CN113224955A - Five-level high-power shore power supply system with low harmonic and high performance - Google Patents
Five-level high-power shore power supply system with low harmonic and high performance Download PDFInfo
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- CN113224955A CN113224955A CN202110546192.6A CN202110546192A CN113224955A CN 113224955 A CN113224955 A CN 113224955A CN 202110546192 A CN202110546192 A CN 202110546192A CN 113224955 A CN113224955 A CN 113224955A
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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
- H02M5/00—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases
- H02M5/40—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases with intermediate conversion into dc
- H02M5/42—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases with intermediate conversion into dc by static converters
- H02M5/44—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases with intermediate conversion into dc by static converters using discharge tubes or semiconductor devices to convert the intermediate dc into ac
- H02M5/453—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases with intermediate conversion into dc by static converters using discharge tubes or semiconductor devices to convert the intermediate dc into ac using devices of a triode or transistor type requiring continuous application of a control signal
- H02M5/458—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases with intermediate conversion into dc by static converters using discharge tubes or semiconductor devices to convert the intermediate dc into ac using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only
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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
- H02M1/00—Details of apparatus for conversion
- H02M1/12—Arrangements for reducing harmonics from ac input or output
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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
- H02M5/00—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases
- H02M5/02—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases without intermediate conversion into dc
- H02M5/04—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases without intermediate conversion into dc by static converters
- H02M5/10—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases without intermediate conversion into dc by static converters using transformers
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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
- H02M5/00—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases
- H02M5/40—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases with intermediate conversion into dc
- H02M5/42—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases with intermediate conversion into dc by static converters
- H02M5/44—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases with intermediate conversion into dc by static converters using discharge tubes or semiconductor devices to convert the intermediate dc into ac
- H02M5/453—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases with intermediate conversion into dc by static converters using discharge tubes or semiconductor devices to convert the intermediate dc into ac using devices of a triode or transistor type requiring continuous application of a control signal
- H02M5/458—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases with intermediate conversion into dc by static converters using discharge tubes or semiconductor devices to convert the intermediate dc into ac using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only
- H02M5/4585—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases with intermediate conversion into dc by static converters using discharge tubes or semiconductor devices to convert the intermediate dc into ac using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only having a rectifier with controlled 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
- 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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- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Inverter Devices (AREA)
Abstract
The invention provides a five-level high-power shore power supply system with low harmonic and high performance, which comprises a 36-pulse rectification phase-shifting transformer, a rectification circuit and a double-layer cascade H-bridge inverter circuit. 6 three-phase windings on the secondary side of the transformer are required to be subjected to phase shifting, the phase shifting angle phase difference is 60 degrees/6 =10 degrees, 36 pulse wave rectification is formed in total, the current waveform of the network side is greatly improved, the harmonic pollution of a power grid is eliminated, and the power factor is improved, so that the input side and the output side of the transformer are not required to be provided with filtering devices; the rectification circuit adopts an IGBT controllable rectification circuit or a diode uncontrolled rectification circuit to provide a direct current power supply for the inverter circuit; the inverter circuit adopts a double-layer cascade H-bridge circuit, the output phase voltage is five levels, the output voltage harmonic wave of the inverter can be reduced, the switching frequency is reduced, and the inverter has wide engineering application value.
Description
Technical Field
The invention relates to the field of all high-power inverter power supplies such as a high-power medium-low voltage frequency converter, a test power supply and a shore power supply, in particular to a low-harmonic high-performance five-level high-power shore power supply system.
Background
In the field of high-power inverter power supply application, a transformer is generally adopted to supply power to power units, and if 6 three-phase output power units are provided, two layers of 6 three-phase windings on the secondary side of the transformer are generally provided to supply power to the 6 power units respectively. In order to reduce harmonic pollution of a rectification module to a power grid side, the conventional solution mostly adopts a method of adding a filter or using a phase-shifting transformer, the former increases system cost and volume, and the latter does not shift the phase of 3 three-phase windings of each layer of the secondary side of the transformer in the conventional solution and only shifts the phase between two layers, the phase shift angle phase difference is 60 DEG/2 =30 DEG, 12-pulse rectification is formed altogether, harmonics of 11 times or more still exist on the power grid side, current harmonic pollution is large, and the power factor is low. In addition, if the inverter circuit adopts a single-layer structure, the inverter circuit has the defects of low output voltage level, large harmonic wave and the like.
Disclosure of Invention
The invention improves the problems existing in the prior art, and provides a scheme of a five-level high-power shore power supply system with low harmonic and high performance, the current harmonic at the side of a power grid is reduced by a transformer with a novel phase-shifting angle, and an additional filtering device is not needed; meanwhile, the output level is five, so that the output voltage harmonic wave of the inverter can be obviously reduced, the switching frequency can be reduced, and the performance can be improved while the system cost is reduced.
