CN112510994B - Three-phase LLC resonant DC converter with multiple voltage reduction - Google Patents
Three-phase LLC resonant DC converter with multiple voltage reduction Download PDFInfo
- Publication number
- CN112510994B CN112510994B CN202011141787.5A CN202011141787A CN112510994B CN 112510994 B CN112510994 B CN 112510994B CN 202011141787 A CN202011141787 A CN 202011141787A CN 112510994 B CN112510994 B CN 112510994B
- Authority
- CN
- China
- Prior art keywords
- phase
- resonant
- capacitor
- direct current
- converter
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M3/00—Conversion of dc power input into dc power output
- H02M3/02—Conversion of dc power input into dc power output without intermediate conversion into ac
- H02M3/04—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters
- H02M3/06—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using resistors or capacitors, e.g. potential divider
- H02M3/07—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using resistors or capacitors, e.g. potential divider using capacitors charged and discharged alternately by semiconductor devices with control electrode, e.g. charge pumps
-
- 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
- H02M3/00—Conversion of dc power input into dc power output
- H02M3/22—Conversion of dc power input into dc power output with intermediate conversion into ac
- H02M3/24—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters
- H02M3/28—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac
-
- 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
- H02M3/00—Conversion of dc power input into dc power output
- H02M3/22—Conversion of dc power input into dc power output with intermediate conversion into ac
- H02M3/24—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters
- H02M3/28—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac
- H02M3/325—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal
- H02M3/335—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only
- H02M3/33569—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only having several active switching elements
-
- 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
- H02M3/00—Conversion of dc power input into dc power output
- H02M3/22—Conversion of dc power input into dc power output with intermediate conversion into ac
- H02M3/24—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters
- H02M3/28—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac
- H02M3/325—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal
- H02M3/335—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only
- H02M3/33569—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only having several active switching elements
- H02M3/33576—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only having several active switching elements having at least one active switching element at the secondary side of an isolation transformer
- H02M3/33584—Bidirectional converters
-
- 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
- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y02B70/00—Technologies for an efficient end-user side electric power management and consumption
- Y02B70/10—Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes
Abstract
The invention discloses a multi-step-down three-phase LLC resonant DC converter. The traditional direct current converter has the problems of low voltage resistance, small capacity, low efficiency and the like, and when the direct current converter is applied to a direct current power grid, the direct current converter has large loss and causes resource waste. The technical scheme adopted by the invention is as follows: a multi-step-down three-phase LLC resonant DC converter comprises a first DC capacitor, a second DC capacitor and a third DC capacitor, wherein the three DC capacitors are connected in series and then connected in parallel with a DC input power supply; energy transfer and voltage balance among the first direct current capacitor, the second direct current capacitor and the third direct current capacitor are achieved through the three-phase resonant switch capacitor units, and then energy transmission and output voltage regulation at two ends of the transformer are achieved through the LLC resonant cavity. The invention realizes high voltage resistance, large capacity and high efficiency of the DC converter.
Description
Technical Field
The invention belongs to the field of direct current power grids, and particularly relates to a multi-step-down three-phase LLC resonant direct current converter.
Background
The existing alternating-current power distribution network faces the problems of difficulty in grid connection of distributed power supplies, small transmission capacity, low transmission efficiency and the like, and faces huge challenges in practical application. With the continuous development of power electronic technology, direct current power distribution networks based on power electronic transformers are widely researched. In addition, the application of the direct current distribution network accelerates research in the fields of electric vehicles, super capacitors, fuel cells and the like. In recent years, flexible direct current power generation systems are built rapidly, and possibility is provided for grid connection of distributed energy sources. The direct current converter is mainly used for realizing interconnection between direct current power grids with different voltage levels. The direct current converter is one of core devices of a direct current power distribution network, is widely researched at home and abroad, and various topologies with high efficiency and high power density are applied to the direct current power distribution network to reduce energy consumption.
Usually, a dc converter in a dc distribution network needs to satisfy both isolation and voltage conversion requirements, and common schemes include a dual active bridge converter and a resonant LLC converter. The resonant LLC converter has the advantages of high efficiency, small size and the like, and is widely applied in practice.
In a direct-current power distribution network, the capacity of the power grid is large, the voltage level is high, and the high-voltage and high-power design of a direct-current converter becomes a research difficulty. In order to face a direct-current power distribution network with larger capacity, a three-phase LLC converter is proposed by a student, and the power grade of the converter is greatly improved. However, in the interconnection link of the medium-high voltage direct current distribution network and the low-voltage direct current distribution network, higher requirements are put forward on the voltage withstanding grade of the switching device. If a high-voltage device is adopted in the three-phase LLC converter, the switching frequency is difficult to be further increased, so that the miniaturization design of the converter faces challenges.
