CN114142519A - Anti-reflux method and device for photovoltaic power supply system, terminal and storage medium - Google Patents
Anti-reflux method and device for photovoltaic power supply system, terminal and storage medium Download PDFInfo
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- CN114142519A CN114142519A CN202111265675.5A CN202111265675A CN114142519A CN 114142519 A CN114142519 A CN 114142519A CN 202111265675 A CN202111265675 A CN 202111265675A CN 114142519 A CN114142519 A CN 114142519A
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/38—Arrangements for parallely feeding a single network by two or more generators, converters or transformers
- H02J3/381—Dispersed generators
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
- H02H7/26—Sectionalised protection of cable or line systems, e.g. for disconnecting a section on which a short-circuit, earth fault, or arc discharge has occured
- H02H7/28—Sectionalised protection of cable or line systems, e.g. for disconnecting a section on which a short-circuit, earth fault, or arc discharge has occured for meshed systems
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/38—Arrangements for parallely feeding a single network by two or more generators, converters or transformers
- H02J3/46—Controlling of the sharing of output between the generators, converters, or transformers
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Abstract
The invention provides a method, a device, a terminal and a storage medium for preventing a reverse flow of a photovoltaic power supply system, wherein the method comprises the following steps: acquiring electric energy data of the low-voltage power grid side in real time; subtracting the electric energy data at the current moment from the electric energy data at the previous moment to obtain an electric energy difference value; if the electric energy difference value is larger than a first preset threshold value, the photovoltaic inverter is adjusted based on the electric energy difference value so as to reduce the output power of the photovoltaic inverter; if the electric energy difference value is larger than a second preset threshold value, controlling the photovoltaic inverter to stop; if the electric energy difference value is larger than a third preset threshold value, controlling the contactor to be disconnected; the first preset threshold is smaller than the second preset threshold, and the second preset threshold is smaller than the third preset threshold. Through the scheme, the anti-backflow control can be performed according to the size of the local load sudden drop when the local load suddenly drops, so that the anti-backflow response speed is improved, and the benefits of photovoltaic power generation users are guaranteed.
Description
Technical Field
The invention relates to the technical field of photovoltaic power supply, in particular to a method, a device, a terminal and a storage medium for preventing backflow of a photovoltaic power supply system.
Background
Photovoltaic power generation is a technology of directly converting light energy into electric energy by using the photovoltaic effect of a semiconductor interface. In order to save electricity charges, many users adopt photovoltaic devices to supply power to local loads, at the moment, a power supply circuit diagram is shown in fig. 1, a photovoltaic module is respectively connected with a low-voltage grid end and the local loads through a photovoltaic inverter, and when the local loads suddenly reduce power, the output electric energy of the photovoltaic module flows back to a power grid, so that the current of the power grid flows back.
At present, the reverse flow is prevented by adopting a mode of regulating the output power of the photovoltaic inverter when the load suddenly drops in the field, but the method has a slow response speed and an undesirable reverse flow prevention effect.
Disclosure of Invention
In view of this, the invention provides a method, a device, a terminal and a storage medium for preventing a reverse current of a photovoltaic power supply system, which can solve the problem of slow response speed of a reverse current prevention method in the prior art.
In a first aspect, an embodiment of the present invention provides a method for preventing a reverse current of a photovoltaic power supply system, where the photovoltaic power supply system includes a photovoltaic inverter and a contactor; the photovoltaic inverter is connected with the first end of the contactor, and the second end of the contactor is respectively used for connecting a low-voltage power grid and a local load;
the method comprises the following steps:
acquiring electric energy data of the low-voltage power grid side in real time;
subtracting the electric energy data at the current moment from the electric energy data at the previous moment to obtain an electric energy difference value;
if the electric energy difference value is larger than a first preset threshold value, the photovoltaic inverter is adjusted based on the electric energy difference value so as to reduce the output power of the photovoltaic inverter;
if the electric energy difference value is larger than a second preset threshold value, controlling the photovoltaic inverter to stop;
if the electric energy difference value is larger than a third preset threshold value, controlling the contactor to be disconnected;
the first preset threshold is smaller than the second preset threshold, and the second preset threshold is smaller than the third preset threshold.
