CN114825941A - Power conversion system, control method of conversion device and flyback power conversion system - Google Patents
Power conversion system, control method of conversion device and flyback power conversion system Download PDFInfo
- Publication number
- CN114825941A CN114825941A CN202210698803.3A CN202210698803A CN114825941A CN 114825941 A CN114825941 A CN 114825941A CN 202210698803 A CN202210698803 A CN 202210698803A CN 114825941 A CN114825941 A CN 114825941A
- Authority
- CN
- China
- Prior art keywords
- input
- unit
- input voltage
- conversion system
- switching
- 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
- 238000006243 chemical reaction Methods 0.000 title claims abstract description 93
- 238000000034 method Methods 0.000 title claims abstract description 9
- 238000002955 isolation Methods 0.000 claims abstract description 32
- 239000003990 capacitor Substances 0.000 claims description 51
- 238000004804 winding Methods 0.000 claims description 41
- 238000010586 diagram Methods 0.000 description 10
- 239000000463 material Substances 0.000 description 2
- 230000000694 effects Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000003912 environmental pollution Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
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
- H02M3/22—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
- H02M3/33507—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 with automatic control of the output voltage or current, e.g. flyback converters
- H02M3/33523—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 with automatic control of the output voltage or current, e.g. flyback converters with galvanic isolation between input and output of both the power stage and the feedback loop
-
- 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
- H02M3/3353—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 at least two simultaneously operating switches on the input side, e.g. "double forward" or "double (switched) flyback" converter
-
- 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
- H02S—GENERATION OF ELECTRIC POWER BY CONVERSION OF INFRARED RADIATION, VISIBLE LIGHT OR ULTRAVIOLET LIGHT, e.g. USING PHOTOVOLTAIC [PV] MODULES
- H02S40/00—Components or accessories in combination with PV modules, not provided for in groups H02S10/00 - H02S30/00
- H02S40/30—Electrical components
- H02S40/32—Electrical components comprising DC/AC inverter means associated with the PV module itself, e.g. AC modules
-
- 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
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Dc-Dc Converters (AREA)
Abstract
The invention provides a power supply conversion system, a control method of a conversion device and a flyback power supply conversion system, which relate to the field of power supplies, wherein the input ends of n isolation power supply converters are connected in series and the output ends are connected in parallel, and the number of the isolation power supply converters needing to work is judged according to the magnitude of input voltage, so that the input voltage range of each isolation power supply converter can be reduced to 1/M (taking M isolation power supply converters as an example) of the original input voltage range, the voltage resistance of a required switching tube can be greatly reduced, the selectable space of a low-voltage-resistant device market is large, the switching device can work at higher frequency under the low voltage and the high voltage of the input voltage, and the conduction impedance is small; the number of the isolated power supply converters can be randomly expanded, so that the voltage input capability of the isolated power supply conversion device can be improved, and the efficiency of the whole isolated power supply conversion device is not influenced; the bus voltage between each isolated power converter can also be well balanced.
Description
Technical Field
The invention relates to the field of power supplies, in particular to a power supply conversion system, a control method of a conversion device and a flyback power supply conversion system.
Background
Under the condition of energy shortage at present, solar energy attracts wide attention as a renewable energy source with little environmental pollution.
In practice, a power conversion system is required to convert solar energy into electrical energy suitable for use by a load. With social progress and development of power supply technology, the market puts higher demands on high efficiency of a power supply conversion system. It is also desirable that the power conversion system be designed as simply as possible to reduce labor costs.
In practical applications, the solar cell set provides a dc input voltage to the power conversion system, and the voltage range of the solar cell set is very wide, the low voltage is usually tens of volts, and the high voltage can reach several kilovolts (e.g. above 1500 volts).
The high voltage provided by the solar battery pack correspondingly raises the withstand voltage of a switch tube in the power conversion system, however, the switch tube with withstand voltage reaching more than 1500 volts on the market is very limited and expensive, and only a few SiC devices are on the market. When the switch tube with high voltage resistance works under low voltage, the on resistance is larger, and the low-voltage efficiency is low. That is, the high efficiency of the current power conversion system at low power and high voltage is difficult to be considered, so that the overall efficiency of the power conversion system is poor, and the material selection is difficult.
In summary, in the field of solar power supply, a power conversion system cannot give consideration to high efficiency within a full voltage range at present, and material selection is limited, so that great inconvenience is brought to design.
