Photovoltaic string control system

Abstract

The embodiment of the invention discloses a photovoltaic group string control system, the photovoltaic group string control system comprises a control circuit and a server, the control circuit comprises a photovoltaic group string, a detection unit and a transmitter, the detection unit is coupled with the photovoltaic group string and is configured to obtain a detection signal of the photovoltaic group string, and the transmitter is configured to transmit the detection signal to the server. The detection signal at least comprises a current value, and the transmitter is connected with the detection unit and is configured to send the detection signal to the server. Therefore, remote monitoring and operation of the photovoltaic string can be realized.

Description

Technical Field

[0001] The present invention relates to the field of photovoltaic power generation, and in particular to a photovoltaic string control system. Background Art

[0002] In the current photovoltaic power generation field, the status detection of photovoltaic strings is a crucial aspect. By setting up a photovoltaic string control system to detect the status of photovoltaic strings, it can ensure that the photovoltaic strings are in a good power generation state, thereby improving the power generation efficiency of the photovoltaic strings.

[0003] However, with current technology, it is impossible to remotely monitor and operate the photovoltaic strings after a hidden danger is discovered in a photovoltaic power station. Summary of the invention

[0004] In view of this, an embodiment of the present invention provides a photovoltaic string control system, thereby enabling remote monitoring and operation of the photovoltaic strings.

[0005] An embodiment of the present invention provides a photovoltaic string control system, the system comprising:

[0006] control circuits; and

[0007] server;

[0008] Wherein, the control circuit comprises:

[0009] Photovoltaic strings;

[0010] A detection unit, coupled to the photovoltaic string, configured to obtain a detection signal of the photovoltaic string, wherein the detection signal at least includes a current value;

[0011] The transmitter is connected to the detection unit and is configured to send the detection signal to the server.

[0012] In some embodiments, the server is configured to determine and send a first control instruction based on a detection signal sent by the transmitter;

[0013] Wherein, the transmitter is further configured to control the state of the photovoltaic string according to the first control instruction.

[0014] In some embodiments, the server is configured to generate the first control instruction as a shutdown instruction to control the photovoltaic string circuit to shut down in response to the detection signal being not within a preset range.

[0015] In some embodiments, the photovoltaic string includes a photovoltaic component and a shut-off device, wherein the shut-off device is connected to both ends of the photovoltaic component, and the transmitter is further configured to shut down the photovoltaic string by controlling the shut-off device in response to receiving the first control instruction as a shut-off instruction.

[0016] In some embodiments, the system further comprises:

[0017] The coupling coil is coupled between the photovoltaic string and the transmitter and is configured to transmit a carrier signal.

[0018] In some embodiments, the system further comprises a terminal device;

[0019] The server is further configured to generate notification information according to the detection signal and send it to the terminal device, the terminal device is further configured to obtain a second control instruction input by the user and send it to the server, and the server is further configured to send the second control instruction to the transmitter.

[0020] In some embodiments, the notification information includes a line graph of changes.

[0021] In some embodiments, the notification information includes an alarm signal, and the server is further configured to determine the alarm signal according to an abnormal value of the detection signal.

[0022] In some embodiments, the detection unit is a Hall current sensor.

[0023] In some embodiments, the control circuit further comprises:

[0024] An inverter is configured to obtain a power value of the photovoltaic string and send the power value to the server through the transmitter;

[0025] The server is configured to determine a voltage value of the photovoltaic string according to the power value and the current value in the detection signal.

[0026] The technical solution of the embodiment of the present invention is to set a control circuit and a server in a photovoltaic string control system, wherein the control circuit includes a photovoltaic string, a detection unit and a transmitter, the detection unit is coupled to the photovoltaic string, and is configured to obtain a detection signal of the photovoltaic string, the detection signal at least includes a current value, and the transmitter is connected to the detection unit and is configured to send the detection signal to the server. Thus, remote monitoring and operation of the photovoltaic string can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The above and other objects, features and advantages of the present invention will become more apparent through the following description of the embodiments of the present invention with reference to the accompanying drawings, in which:

[0028] Figure 1 is a schematic diagram of a photovoltaic string control system of the prior art;

[0029] Figure 2 is a circuit diagram of a photovoltaic string control system according to an embodiment of the present invention;

[0030] Figure 3 is a schematic diagram of a photovoltaic string according to an embodiment of the present invention;

[0031] Figure 4 is a schematic diagram of a photovoltaic string control system according to another embodiment of the present invention;

[0032] Figure 5 It is a schematic diagram of a change line graph according to an embodiment of the present invention. DETAILED DESCRIPTION

[0033] The present application is described below based on embodiments, but the present application is not limited to these embodiments. In the detailed description of the present application below, some specific details are described in detail. It is possible for those skilled in the art to fully understand the present application without the description of these details. In order to avoid confusing the essence of the present application, known methods, processes, flows, components and circuits are not described in detail.