In a second aspect, an embodiment of the present invention provides an anti-backflow device for a photovoltaic power supply system, where the photovoltaic power supply system includes a photovoltaic inverter and a contactor; the photovoltaic inverter is connected with the first end of the contactor, and the second end of the contactor is respectively used for connecting a low-voltage power grid and a local load;
the device comprises:
the electric energy data acquisition module is used for acquiring electric energy data of the low-voltage power grid side in real time;
the difference value calculation module is used for subtracting the electric energy data at the current moment from the electric energy data at the previous moment to obtain an electric energy difference value;
the first anti-reflux module is used for adjusting the photovoltaic inverter based on the electric energy difference value to reduce the output power of the photovoltaic inverter if the electric energy difference value is larger than a first preset threshold value;
the second anti-reflux module is used for controlling the photovoltaic inverter to stop if the electric energy difference value is larger than a second preset threshold value;
the third anti-backflow module is used for controlling the contactor to be disconnected if the electric energy difference value is larger than a third preset threshold value;
the first preset threshold is smaller than the second preset threshold, and the second preset threshold is smaller than the third preset threshold.
In a third aspect, an embodiment of the present invention provides a terminal, which includes a memory, a processor, and a computer program stored in the memory and executable on the processor, where the processor, when executing the computer program, implements the steps of the method according to any one of the possible implementation manners of the first aspect.
In a fourth aspect, the present invention provides a computer-readable storage medium, where a computer program is stored, and when the computer program is executed by a processor, the computer program implements the steps of the method according to any one of the possible implementation manners of the first aspect.
Compared with the prior art, the embodiment of the invention has the following beneficial effects: according to the embodiment of the invention, the electric energy data of the low-voltage power grid side is obtained; subtracting the electric energy data at the current moment from the electric energy data at the previous moment to obtain an electric energy difference value; if the electric energy difference value is larger than a first preset threshold value, the photovoltaic inverter is adjusted based on the electric energy difference value so as to reduce the output power of the photovoltaic inverter; if the electric energy difference value is larger than a second preset threshold value, controlling the photovoltaic inverter to stop; if the electric energy difference value is larger than a third preset threshold value, controlling the contactor to be disconnected; the first preset threshold is smaller than the second preset threshold, and the second preset threshold is smaller than the third preset threshold. Through the scheme, the anti-backflow control can be performed according to the size of the local load sudden drop in a grading mode when the local load sudden drop occurs, so that the anti-backflow response speed is improved, and the benefits of photovoltaic power generation users are guaranteed.
Drawings
In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the embodiments or the prior art descriptions will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without inventive exercise.
Fig. 1 is a schematic circuit connection diagram of a photovoltaic power supply system provided by an embodiment of the invention;
fig. 2 is a flowchart of an implementation of a method for preventing backflow in a photovoltaic power supply system according to an embodiment of the present invention;
fig. 3 is a schematic structural diagram of a backflow prevention device of a photovoltaic power supply system according to an embodiment of the present invention;
fig. 4 is a schematic diagram of a terminal according to an embodiment of the present invention.
Detailed Description
In the following description, for purposes of explanation and not limitation, specific details are set forth, such as particular system structures, techniques, etc. in order to provide a thorough understanding of the embodiments of the invention. It will be apparent, however, to one skilled in the art that the present invention may be practiced in other embodiments that depart from these specific details. In other instances, detailed descriptions of well-known systems, devices, circuits, and methods are omitted so as not to obscure the description of the present invention with unnecessary detail.
In order to make the objects, technical solutions and advantages of the present invention more apparent, the following description is made by way of specific embodiments with reference to the accompanying drawings.