Disclosure of Invention
The application provides a power conversion system, includes: n isolated power converters, each isolated power converter comprising: a transformer unit including a primary side winding and a secondary side winding; the switch unit comprises at least one switch tube, a first end and a second end, wherein the second end of the switch unit is connected with two ends of the primary side winding of the transformer unit, and the first end of the switch unit is connected with two ends of an input capacitor; the first end of the rectifying unit is connected with two ends of a secondary side winding of the transformer unit, and the second end of the rectifying unit is connected with an output capacitor to form an output end of the power conversion system; the N input capacitors connected with the first ends of the N switch units are connected in series to form an input end of the power supply conversion system; the solar battery pack is connected with the input end of the power supply conversion system to provide input voltage for the input end of the power supply conversion system; and the control unit is used for receiving the input voltage and outputting a switch control signal according to the input voltage so as to control the switching tubes in the switching units in the M isolation power converters to be in a high-frequency switching state, wherein the switching tubes in the switching units in the K isolation power converters are normally closed, N is a positive integer greater than or equal to 2, K and M are integers greater than or equal to 0, and K = N-M.
Furthermore, when the M isolated power converters work, the sum of withstand voltages of all the switching tubes in the switching unit in the high-frequency switching state is greater than the input voltage at the same time.
Furthermore, the input voltage of each of the M isolated power converters is smaller than the sum of the withstand voltages of the switching tubes in the high-frequency switching state in the switching unit of each isolated power converter.
Furthermore, in M isolated power converters, the sum of withstand voltages of all switching tubes in a high-frequency switching state in any M-1 switching units at the same time is smaller than the input voltage.
Furthermore, the switch unit is a full-bridge switch unit, a half-bridge switch unit or a forward switch unit.
Furthermore, the rectification unit is a full-bridge rectification unit, a current-doubler rectification unit, a full-wave rectification unit or a half-wave rectification unit.
Furthermore, the capacitance values of the N input capacitors are equal, and the structures and the devices of the N isolation power supply transformers are the same.
The present application further provides a flyback power conversion system, including: n flyback power converters, each flyback power converter including: the transformer unit comprises a primary side winding, a secondary side winding and a switching tube, wherein a first end of the switching tube is connected with a first end of the primary side winding, a second end of the switching tube is connected with a second end of an input capacitor, and a second end of the primary side winding is connected with a first end of the input capacitor; the first end of the rectification switch tube is connected with the first end of the secondary side winding, the second end of the rectification switch tube is connected with the first end of the output capacitor, the second end of the secondary side winding is connected with the second end of the output capacitor, the N input capacitors are connected in series to form the input end of the flyback power supply conversion system, and the first end and the second end of the output capacitor form the output end of the flyback power supply conversion system; the solar battery pack is connected with the input end of the flyback power supply conversion system so as to provide input voltage for the input end of the flyback power supply conversion system; and the control unit is used for receiving the input voltage and outputting a switch control signal according to the input voltage so as to control M switching tubes to be in a high-frequency switching state, so that the M flyback power converters work, wherein K switching tubes are normally closed, N is a positive integer greater than or equal to 2, K and M are integers greater than or equal to 0, and K = N-M.
Further, the sum of withstand voltages of the M switching tubes is greater than the input voltage.
Furthermore, the input voltage of each flyback power converter in the M flyback power converters is smaller than the withstand voltage of the switching tube therein.
Furthermore, in the M flyback power converters, the sum of withstand voltages of any M-1 switching tubes is smaller than the input voltage.
Furthermore, the rectifier switch tube is a diode, a first end of the rectifier switch tube is an anode, and a second end of the rectifier switch tube is a cathode.
The present application further provides a control method of an isolated power conversion apparatus, where the isolated power conversion apparatus includes: n isolated power converters, each isolated power converter comprising: a transformer unit including a primary side winding and a secondary side winding; the switch unit comprises at least one switch tube, a first end and a second end, wherein the second end of the switch unit is connected with two ends of the primary side winding of the transformer unit, and the first end of the switch unit is connected with two ends of an input capacitor; the rectifier unit comprises a first end and a second end, the first end of the rectifier unit is connected with two ends of the secondary side winding of the transformer unit, and the second end of the rectifier unit is connected with an output capacitor to form an output end of the isolated power conversion device; connect N input capacitance series connection of the first end of N switching unit, form the input of isolation power conversion device, include: obtaining input voltage of an input end of an isolation power supply conversion device and withstand voltage of a switch tube in a switch unit in N isolation power supply converters; controlling so that the switching tubes in the switching units in the M isolated power converters are in a high-frequency switching state when the following three conditions are met, wherein the switching tubes in the switching units in the K isolated power converters are normally closed, wherein N is a positive integer greater than or equal to 2, K and M are integers greater than or equal to 0, and K = N-M, wherein the first condition is: when the M isolation power supply converters work, the sum of withstand voltages of all switching tubes in a high-frequency switching state is larger than the input voltage at the same moment; the second condition is as follows: when the M isolation power converters work, at the same moment, the sum of withstand voltages of all switching tubes in a high-frequency switching state in any M-1 isolation power converters in the M isolation power converters is smaller than the input voltage; the third condition is as follows: when the M isolation power converters work, the input voltage of each isolation power converter in the M isolation power converters is smaller than the sum of the withstand voltages of all the switching tubes in the high-frequency switching state in each isolation power converter.