The invention relates to a low-harmonic high-performance five-level high-power shore power supply system, which comprises: 36 pulse wave rectification phase-shifting transformer, rectifier circuit, double-layer cascade H bridge inverter circuit. The primary side winding of the 36-pulse rectification phase-shifting transformer is connected to a power grid, two layers of 6 three-phase windings are arranged on the secondary side, wherein the 3 three-phase windings on the first layer are respectively named as a1, b1 and c1, the 3 three-phase windings on the second layer are respectively named as a2, b2 and c2, and the phase shifting is carried out by adopting an edge-extending triangle principle; compared with the traditional phase-shifting transformer in the existing solution, the phase-shifting transformer in the scheme has the advantages that the phase shift is carried out between 3 three-phase windings on each layer of the secondary side of the phase-shifting transformer, the phase shift angle phase difference is 60 degrees/6 =10 degrees, and 36 pulse wave rectification is formed in total; the power grid side only generates higher harmonics of more than 35 times, so that the current waveform of the power grid side is greatly improved, the power factor is improved, and therefore, the input side and the output side of the transformer do not need to be provided with filtering devices, the system volume is reduced, the cost is saved, and the standardization and the maintenance are convenient.
The rectifying circuit and the inverter circuit are connected in series to form 6 power units which are named as A1, B1, C1, A2, B2 and C2 respectively. The input of the rectification circuit is connected to a three-phase winding on the secondary side of the transformer, the output of the rectification circuit provides a direct-current power supply for the later-stage inverter circuit, and the topological structure of the rectification circuit can be selected according to different application occasions: when the application occasion does not need to release energy and feed back energy, the rectifying circuit can adopt a diode uncontrolled rectifying circuit; when the energy release is needed in the application occasion, a braking unit can be added on the basis of the diode uncontrolled rectifying circuit; when energy feedback is needed in application occasions, the rectification circuit can adopt an IGBT controllable rectification circuit.
The inverter circuit adopts a double-layer cascade H-bridge circuit, the phase voltage output by a single H-bridge unit is 350V, the phase voltage output by the double-layer cascade H-bridge unit is 700V, and the voltage form is five levels; the low-voltage unit superposes and outputs high voltage, so that the output voltage harmonic wave of the inverter is reduced, the switching frequency is reduced, and the cost of the sine wave reactor on the output side of the inverter can be effectively reduced; and the dv/dt of the output voltage is reduced, so that the load can be effectively protected.
The five-level high-power shore power supply system with low harmonic and high performance has the advantages of small volume, low cost, high performance and the like, and has wide engineering application value.
Drawings
The invention is described in further detail below with reference to the following figures and detailed description:
fig. 1 is a schematic structural diagram of a five-level high-power shore power supply system with low harmonic and high performance.
FIG. 2 is a schematic diagram of the secondary winding and phase shifting principle of a 36-pulse rectification phase-shifting transformer according to the present invention and the conventional scheme.
Fig. 3 is a schematic diagram of a double-layer rectification and cascade H-bridge inverter circuit structure.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail below with reference to the accompanying drawings.
Fig. 1 shows a schematic structural diagram of a five-level high-power shore power supply system with low harmonic and high performance, which includes: 36 pulse wave rectification phase-shifting transformer, rectifier circuit, double-layer cascade H bridge inverter circuit. The primary side of the transformer is directly connected to a 10kV/50Hz high-voltage power grid, the secondary side of the transformer is provided with two layers of 6 three-phase windings, wherein the 3 three-phase windings on the first layer are respectively named as a1, B1 and C1, the 3 three-phase windings on the second layer are respectively named as a2, B2 and C2, and three-phase power supplies are respectively provided for 6 power units A1, B1, C1, A2, B2 and C2 on the rear stage. The power unit comprises a rectification part and an inversion part, wherein the rectification circuit can selectively adopt an IGBT controllable rectification circuit or a diode uncontrollable rectification circuit according to application occasions, and the inversion circuit adopts a double-layer cascade H-bridge circuit.
Fig. 2 shows the secondary winding and phase-shifting principle of the 36-pulse rectification phase-shifting transformer of the present invention and the conventional scheme. The secondary side of the transformer comprises two layers of 6 three-phase windings, and the phase shift is carried out by adopting the edge-extending triangle principle.
Fig. 2(a) shows a schematic diagram of phase shift angles of secondary windings of a conventional phase-shifting transformer, wherein 3 three-phase windings on each layer are not phase-shifted, and only two layers are phase-shifted, so that the phase shift angle phase difference is 60 °/2=30 °, 12-pulse rectification is formed in total, 11 times or more of harmonics still exist on the power grid side, and harmonic pollution is large. As shown in the figure, the phase shift angles of the first layer 3 windings a1, b1 and c1 are all-15 degrees, the phase shift angles of the second layer 3 windings a2, b2 and c2 are all +15 degrees, and the phase difference between the two layers is 30 degrees.