In the present embodiment, as shown in fig. 1, fig. 1 shows a circuit connection schematic diagram of a photovoltaic power supply system, as shown in fig. 1, the photovoltaic power supply system includes a photovoltaic module, a photovoltaic inverter and a contactor; the output end of the photovoltaic module is connected with the first end of the photovoltaic inverter, the second end of the photovoltaic inverter is connected with the first end of the contactor, and the second end of the contactor is respectively used for connecting a low-voltage power grid and a local load.
Specifically, the execution main body (terminal) of the present embodiment is a graded anti-backflow controller in the graded anti-backflow control cabinet in fig. 1, and the graded anti-backflow controller is respectively connected with the photovoltaic inverter and the contactor. The contactor may be located in a staged anti-reflux control cabinet.
As shown in fig. 2, fig. 2 shows an implementation flow of an anti-backflow method for a photovoltaic power supply system, and a process thereof is detailed as follows:
s101: and acquiring the electric energy data of the low-voltage power grid side in real time.
In the present embodiment, the power data may be any one of power and current. When the electric energy data is power, the specific implementation process of S101 in fig. 2 includes:
acquiring voltage and current of the low-voltage power grid side in real time;
and calculating the power of the low-voltage power grid side according to the voltage and the current of the low-voltage power grid side.
In this embodiment, the hierarchical anti-reflux controller obtains the voltage on the low-voltage power grid side through the voltage transformer, collects the current on the low-voltage power grid side through the current transformer, and then multiplies the voltage and the current to obtain the power on the low-voltage power grid side.
Specifically, under normal conditions, both the photovoltaic inverter and the low-voltage grid serve as power supplies to supply power to the local load, when the local load suddenly drops, the power output by the photovoltaic inverter is unchanged, the power output by the photovoltaic inverter is transmitted to the low-voltage grid, and at this time, the low-voltage grid side is equivalent to the other load of the photovoltaic inverter, and the current on the low-voltage grid side is caused to flow reversely.
S102: and subtracting the electric energy data at the current moment from the electric energy data at the previous moment to obtain an electric energy difference value.
S103: and if the electric energy difference value is larger than a first preset threshold value, adjusting the photovoltaic inverter based on the electric energy difference value so as to reduce the output power of the photovoltaic inverter.
In order to avoid the influence of the output power of the photovoltaic inverter on the voltage of the low-voltage power grid when the output power flows to the low-voltage power grid side. In this embodiment, the electric energy data of the low-voltage power grid side is monitored in real time, the electric energy data of the current moment is subtracted from the electric energy data of the previous moment to obtain an electric energy difference value, and when the electric energy difference value of two adjacent moments is large, the hierarchical anti-backflow control needs to be started.
Specifically, when the electric energy difference value between the current moment and the previous moment is greater than a first preset threshold value, the grading anti-reverse-flow controller controls the photovoltaic inverter to reduce the output power. The first preset threshold value can be set by a user, when the electric energy data is power, the first preset threshold value is also power, and the setting range of the first preset threshold value can be 15KW-35 KW. Preferably, the first preset threshold may be set to 20 KW.
S104: and if the electric energy difference value is larger than a second preset threshold value, controlling the photovoltaic inverter to stop.
Specifically, the second preset threshold may also be set by the user, when the electric energy data is power, the second preset threshold is also power, and the setting range of the second preset threshold may be 45KW to 70 KW. Preferably, the second preset threshold may be set to 50 KW.
In this embodiment, the second preset threshold is greater than the first preset threshold, and when the electric energy difference is greater than the second preset threshold, it indicates that the local load drop is large, and it is difficult to quickly respond by controlling the output power of the photovoltaic inverter, and at this time, the photovoltaic inverter can be directly controlled to stop, so that the anti-backflow control is accelerated.
S105: and if the electric energy difference value is larger than a third preset threshold value, controlling the contactor to be disconnected.
The first preset threshold is smaller than the second preset threshold, and the second preset threshold is smaller than the third preset threshold.
