CN110535171A - A kind of alternating current-direct current mixing photovoltaic generating system - Google Patents
A kind of alternating current-direct current mixing photovoltaic generating system Download PDFInfo
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Abstract
The present invention provides a kind of alternating current-direct current mixing photovoltaic generating system, its optimizer group being connected with the input terminal of high_voltage isolation type DC/DC converter includes at least one optimizer, and it is realized the MPPT control of DC power supply by the optimizer respectively connected respectively, each high_voltage isolation type DC/DC converter is set to no longer need to carry out the photovoltaic panel connected MPPT control and real-time pressure regulation, therefore the gain ranging of high_voltage isolation type DC/DC converter can take lesser value, and then promote the efficiency of high_voltage isolation type DC/DC converter further compared with prior art.
Description
Technical Field
The invention relates to the technical field of photovoltaic power generation, in particular to an alternating current-direct current hybrid photovoltaic power generation system.
Background
In the field of photovoltaic power generation, with the development of power electronic technology, a solid-state transformer, a device which is constructed based on components such as a power semiconductor, a capacitor and an inductor and at least has the functions of isolating and transforming a power transformer, is being deeply researched and gradually popularized; the inverter and the solid-state transformer are integrated into a whole, so that the photovoltaic solid-state transformer is called as a photovoltaic solid-state transformer, has a synergistic effect, has higher overall benefit than a pure solid-state transformer, and becomes the research direction of experts of numerous scholars.
The photovoltaic solid-state transformer in the prior art is composed of a DC/DC and a DC/AC, wherein the DC/DC generally adopts an isolated DC/DC converter and is used for realizing MPPT control of a connected photovoltaic panel; the main circuit of the DC/AC generally adopts an H-bridge topology or an MMC (Modular multilevel converter) for controlling the grid-connected current and the corresponding DC bus voltage to be constant.
However, in the above solutions of the prior art, because the MPPT voltage of the photovoltaic panel is affected by factors such as illumination and temperature of the battery panel, and has a wide variation range, the isolated DC/DC converter needs to adjust the voltage in real time to realize the MPPT control of the connected photovoltaic panel, and the output voltage of the isolated DC/DC converter is controlled to be a constant value by the rear-stage H-bridge or MMC, so the gain of the input and output voltages of the isolated DC/DC converter needs to have a wide range, but the efficiency of the isolated DC/DC converter is difficult to be high.
Disclosure of Invention
The invention provides an alternating current-direct current hybrid photovoltaic power generation system, which aims to solve the problem that an isolation type DC/DC converter in the prior art is low in efficiency.
In order to achieve the purpose, the technical scheme provided by the application is as follows:
an AC-DC hybrid photovoltaic power generation system, comprising: the system comprises a plurality of optimizer groups, a plurality of high-voltage isolated DC/DC converters, M upper bridge arms, M lower bridge arms, M inductance devices and a filter; wherein:
one end of each upper bridge arm is connected with one end of the corresponding lower bridge arm through one inductance device;
the middle point of each inductance device is connected with an alternating current power grid through the filter;
the other end of each upper bridge arm is connected, and the connecting point is connected with the anode of a direct current power grid;
the other end of each lower bridge arm is connected, and a connecting point is connected with the negative electrode of the direct current power grid;
the upper bridge arm and the lower bridge arm respectively comprise N cascade modules which are connected in series through an alternating current side, and N is a positive integer;
the high-voltage isolation type DC/DC converter is used for performing voltage conversion on the received direct current electric energy and outputting the direct current electric energy after the voltage conversion to the corresponding cascade module;
the high-voltage isolation type DC/DC converter comprises: the isolation voltage grade between the primary side and the secondary side of the high-frequency transformer is more than or equal to 10 kV;
the input end of the high-voltage isolation type DC/DC converter is connected with the output end of at least one optimizer group;
the optimizer group comprises at least one optimizer, the output ends of the optimizers are connected in series, the two ends of the series connection are the output ends of the optimizer group, and the input end of the optimizer is connected with a direct-current power supply;
the optimizer is used for realizing Maximum Power Point Tracking (MPPT) control on a connected direct current power supply.