[0034] In addition, persons of ordinary skill in the art will appreciate that the drawings provided herein are for illustration purposes and are not necessarily drawn to scale.

[0035] Unless the context clearly requires otherwise, the words "include", "comprising" and similar words throughout the application should be interpreted as including rather than exclusive or exhaustive; that is, the meaning is "including but not limited to".

[0036] In the description of this application, it should be understood that the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. In addition, in the description of this application, unless otherwise specified, the meaning of "plurality" is two or more.

[0037] According to the latest requirements of the sunspec protocol and NEC (National Electrical Code), the photovoltaic system needs to include a photovoltaic hazard control system to achieve component-level shutdown of the photovoltaic system. Therefore, many photovoltaic power stations will install RSD (Rapid Shutdown Devices) to be used together with the transmitter.

[0038] Figure 1is a schematic diagram of a photovoltaic string control system of the prior art, such as Figure 1 As shown, the photovoltaic string control system includes RSD (Rapid Shutdown Devices), a transmitter, an inverter and a photovoltaic module. Among them, each RSD is used to control the shutdown and conduction of the corresponding photovoltaic module. Specifically, the default state of RSD is closed. When the photovoltaic module needs to generate electricity, a carrier signal is sent to RSD through the transmitter, and RSD turns on the voltage of the photovoltaic module after receiving the signal. When encountering an emergency, the transmitter stops sending signals to RSD, and RSD is turned off, thereby achieving rapid shutdown between strings. Among them, RSD is used to cut off the current of the photovoltaic system. Specifically, RSD can cut off the power connection between the photovoltaic module and the power grid, thereby eliminating the current in the circuit. The inverter tracks the changes in solar radiation and adjusts the working point of the photovoltaic panel to keep it in the maximum power output state at all times, thereby ensuring the maximum power generation efficiency of the photovoltaic string under changing lighting conditions.

[0039] However, based on the photovoltaic string control system in the prior art, shutting down the photovoltaic string through the RSD requires stopping the transmission of the carrier signal to the RSD through the transmitter, and changing the state of the transmitter requires the relevant staff to go to the site to operate. Therefore, the control system in the prior art cannot realize remote monitoring and operation of the photovoltaic string.

[0040] Figure 2 is a circuit diagram of a photovoltaic string control system according to an embodiment of the present invention, such as Figure 2 As shown, the photovoltaic string control system includes a control circuit 1 and a server 2. The control circuit 1 includes a photovoltaic string 11, a detection unit 12 and a transmitter 13.

[0041] The photovoltaic string 11 is specifically used for photovoltaic power generation, and the photovoltaic string 11 is composed of multiple photovoltaic modules connected in series. By connecting multiple photovoltaic modules in series, the total voltage and power output of the entire photovoltaic system can be significantly improved. When connected in series, the positive and negative electrodes of the photovoltaic modules are connected in sequence, so that the current flows from one module to another, thereby forming a current loop, and the voltage generated by each module is superimposed to form a larger total voltage.

[0042] The detection unit 12 is coupled to the photovoltaic string 11 and is configured to obtain a detection signal of the photovoltaic string 11, wherein the detection signal includes at least a current value. The detection signal also includes a voltage value and a temperature value, and may also include other circuit parameters, which are not limited in the embodiment of the present invention. By acquiring the detection signal of the photovoltaic string 11, the actual working state of the photovoltaic string 11 is fed back in the form of data, thereby determining the working state of the photovoltaic string 11 according to the detection signal.