Disclosure of Invention
The invention aims to overcome the defects in the prior art and provide a three-phase LLC resonant direct-current converter with high voltage resistance, large capacity and high efficiency.
To this end, the present inventionThe following technical scheme is obviously adopted: a multi-step-down three-phase LLC resonant DC converter comprises a first DC capacitorC 1 A second DC capacitorC 2 And a third DC capacitorC 3 The three direct current capacitors are connected in series and then connected in parallel with a direct current input power supply;
realizing a first DC capacitor by three-phase resonant switched capacitor unitsC 1 A second DC capacitorC 2 And a third DC capacitorC 3 Energy transfer and voltage balance between the two ends of the transformer are realized, and then energy transmission and output voltage regulation at the two ends of the transformer are realized through the LLC resonant cavity.
The preceding stage realizes preliminary voltage conversion through resonance switch capacitor unit, reduces switching device's voltage stress, and secondary voltage conversion and electrical isolation are realized to the switching device that adopts three-phase LLC circuit in the second level, multiplexing resonance switch capacitor unit reduces the device loss, realizes high-voltage, high efficiency, high-gain's direct current conversion.
As a supplement to the above technical solution, each resonant switched capacitor unit is composed of three half-bridge modules connected in series and two resonant cavities, and the connection mode of the resonant switched capacitor unit is as follows: each half-bridge module comprises two switching devices connected in series, the switching devices are all-control type devices, and the three half-bridge modules are respectively connected with corresponding direct current capacitors in parallelL mrn AndC mrn the resonant cavities formed by series connection are connected to the middle points (m =1,2,3, n =1, 2) of the half-bridge modules, and direct current capacitance energy transfer and soft switching of the switching devices are achieved.
In addition to the above technical solutions, the midpoints of the three resonant switched capacitor units are respectivelya、b、cRespectively connected with three-phase LLC resonant cavitiesL mk AndC mk and voltage transformation and electrical isolation are realized through a three-phase high-frequency transformer, and secondary voltage regulation is realized by changing the transformation ratio of the three-phase high-frequency transformer.
As a supplement to the above technical solution, the three-phase high-frequency transformer is star-connected or angle-connected.
As a supplement to the technical scheme, the rear end of the three-phase high-frequency transformer is connected with a three-phase rectifier bridge to convert high-frequency low-voltage alternating current into direct-current voltage.
In addition to the above technical solution, output voltage regulation is realized by changing the switching frequency.
As a supplement to the technical scheme, the three-phase rectifier bridge adopts a three-phase uncontrolled rectifier structure on the occasion that energy is not required to be transmitted in two directions.
As a supplement to the technical scheme, the three-phase rectifier bridge adopts a three-phase fully-controlled bridge type rectifier structure on occasions needing energy bidirectional transmission.
In addition to the above technical solution, the fully-controlled device is a MOSFET, an IGBT or a GaN.
The invention has the following beneficial effects: the invention realizes high voltage resistance, large capacity and high efficiency of the DC converter.
The topology of the invention adopts a three-phase staggered structure, thereby obviously reducing the input current and reducing the voltage ripple of the direct current power grid; the series structure of the preceding stage resonant switch capacitor unit reduces the voltage stress of the switch device; the two-stage voltage regulation design is adopted, so that the voltage transformation ratio of the direct-current converter is improved, and the design difficulty of the high-frequency transformer is reduced; in high-voltage application occasions, the voltage stress of a switching device can be reduced by increasing the number of switch half-bridges connected in series in the direct-current capacitor and the resonant switch capacitor unit.
Drawings
FIG. 1 is a circuit schematic of the present invention;
FIG. 2 is a diagram of a fully-controlled switching device employed in the present invention;
FIG. 3 is a switch sequence diagram of the present invention;
fig. 4 is a schematic diagram of the circuit of the present invention using fully controlled rectification.
Detailed Description
The invention will be further described with reference to the accompanying drawings, but the scope of protection of the invention is not limited to the following description. Any modification and variation of the present invention within the spirit of the present invention and the scope of the claims should fall within the scope of the present invention.
The invention provides a multi-step-down three-phase LLC resonant DC converter, and a circuit schematic diagram of the multi-step-down three-phase LLC resonant DC converter is shown in figure 1. Firstly, a DC input power supply passes through a first DC capacitorC 1 A second DC capacitorC 2 And a third DC capacitorC 3 And (5) dividing the pressure to realize primary pressure reduction. Then realized by a three-phase resonance switch capacitor unitC 1 、C 2 AndC 3 energy transfer therebetween.