Preferably, the direct current side of the cascade module is connected to the output end of at least one of the high-voltage isolated DC/DC converters.
Preferably, the cascade module controls the ratio of the maximum value to the minimum value of the voltage at the input end of the cascade module to be less than or equal to 1.2.
Preferably, the direct current side of the cascade module is suspended;
the plurality of conversion units are connected in series through output ends to form converter strings, and at least one converter string is connected between the positive pole and the negative pole of the direct-current power grid; the transformation unit includes: one high-voltage isolation type DC/DC converter or at least two high-voltage isolation type DC/DC converters with output ends connected in parallel.
Preferably, the input end of each high-voltage isolated DC/DC converter is connected to the output end of at least one optimizer group corresponding to each high-voltage isolated DC/DC converter; or,
the input ends of the high-voltage isolated DC/DC converters in the converter string are connected in parallel, and the two ends after being connected in parallel are connected with the output end of at least one optimizer group; in the alternative to this, either,
in the converter string, the input ends of the high-voltage isolation type DC/DC converters in the conversion units with a plurality of output ends connected in series are connected in parallel, and the two ends after being connected in parallel are connected with the output end of at least one optimizer group.
Preferably, the method further comprises the following steps: and the combiner box is used for combining the outputs of the connected optimizer groups and outputting the combined direct current electric energy to the corresponding high-voltage isolation type DC/DC converter.
Preferably, the main circuit of the cascade module is a half-bridge topology or a full-bridge topology.
Preferably, the main circuit of the high-voltage isolation type DC/DC converter is any one of an LC series resonance topology, an LLC series resonance topology, a dual-active DC/DC topology, and a full-bridge DC/DC topology.
Preferably, the optimizer is a non-isolated DC/DC converter.
Preferably, the inductance device comprises two same inductors connected in series, and the connection point of the two same inductors is the midpoint of the inductance device;
or, the inductance device is an inductance with a center tap, and the center tap is the center point of the inductance device.
Preferably, the direct current power supply connected with each optimizer is at least one photovoltaic module; or,
when the number of the parallel branches is larger than 1, the direct current power supply connected with each optimizer in at least one parallel branch is at least one photovoltaic module, and the direct current power supply connected with each optimizer in at least one parallel branch is a storage battery; the parallel branch is a branch comprising a plurality of parallel optimizer groups.
According to the alternating current-direct current hybrid photovoltaic power generation system, the optimizer groups connected with the input end of the high-voltage isolation type DC/DC converter respectively comprise at least one optimizer, MPPT control on a direct current power supply is realized by the optimizers respectively connected with the high-voltage isolation type DC/DC converter, and the high-voltage isolation type DC/DC converter does not need to carry out MPPT control and real-time voltage regulation on a connected photovoltaic panel, so that the gain range of the high-voltage isolation type DC/DC converter can take a smaller value, and the efficiency of the high-voltage isolation type DC/DC converter is further improved compared with the prior art. In addition, the isolation voltage grade between the primary side and the secondary side of the high-frequency transformer in the high-voltage isolation type DC/DC converter is greater than or equal to 10kV, so that the alternating-current and direct-current hybrid photovoltaic power generation system can be used for merging electric energy in the connected direct-current power supply into a medium-high voltage direct-current power grid, and further, the electric energy is transmitted with smaller loss.
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In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.
Fig. 1a to fig. 1e are schematic structural diagrams of five main circuits in an ac/dc hybrid photovoltaic power generation system according to an embodiment of the present invention;
FIGS. 2a to 2b are schematic diagrams of two kinds of circuits of a main circuit in a cascade module according to an embodiment of the present invention;
fig. 3a to fig. 3d are schematic diagrams of four circuits of a main circuit in a high-voltage isolated DC/DC converter according to an embodiment of the present invention.