[0043] When obtaining the current of a photovoltaic string, contact measurement is required, that is, the measuring instrument or sensor is connected in series in the circuit. However, due to the large voltage and current fluctuations of the photovoltaic string, the maximum voltage is high when working at full power, and the measuring device is easily damaged during measurement, and there are also large safety hazards during manual measurement. Therefore, in an embodiment of the present invention, the detection unit is a Hall current sensor. The Hall current sensor is a magnetoelectric conversion device based on the Hall effect principle, which is used to measure current in a non-contact manner. When current passes through a conductor, if the conductor is in a magnetic field, and the current direction is perpendicular to the magnetic field direction, a transverse potential difference will be generated in a direction perpendicular to both the magnetic field and the current direction. This phenomenon is called the Hall effect, and the generated potential difference is called the Hall voltage. Specifically, the Hall current sensor calculates the magnitude of the current by measuring the Hall voltage. In an embodiment of the present invention, the advantage of the Hall current sensor is that it is measured under electrical isolation conditions, without direct contact with the current being measured, avoiding the safety hazards of traditional contact current sensors. Measuring the current in the string by a non-contact Hall current sensor is more convenient and safer than the prior art. In addition, according to actual conditions, the transmitter 13 can be connected to multiple Hall current sensors to monitor multiple strings respectively.

[0044] The transmitter 13 is connected to the detection unit 12, and is configured to send a detection signal to the server 2 so that the server 2 processes the detection signal. In an embodiment of the present invention, the transmitter 13 is used to receive the detection signal of the detection unit 12 connected thereto, and send it to the server. The transmitter can upload to the remote server through wired communication or wireless communication, wherein the wireless technology includes 4G (4th Generation, fourth generation mobile communication technology), 5G (5th Generation, fifth generation mobile communication technology), wifi (Wireless Fidelity, wireless local area network), NB-IoT (Narrow Band Internet of Things, narrowband Internet of Things), Cat.1 (UE-Category 1, user equipment category 1) and other methods. The embodiment of the present invention does not limit the specific method of wireless communication. Specifically, the communication method between the transmitter and the remote server can be selected according to actual conditions. Specifically, when used in areas with good mobile cellular network coverage, choose wireless communication forms such as 4G, 5G, and Cat.1. In environments with poor wireless environments such as deserts and grasslands, you can first connect via a wired optical cable, and then use relay switching or direct access to the control center to monitor and send and receive data.

[0045] The server 2 receives the detection signal sent by the transmitter 13 and is configured to determine and send the first control instruction according to the detection signal sent by the transmitter. The server 2 can be a cloud server or other types of servers, and the embodiment of the present invention does not limit this. Specifically, the server 2 is configured to determine and send the first control instruction according to the detection signal sent by the transmitter 13 after obtaining the detection signal sent by the transmitter 13, and the first control instruction is used to control the state of the photovoltaic string 11. Specifically, the state of the photovoltaic string 11 is determined according to the detection signal, and a processing method for the photovoltaic string is determined based on the state of the photovoltaic string 11 to generate a first control instruction to control the photovoltaic string. At this time, the transmitter 13 is also configured to control the state of the photovoltaic string according to the first control instruction in response to receiving the first control instruction. The state of the photovoltaic string can include multiple control methods, such as shutting down the photovoltaic string, reducing the current in the photovoltaic string, and maintaining the existing working state, and the embodiment of the present invention does not limit this.

[0046] Taking the detection signal including the current value as an example for specific description, it should be understood that the processing method for other types of detection signals is also similar to that of the current, and the embodiments of the present invention will not be described in detail. Correspondingly, the server 2 stores a preset range of current values. This is because when the photovoltaic string 11 is working normally, the current value of the photovoltaic string 11 should be stable within a preset range. In response to the detection signal being within the preset range, the photovoltaic string is in a normal working state, and the first control instruction is a hold instruction, which is used to maintain the current working state of the photovoltaic string. In response to the detection signal not being within the preset range, the photovoltaic string is in an abnormal state, and the first control instruction is a shutdown instruction, which is specifically used to shut down the photovoltaic string 11. Specifically, the transmitter 13 controls the photovoltaic string 11 to shut down according to the shutdown instruction.

[0047] For example, assuming that the preset range is 29A-31A, when the current value in the detection signal is 29.5A, the detection signal is within the preset range, the photovoltaic string is in a normal state, and the server 2 generates the first control instruction as a hold instruction to keep the current working state of the photovoltaic string 11 unchanged. When the current value in the detection signal is 35A, the detection signal is not within the preset range, the photovoltaic string is in an abnormal state, the server 2 generates the first control instruction as a shutdown instruction and sends it to the transmitter 13, and the transmitter 13 controls the photovoltaic string 11 according to the shutdown instruction.

