Granted
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
-
- 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
- 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
- H02J3/38—Arrangements for parallely feeding a single network by two or more generators, converters or transformers
- H02J3/381—Dispersed generators
-
- 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
-
- 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
- H02J2203/00—Indexing scheme relating to details of circuit arrangements for AC mains or AC distribution networks
- H02J2203/20—Simulating, e g planning, reliability check, modelling or computer assisted design [CAD]
-
- 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
- H02J2300/00—Systems for supplying or distributing electric power characterised by decentralized, dispersed, or local generation
- H02J2300/20—The dispersed energy generation being of renewable origin
-
- 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 modular combined direct current transformer and a control method thereof, wherein the direct current transformer is formed by serially connecting 2N MMC, a converter transformer in an MMC converter station is cancelled, and the complexity and the manufacturing cost of equipment are greatly reduced. In addition, the MMC modules adopted by the direct current transformer are the same, the expansion and the maintenance are easy, and meanwhile, the modular combined direct current transformer can be connected with a direct current power grid with any voltage level. Meanwhile, the alternating current part in the direct current transformer adopts 100-400 Hz medium-frequency alternating current transmission, so that the size and the weight of related equipment can be greatly reduced compared with a power frequency system, and the economy of the whole modularized combined direct current transformer can be directly improved.
Description
Technical Field
The invention belongs to the technical field of power systems, and particularly relates to a modular combined direct-current transformer and a control method thereof.
Background
Due to the introduction of the global energy internet concept, large-scale renewable energy grid connection and interconnection of existing and to-be-built power transmission systems become current research hotspots. In China, the characteristic of unbalanced energy distribution and electric load center distribution needs a long-distance high-capacity extra-high voltage transmission technology; compared with high-voltage alternating-current power transmission, the high-voltage/extra-high-voltage direct-current power transmission technology has the advantages of low investment cost, small running loss, high controllability, power transmission corridor saving and the like. The development and utilization of renewable energy sources are dedicated to solve the problems of increasing shortage of traditional energy sources and environmental pollution on a global scale, however, the renewable energy sources have the defects of intermittency, high volatility and remote distribution, and the development of a flexible multi-terminal direct current transmission technology provides a new idea for solving the problem of large-scale renewable energy source access.
With the continuous construction of global large-scale direct-current transmission projects, the interconnection of direct-current power grids is also scheduled; because no unified standard exists for the construction of the direct current power grid at present, the voltage levels of the direct current power grids are different, the development of the multi-voltage-level flexible direct current power grid is severely restricted, and great challenges are brought to the interconnection of the direct current power grids. One way to achieve interconnection of direct current grids of different voltage classes is to interconnect them by direct current transformers, the basic principle of which is to connect direct current grids of different voltage classes by DC/AC/DC power conversion, but the researches on the topology of direct current transformers are not the same; the topological structure of the direct current transformer is complex, and the disadvantage of high cost becomes a disadvantageous factor restricting the development of the direct current transformer.
The Modular Multilevel Converter (MMC) has the advantages of low requirement on voltage sharing of devices, good expansibility, good quality of output voltage waveform, low running loss and the like, so that the DC transformer based on the MMC has better working performance, the topology can output high-quality voltage waveform while ensuring economy, and the DC transformer based on the MMC can be rapidly applied to the occasions of new energy grid connection, offshore wind power transmission and the like in recent years and becomes a very competitive choice. The MMC direct-current transformer can be divided into three types of an isolated type, a non-isolated type and a self-coupled type: the isolation type MMC direct-current transformer adopts the alternating-current isolation transformer, so that the requirement of large transformation ratio can be met, but the defects of high device cost, large volume and large operation loss exist; the non-isolated MMC direct-current transformer does not comprise an alternating-current transformer, and the transformation ratio range is limited; compared with other topologies, the self-coupling MMC direct-current transformer has the advantages of low cost, high operation efficiency and low loss.
Forest satellite and the like propose a direct current autotransformer in the document DC-DC autotransformer, the report of Chinese Motor engineering, 36 2014, wherein direct electrical connection exists between direct current systems on two sides of the direct current autotransformer, a used converter is small in capacity, low in operation loss and obvious in advantages when the levels of direct current voltages on two sides are close; however, this configuration requires a large number of high-cost converter transformers, and thus limits its application.