Furthermore, the input voltage is provided to the input end of the isolated power conversion device by the solar battery pack.
Drawings
Fig. 1 is a schematic diagram of a power conversion system according to an embodiment of the invention.
Fig. 2 is a schematic diagram of a power conversion system according to another embodiment of the invention.
Fig. 3 is a schematic diagram of a power conversion system according to another embodiment of the invention.
Fig. 4 is a schematic diagram of a switching unit in a full-bridge inverter.
Fig. 5 is a schematic diagram of an isolated power converter according to an embodiment of the invention.
Detailed Description
The technical solutions in the present invention will be described clearly and completely with reference to the accompanying drawings, and it should be understood that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.
In an embodiment of the present invention, a power conversion system is provided, please refer to fig. 1, which is a schematic diagram of a power conversion system according to an embodiment of the present invention. The power conversion system includes:
the power conversion apparatus, as indicated by reference numeral 100 in fig. 1, includes: n power converters, such as the first power converter 110, the second power converter 120, and up to the nth power converter 1N0 in fig. 1, each of which includes at least one switch, a positive input terminal, a negative input terminal, a positive output terminal, and a negative output terminal, as shown in fig. 1, the positive output terminals of the N power converters being connected to each other, and the negative output terminals of the N power converters being connected to each other, so as to form an output terminal dout of the power conversion apparatus; n input capacitors, such as a first input capacitor Cin1, a second input capacitor Cin2, and an nth input capacitor Cin in fig. 1, wherein one of the input capacitors is connected between the positive input end and the negative input end of each power converter, as shown in fig. 1, a first input capacitor Cin1 is connected between the positive input end and the negative input end of the first power converter 110, a second input capacitor Cin2 is connected between the positive input end and the negative input end of the second power converter 120, an nth input capacitor Cin is connected between the positive input end and the negative input end of the nth power converter 1N0, and the N input capacitors are connected in series to form an input terminal din of the power conversion device;
a solar battery, as shown in fig. 1, the solar battery 200 is connected to an input end din of the power conversion device to provide an input voltage Vin to the input end din of the power conversion device;
the control unit, as shown in fig. 1, the control unit 300 receives an input voltage Vin, and outputs a switch control signal according to the input voltage Vin, so as to control M power converters to operate, where switching tubes in K power converters are normally closed, where N is a positive integer greater than or equal to 2, K and M are integers greater than or equal to 0, and K = N-M.
The operation of the power converter means that a switching tube in the power converter is in a high-frequency switching state, so that the voltage at the input end of the power converter is converted into the voltage at the output end. Taking the first power converter 110 in fig. 1 as an example, when the switching tube in the first power converter 110 is in a high-frequency switching state, the first power converter 110 converts the bus voltage of the first input capacitor Cin1 into an output voltage, and the output voltage is connected in parallel with the output voltage of another power converter to be used as the output voltage of the power conversion device.
The normally closed state of the switching tubes in the K power converters means that the switching tubes in the power converters are in a always conducting state, so that the power converters do not perform voltage conversion.
Therefore, the input ends of the n power converters are connected in series and the output ends of the n power converters are connected in parallel, the number of the power converters needing to work is judged according to the size of the input voltage, the input voltage range of each power converter can be reduced to 1/M of the original input voltage range (taking M power converters as an example), the voltage resistance of a required switching tube can be greatly reduced, the selectable space of a low-voltage-resistant device market is large, the price and the performance can be considered, the low-voltage and high-voltage input voltage can work at higher frequency, the on-resistance is small, the high efficiency in the full voltage range can be considered, and the efficiency of the whole power conversion device is improved. The number of the power converters can be expanded at will, and the solar cell module can be further suitable for solar cell sets of any voltage grade, so that the voltage input capacity of the power conversion device can be improved, and the efficiency of the whole power conversion device is not influenced. Meanwhile, during normal operation, the instantaneous current of each power converter during operation is determined by the voltage of the input capacitor of each power converter, so that the bus voltage between each power converter can be well balanced.