In this embodiment, the third preset threshold is greater than the second preset threshold, the third preset threshold may also be set by the user, when the electric energy data is power, the third preset threshold is also power, and the setting range of the third preset threshold may be 90KW to 120 KW. Preferably, the third preset threshold may be set to 100 KW. When the electric energy difference value is larger than a third preset threshold value, the local load sudden drop is very large, and at the moment, the photovoltaic side and the power grid side can be directly disconnected by a method of disconnecting the contactor, so that the anti-backflow control is realized more quickly.
In this embodiment, when the electric energy data is a current, the first preset threshold, the second preset threshold and the third preset threshold are current values, and the current values of the first preset threshold, the second preset threshold and the third preset threshold may be set based on a user requirement.
As can be seen from the above embodiments, in the embodiments of the present invention, the electric energy data of the low voltage grid side is obtained; subtracting the electric energy data at the current moment from the electric energy data at the previous moment to obtain an electric energy difference value; if the electric energy difference value is larger than a first preset threshold value, the photovoltaic inverter is adjusted based on the electric energy difference value so as to reduce the output power of the photovoltaic inverter; if the electric energy difference value is larger than a second preset threshold value, controlling the photovoltaic inverter to stop; if the electric energy difference value is larger than a third preset threshold value, controlling the contactor to be disconnected; the first preset threshold is smaller than the second preset threshold, and the second preset threshold is smaller than the third preset threshold. Through the scheme, the anti-backflow control can be performed according to the size of the local load sudden drop in a grading mode when the local load sudden drop occurs, so that the anti-backflow response speed is improved, and the benefits of photovoltaic power generation users are guaranteed.
In one embodiment, the specific implementation flow of S103 includes:
if the electric energy difference value is larger than the first preset threshold value, generating a power reduction instruction based on the electric energy difference value, and sending the power reduction instruction to the photovoltaic inverter through a digital communication interface, so that the photovoltaic inverter adjusts the duty ratio of an internal switching tube to reduce the output power of the photovoltaic inverter.
In this embodiment, the data communication interface may be an RS485 communication interface, and when the electric energy difference is greater than the first preset threshold, the hierarchical anti-backflow controller sends a power reduction instruction to the photovoltaic inverter through the RS485 communication interface, and after receiving the power reduction instruction, the photovoltaic inverter reduces the duty ratio of the switching tube driving signal according to the power reduction instruction, thereby reducing the output power of the photovoltaic inverter.
Specifically, a power reduction command is generated based on the power difference value, the power reduction command being used to adjust the output power of the photovoltaic inverter to a range that does not exceed the local load.
In one embodiment, the specific implementation flow of S104 in fig. 2 includes:
and if the electric energy difference value is larger than the second preset threshold value, controlling the photovoltaic inverter to stop through a dry contact.
The dry contact mentioned in this embodiment is a dry contact for controlling the start and stop of the photovoltaic inverter, and because the response speed of the dry contact communication mode is faster than that of the digital communication mode, the dry contact is adopted to control the photovoltaic inverter to stop when the electric energy difference is greater than the second preset threshold, so that the backflow control can be more quickly realized, and the photovoltaic output power is prevented from being transmitted to the power grid.
In one embodiment, the photovoltaic inverter includes a plurality; another implementation flow of S104 in fig. 2 includes:
if the electric energy difference value is larger than the second preset threshold value, determining a first quantity according to the electric energy difference value;
and controlling the first number of photovoltaic inverters to stop through the dry contact.
In an embodiment of the invention, when there are a plurality of photovoltaic inverters, the photovoltaic inverter can be controlled by adopting the anti-backflow control method corresponding to the first preset threshold and the anti-backflow control method corresponding to the second preset threshold, which both need to be calculated, and the response speed is slow, and when the electric energy difference is greater than the third preset threshold, it indicates that the local load sudden drop degree is very heavy, and the connection between the photovoltaic power generation system and the low-voltage power grid needs to be cut off immediately, so that at this time, the plurality of photovoltaic inverters on the right side in fig. 2 can be directly disconnected from the low-voltage power grid side by disconnecting the contactor, so as to realize the quick response of the anti-backflow control, and ensure that the output power of the photovoltaic inverters cannot be transmitted to the low-voltage power grid, thereby ensuring the voltage stability of the low-voltage power grid side, and protecting the benefits of photovoltaic power generation users.