Zhang glu et al in the document "novel DC autotransformer [ J ] applied to DC grid Power grid technology, 2019, v.43; no.430(09): 270-278) proposes a novel direct current autotransformer topology based on an improved bidirectional isolation type DC/DC converter series-parallel connection structure, only partial power is transmitted through a transformer, the capacity and the design cost of the transformer can be partially reduced, and the filtering inductance and the capacitance of a submodule are reduced by adopting staggered parallel connection control, so that the volume and the cost of the submodule are reduced; however, a large number of ac transformers still need to be adopted in the topology, so that the scheme is high in cost and poor in economical efficiency.
Generally, the current technical scheme of the direct current transformer has the problems of complex topological structure, high cost, inconvenient equipment maintenance and the like, and a novel direct current transformer topological structure is urgently needed.
Disclosure of Invention
In view of the above, the invention provides a modular combined type direct current transformer and a control method thereof, and the topological structure is simple, the application scene is wide, and the modular combined type direct current transformer has a great use value in engineering.
The utility model provides a modular combination formula direct current transformer for direct current voltage conversion between high pressure and the low pressure both sides converter station, it is established ties in proper order by 2N MMC and forms, and jth MMC direct current side negative pole is connected with jth +1 MMC direct current side positive pole, MMC's alternating current side loops through reactance and electric capacity and is connected to public alternating current generating line, and j is the natural number and 1 is less than or equal to j and is less than or equal to 2N-1, and N is for being greater than 0 natural number.
Further, the values of the reactance and the capacitance are calculated and determined by the following formula;
wherein: cjIs the capacitance value, L, of the capacitor connected to the AC side of the jth MMCjThe inductance value of a reactance connected to the AC side of the jth MMC, k is the ratio of direct current voltages of a high-voltage side converter station and a low-voltage side converter station, P is the transmission power between the high-voltage side converter station and the low-voltage side converter station, alpha is the voltage fluctuation rate (generally controlled at 2%) of a capacitance connected to the AC side of the jth MMC (U is controlled at 2%)dcThe direct current voltage of the MMC (the direct current voltage of each MMC is the same), and f is the rated frequency of the AC side of the MMC.
Furthermore, the rated frequency f of the AC side of the MMC is 100-400 Hz, namely the reactance and the capacitance connected with the AC side of the MMC are also 100-400 Hz, so that the volume and the cost of the devices are greatly reduced.
Further, if the ratio of the direct-current voltages of the high-voltage side converter station and the low-voltage side converter station is m: N, m and N are natural numbers, and m > N, the number 2N of the MMCs in the modular combined direct-current transformer is determined to be 2m, wherein the number of the MMCs connected to the high-voltage side converter station is 2m, and the number of the MMCs connected to the low-voltage side converter station is 2N.
Furthermore, in the modular combined type direct current transformer, the positive pole of the direct current side of the 1 st MMC and the negative pole of the direct current side of the 2N MMC are respectively connected with the positive pole and the negative pole of the direct current side of the high-voltage side converter station, and the positive pole of the direct current side of the (m-N + 1) th MMC and the negative pole of the direct current side of the (m + N) th MMC are respectively connected with the positive pole and the negative pole of the direct current side of the low-voltage side converter station.
Furthermore, the negative pole of the direct current side of the nth MMC in the modular combined direct current transformer is connected with the positive pole of the direct current side of the (N + 1) th MMC and is grounded, and the negative pole serves as a neutral point of the whole modular combined direct current transformer. Thereby, the dc transformer may be connected to a converter station having a structure of a symmetrical dipole, a symmetrical monopole or an asymmetrical monopole.
The control method of the modular combined direct current transformer comprises the following steps: when the high-voltage side converter station adopts passive control or constant active power control and the low-voltage side converter station adopts constant direct-current voltage control, the (m-n + 1) th to (m + n) th MMCs in the modular combined direct-current transformer adopt passive control strategies, the other MMCs adopt constant direct-current voltage and constant reactive power control strategies, the direct-current voltage instruction value is determined by the voltage grade of the high-voltage side converter station, and the reactive power instruction value is set to be 0; when the high-voltage side converter station adopts constant direct-current voltage control and the low-voltage side converter station adopts passive control or constant active power control, the m-n +1 th to m + n th MMCs in the modular combined type direct-current transformer adopt constant direct-current voltage and constant reactive power control strategies, the rest of the MMCs adopt passive control strategies, the direct-current voltage instruction value is determined by the voltage grade of the low-voltage side converter station, and the reactive power instruction value is set to be 0.