In an embodiment of the present invention, each power converter is an isolated converter, please refer to fig. 2 showing a schematic diagram of a power conversion system according to another embodiment of the present invention, as shown in fig. 2, each of the N isolated power converters includes:
a transformer unit, such as the first transformer unit TX1 in the first isolated power converter 110 in fig. 2, through the nth transformer unit Tn1 in the nth isolated power converter 1n0, the transformer unit including a primary winding Lp and a secondary winding Ls;
the switching units, such as the first to nth isolated power converters 110 to 1N0 in fig. 2, each include a switching unit, each including at least one switching tube, a first terminal and a second terminal, the second terminals of the switching units are connected to two terminals of the primary winding Lp of the transformer unit, and the first terminals of the switching units are connected to one of the N input capacitors, such as in fig. 2, the first terminals of the switching units in the first isolated power converter 110 are connected to the first input capacitor Cin 1;
the rectifying units, such as the first to nth isolated power converters 110 to 1n0 shown in fig. 2, respectively include a rectifying unit, each of which includes a first end and a second end, the first end of the rectifying unit is connected to two ends of the secondary winding Ls of the transformer unit, the second end of the rectifying unit is connected to an output capacitor Cout, so as to form an output terminal dout of the power conversion system,
wherein the control makes M among them power converter work, and wherein the switching tube normal close in K power converter is: and controlling the switching tubes in the switching units in the M isolated power converters to be in a high-frequency switching state, wherein the switching tubes in the switching units in the K isolated power converters are normally closed.
More specifically, referring to fig. 3 showing a schematic diagram of a power conversion system according to another embodiment of the present invention, as shown in fig. 3, N isolation power converters are flyback power converters, and each of the switch units shown in fig. 2 includes a switch tube. As shown in fig. 3, taking the first flyback converter 110 as an example, the first end of the switching tube S1 is connected to the first end of the primary winding Lp, the second end of the switching tube S1 is connected to the second end of the first input capacitor Cin1, and the second end of the primary winding Lp is connected to the first end of the first input capacitor Cin 1. As shown in fig. 3, taking the first flyback converter 110 as an example, a first end of the rectifying switching tube D1 is connected to a first end of the secondary winding Ls, a second end of the rectifying switching tube D1 is connected to a first end of the output capacitor Cout, and a second end of the secondary winding Ls is connected to a second end of the output capacitor Cout. In fig. 3, the rectifying switch tube D1 is taken as an example of a diode, and the first terminal is an anode and the second terminal is a cathode, which may be other controllable switches in practical applications.
When the flyback power converter system actually operates, the control unit 300 receives an input voltage Vin, and outputs a switch control signal according to the input voltage Vin to control M switching tubes (M of S1 to Sn) to be in a high-frequency switching state, so as to operate the M flyback power converters, wherein K switching tubes (K of S1 to Sn) are normally closed, where N is a positive integer greater than or equal to 2, K and M are integers greater than or equal to 0, and K = N-M.
As described above, in actual operation, the number of isolated power converters to be operated is determined by the magnitude of the actual input voltage. As follows, the flyback power conversion system shown in fig. 3 includes three flyback power converters as an example to explain the principle, where the withstand voltage of the first switching tube S1 is 600V, the withstand voltage of the second switching tube S2 is 400V, the withstand voltage of the third switching tube S3 is 400V, and the capacitance-to-value ratio among the first input capacitor Cin1, the second input capacitor Cin2, and the third input capacitor Cin3 is 2: 3: 3, the flyback power converter system can support a solar battery pack with a high voltage slightly less than 1400V (such as 1300V), and each flyback power converter can work with high efficiency.
Specifically, in actual operation, if the input voltage provided by the solar cell set 200 is 1200V, the input voltage of the first flyback power converter is about 514V, and the input voltages of the second and third flyback power converters are about 343V, the sum of the withstand voltages of the first switching tube S1 to the third switching tube S3 is 1400V, which is greater than the input voltage 1200V, the withstand voltage of the first switching tube S1 is greater than the input voltage of the first flyback power converter, the withstand voltage of the second switching tube S2 is greater than the input voltage of the second flyback power converter, and the withstand voltage of the third switching tube S3 is greater than the input voltage of the third flyback power converter, so that 3 flyback power converters can be controlled to operate. Furthermore, if any one of the three flyback power converters does not work, the sum of withstand voltages of the switching tubes is less than 1200V of the input voltage, so that the efficiency of the power converter can be improved to the maximum extent by all 3 flyback power converters working.
Specifically, during actual operation, if the input voltage provided by the solar cell set 200 is 800V, the input voltage of the first flyback power converter is about 343V, the input voltages of the second and third flyback power converters are about 228.5V, the sum of the withstand voltages of the first switching tube S1 and the third switching tube S3 is 1000V, which is greater than the input voltage 800V, the withstand voltage of the first switching tube S1 is greater than the input voltage of the first flyback power converter, and the withstand voltage of the third switching tube S3 is greater than the input voltage of the third flyback power converter, so that the first and third flyback power converters can be controlled to operate (i.e., the first switching tube S1 and the third switching tube S3 are in a high-frequency switching state), and the second flyback power converter (i.e., the second switching tube S2 is in a constantly conducting state). Furthermore, if any one of the first flyback power converter and the third flyback power converter does not work, the withstand voltage of the switching tube is always smaller than the input voltage of 800V, so that the efficiency of the power converter can be improved to the maximum extent by working 2 flyback power converters. Of course, the first and second flyback power converters may be operated, and the third flyback power converter may not be operated.