In one embodiment, the power data includes power, and the power difference includes a power difference; after S104, the method provided in this embodiment further includes:
controlling the photovoltaic inverter to start and increase the output power from zero until a target power is reached, wherein the target power is obtained by subtracting the power difference value from the first power; the first power is the output power of the photovoltaic inverter before the contactor is disconnected.
In one embodiment, the power data includes power, and the power difference includes a power difference; after S105, the method provided in this embodiment further includes:
closing the contactor;
controlling the photovoltaic inverter to start and increase the output power from zero until a target power is reached, wherein the target power is obtained by subtracting the power difference value from the first power; the first power is the output power of the photovoltaic inverter before the contactor is disconnected.
According to the embodiment, the power generation benefit of the photovoltaic power generation system can be ensured on the basis of preventing countercurrent, and the waste of electric energy is avoided, so that the benefit of photovoltaic power generation users is further ensured.
It should be understood that, the sequence numbers of the steps in the foregoing embodiments do not imply an execution sequence, and the execution sequence of each process should be determined by its function and inherent logic, and should not constitute any limitation to the implementation process of the embodiments of the present invention.
The following are embodiments of the apparatus of the invention, reference being made to the corresponding method embodiments described above for details which are not described in detail therein.
Fig. 3 shows a schematic structural diagram of a backflow prevention device of a photovoltaic power supply system provided by an embodiment of the present invention, and for convenience of description, only parts related to the embodiment of the present invention are shown, which are detailed as follows:
as shown in fig. 3, the photovoltaic power supply system includes a photovoltaic inverter and a contactor; the photovoltaic inverter is connected with the first end of the contactor, and the second end of the contactor is respectively used for connecting a low-voltage power grid and a local load; the backflow prevention device 100 of the photovoltaic power supply system includes:
the electric energy data acquisition module 110 is configured to acquire electric energy data of the low voltage power grid side in real time;
a difference value calculating module 120, configured to subtract the electric energy data at the current moment from the electric energy data at the previous moment to obtain an electric energy difference value;
the first anti-backflow module 130 is configured to adjust the photovoltaic inverter based on the electric energy difference value if the electric energy difference value is greater than a first preset threshold value, so as to reduce the output power of the photovoltaic inverter;
the second anti-reflux module 140 is configured to control the photovoltaic inverter to stop if the electric energy difference is greater than a second preset threshold;
the third anti-reflux module 150 is configured to control the contactor to be turned off if the electric energy difference is greater than a third preset threshold;
the first preset threshold is smaller than the second preset threshold, and the second preset threshold is smaller than the third preset threshold.
In one embodiment, the first backflow prevention module 130 is specifically configured to:
if the electric energy difference value is larger than the first preset threshold value, generating a power reduction instruction based on the electric energy difference value, and sending the power reduction instruction to the photovoltaic inverter through a digital communication interface, so that the photovoltaic inverter adjusts the duty ratio of an internal switching tube to reduce the output power of the photovoltaic inverter.
In one embodiment, the second backflow prevention module 140 is specifically configured to:
and if the electric energy difference value is larger than the second preset threshold value, controlling the photovoltaic inverter to stop through a dry contact.
In one embodiment, the photovoltaic inverter includes a plurality; the second backflow prevention module 140 is specifically configured to:
if the electric energy difference value is larger than the second preset threshold value, determining a first quantity according to the electric energy difference value;
and controlling the first number of photovoltaic inverters to stop through the dry contact.
In one embodiment, the power data includes power, and the power data acquisition module 110 includes:
acquiring voltage and current of the low-voltage power grid side in real time;
and calculating the power of the low-voltage power grid side according to the voltage and the current of the low-voltage power grid side.