Based on the technical scheme, the invention has the following beneficial technical effects:
1. the direct current transformer cancels a converter transformer in an MMC converter station, thereby greatly reducing the complexity and the manufacturing cost of equipment.
2. The MMC modules adopted by the direct current transformer are the same, the expansion and the maintenance are easy, and meanwhile, the modular combined direct current transformer can be connected with a direct current power grid with any voltage grade.
3. The alternating current part in the direct current transformer adopts 100-400 Hz medium-frequency alternating current transmission, so that compared with a power frequency system, the size and the weight of related equipment can be greatly reduced, and the economy of the whole modularized combined direct current transformer can be directly improved.
Drawings
Fig. 1 is a schematic structural diagram of a modular combined dc transformer according to the present invention.
Fig. 2 is a schematic diagram of a simulation waveform of the transmission power of each MMC in the modular combined dc transformer according to the present invention.
Fig. 3 is a schematic diagram of a simulation waveform of a phase current at an ac side of each MMC in the modular dc transformer according to the present invention.
Fig. 4 is a schematic diagram of a simulated waveform of the common ac bus voltage in the modular combined dc transformer according to the present invention.
Fig. 5 is a schematic diagram of a simulation waveform of the dc voltage of each MMC in the modular dc transformer according to the present invention.
Fig. 6 is a schematic diagram of a simulation waveform of the dc current at the dc high/low voltage side of the modular combined dc transformer according to the present invention.
Fig. 7 is a schematic diagram of a simulation waveform of the dc-side positive voltage of the modular combined dc transformer according to the present invention.
FIG. 8 shows a capacitor C of the modular combined DC transformer of the present invention1～C4And (3) a simulation waveform schematic diagram of the voltage.
Detailed Description
In order to more specifically describe the present invention, the following detailed description is provided for the technical solution of the present invention with reference to the accompanying drawings and the specific embodiments.
The existing modularized combined direct current transformer adopting the alternating current transformer has poor economy due to high manufacturing cost and maintenance cost of the alternating current transformer. Fig. 1 shows a modular dc transformer according to the invention, in which the ac transformer is omitted.
The modular combined type direct current transformer is used for realizing power transmission between two direct current power networks with different voltage grades, as shown in figure 1, the direct current transformer comprises 2N identical MMC, the j-1 th MMC cathode and the j-th MMC anode on the direct current side are sequentially connected in series, and the alternating current side is connected with an alternating current bus through a capacitor and a reactor, wherein 2N is the number of the MMC in the modular combined type direct current transformer, and j is a positive integer which is not more than 2N and is more than 1.
Capacitor C at AC side of jth MMCjAnd an inductor LjThe value-taking method is determined by the following formula:
wherein: k represents the ratio of the voltages of the direct-current high-voltage and low-voltage power grids, k is a positive number greater than 1, P represents the power transmitted between the direct-current high-voltage and low-voltage power grids,alpha is a capacitance CjThe voltage fluctuation rate of (1) is generally controlled to be 2%, UdcFor the direct current voltage of MMC, the direct current voltage of each MMC is the same, f is the rated frequency of the alternating current side of the MMC and is 100-400 Hz.
The ratio of the voltages of the direct-current high-voltage power grid and the direct-current low-voltage power grid connected with the direct-current transformer can be expressed as m: N, wherein m and N are natural numbers, m is larger than N, m: N is simplified into the simplest form, the number of needed MMCs in the modular combined direct-current transformer can be determined to be 2N-2 m according to the ratio of the voltages of the connected direct-current high-voltage power grid and the connected direct-current low-voltage power grid, and the number of the MMCs respectively connected into the direct-current high-voltage power grid and the connected direct-current low-voltage power grid is 2 m.
After numbering 2N MMC in proper order, the positive pole of 1 MMC and the negative pole of 2N MMC correspond with high voltage direct current electric wire netting just, the negative pole is connected respectively, and the positive pole of m-N +1 MMC and the negative pole of m + N MMC correspond with low pressure direct current electric wire netting just, the negative pole is connected respectively.
And a connection point between the negative pole of the N-th MMC and the positive pole of the (N + 1) -th MMC is grounded and serves as a neutral point of the whole modular combined type direct current transformer. Therefore, the modular combined direct current transformer can be connected with a direct current power grid with a structure of a symmetrical double pole, a symmetrical single pole or an asymmetrical single pole.