Detailed Description
The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.
The invention provides an alternating current-direct current hybrid photovoltaic power generation system, which aims to solve the problem that an isolation type DC/DC converter in the prior art is low in efficiency.
Referring to fig. 1a to 1e, the ac/dc hybrid photovoltaic power generation system includes: a plurality of optimizer groups, a plurality of high-voltage isolated DC/DC converters 101, M upper bridge arms 201, M lower bridge arms 202, M inductance devices 102, and a filter 103, where a value of M may be determined according to a specific application environment, for example, any one of values 2 to 6 (fig. 1a to 1d show that M is 3 as an example), which is not limited herein and is within a protection scope of the present application; wherein:
one end of each upper bridge arm 201 is connected with one end of the corresponding lower bridge arm 202 through an inductance device 102;
the middle point of each inductance device 102 is connected with an alternating current power grid through a filter 103;
the other end of each upper bridge arm 201 is connected, and the connecting point is connected with the anode of a direct current power grid;
the other end of each lower bridge arm 202 is connected, and the connecting point is connected with the negative electrode of the direct current power grid;
the upper bridge arm 201 and the lower bridge arm 202 both comprise N cascade modules connected in series through an alternating current side, and N is a positive integer;
the high-voltage isolation type DC/DC converter 101 is used for performing voltage conversion on the received direct current electric energy and outputting the direct current electric energy after the voltage conversion to the corresponding cascade module;
the input end of the high-voltage isolation type DC/DC converter 101 is connected with the output end of at least one optimizer group, and when the number of the connected optimizer groups is multiple, the optimizer groups are connected in parallel to form a parallel branch;
the optimizer group comprises at least one optimizer, the output ends of the optimizers are connected in series, the two ends of the series connection are the output ends of the optimizer group, and the input end of the optimizer is connected with the direct-current power supply;
the optimizer is used to implement MPPT (Maximum Power Point Tracking) control for the connected dc Power supply.
Regarding the connection manner of the DC side of the cascade module, optionally, referring to fig. 1a and 1b, the DC side of the cascade module is connected to the output terminal of at least one high-voltage isolated DC/DC converter 101.
At the moment, the cascade module controls the ratio of the maximum value to the minimum value of the voltage of the input end of the cascade module to be less than or equal to 1.2, so that the amplitude fluctuation of the voltage of the input end is in a small range.
Alternatively, referring to fig. 1c to 1e, the dc side of the cascade module is suspended;
at the moment, a plurality of conversion units are connected in series through output ends to form converter strings, and at least one converter string is connected between the positive pole and the negative pole of the direct-current power grid; the transformation unit includes: and the high-voltage isolated DC/DC converter 101 is arranged, or at least two high-voltage isolated DC/DC converters 101 with output ends connected in parallel are arranged.
For the input end of each high-voltage isolated DC/DC converter 101 in the converter string, it can be as shown in FIG. 1c, and is respectively connected with the output end of at least one optimizer group; as shown in fig. 1d, the input ends of the high-voltage isolated DC/DC converters 101 in the converter string are connected in parallel, and the two ends after being connected in parallel are connected to the output end of at least one optimizer group; or, as shown in fig. 1e, in the converter string, the input ends of the high-voltage isolated DC/DC converters 101 in the conversion units with a plurality of output ends connected in series are connected in parallel, and the two ends after parallel connection are connected with the output end of at least one optimizer group.
Preferably, the ac/dc hybrid photovoltaic power generation system may further include: the combiner box is used for combining the outputs of the connected optimizer groups and outputting the combined direct current electric energy to the corresponding high-voltage isolation type DC/DC converter 101; FIG. 1b is an illustration of the addition of a combiner box to the situation shown in FIG. 1 a; in the case where a plurality of high-voltage isolated DC/DC converters 101 are connected in series through output terminals to form a converter string, a combiner box (not shown) having the above-described function may be added. In fig. 1b, one bus box is connected to each input terminal of the high-voltage isolated DC/DC converter 101, and a plurality of bus boxes may be connected in practical use.