Fig. 2(b) shows a schematic diagram of a phase shift angle of a secondary winding of a 36-pulse rectification phase-shifting transformer, 6 three-phase windings on a secondary side of the transformer need to be phase-shifted, the phase shift angle phase difference is 60 °/6=10 °, 36-pulse rectification is formed in total, only higher harmonics with the frequency of more than 35 are generated on a power grid side, the current harmonics on the power grid side are smaller, and the power factor is higher, so that an additional filter device is not required to be arranged on an input side and an output side of the transformer. The phase-shifting angles of the 6 three-phase windings are respectively-25 degrees, -15 degrees, -5 degrees, +15 degrees and +25 degrees. Wherein the-25 ° and-15 ° windings are used as input to power cells a1 and a2, respectively, the-5 ° and +5 ° windings are used as input to power cells B1 and B2, respectively, and the +15 ° and +25 ° windings are used as input to power cells C1 and C2, respectively.
FIG. 2(c) shows a schematic diagram of the extended triangle phase shift principle, in which part of the windings on the secondary side of the transformer are connected into a triangle rst according to delta-connection, and the number of turns isk 1(ii) a Winding the rest part into an extension winding of triangular rstk 2And the final output voltage triangle is marked as RST, and different winding turn ratios are designedk 1:k 2Can make the output voltage UROAnd UrOThe phase difference between the two phases is-25 degrees, -15 degrees, -5 degrees, +15 degrees and +25 degrees respectively, thereby achieving the phase shifting purpose.
Fig. 3 shows a schematic structural diagram of a double-layer rectification and cascade H-bridge inverter circuit according to the present invention, in which a three-phase RST input of a rectification circuit is directly connected to a three-phase winding RST on a secondary side of a transformer. The topological structure of the rectifying circuit can be selected according to different application occasions:
FIG. 3(a) shows that when the application does not need energy release and energy feedback, the rectifier circuit can adopt a diode-free rectifier circuit, CdIs a direct current filter capacitor;
FIG. 3(b) shows that when the application needs to release energy, a braking unit can be incorporated on the basis of a diode-controlled rectifying circuit, and the braking unit comprises two parts of a switching tube IGBT and a discharging resistor R which are connected in series;
fig. 3(c) shows that when the application needs energy feedback, the rectifier circuit can adopt an IGBT controllable rectifier circuit.
The inverter circuit adopts a double-layer cascade H-bridge circuit, the phase voltage output by a single H-bridge unit is 350V, the phase voltage output by the double-layer cascade H-bridge unit is 700V, and the voltage form is five levels. The low-voltage unit superposes and outputs high voltage, so that the output voltage harmonic wave of the inverter is reduced, the switching frequency is reduced, and the cost of the sine wave reactor on the output side of the inverter can be effectively reduced. And the dv/dt of the output voltage is reduced, so that the load can be effectively protected.
It should be noted that variations and modifications can be made by those skilled in the art without departing from the principle of the present invention, and these should also be construed as falling within the scope of the present invention.
Claims (4)
1. A low-harmonic high-performance five-level high-power shore power supply system comprises: a transformer, a rectifying circuit and an inverter circuit; the method is characterized in that: the transformer adopts a 36-pulse rectification phase-shifting transformer; the rectification circuit adopts an IGBT controllable rectification circuit or a diode uncontrolled rectification circuit; the inverter circuit adopts a double-layer cascade H-bridge circuit.
2. The low-harmonic high-performance five-level high-power shore power supply system according to claim 1, wherein: a primary side winding of the 36-pulse rectification phase-shifting transformer is connected to a power grid, two layers of 6 three-phase windings are arranged on a secondary side, the 6 three-phase windings are subjected to phase shifting by adopting an edge-extending triangle principle, phase-shifting angles of the 6 three-phase windings are different, and the phase-shifting angle phase difference is 60 degrees/6 =10 degrees.
3. The low-harmonic high-performance five-level high-power shore power supply system according to claim 1, wherein: the input side and the output side of the transformer are free of filtering devices.
4. The low-harmonic high-performance five-level high-power shore power supply system according to claim 1, wherein: the inverter circuit adopts a double-layer cascade H-bridge circuit, and the output voltage form is five levels; the phase voltage output by the single H-bridge unit is 350V, and the phase voltage output by the double-layer cascade H-bridge unit is 700V.
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| Application Number | Priority Date | Filing Date | Title |
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| CN202110546192.6A CN113224955A (en) | 2021-05-19 | 2021-05-19 | Five-level high-power shore power supply system with low harmonic and high performance |
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| CN202110546192.6A CN113224955A (en) | 2021-05-19 | 2021-05-19 | Five-level high-power shore power supply system with low harmonic and high performance |
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| CN113224955A true CN113224955A (en) | 2021-08-06 |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN115333406A (en) * | 2022-07-27 | 2022-11-11 | 新风光电子科技股份有限公司 | Step-down type multi-machine combined frequency converter system |
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Application publication date: 20210806 |