In one embodiment, the power data includes power, and the power difference includes a power difference; the anti-reflux device 100 of the photovoltaic power supply system further comprises a first inverter recovery module for:
controlling the photovoltaic inverter to start and increase the output power from zero until a target power is reached, wherein the target power is obtained by subtracting the power difference value from the first power; the first power is the output power of the photovoltaic inverter before the contactor is disconnected.
In one embodiment, the power data includes power, and the power difference includes a power difference; the anti-reflux device 100 of the photovoltaic power supply system further comprises a second inverter recovery module for:
closing the contactor;
controlling the photovoltaic inverter to start and increase the output power from zero until a target power is reached, wherein the target power is obtained by subtracting the power difference value from the first power; the first power is the output power of the photovoltaic inverter before the contactor is disconnected.
As can be seen from the above embodiments, in the embodiments of the present invention, the electric energy data of the low voltage grid side is obtained; subtracting the electric energy data at the current moment from the electric energy data at the previous moment to obtain an electric energy difference value; if the electric energy difference value is larger than a first preset threshold value, the photovoltaic inverter is adjusted based on the electric energy difference value so as to reduce the output power of the photovoltaic inverter; if the electric energy difference value is larger than a second preset threshold value, controlling the photovoltaic inverter to stop; if the electric energy difference value is larger than a third preset threshold value, controlling the contactor to be disconnected; the first preset threshold is smaller than the second preset threshold, and the second preset threshold is smaller than the third preset threshold. Through the scheme, the anti-backflow control can be performed according to the size of the local load sudden drop in a grading mode when the local load sudden drop occurs, so that the anti-backflow response speed is improved, and the benefits of photovoltaic power generation users are guaranteed.
Fig. 4 is a schematic diagram of a terminal according to an embodiment of the present invention. As shown in fig. 4, the terminal 4 of this embodiment includes: a processor 40, a memory 41 and a computer program 42 stored in said memory 41 and executable on said processor 40. The processor 40, when executing the computer program 42, implements the steps in the above-mentioned embodiments of the anti-backflow method for the photovoltaic power supply system, such as the steps 101 to 105 shown in fig. 2. Alternatively, the processor 40, when executing the computer program 42, implements the functions of each module/unit in each device embodiment described above, for example, the functions of the units 110 to 150 shown in fig. 3.
Illustratively, the computer program 42 may be partitioned into one or more modules/units that are stored in the memory 41 and executed by the processor 40 to implement the present invention. The one or more modules/units may be a series of computer program instruction segments capable of performing specific functions, which are used to describe the execution of the computer program 42 in the terminal 4.
The terminal 4 may include, but is not limited to, a processor 40, a memory 41. Those skilled in the art will appreciate that fig. 4 is only an example of a terminal 4 and does not constitute a limitation of terminal 4 and may include more or less components than those shown, or some components in combination, or different components, for example, the terminal may also include input output devices, network access devices, buses, etc.
The Processor 40 may be a Central Processing Unit (CPU), other general purpose Processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) or other Programmable logic device, discrete Gate or transistor logic, discrete hardware components, etc. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like.
The memory 41 may be an internal storage unit of the terminal 4, such as a hard disk or a memory of the terminal 4. The memory 41 may also be an external storage device of the terminal 4, such as a plug-in hard disk, a Smart Media Card (SMC), a Secure Digital (SD) Card, a Flash memory Card (Flash Card) and the like provided on the terminal 4. Further, the memory 41 may also include both an internal storage unit and an external storage device of the terminal 4. The memory 41 is used for storing the computer program and other programs and data required by the terminal. The memory 41 may also be used to temporarily store data that has been output or is to be output.
It will be apparent to those skilled in the art that, for convenience and brevity of description, only the above-mentioned division of the functional units and modules is illustrated, and in practical applications, the above-mentioned function distribution may be performed by different functional units and modules according to needs, that is, the internal structure of the apparatus is divided into different functional units or modules to perform all or part of the above-mentioned functions. Each functional unit and module in the embodiments may be integrated in one processing unit, or each unit may exist alone physically, or two or more units are integrated in one unit, and the integrated unit may be implemented in a form of hardware, or in a form of software functional unit. In addition, specific names of the functional units and modules are only for convenience of distinguishing from each other, and are not used for limiting the protection scope of the present application. The specific working processes of the units and modules in the system may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.