In a specific actual design process, because the MPPT control function belonging to the DC/DC converter in the prior art is handed over to the corresponding optimizer, the high-voltage isolated DC/DC converter 101 does not need to perform MPPT control and real-time voltage regulation on the connected photovoltaic panel, so that the gain range thereof, i.e., the quotient of the maximum gain value of the ratio of the output voltage to the input voltage divided by the minimum gain value of the ratio of the output voltage to the input voltage, can be designed to be smaller, and further the efficiency of the high-voltage isolated DC/DC converter 101 is further improved compared with the prior art, thereby improving the system efficiency, and the maximum efficiency is more than 98.5%.
Specifically, due to the use of the optimizer, the gain range of the high-voltage isolated DC/DC converter 101 can be greater than or equal to 1 and less than 1.5, for example, the gain range can be designed to be less than 1.5 times, and even the high-voltage isolated DC/DC converter 101 can be designed to have a fixed gain for open-loop control, so that the control function of the high-voltage isolated DC/DC converter 101 is simplified, and the design difficulty of the high-voltage isolated DC/DC converter 101 is reduced. Meanwhile, the problem of component series-parallel mismatch existing in the single MPPT control corresponding to the original direct current bus is solved by the application of the optimizer, the component-level MPPT control is realized, the system power generation capacity is improved, and each photovoltaic component can be monitored; in addition, the pressure of the high-frequency transformer in the photovoltaic high-voltage isolated DC/DC converter 101 can be reduced. And the whole system scheme improves the power density compared with the conventional system.
It is worth mentioning that, with the development of technology, future power systems will include situations where a dc grid and an ac grid coexist, which means that future photovoltaic power generation systems may need to connect the ac grid and the dc grid at the same time; as is well known, a medium-high voltage dc power grid can transmit electric energy with less loss than a medium-high voltage ac power grid, and is more suitable for transmitting electric energy over a long distance. Therefore, in the field of new energy power generation, a medium-high voltage direct current power grid and/or a medium-high voltage alternating current-direct current hybrid power grid are increasingly adopted for electric energy transmission in the future; however, the prior art solutions are generally only capable of connecting one of the ac and low-voltage dc networks.
On one hand, the ac/dc hybrid photovoltaic power generation system provided by this embodiment uses the above connection manner by the modular multilevel cascade module, so that the whole photovoltaic power generation system can be connected to an ac power grid and a dc power grid at the same time; on the other hand, the high-voltage isolation type DC/DC converter 101 in the present embodiment includes: the isolation voltage grade between the primary side and the secondary side of the high-frequency transformer is more than or equal to 10kV, so that the alternating current-direct current hybrid photovoltaic power generation system can be used for merging electric energy in a connected direct current power supply into a medium-high voltage power grid; the voltage grade between the primary side and the secondary side can be set according to specific application environments so as to adapt to different photovoltaic system applications; it is not specifically limited herein and is within the scope of the present application.
Another embodiment of the present invention further provides a specific ac/dc hybrid photovoltaic power generation system, based on the above embodiment and fig. 1a to 1 e:
optionally, the main circuit of the cascaded module is a half-bridge topology (as shown in fig. 2 a) or a full-bridge topology (as shown in fig. 2 b).
Optionally, the main circuit of the high-voltage isolation type DC/DC converter 101 is any one of an LC series resonance topology (as shown in fig. 3 a), an LLC series resonance topology (as shown in fig. 3 b), a dual-active DC/DC topology (as shown in fig. 3 c), and a full-bridge DC/DC topology (as shown in fig. 3 d); fig. 3a to 3d are only examples of two-level topologies, and are not limited thereto, in practical applications, the LC series resonance topology, the LLC series resonance topology, and the dual-active DC/DC topology may also be three-level topologies, and of course, other topologies may be selected according to the specific application environment, and the topologies are not specifically limited herein, and all are within the protection scope of the present application.