That is, for the flyback power conversion system, the sum of withstand voltages of the M operating switching tubes needs to be greater than the input voltage Vin. Furthermore, the input voltage Vin of each flyback power converter in the M flyback power converters in operation is smaller than the withstand voltage of the switching tube therein. Furthermore, in the M flyback power converters, the sum of withstand voltages of any M-1 switching tubes is smaller than the input voltage Vin.
In practical applications, the isolated power converter is not limited to be a flyback power converter, but may also be another isolated converter, such as a full-bridge converter, a half-bridge converter, or a forward converter. Referring to fig. 4, a schematic diagram of a switching unit in a full-bridge converter includes a first branch formed by connecting a switching tube S11 and a switching tube S12 in series, a second branch formed by connecting a switching tube S21 and a switching tube S22 in series, and the first branch and the second branch are connected in parallel. When the full-bridge converter operates, the switch tube S11 and the switch tube S22 operate simultaneously, or the switch tube S21 and the switch tube S12 operate simultaneously, and when the converter in fig. 1 and 2 is a full-bridge converter, the isolated power supply converter operates, at the same time, the sum of the withstand voltages of all the switch tubes in the high-frequency switching state in the switch unit is the sum of the withstand voltages of the switch tube S11 and the switch tube S22, or the sum of the withstand voltages of the switch tube S21 and the switch tube S12. When the isolated power converter does not work, the switch tube S11 and the switch tube S22 are always conducted, or the switch tube S21 and the switch tube S12 are always conducted.
In practical applications, the specific structure of the rectifying unit is not limited, and the rectifying unit may be a full-bridge rectifying unit, a current-doubler rectifying unit, a full-wave rectifying unit, a half-wave rectifying unit, or the like.
That is, as shown in fig. 1 and 2, when the M power converters are operated, the sum of withstand voltages of all the switching tubes in the switching unit in the M power converters in the high-frequency switching state is larger than the input voltage Vin at the same time. Furthermore, the input voltage of each of the M power converters is smaller than the sum of the withstand voltages of the switching tubes in the high-frequency switching state in the switching unit of each power converter. Furthermore, in M power converters, the sum of withstand voltages of all the switch tubes in the high-frequency switch state in any M-1 switch units at the same time is less than the input voltage Vin. So as to ensure that the power conversion system can reliably work and each power converter has the highest efficiency.
Referring to fig. 2 and 3, the isolated converters include transformer units, and the power conversion system provided by the present application can reduce the input voltage range of each isolated power converter, and therefore, the turn ratio range of each transformer unit, thereby greatly reducing the design difficulty of the transformer units and improving the efficiency. Similarly, the withstand voltage of the switching tube in the rectifying unit can be reduced, and as with the switching unit connected to the primary winding, the selection space of the switching tube in the rectifying unit can be increased, the efficiency can be improved, and the cost can be reduced.
In an embodiment of the present invention, the capacitance values of the N input capacitors are equal, and the structures and devices of the N power converters are the same, so that the isolated power converters in each path are the same. The capacitance values of the N input capacitors may also be different, and the structures and devices of the N power converters may also be different, so that each path of the isolated power converter is designed independently. The power conversion system can be flexibly designed according to actual requirements, and the application range of the power conversion system is enlarged.
In an embodiment of the present invention, a method for controlling a power conversion apparatus is further provided, where the power conversion apparatus is shown by reference numeral 100 in fig. 1, and specifically, refer to a schematic diagram of an isolated power conversion apparatus shown in fig. 5, where the isolated power conversion apparatus includes: n isolated power converters, e.g., the first isolated power converter 110 of fig. 5 through the nth isolated power converter 1N0, each isolated power converter including a transformer unit, e.g., the first transformer unit TX1 in the first isolated power converter 110 of fig. 5 through the nth transformer unit Tn1 in the nth isolated power converter 1N0, the transformer unit including a primary winding Lp and a secondary winding Ls; the switching units, such as the first to nth isolated power converters 110 to 1n0 in fig. 5, respectively include a switching unit, which includes at least one switching tube, a first terminal and a second terminal, the second terminal of the switching unit is connected to two terminals of the primary winding Lp of the transformer unit, and the first terminal of the switching unit is connected to two terminals of an input capacitor, such as the first terminal of the switching unit in the first isolated power converter 110 is connected to the first input capacitor Cin1 in fig. 5; a rectifying unit, such as the first isolated power converter 110 to the nth isolated power converter 1n0 shown in fig. 5, respectively including a rectifying unit having a first end and a second end, wherein the first end of the rectifying unit is connected to two ends of the secondary winding Ls of the transformer unit, and the second end of the rectifying unit is connected to an output capacitor Cout, which forms an output terminal dout of the isolated power converter; and the N input capacitors connected with the first ends of the N switch units are connected in series to form an input end din of the isolated power supply conversion device. The control method of the isolated power supply conversion device comprises the following steps:
obtaining the input voltage of an input end din of a power supply conversion device and the withstand voltage of a switching tube in the power supply converter;
controlling to operate M power converters when the following three conditions are met, wherein switching tubes in K power converters are normally closed, wherein N is a positive integer greater than or equal to 2, K and M are integers greater than or equal to 0, and K = N-M, wherein the first condition is: when the M power converters work, at the same moment, the sum of withstand voltages of all switching tubes in a high-frequency switching state is larger than the input voltage; the second condition is as follows: when the M power converters work, at the same moment, the sum of withstand voltages of all switching tubes in a high-frequency switching state in any M-1 power converters in the M power converters is smaller than the input voltage; the third condition is as follows: when the M power converters work, the input voltage of each power converter in the M power converters is smaller than the sum of withstand voltages of all the switching tubes in the high-frequency switching state in each power converter.