[0048] Figure 3 Schematic diagram of a photovoltaic string according to an embodiment of the present invention. Figure 3As shown, the photovoltaic string includes a plurality of photovoltaic components 111a, 111b, 111c and a plurality of shutoff devices 112a, 112b, 112c. The photovoltaic component 111 is a component that converts sunlight into electrical energy using the photovoltaic effect, and uses semiconductor materials to directly convert sunlight into electrical energy through the photovoltaic effect. The shutoff device 112 is connected to both ends of the corresponding photovoltaic component 111, and is configured to control the conduction and shutoff of the photovoltaic component 111. The shutoff device 112 can be specifically an RSD, and the embodiment of the present invention does not limit this.

[0049] Specifically, when the circuit triggers the shutdown condition, the RSD cuts off the connection between the photovoltaic module and the circuit, so that the voltage of the photovoltaic system drops to a safe level within a specified time. Specifically, by connecting the RSDs on both sides of each photovoltaic module, independent control of each module in the photovoltaic string is achieved to ensure maximum safety. The transmitter 13 is also configured to control the photovoltaic module 111 to shut down by controlling the shutdown device 112 in response to receiving a shutdown instruction, thereby shutting down the photovoltaic module 111. Specifically, for example, the shutdown instruction is used to shut down the photovoltaic module 111b, and the transmitter controls the photovoltaic module 111b to shut down by controlling the shutdown device 112b corresponding to the photovoltaic module.

[0050] In some embodiments, the control circuit 1 also includes a coupling coil 14, which is coupled between the photovoltaic string 11 and the transmitter 13, and is used to transmit a carrier signal. Specifically, the coupling coil 14 is used to realize communication between the photovoltaic string 11 and the detection unit 12 and the transmitter 13. The coupling coil 14 is composed of two or more coils. For example, the coupling coil includes two coils, one of which is called a main coil and the other is called a slave coil. The main coil and the slave coil are coupled to each other through a magnetic field to realize non-contact transmission of energy. When the carrier signal in the main coil changes, the induced electromotive force in the slave coil will also change accordingly, thereby realizing the transmission of the carrier signal.

[0051] In some embodiments, the control circuit 1 further includes an inverter 15, which is configured to obtain the power of the photovoltaic string and send it to the server 2 through the transmitter 13. Since the detection signal obtained by the server 2 includes the current of the photovoltaic string 11, the server 2 can determine the voltage value of the photovoltaic string according to the power of the photovoltaic string and the current of the photovoltaic string 11. By obtaining the voltage value of the photovoltaic string 11, the server 2 can compare the voltage value with a predetermined range to determine the working state of the photovoltaic string.

[0052] The embodiment of the present invention sets a control circuit and a server in a photovoltaic string control system, wherein the control circuit includes a photovoltaic string, a detection unit and a transmitter, wherein the detection unit is coupled to the photovoltaic string and configured to obtain a detection signal of the photovoltaic string, wherein the detection signal includes at least a current value, and the transmitter is connected to the detection unit and configured to send the detection signal to the server. Thus, remote monitoring and operation of the photovoltaic string can be achieved.

[0053] Figure 4 It is a schematic diagram of a photovoltaic string control system according to another embodiment of the present invention, and the system further includes a terminal device 3. The terminal device 3 may be an electronic device such as a mobile phone, a computer, or a tablet computer, and the embodiment of the present invention does not limit this. In an embodiment of the present invention, the terminal device 3 is specifically a device controlled by relevant staff. The server 2 is also configured to generate notification information based on the detection signal and send it to the terminal device 3. The function of the notification information is specifically to show the working status of the photovoltaic string to relevant staff more intuitively. The notification information may include at least one of a change line graph and an alarm signal. The server 2 generates a change line graph based on the data in the detection signal. Specifically, the line graph may be Figure 5 As shown, in Figure 5 In the line graph shown, the horizontal axis is time and the vertical axis is current value. The line graph in the example is specifically drawn with 5 minutes as a time period, and the embodiment of the present invention does not limit this. In this way, the change of the current value of the photovoltaic string 11 over time can be clearly displayed. The specific method for determining the alarm signal is: the server 2 determines the abnormal value in the detection signal as an alarm signal by judging the detection signal. Specifically, the alarm signal can be sent according to the time period where the abnormal value is located. For example, the alarm signal can be: "During 15:30-15:35, the current value is high! The average current value is 35A and the maximum value is 38A!" It should be noted that the alarm signal can be sent in a variety of forms. For example, the alarm signal can be a text alarm or a voice alarm, and the embodiment of the present invention does not limit this.