Each resonance unit is formed by connecting three half-bridge modules in series, each half-bridge module comprises two switching devices connected in series, and the switching devices can be full-control devices such as MOSFET, IGBT, gaN and the like, as shown in FIG. 2. Fig. 2 (a) shows a MOSFET, fig. 2 (b) shows an IGBT, and fig. 2 (c) shows GaN.
Three half-bridge modules are respectively connected in parallel with the DC capacitorL mrn AndC mrn the series resonant cavity is connected to the midpoint of each half-bridge module (m =1,2,3, n =1, 2), thereby realizing direct current capacitive energy transfer and soft switching of the switching device.
The middle points of the three resonant switch units are respectivelya、b、cAnd the three-phase LLC resonant cavities are respectively connected, and voltage conversion and electrical isolation are realized through a three-phase high-frequency transformer. The secondary voltage regulation can be realized by changing the transformation ratio of the transformer, and the transformer can adopt star connection or angle connection. The rear end of the transformer is connected with a three-phase rectifier bridge to convert high-frequency low-voltage alternating current into direct-current voltage.
The switching sequence of the invention is shown in fig. 3, for each resonant switched-capacitor cell, S m1 、S m3 And S m5 Simultaneous opening, S m2 、S m4 And S m6 And simultaneously, the two groups of switches are switched on, the conduction time of the two groups of switches is 180 degrees different from each other, and the phase difference between the switching sequences of the three phases a, b and c is 120 degrees.
Fig. 4 is a schematic diagram of a multi-step-down three-phase LLC full-control rectifier circuit implemented by the scheme of the present invention, in which a switch half bridge in a resonant switched capacitor unit uses an MOSFET as a switching device to implement step-down of input voltage and primary voltage regulation, and a three-phase full-control rectifier structure is used to implement bidirectional energy transfer.
Claims (7)
1. A multi-step-down three-phase LLC resonant DC converter is characterized by comprising a first DC capacitorC 1 A second DC capacitorC 2 And a third DC capacitorC 3 The three direct current capacitors are connected in series and then connected in parallel with the direct current input power supply;
realizing a first DC capacitor by a three-phase resonant switched capacitor unitC 1 A second DC capacitorC 2 And a third DC capacitorC 3 Energy transfer and voltage balance are carried out between the two ends of the transformer, and then energy transmission and output voltage regulation at the two ends of the transformer are realized through the LLC resonant cavity;
each resonant switch capacitor unit is composed of three half-bridge modules connected in series and two resonant cavities, and the wiring mode of the resonant switch capacitor unit is as follows: each half-bridge module comprises two switching devices connected in series, and the switching devices are all-control devices; three half-bridge modules are respectively connected with corresponding direct current capacitors in parallelL mrn AndC mrn the resonant cavities formed by series connection are connected to the middle points of the half-bridge modules, and m =1,2,3, n =1 and 2, so that direct-current capacitor energy transfer and soft switching of a switching device are realized;
the middle points of the three resonant switched capacitor units are respectivelya、b、c，aPoint is located atL 1r1 、C 1r1 Formed resonant cavity andL 1r2 、C 1r2 the resonant cavities are formed by the two parts,bpoint is located atL 2r1 、C 2r1 Formed resonant cavity andL 2r2 、C 2r2 the resonant cavities are formed by the two groups of the resonant cavities,cpoint is located atL 3r1 、C 3r1 Formed resonant cavity andL 3r2 、C 3r2 the three-phase staggered parallel structure is adopted among the formed resonant cavities and is realized by a three-phase high-frequency transformerThe existing voltage conversion and electrical isolation realize secondary voltage regulation by changing the transformation ratio of the three-phase high-frequency transformer.
2. The multi-step-down three-phase LLC resonant DC converter according to claim 1, wherein said three-phase high-frequency transformer is star-connected or angle-connected.
3. The multi-step-down three-phase LLC resonant DC converter according to claim 1, wherein a three-phase high-frequency transformer is connected at its rear end with a three-phase rectifier bridge for converting the high-frequency AC voltage into DC voltage.
4. The multi-buck three-phase LLC resonant DC converter according to claim 1, wherein the three-phase switching sequences differ by 120 ° in output voltage regulation is achieved by changing the operating frequency of the switching devices.
5. The multi-buck three-phase LLC resonant DC converter according to claim 1, wherein the three-phase rectifier bridge is of a three-phase uncontrolled rectifier configuration where bidirectional energy transfer is not required.
6. The multi-buck three-phase LLC resonant DC converter according to claim 1, wherein the three-phase rectifier bridge is of a three-phase fully-controlled bridge type rectification structure in the case of bidirectional energy transfer.