In practical application, the input voltage is provided to the input end of the isolated power conversion device by the solar battery pack.
The principle and effect are the same as those of the power conversion system, and are not described herein again.
Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.
Claims (14)
1. A power conversion system, comprising:
n isolated power converters, each isolated power converter comprising:
a transformer unit including a primary side winding and a secondary side winding;
the switch unit comprises at least one switch tube, a first end and a second end, wherein the second end of the switch unit is connected with two ends of the primary side winding of the transformer unit, and the first end of the switch unit is connected with two ends of an input capacitor;
the first end of the rectifying unit is connected with two ends of a secondary side winding of the transformer unit, and the second end of the rectifying unit is connected with an output capacitor to form an output end of the power conversion system;
the N input capacitors connected with the first ends of the N switch units are connected in series to form an input end of the power supply conversion system;
the solar battery pack is connected with the input end of the power supply conversion system to provide input voltage for the input end of the power supply conversion system;
and the control unit is used for receiving the input voltage and outputting a switch control signal according to the input voltage so as to control the switching tubes in the switching units in the M isolation power converters to be in a high-frequency switching state, wherein the switching tubes in the switching units in the K isolation power converters are normally closed, N is a positive integer greater than or equal to 2, K and M are integers greater than or equal to 0, and K = N-M.
2. The power conversion system according to claim 1, wherein when the M isolated power converters are operating, the sum of withstand voltages of all switching tubes in the switching unit in the high-frequency switching state is greater than the input voltage at the same time.
3. The power conversion system according to claim 2, wherein the input voltage of each of the M isolated power converters is smaller than the sum of withstand voltages of switching tubes in a high-frequency switching state in a switching unit in each isolated power converter.
4. The power conversion system according to claim 3, wherein, in the M isolated power converters, the sum of withstand voltages of all switching tubes in the high-frequency switching state in any M-1 switching units is smaller than the input voltage at the same time.
5. The power conversion system of claim 1, wherein the switch unit is a full-bridge switch unit, a half-bridge switch unit, or a forward switch unit.
6. The power conversion system according to claim 1, wherein the rectification unit is a full-bridge rectification unit, a current-doubler rectification unit, a full-wave rectification unit, or a half-wave rectification unit.
7. The power conversion system of claim 1, wherein the N input capacitors have equal capacitance values, and the N isolated power converters have the same structure and device.
8. A flyback power conversion system, comprising:
n flyback power converters, each flyback power converter including:
a transformer unit including a primary side winding and a secondary side winding;
a first end of the switch tube is connected with a first end of the primary side winding, a second end of the switch tube is connected with a second end of an input capacitor, and a second end of the primary side winding is connected with a first end of the input capacitor;
a rectifier switch tube, a first end of the rectifier switch tube is connected with a first end of the secondary side winding, a second end of the rectifier switch tube is connected with a first end of the output capacitor, a second end of the secondary side winding is connected with a second end of the output capacitor,
the input capacitors are connected in series to form an input end of the flyback power conversion system, and a first end and a second end of each output capacitor form an output end of the flyback power conversion system;
the solar battery pack is connected with the input end of the flyback power supply conversion system so as to provide input voltage for the input end of the flyback power supply conversion system;
and the control unit is used for receiving the input voltage and outputting a switch control signal according to the input voltage so as to control M switching tubes to be in a high-frequency switching state, so that the M flyback power converters work, wherein K switching tubes are normally closed, N is a positive integer greater than or equal to 2, K and M are integers greater than or equal to 0, and K = N-M.
9. The flyback power converter system of claim 8, wherein a sum of withstand voltages of the M switching tubes is greater than the input voltage.