When the direct-current high-voltage power grid adopts passive control or constant active power control and the direct-current low-voltage power grid adopts constant direct-current voltage control, the m-n +1 to m + n MMCs adopt passive control. For 1 st to m-N th and m + N +1 th to 2N MMC, the active control is constant direct current voltage control, and the instruction value is determined according to the voltage grade of the high-voltage direct current system; the reactive control is constant reactive power control, and the instruction value is zero.
When the direct-current high-voltage power grid adopts constant direct-current voltage control and the direct-current low-voltage power grid adopts passive control or constant active power control, the 1 st to the m-N th and the m + N +1 to the 2N th MMC adopt passive control. The active control of the (m-n + 1) th to (m + n) th MMC is constant direct-current voltage control, and the instruction value is determined according to the voltage grade of a low-voltage direct-current system; the reactive control is constant reactive power control, and the instruction value is zero.
The embodiment has a symmetrySimulation verification is carried out by taking a double-end direct-current power grid with a bipolar structure as an example, a primary side of the modular combined direct-current transformer is a +/-400 kV high-voltage direct-current power grid, and a converter station with a secondary side of low voltage +/-200 kV is connected to an alternating-current synchronous power grid. Under the normal working condition, the rated direct current power transmitted from the high-voltage side to the low-voltage side is 400MW, the parameters of a main loop of a single converter in a secondary low-voltage converter station are shown in table 1, an alternating current bus in the modular combined direct current transformer is grounded in series through a 3H reactance and a 3k omega resistor, a capacitor is 2000 muF, and an electric reactor is 5.05 multiplied by 10-3H, the major loop parameters of the MMC are shown in a table 2, and the control strategy of each MMC is shown in a table 3.
TABLE 1
| Rated capacity/MVA of |
200 |
| DC voltage/ |
200 |
| Rated capacity/MVA of |
240 |
| Voltage ratio of connecting |
220/210 |
| Short-circuit impedance of connecting transformer (%) | 15 |
| Bridge |
200 |
| Sub-module rated voltage/kV | 1.0 |
| Sub-module capacitance value/. mu.F | 666 |
| Bridge arm reactance/H | 0.076 |
| Converter station outlet smoothing reactor/H | 0.1 |
TABLE 2
| Rated capacity/MVA of |
100 |
| DC voltage/ |
200 |
| Bridge |
100 |
| Sub-module rated voltage/kV | 1.0 |
| Sub-module capacitance value/. mu.F | 666 |
| Bridge arm reactance/H | 0.076 |
TABLE 3
When the system operates in a steady state, the high-voltage direct-current power grid transmits 200MW of direct-current power to the low-voltage direct-current power grid, the system is already in the steady state at 0s, the transmission power is increased from 200MW to 400MW when the time t is 0.5s, the transmission power is changed from 400MW to-200 MW when the time t is 1.5s, the whole simulation test lasts for 4s, and the corresponding simulation waveforms are shown in fig. 2 to 8. It can be seen that when the transmission power is stepped, the dc voltages at the two sides of the modular combined dc transformer can be maintained relatively stable, which indicates that the control strategy adopted by the modular combined dc transformer of the invention is reasonable and the device has better working performance.
The embodiments described above are presented to enable a person having ordinary skill in the art to make and use the invention. It will be readily apparent to those skilled in the art that various modifications to the above-described embodiments may be made, and the generic principles defined herein may be applied to other embodiments without the use of inventive faculty. Therefore, the present invention is not limited to the above embodiments, and those skilled in the art should make improvements and modifications to the present invention based on the disclosure of the present invention within the protection scope of the present invention.
Claims (8)
1. A modular combined DC transformer for DC voltage conversion between high and low voltage side converter stations, characterized in that: the modular combined type direct current transformer is formed by sequentially connecting 2N MMC in series, the direct current side cathode of the jth MMC is connected with the direct current side anode of the jth +1 MMC, the alternating current side of the MMC is connected to a public alternating current bus through a reactance and a capacitor in sequence, j is a natural number, j is not less than 1 and not more than 2N-1, and N is a natural number greater than 0.
2. The modular combined dc transformer of claim 1, wherein: the values of the reactance and the capacitance are calculated and determined by the following formula;
wherein: cjIs the capacitance value, L, of the capacitor connected to the AC side of the jth MMCjIs the inductance value of the reactance connected with the j-th MMC AC side, k is the ratio of the DC voltage of the high-voltage side converter station and the DC voltage of the low-voltage side converter station, P is the transmission power between the high-voltage side converter station and the low-voltage side converter station, alpha is the voltage fluctuation ratio of the capacitance connected with the j-th MMC AC side, U is the voltage fluctuation ratio of the capacitance connected with the j-th MMC AC sidedcIs the DC voltage of the MMC, and f is the rated frequency of the AC side of the MMC.