7. The multi-buck three-phase LLC resonant DC converter according to claim 6, wherein said fully controlled devices are MOSFETs, IGBTs or GaN.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011141787.5A CN112510994B (en) | 2020-10-22 | 2020-10-22 | Three-phase LLC resonant DC converter with multiple voltage reduction |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011141787.5A CN112510994B (en) | 2020-10-22 | 2020-10-22 | Three-phase LLC resonant DC converter with multiple voltage reduction |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN112510994A CN112510994A (en) | 2021-03-16 |
| CN112510994B true CN112510994B (en) | 2023-03-07 |
Family
ID=74954205
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202011141787.5A Active CN112510994B (en) | 2020-10-22 | 2020-10-22 | Three-phase LLC resonant DC converter with multiple voltage reduction |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112510994B (en) |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103296882A (en) * | 2013-05-29 | 2013-09-11 | 浙江大学 | DC-DC (direct-current to direct-current) resonant converter with automatic voltage equalizing function |
| CN111669058A (en) * | 2020-05-26 | 2020-09-15 | 中国科学院电工研究所 | Three-phase CLLC bidirectional DC converter and control method thereof |
| CN111711363A (en) * | 2020-06-10 | 2020-09-25 | 北京交通大学 | Active voltage regulation control method for voltage-sharing converter |
| US10797604B1 (en) * | 2019-05-30 | 2020-10-06 | Asian Power Devices Inc. | LLC resonant converter |
| CN112350569A (en) * | 2020-09-29 | 2021-02-09 | 北京交通大学 | Isolated resonant switch capacitor converter |
-
2020
- 2020-10-22 CN CN202011141787.5A patent/CN112510994B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103296882A (en) * | 2013-05-29 | 2013-09-11 | 浙江大学 | DC-DC (direct-current to direct-current) resonant converter with automatic voltage equalizing function |
| US10797604B1 (en) * | 2019-05-30 | 2020-10-06 | Asian Power Devices Inc. | LLC resonant converter |
| CN111669058A (en) * | 2020-05-26 | 2020-09-15 | 中国科学院电工研究所 | Three-phase CLLC bidirectional DC converter and control method thereof |
| CN111711363A (en) * | 2020-06-10 | 2020-09-25 | 北京交通大学 | Active voltage regulation control method for voltage-sharing converter |
| CN112350569A (en) * | 2020-09-29 | 2021-02-09 | 北京交通大学 | Isolated resonant switch capacitor converter |
Also Published As
| Publication number | Publication date |
|---|---|
| CN112510994A (en) | 2021-03-16 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102005957B (en) | Single-power supply cascade multi-level converter | |
| CN102185480B (en) | Bidirectional isolation direct-current converter | |
| CN104578803A (en) | High-voltage direct current-direct current power electronic transformer | |
| CN102013823A (en) | Transformer-free solar inverter topological structure based on MMC | |
| CN102158071B (en) | Series-connected bridge-type impedance network power converter | |
| CN209448659U (en) | A kind of more DC port inverters | |
| CN107370391A (en) | Bridge arm towards mesohigh intelligent distribution network is multiplexed electric power electric transformer | |
| CN204578370U (en) | A kind of high voltage direct current-direct current power electronic transformer | |
| CN110401348A (en) | A kind of two-way resonance DC-DC transfer circuit and uninterruptible power supply | |
| CN103427658A (en) | High-voltage DC-DC conversion device based on multi-winding transformer | |
| Ding et al. | A single-switch high step-up DC–DC converter based on three-winding coupled inductor and pump capacitor unit | |
| CN204145305U (en) | A kind of novel DC-AC-DC converter being applied to high voltage direct current transmission | |
| CN106505902B (en) | LCC/VSC direct current interconnects transformer | |
| CN107834581A (en) | A kind of battery energy storage system of Multiple coil resonance separate current control | |
| CN103066834A (en) | Staggered parallel high-gain boost type direct current (DC) converter | |
| CN103441676A (en) | Modularized device for conversion between high-voltage direct current and direct current | |
| CN113890122A (en) | Alternating current-direct current multiport power distribution system for office residential area | |
| CN102403920B (en) | Three-level half-bridge photovoltaic grid connected inverter | |
| CN112510994B (en) | Three-phase LLC resonant DC converter with multiple voltage reduction | |
| CN108023496B (en) | Series simultaneous selection switch voltage type single-stage multi-input low-frequency link inverter | |
| CN108023497B (en) | Series simultaneous power supply forward cycle conversion type single-stage multi-input high-frequency link inverter | |
| CN106208788A (en) | A kind of multimode voltage source inverter based on AAC | |
| CN207069910U (en) | A kind of two-way DC/DC transformation systems based on three-level topology | |
| CN202334357U (en) | Three-level half-bridge photovoltaic grid-connected inverter | |
| CN211127568U (en) | DC-DC electric energy 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 |