10. The flyback power converter system of claim 9 wherein the input voltage of each of the M flyback power converters is less than the withstand voltage of the switching tube therein.
11. The flyback power converter system of claim 10 wherein a sum of withstand voltages of any M-1 switching tubes in the M flyback power converters is less than the input voltage.
12. The flyback power converter system of claim 8, wherein the rectifying switch tube is a diode, the first end of the rectifying switch tube is an anode, and the second end of the rectifying switch tube is a cathode.
13. A control method of an isolated power conversion device, the isolated power conversion device comprising: n isolated power converters, each isolated power converter comprising: a transformer unit including a primary side winding and a secondary side winding; the switch unit comprises at least one switch tube, a first end and a second end, wherein the second end of the switch unit is connected with two ends of the primary side winding of the transformer unit, and the first end of the switch unit is connected with two ends of an input capacitor; the rectifier unit comprises a first end and a second end, the first end of the rectifier unit is connected with two ends of the secondary side winding of the transformer unit, and the second end of the rectifier unit is connected with an output capacitor to form an output end of the isolated power conversion device; connect N input capacitance series connection of the first end of N switch element forms the input of isolation power conversion device, its characterized in that includes:
obtaining input voltage of an input end of an isolation power supply conversion device and withstand voltage of a switch tube in a switch unit in N isolation power supply converters;
controlling so that the switching tubes in the switching units in the M isolated power converters are in a high-frequency switching state when the following three conditions are met, wherein the switching tubes in the switching units in the K isolated power converters are normally closed, wherein N is a positive integer greater than or equal to 2, K and M are integers greater than or equal to 0, and K = N-M, wherein the first condition is: when the M isolation power supply converters work, the sum of withstand voltages of all switching tubes in a high-frequency switching state is larger than the input voltage at the same moment; the second condition is as follows: when the M isolation power converters work, at the same moment, the sum of withstand voltages of all switching tubes in a high-frequency switching state in any M-1 isolation power converters in the M isolation power converters is smaller than the input voltage; the third condition is as follows: when the M isolation power converters work, the input voltage of each isolation power converter in the M isolation power converters is smaller than the sum of the withstand voltages of all the switching tubes in the high-frequency switching state in each isolation power converter.
14. The isolated power converter control method of claim 13, wherein the input voltage is provided to the input of the isolated power converter by a solar cell.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210698803.3A CN114825941B (en) | 2022-06-20 | 2022-06-20 | Power conversion system, control method of conversion device and flyback power conversion system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210698803.3A CN114825941B (en) | 2022-06-20 | 2022-06-20 | Power conversion system, control method of conversion device and flyback power conversion system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN114825941A true CN114825941A (en) | 2022-07-29 |
| CN114825941B CN114825941B (en) | 2022-09-09 |
Family
ID=82521460
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210698803.3A Active CN114825941B (en) | 2022-06-20 | 2022-06-20 | Power conversion system, control method of conversion device and flyback power conversion system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114825941B (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115622201A (en) * | 2022-12-13 | 2023-01-17 | 麦田能源有限公司 | Power supply conversion system, power supply conversion device and battery pack voltage balance control method |
| CN116799803A (en) * | 2023-08-28 | 2023-09-22 | 广东省洛仑兹技术股份有限公司 | AC power distribution method compatible with multiple power grid system inputs |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008187817A (en) * | 2007-01-30 | 2008-08-14 | Fuji Electric Systems Co Ltd | Dc power supply unit |
| CN101345473A (en) * | 2008-05-04 | 2009-01-14 | 南京航空航天大学 | Input-series-output-parallel automatic voltage equalizing DC transformer based on full-bridge topological structure |
| CN102013806A (en) * | 2010-03-10 | 2011-04-13 | 杭州中恒电气股份有限公司 | DC/DC converter suitable for high-voltage input high-power output |
| CN104852588A (en) * | 2015-06-09 | 2015-08-19 | 黑龙江大学 | Auxiliary power supply suitable for high-voltage input and multi-output occasions |
| JP2015226356A (en) * | 2014-05-27 | 2015-12-14 | サンケン電気株式会社 | Power converter |