3. The modular combined dc transformer of claim 2, wherein: the rated frequency f of the MMC alternating current side is 100-400 Hz, namely the reactance and the capacitance connected with the MMC alternating current side are also 100-400 Hz, so that the volume and the cost of the devices are greatly reduced.
4. The modular combined dc transformer of claim 1, wherein: and if the ratio of the direct-current voltages of the high-voltage side converter station and the low-voltage side converter station is m: N, wherein m and N are natural numbers and m is larger than N, determining that the number 2N of the MMCs in the modular combined type direct-current transformer is 2m, wherein the number of the MMCs connected to the high-voltage side converter station is 2m, and the number of the MMCs connected to the low-voltage side converter station is 2N.
5. The modular combined dc transformer of claim 4, wherein: wherein, the positive pole of the direct current side of the 1 st MMC and the negative pole of the direct current side of the 2N MMC are respectively connected with the positive pole and the negative pole of the direct current side of the high-voltage side converter station, and the positive pole of the direct current side of the (m-N + 1) th MMC and the negative pole of the direct current side of the (m + N) th MMC are respectively connected with the positive pole and the negative pole of the direct current side of the low-voltage side converter station.
6. The modular combined dc transformer of claim 1, wherein: the negative pole of the direct current side of the Nth MMC is connected with the positive pole of the direct current side of the (N + 1) th MMC and is grounded, and the negative pole of the direct current side of the Nth MMC is used as a neutral point of the whole modular combined direct current transformer.
7. The method of claim 4, wherein: when the high-voltage side converter station adopts passive control or constant active power control and the low-voltage side converter station adopts constant direct-current voltage control, the (m-n + 1) th to (m + n) th MMCs in the modular combined direct-current transformer adopt passive control strategies, the other MMCs adopt constant direct-current voltage and constant reactive power control strategies, the direct-current voltage instruction value is determined by the voltage grade of the high-voltage side converter station, and the reactive power instruction value is set to be 0; when the high-voltage side converter station adopts constant direct-current voltage control and the low-voltage side converter station adopts passive control or constant active power control, the m-n +1 th to m + n th MMCs in the modular combined type direct-current transformer adopt constant direct-current voltage and constant reactive power control strategies, the rest of the MMCs adopt passive control strategies, the direct-current voltage instruction value is determined by the voltage grade of the low-voltage side converter station, and the reactive power instruction value is set to be 0.
8. The modular combined dc transformer of claim 1, wherein: the direct current transformer cancels a converter transformer in an MMC converter station, greatly reduces the complexity and the manufacturing cost of equipment, adopts the same MMC modules, is easy to expand and maintain, and can be connected with converter stations with structures of symmetrical double poles, symmetrical single poles or asymmetrical single poles of any voltage class.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011454589.4A CN112436739B (en) | 2020-12-10 | 2020-12-10 | Modular combined direct-current transformer and control method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011454589.4A CN112436739B (en) | 2020-12-10 | 2020-12-10 | Modular combined direct-current transformer and control method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN112436739A true CN112436739A (en) | 2021-03-02 |
| CN112436739B CN112436739B (en) | 2021-09-28 |
Family
ID=74692507
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202011454589.4A Active CN112436739B (en) | 2020-12-10 | 2020-12-10 | Modular combined direct-current transformer and control method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112436739B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113794221A (en) * | 2021-09-08 | 2021-12-14 | 中国南方电网有限责任公司超高压输电公司检修试验中心 | Sending end topological structure of direct current transmission system and direct current transmission system |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2568594A1 (en) * | 2011-09-12 | 2013-03-13 | Green Power Technologies, S.L. | DC time-multiplexed power converter and its modulation technique |
| CN103887788A (en) * | 2014-03-25 | 2014-06-25 | 华中科技大学 | Multiport DC-DC autotransformer and application thereof |
| CN105703388A (en) * | 2014-08-25 | 2016-06-22 | 特变电工新疆新能源股份有限公司 | Photovoltaic grid-connected power generation system based on middle and high voltage direct current access |