Optionally, the optimizer is a non-isolated DC/DC converter.
Optionally, the inductance device 102 includes two identical inductances connected in series, and a connection point of the series connection is a midpoint of the inductance device 102;
alternatively, inductive device 102 is an inductor with a center tap, and the midpoint tap is the midpoint of inductive device 102.
Optionally, the dc power source connected to each optimizer is at least one photovoltaic module (fig. 1a to 1e show dc power sources as one photovoltaic module); or,
when the number of the parallel branches is larger than 1, the direct current power supply connected with each optimizer in at least one parallel branch is at least one photovoltaic module, and the direct current power supply connected with each optimizer in at least one parallel branch is a storage battery; so that the alternating current-direct current hybrid photovoltaic power generation system has a direct current energy storage function; the parallel branch comprises a plurality of parallel optimizer groups; it is not specifically limited herein, and is within the scope of the present application, depending on the particular environment in which it is used.
In addition, in practical applications, the filter 103 may be: any one of an L filter, an LC filter, an LCL filter and a high-order filter; of course, other topologies may be selected according to the specific application environment, and are not specifically limited herein and are within the scope of the present application.
In practical application, the ac/dc hybrid photovoltaic power generation system should further include: the system comprises a system communication module, a system detection module, a system auxiliary power supply and at least one system controller;
the system controller is used for realizing grid-connected control on each cascade module;
the system detection module is used for detecting the voltage, the current, the temperature and the electric arc of the alternating current-direct current hybrid photovoltaic power generation system;
the system communication module is used for realizing communication between the system controller and other controllers and the outside;
the system auxiliary power supply is used for supplying power to the system communication module, the system detection module and the system controller.
Preferably, the cascade module comprises: the device comprises a main circuit, a communication module, a detection module, an auxiliary power supply and at least one controller;
the controller is used for controlling the action of a switching tube in the main circuit;
the detection module is used for realizing the voltage, current, temperature and arc detection of the cascade module;
the communication module is used for realizing the communication between the controller and the system controller;
the auxiliary power supply is used for supplying power for the communication module, the detection module and the controller.
Preferably, the high-voltage isolation type DC/DC converter 101 includes: the device comprises a main circuit, a communication module, a detection module, an auxiliary power supply and at least one controller;
the controller is used for detecting and outputting the state of the high-voltage isolation type DC/DC converter 101;
the detection module is used for detecting the voltage, the current, the temperature and the electric arc of the high-voltage isolation type DC/DC converter 101;
the communication module is used for realizing communication between the controller and a system controller or a cascade module connected with the high-voltage isolation type DC/DC converter 101;
the auxiliary power supply is used for supplying power for the communication module, the detection module and the controller.
In a Specific practical Application, the system controller of the ac/DC hybrid photovoltaic power generation system, the controller in the high-voltage isolated DC/DC converter 101, and the controller of the cascade module may be multiple ones, and may be implemented by any one of a CPU (central processing Unit), an MCU (micro controller Unit), a DSP (digital signal Processor), an ARM Processor, an FPGA (Field Programmable gate array), a CPLD (Complex Programmable Logic Device), and an ASIC (Application Specific integrated circuit) chip, which are not specifically limited herein depending on the Specific Application environment, and are all within the protection scope of the present Application.
The specific implementation forms of the communication module, the detection module and the auxiliary power supply may all be determined according to the environment, and are not specifically limited herein and are within the scope of the present application.
The rest of the principle is the same as the above embodiments, and is not described in detail here.
The embodiments of the invention are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments can be referred to each other. The device disclosed by the embodiment corresponds to the method disclosed by the embodiment, so that the description is simple, and the relevant points can be referred to the method part for description.