In the above embodiments, the descriptions of the respective embodiments have respective emphasis, and reference may be made to the related descriptions of other embodiments for parts that are not described or illustrated in a certain embodiment.
Those of ordinary skill in the art will appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention.
In the embodiments provided in the present invention, it should be understood that the disclosed apparatus/terminal and method may be implemented in other ways. For example, the above-described apparatus/terminal embodiments are merely illustrative, and for example, the division of the modules or units is only one logical division, and there may be other divisions when actually implemented, for example, a plurality of units or components may be combined or may be integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices or units, and may be in an electrical, mechanical or other form.
The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.
In addition, functional units in the embodiments of the present invention may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit. The integrated unit can be realized in a form of hardware, and can also be realized in a form of a software functional unit.
The integrated modules/units, if implemented in the form of software functional units and sold or used as separate products, may be stored in a computer readable storage medium. Based on such understanding, all or part of the flow in the method of the above embodiments may be implemented by a computer program, which may be stored in a computer readable storage medium, and when the computer program is executed by a processor, the steps of the above embodiments of the backflow prevention method for the photovoltaic power supply system may be implemented. Wherein the computer program comprises computer program code, which may be in the form of source code, object code, an executable file or some intermediate form, etc. The computer-readable medium may include: any entity or device capable of carrying the computer program code, recording medium, usb disk, removable hard disk, magnetic disk, optical disk, computer Memory, Read-Only Memory (ROM), Random Access Memory (RAM), electrical carrier wave signals, telecommunications signals, software distribution medium, and the like. It should be noted that the computer readable medium may contain other components which may be suitably increased or decreased as required by legislation and patent practice in jurisdictions, for example, in some jurisdictions, computer readable media which may not include electrical carrier signals and telecommunications signals in accordance with legislation and patent practice.
The above-mentioned embodiments are only used for illustrating the technical solutions of the present invention, and not for limiting the same; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications and substitutions do not substantially depart from the spirit and scope of the embodiments of the present invention, and are intended to be included within the scope of the present invention.
Claims (10)
1. The anti-reflux method of the photovoltaic power supply system is characterized in that the photovoltaic power supply system comprises a photovoltaic inverter and a contactor; the photovoltaic inverter is connected with the first end of the contactor, and the second end of the contactor is respectively used for connecting a low-voltage power grid and a local load;
the method comprises the following steps:
acquiring electric energy data of the low-voltage power grid side in real time;
subtracting the electric energy data at the current moment from the electric energy data at the previous moment to obtain an electric energy difference value;
if the electric energy difference value is larger than a first preset threshold value, the photovoltaic inverter is adjusted based on the electric energy difference value so as to reduce the output power of the photovoltaic inverter;
if the electric energy difference value is larger than a second preset threshold value, controlling the photovoltaic inverter to stop;
if the electric energy difference value is larger than a third preset threshold value, controlling the contactor to be disconnected;
the first preset threshold is smaller than the second preset threshold, and the second preset threshold is smaller than the third preset threshold.
2. The method for preventing backflow of the photovoltaic power supply system according to claim 1, wherein if the power difference is greater than a first preset threshold, the adjusting the photovoltaic inverter based on the power difference to reduce the output power of the photovoltaic inverter comprises:
if the electric energy difference value is larger than the first preset threshold value, generating a power reduction instruction based on the electric energy difference value, and sending the power reduction instruction to the photovoltaic inverter through a digital communication interface, so that the photovoltaic inverter adjusts the duty ratio of an internal switching tube to reduce the output power of the photovoltaic inverter.
3. The method for preventing backflow of the photovoltaic power supply system according to claim 1, wherein if the electric energy difference is greater than a second preset threshold, controlling the photovoltaic inverter to stop comprises:
and if the electric energy difference value is larger than the second preset threshold value, controlling the photovoltaic inverter to stop through a dry contact.