| CN105846685A (en) * | 2016-05-12 | 2016-08-10 | 华中科技大学 | Cascaded voltage step-up type unidirectional direct current voltage transformer |
| CN106130056A (en) * | 2016-07-05 | 2016-11-16 | 清华大学 | Flexible direct current power transmission system based on combined modular Multilevel Inverters |
| CN212012496U (en) * | 2020-05-09 | 2020-11-24 | 中国石油大学(华东) | Multi-port non-latching direct-current autotransformer |
-
2020
- 2020-12-10 CN CN202011454589.4A patent/CN112436739B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2568594A1 (en) * | 2011-09-12 | 2013-03-13 | Green Power Technologies, S.L. | DC time-multiplexed power converter and its modulation technique |
| CN103887788A (en) * | 2014-03-25 | 2014-06-25 | 华中科技大学 | Multiport DC-DC autotransformer and application thereof |
| CN105703388A (en) * | 2014-08-25 | 2016-06-22 | 特变电工新疆新能源股份有限公司 | Photovoltaic grid-connected power generation system based on middle and high voltage direct current access |
| CN105846685A (en) * | 2016-05-12 | 2016-08-10 | 华中科技大学 | Cascaded voltage step-up type unidirectional direct current voltage transformer |
| CN106130056A (en) * | 2016-07-05 | 2016-11-16 | 清华大学 | Flexible direct current power transmission system based on combined modular Multilevel Inverters |
| CN212012496U (en) * | 2020-05-09 | 2020-11-24 | 中国石油大学(华东) | Multi-port non-latching direct-current autotransformer |
Non-Patent Citations (1)
| Title |
|---|
| YUZHE XU 等: "A Novel Circulating Current Controller for MMC Capacitor Voltage Fluctuation Suppression", 《 IEEE ACCESS》 * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113794221A (en) * | 2021-09-08 | 2021-12-14 | 中国南方电网有限责任公司超高压输电公司检修试验中心 | Sending end topological structure of direct current transmission system and direct current transmission system |
Also Published As
| Publication number | Publication date |
|---|---|
| CN112436739B (en) | 2021-09-28 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN110829478B (en) | Low-frequency alternating-current uncontrolled rectification power transmission system of offshore wind power plant | |
| CN103337972B (en) | Mixed type transverter and wind power generation system | |
| WO2021082601A1 (en) | Offshore wind farm high-frequency uncontrolled rectification direct-current electric power transmission system | |
| CN204578106U (en) | A kind of offshore wind farm modular multi-level flexible direct-current transmission system | |
| CN107834602B (en) | Micro-grid system with micro-source half-bridge converter connected in series | |
| CN105811453A (en) | Distributed energy intelligent access system and access method thereof | |
| CN102148501B (en) | Disturbance generation device for wind power station | |
| CN109888811B (en) | Coordination control method for improving transient stability of direct current transmission system by using energy storage | |
| CN110266034A (en) | A kind of offshore wind farm DC transmission system | |
| CN109687514A (en) | The more low-voltage direct buses of high-frequency isolation type, which collect, presses grid-connected system in photovoltaic | |
| WO2014107842A1 (en) | Multi-terminal direct-current transmission system for wind power generation through large-scale remote grid connection | |
| Guo et al. | Characteristics and performance of Xiamen VSC-HVDC transmission demonstration project | |
| CN107888073B (en) | Alternating current-direct current hybrid energy router of all-round soft switch | |
| CN112436739B (en) | Modular combined direct-current transformer and control method thereof | |
| CN113890122A (en) | Alternating current-direct current multiport power distribution system for office residential area | |
| CN108023497B (en) | Series simultaneous power supply forward cycle conversion type single-stage multi-input high-frequency link inverter | |
| Ge et al. | A novel topology for HVDC link connecting to offshore wind farms | |
| CN105429472A (en) | Star angle-shape rectifier-type high-power DC step-up converter and control method thereof | |
| CN112467777B (en) | Method for controlling asymmetric direct current by using modular combined direct current transformer | |
| CN112928771B (en) | Low-voltage high-power grid-connected hydrogen production power supply device and control method | |
| CN108054946B (en) | Voltage type single-stage multi-input low-frequency link inverter with built-in parallel time-sharing selection switch | |
| CN202034793U (en) | Non-transformer wind power generation grid connection topology structure based on H bridge | |
| Xu et al. | MMC-DC/DC Converter and Its Control Strategy for Offshore Full DC Wind Power System | |
| Zhang | Design and Simulation Implementation of All-DC Offshore Wind Power System | |
| CN216215929U (en) | Alternating current-direct current multiport power distribution system for office residential area |
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 |