The foregoing is merely a preferred embodiment of the invention and is not intended to limit the invention in any manner. Although the present invention has been described with reference to the preferred embodiments, it is not intended to be limited thereto. Those skilled in the art can make numerous possible variations and modifications to the present teachings, or modify equivalent embodiments to equivalent variations, without departing from the scope of the present teachings, using the methods and techniques disclosed above. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention are still within the scope of the protection of the technical solution of the present invention, unless the contents of the technical solution of the present invention are departed.
Claims (11)
1. An alternating current and direct current hybrid photovoltaic power generation system, comprising: the system comprises a plurality of optimizer groups, a plurality of high-voltage isolated DC/DC converters, M upper bridge arms, M lower bridge arms, M inductance devices and a filter; wherein:
one end of each upper bridge arm is connected with one end of the corresponding lower bridge arm through one inductance device;
the middle point of each inductance device is connected with an alternating current power grid through the filter;
the other end of each upper bridge arm is connected, and the connecting point is connected with the anode of a direct current power grid;
the other end of each lower bridge arm is connected, and a connecting point is connected with the negative electrode of the direct current power grid;
the upper bridge arm and the lower bridge arm respectively comprise N cascade modules which are connected in series through an alternating current side, and N is a positive integer;
the high-voltage isolation type DC/DC converter is used for performing voltage conversion on the received direct current electric energy and outputting the direct current electric energy after the voltage conversion to the corresponding cascade module;
the high-voltage isolation type DC/DC converter comprises: the isolation voltage grade between the primary side and the secondary side of the high-frequency transformer is more than or equal to 10 kV;
the input end of the high-voltage isolation type DC/DC converter is connected with the output end of at least one optimizer group;
the optimizer group comprises at least one optimizer, the output ends of the optimizers are connected in series, the two ends of the series connection are the output ends of the optimizer group, and the input end of the optimizer is connected with a direct-current power supply;
the optimizer is used for realizing Maximum Power Point Tracking (MPPT) control on a connected direct current power supply.
2. The AC-DC hybrid photovoltaic power generation system according to claim 1, wherein the DC side of the cascade module is connected to the output of at least one of the high-voltage isolated DC/DC converters.
3. The alternating current-direct current hybrid photovoltaic power generation system according to claim 1, wherein the cascade module controls the ratio of the maximum value to the minimum value of the voltage at the input end of the cascade module to be less than or equal to 1.2.
4. The ac-dc hybrid photovoltaic power generation system according to claim 1, wherein the dc side of the cascade module is floating;
the plurality of conversion units are connected in series through output ends to form converter strings, and at least one converter string is connected between the positive pole and the negative pole of the direct-current power grid; the transformation unit includes: one high-voltage isolation type DC/DC converter or at least two high-voltage isolation type DC/DC converters with output ends connected in parallel.
5. The alternating current-direct current hybrid photovoltaic power generation system according to claim 4, wherein the input end of each high-voltage isolated DC/DC converter is connected with the output end of at least one optimizer group corresponding to each high-voltage isolated DC/DC converter; or,
the input ends of the high-voltage isolated DC/DC converters in the converter string are connected in parallel, and the two ends after being connected in parallel are connected with the output end of at least one optimizer group; in the alternative to this, either,
in the converter string, the input ends of the high-voltage isolation type DC/DC converters in the conversion units with a plurality of output ends connected in series are connected in parallel, and the two ends after being connected in parallel are connected with the output end of at least one optimizer group.
6. The ac-dc hybrid photovoltaic power generation system according to any one of claims 1-5, further comprising: and the combiner box is used for combining the outputs of the connected optimizer groups and outputting the combined direct current electric energy to the corresponding high-voltage isolation type DC/DC converter.
7. The AC-DC hybrid photovoltaic power generation system according to any one of claims 1-5, wherein the main circuit of the cascade module is in a half-bridge topology or a full-bridge topology.