[0054] Specifically, the terminal device 3 is configured to obtain a second control instruction input by a user and send it to the server 2, and the server 2 sends the second control instruction to the transmitter 13. The second control instruction is specifically input by relevant staff. Specifically, after the server 2 sends notification information to the terminal device 3, the relevant staff analyzes the notification information and inputs the second control instruction into the terminal device 3 according to the analysis result to realize the control of the photovoltaic string 11. Specifically, when it is determined that the working state of the photovoltaic string 11 is abnormal, the second control instruction sent by the terminal device 3 to the server 2 is specifically a shutdown instruction, and the server 2 sends a shutdown instruction to the transmitter 13, and the transmitter 13 shuts down the photovoltaic string 11 according to the shutdown instruction. When it is determined that the working state of the photovoltaic string 11 is normal, the terminal device 3 can send a maintenance instruction to the server 2 to maintain the working state of the photovoltaic string 11, or it can not send any instruction to maintain the state of the photovoltaic string 11, and the embodiment of the present invention does not limit this.

[0055] The embodiment of the present invention sets a control circuit and a server in a photovoltaic string control system, wherein the control circuit includes a photovoltaic string, a detection unit and a transmitter, wherein the detection unit is coupled to the photovoltaic string and configured to obtain a detection signal of the photovoltaic string, wherein the detection signal includes at least a current value, and the transmitter is connected to the detection unit and configured to send the detection signal to the server. Thus, remote monitoring and operation of the photovoltaic string can be achieved.

[0056] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, devices (equipment) or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment or an embodiment combining software and hardware. Moreover, the present application may adopt a computer program product implemented on one or more computer-readable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0057] The present application is described with reference to flowcharts of methods, apparatuses (devices) and computer program products according to embodiments of the present application. It should be understood that each process in the flowchart can be implemented by computer program instructions.

[0058] These computer program instructions may be stored in a computer readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture including an instruction device that implements the process Figure 1 A function specified in a process or multiple processes.

[0059] These computer program instructions may also be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device produce the instructions for implementing the process Figure 1 A device that specifies functions in a process or multiple processes.

[0060] Another embodiment of the present invention relates to a non-volatile storage medium for storing a computer-readable program, wherein the computer-readable program is used for a computer to execute part or all of the above method embodiments.

[0061] That is, those skilled in the art can understand that all or part of the steps in the above-mentioned embodiment method can be completed by specifying relevant hardware through a program, and the program is stored in a storage medium, including several instructions for a device (which can be a single-chip microcomputer, chip, etc.) or a processor (processor) to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk and other media that can store program codes.

[0062] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A photovoltaic string control system, characterized in that: The system comprises: control circuits; and server; Wherein, the control circuit comprises: Photovoltaic strings; A detection unit, coupled to the photovoltaic string, configured to obtain a detection signal of the photovoltaic string, wherein the detection signal at least includes a current value; The transmitter is connected to the detection unit and is configured to send the detection signal to the server.

2. The system according to claim 1, characterized in that The server is configured to determine and send a first control instruction according to a detection signal sent by the transmitter; Wherein, the transmitter is further configured to control the state of the photovoltaic string according to the first control instruction.

3. The system according to claim 2, characterized in that The server is configured to generate the first control instruction as a shutdown instruction to control the photovoltaic string to shut down in response to the detection signal being not within a preset range.

4. The system according to claim 3, characterized in that The photovoltaic string includes a photovoltaic component and a shutoff device, wherein the shutoff device is connected to both ends of the photovoltaic component, and the transmitter is further configured to shut off the photovoltaic component by controlling the shutoff device in response to receiving the first control instruction as a shutoff instruction.

5. The system according to claim 1, characterized in that The system further comprises: The coupling coil is coupled between the photovoltaic string and the transmitter and is configured to transmit a carrier signal.

6. The system according to claim 1, characterized in that The system also includes a terminal device; The server is further configured to generate notification information according to the detection signal and send it to the terminal device, the terminal device is further configured to obtain a second control instruction input by the user and send it to the server, and the server is further configured to send the second control instruction to the transmitter.

7. The system according to claim 6, characterized in that The notification information includes a change line graph.

8. The system according to claim 6, characterized in that The notification information includes an alarm signal, and the server is further configured to determine the alarm signal according to an abnormal value of the detection signal.

9. The system according to claim 1, characterized in that The detection unit is a Hall current sensor.

10. The system according to claim 1, characterized in that The control circuit further comprises: An inverter is configured to obtain a power value of the photovoltaic string and send the power value to the server via the transmitter; The server is configured to determine a voltage value of the photovoltaic string according to the power value and the current value in the detection signal.

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