4. The anti-backflow method for the photovoltaic power supply system according to claim 1, wherein the photovoltaic inverter includes a plurality of;
if the electric energy difference value is greater than a second preset threshold value, controlling the photovoltaic inverter to stop, including:
if the electric energy difference value is larger than the second preset threshold value, determining a first quantity according to the electric energy difference value;
and controlling the first number of photovoltaic inverters to stop through the dry contact.
5. The anti-reflux method for a photovoltaic power supply system as set forth in claim 1, wherein said power data includes power, and said power difference includes a power difference; after the controlling the photovoltaic inverter to stop if the electric energy difference is greater than a second preset threshold, the method further includes:
controlling the photovoltaic inverter to start and increase the output power from zero until a target power is reached, wherein the target power is obtained by subtracting the power difference value from the first power; the first power is the output power of the photovoltaic inverter before the contactor is disconnected.
6. The anti-reflux method for a photovoltaic power supply system as set forth in claim 1, wherein said power data includes power, and said power difference includes a power difference; after the controlling the contactor to be turned off if the electric energy difference is greater than a third preset threshold, the method further includes:
closing the contactor;
controlling the photovoltaic inverter to start and increase the output power from zero until a target power is reached, wherein the target power is obtained by subtracting the power difference value from the first power; the first power is the output power of the photovoltaic inverter before the contactor is disconnected.
7. The anti-reflux method for the photovoltaic power supply system according to claim 1, wherein the electric energy data includes power, and the obtaining the electric energy data of the low voltage grid side in real time includes:
acquiring voltage and current of the low-voltage power grid side in real time;
and calculating the power of the low-voltage power grid side according to the voltage and the current of the low-voltage power grid side.
8. The anti-reflux device of the photovoltaic power supply system is characterized in that the photovoltaic power supply system comprises a photovoltaic inverter and a contactor; the photovoltaic inverter is connected with the first end of the contactor, and the second end of the contactor is respectively used for connecting a low-voltage power grid and a local load;
the device comprises:
the electric energy data acquisition module is used for acquiring electric energy data of the low-voltage power grid side in real time;
the difference value calculation module is used for subtracting the electric energy data at the current moment from the electric energy data at the previous moment to obtain an electric energy difference value;
the first anti-reflux module is used for adjusting the photovoltaic inverter based on the electric energy difference value to reduce the output power of the photovoltaic inverter if the electric energy difference value is larger than a first preset threshold value;
the second anti-reflux module is used for controlling the photovoltaic inverter to stop if the electric energy difference value is larger than a second preset threshold value;
the third anti-backflow module is used for controlling the contactor to be disconnected if the electric energy difference value is larger than a third preset threshold value;
the first preset threshold is smaller than the second preset threshold, and the second preset threshold is smaller than the third preset threshold.
9. A terminal comprising a memory, a processor and a computer program stored in the memory and executable on the processor, characterized in that the processor implements the steps of the method according to any of the preceding claims 1 to 7 when executing the computer program.
10. A computer-readable storage medium, in which a computer program is stored which, when being executed by a processor, carries out the steps of the method according to any one of claims 1 to 7.
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116961105A (en) * | 2023-07-31 | 2023-10-27 | 苏州阿诗特能源科技有限公司 | Inverter power supply control method, device, system, electronic equipment and medium |
| CN117457436A (en) * | 2023-11-28 | 2024-01-26 | 浙江鲁高电力科技有限公司 | Breaking method, equipment and medium of vacuum circuit breaker for new energy occasion |
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2021
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116961105A (en) * | 2023-07-31 | 2023-10-27 | 苏州阿诗特能源科技有限公司 | Inverter power supply control method, device, system, electronic equipment and medium |
| CN117457436A (en) * | 2023-11-28 | 2024-01-26 | 浙江鲁高电力科技有限公司 | Breaking method, equipment and medium of vacuum circuit breaker for new energy occasion |
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