8. The AC-DC hybrid photovoltaic power generation system according to any one of claims 1-5, wherein the main circuit of the high-voltage isolated DC/DC converter is any one of an LC series resonance topology, an LLC series resonance topology, a dual-active DC/DC topology and a full-bridge DC/DC topology.
9. The AC-DC hybrid photovoltaic power generation system according to any one of claims 1-5, wherein the optimizer is a non-isolated DC/DC converter.
10. The alternating current-direct current hybrid photovoltaic power generation system according to any one of claims 1 to 5, wherein the inductance device comprises two identical inductances connected in series, and the connection point of the two identical inductances connected in series is the midpoint of the inductance device;
or, the inductance device is an inductance with a center tap, and the center tap is the center point of the inductance device.
11. The alternating current-direct current hybrid photovoltaic power generation system according to any one of claims 1 to 5, wherein the direct current power supply connected to each optimizer is at least one photovoltaic module; or,
when the number of the parallel branches is larger than 1, the direct current power supply connected with each optimizer in at least one parallel branch is at least one photovoltaic module, and the direct current power supply connected with each optimizer in at least one parallel branch is a storage battery; the parallel branch is a branch comprising a plurality of parallel optimizer groups.
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Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN101795066A (en) * | 2009-11-24 | 2010-08-04 | 南京航空航天大学 | Interleaved switching method of Buck-Boost convertor and realization circuit thereof |
WO2016182931A1 (en) * | 2015-05-08 | 2016-11-17 | Sunculture Solar, Inc. | Solar power generation, distribution, and communication system |
CN106953525A (en) * | 2017-01-18 | 2017-07-14 | 上海交通大学 | Impedance type multimode tandem photovoltaic DC booster converter |
CN107104461A (en) * | 2017-05-17 | 2017-08-29 | 阳光电源股份有限公司 | A kind of photovoltaic generating system |
CN107612405A (en) * | 2017-10-30 | 2018-01-19 | 阳光电源股份有限公司 | A kind of photovoltaic solid-state transformer |
CN107706941A (en) * | 2017-10-19 | 2018-02-16 | 江苏固德威电源科技股份有限公司 | Solar energy optimizes system |
CN107834602A (en) * | 2017-11-23 | 2018-03-23 | 兰州理工大学 | A kind of micro- source half-bridge current transformer tandem type micro-grid system |
-
2018
- 2018-05-25 CN CN201810515988.3A patent/CN110535171B/en active Active
Patent Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN101795066A (en) * | 2009-11-24 | 2010-08-04 | 南京航空航天大学 | Interleaved switching method of Buck-Boost convertor and realization circuit thereof |
WO2016182931A1 (en) * | 2015-05-08 | 2016-11-17 | Sunculture Solar, Inc. | Solar power generation, distribution, and communication system |
CN106953525A (en) * | 2017-01-18 | 2017-07-14 | 上海交通大学 | Impedance type multimode tandem photovoltaic DC booster converter |
CN107104461A (en) * | 2017-05-17 | 2017-08-29 | 阳光电源股份有限公司 | A kind of photovoltaic generating system |
CN107706941A (en) * | 2017-10-19 | 2018-02-16 | 江苏固德威电源科技股份有限公司 | Solar energy optimizes system |
CN107612405A (en) * | 2017-10-30 | 2018-01-19 | 阳光电源股份有限公司 | A kind of photovoltaic solid-state transformer |
CN107834602A (en) * | 2017-11-23 | 2018-03-23 | 兰州理工大学 | A kind of micro- source half-bridge current transformer tandem type micro-grid system |
Non-Patent Citations (3)
Title |
---|
王坤 等: "光伏系统分布式功率的优化", 《江南大学学报(自然科学版)》 * |
王志彬: "光伏微逆变器和优化器的研究", 《中国优秀硕士学位论文全文数据库 工程科技II辑》 * |
蔡晓宇: "光伏集成模块发电系统研究", 《中国优秀硕士学位论文全文数据库 工程科技II辑》 * |
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