| JP2016201938A (en) * | 2015-04-13 | 2016-12-01 | 株式会社デンソー | Power conversion device |
| CN107276417A (en) * | 2017-08-09 | 2017-10-20 | 广州金升阳科技有限公司 | A kind of power-supply system |
| CN112072926A (en) * | 2020-09-21 | 2020-12-11 | 广州金升阳科技有限公司 | Voltage-sharing control method and circuit for series input system of switching power supply |
-
2022
- 2022-06-20 CN CN202210698803.3A patent/CN114825941B/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008187817A (en) * | 2007-01-30 | 2008-08-14 | Fuji Electric Systems Co Ltd | Dc power supply unit |
| CN101345473A (en) * | 2008-05-04 | 2009-01-14 | 南京航空航天大学 | Input-series-output-parallel automatic voltage equalizing DC transformer based on full-bridge topological structure |
| CN102013806A (en) * | 2010-03-10 | 2011-04-13 | 杭州中恒电气股份有限公司 | DC/DC converter suitable for high-voltage input high-power output |
| JP2015226356A (en) * | 2014-05-27 | 2015-12-14 | サンケン電気株式会社 | Power converter |
| JP2016201938A (en) * | 2015-04-13 | 2016-12-01 | 株式会社デンソー | Power conversion device |
| CN104852588A (en) * | 2015-06-09 | 2015-08-19 | 黑龙江大学 | Auxiliary power supply suitable for high-voltage input and multi-output occasions |
| CN107276417A (en) * | 2017-08-09 | 2017-10-20 | 广州金升阳科技有限公司 | A kind of power-supply system |
| CN112072926A (en) * | 2020-09-21 | 2020-12-11 | 广州金升阳科技有限公司 | Voltage-sharing control method and circuit for series input system of switching power supply |
Non-Patent Citations (2)
| Title |
|---|
| DESHANG SHA ET AL.: "Control Strategy for Input-Series-Output-Parallel High-Frequency AC Link Inverters", 《IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS》 * |
| 杨双景: "航天器ISOP直流变换器控制策略研究", 《航天器工程》 * |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115622201A (en) * | 2022-12-13 | 2023-01-17 | 麦田能源有限公司 | Power supply conversion system, power supply conversion device and battery pack voltage balance control method |
| CN115622201B (en) * | 2022-12-13 | 2023-04-07 | 麦田能源有限公司 | Power supply conversion system, power supply conversion device and battery pack voltage balance control method |
| CN116799803A (en) * | 2023-08-28 | 2023-09-22 | 广东省洛仑兹技术股份有限公司 | AC power distribution method compatible with multiple power grid system inputs |
| CN116799803B (en) * | 2023-08-28 | 2024-01-12 | 广东省洛仑兹技术股份有限公司 | AC power distribution method compatible with multiple power grid system inputs |
Also Published As
| Publication number | Publication date |
|---|---|
| CN114825941B (en) | 2022-09-09 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN114825941B (en) | Power conversion system, control method of conversion device and flyback power conversion system | |
| US8432709B2 (en) | DC-to-AC power inverting apparatus for photovoltaic modules | |
| CN107592017B (en) | DC-DC converter and control method | |
| CN112072942A (en) | Improved switch coupling inductor quasi Z source inverter | |
| US8503198B2 (en) | High boost ratio DC converter | |
| KR20150046823A (en) | Power supply apparatus and driving method thereof | |
| CN110943617B (en) | Circuit topological structure of double-switch type DC/DC converter | |
| CN107276393B (en) | High-voltage power supply circuit | |
| CN111490717A (en) | Photovoltaic power generation system with isolated photovoltaic optimizer | |
| Niu et al. | A novel switched-capacitor five-level T-type inverter | |
| CN108879651B (en) | DAB-based high-power dual-modular hybrid energy storage system and grid connection method | |
| CN113410990B (en) | High-efficiency high-gain quasi-Z-source soft switching DC-DC converter | |
| CN216599417U (en) | Cascaded switch capacitor coupling inductor high-gain DC-DC converter | |
| CN107395041B (en) | High-conversion-efficiency isolated micro grid-connected inverter and control method thereof | |
| EP3916980A1 (en) | Conversion device | |
| CN209896688U (en) | Series converter module with fault isolation function | |
| CN208849672U (en) | Single-input double-output three-switch-group DC-DC converter | |
| CN208690941U (en) | A kind of inverter and generating equipment | |
| CN112234817A (en) | Buck circuit with large voltage reduction ratio and low voltage stress | |
| KR101022772B1 (en) | A Power Conversion Device for Fuel Cell | |
| CN221202363U (en) | Power conversion device and power supply system | |
| Li et al. | The improvement of cascaded converter design using quadratic boosting structure with high voltage gain and low duty cycle | |
| CN109194147B (en) | Power electronic transformer with redundancy function for intelligent micro-grid | |
| CN112994471B (en) | Power electronic transformer based on series full-bridge resonant circuit | |
| CN217984862U (en) | High-gain direct current converter |
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 | ||
| CP01 | Change in the name or title of a patent holder | ||
| CP01 | Change in the name or title of a patent holder |
Address after: 325024 No. 939, Jinhai Third Road, Konggang new area, Longwan District, Wenzhou City, Zhejiang Province Patentee after: Foxess Co.,Ltd. Address before: 325024 No. 939, Jinhai Third Road, Konggang new area, Longwan District, Wenzhou City, Zhejiang Province Patentee before: Maitian Energy Co.,Ltd. |