Photovoltaic inverter, photovoltaic control device, and photovoltaic power plant

Abstract

The application discloses a photovoltaic inverter, a photovoltaic control device and a photovoltaic power station, and relates to the technical field of photovoltaic technology. The photovoltaic inverter is used for being in communication connection with the photovoltaic control device. The photovoltaic control device is used for outputting a light signal to a photovoltaic module, and the light signal comprises a control instruction. The photovoltaic inverter is used for being connected with the photovoltaic module. When an electric signal output by the photovoltaic module is received, the photovoltaic inverter is used for obtaining the control instruction according to the electric signal, and adjusting output power based on the control instruction. The electric signal is a signal formed by the photovoltaic module based on the received light signal. In this way, the light wireless communication can be introduced into the photovoltaic power station at low cost to meet the time delay requirement in the communication process.

Description

Technical Field

[0001] This application relates to the field of photovoltaic technology, and in particular to a photovoltaic inverter, a photovoltaic control device, and a photovoltaic power station. Background Technology

[0002] In photovoltaic power plants, the output power of photovoltaic inverters needs to be scheduled according to grid connection requirements. This is usually done using power line communication (PLC). The subarray controller acts as the central coordinator (CCO), and the photovoltaic inverters act as stations (STAs). The subarray controller is responsible for controlling and collecting information from the photovoltaic inverters and transmitting scheduling commands to the photovoltaic inverters via the power line. The photovoltaic inverters are responsible for reporting their own working data to the subarray controller.

[0003] With the development of photovoltaic power plants, in order to increase the power generation of photovoltaic power plants, it is necessary to deploy large areas of photovoltaic panels, and the number of photovoltaic inverters is also increasing. However, as the number of photovoltaic inverters managed by a single subarray controller increases, the node density on the power line rises, and the transmission rate and real-time performance of traditional power line carrier communication can hardly meet the latency requirements in the communication process. Summary of the Invention

[0004] This application provides a photovoltaic inverter, a photovoltaic control device, and a photovoltaic power station for introducing optical wireless communication in a photovoltaic power station at low cost to meet the latency requirements in the communication process.

[0005] In a first aspect, this application provides a photovoltaic inverter for communication connection with a photovoltaic control device, which outputs light signals to a photovoltaic module and converts the light signals into electrical signals; the photovoltaic inverter is used to connect to the photovoltaic module and adjust the output power according to the electrical signals when it receives the electrical signals output by the photovoltaic module.

[0006] In this embodiment, optical wireless communication is introduced into the photovoltaic power plant to transmit downlink signals, including control commands, sent by the photovoltaic control device to the photovoltaic inverter. As the node density between the photovoltaic control device and the photovoltaic inverter increases, uplink and downlink signals are transmitted separately using power line carrier communication and optical wireless communication. This overcomes the transmission efficiency limitations and mutual interference between uplink and downlink signals inherent in traditional power line carrier communication schemes, improving signal transmission efficiency and stability to meet latency and communication reliability requirements. Furthermore, since the photovoltaic modules connected to the photovoltaic inverter can receive both natural light and the optical signals emitted by the photovoltaic control device for communication during optical wireless communication, no additional photosensitive devices are needed on the photovoltaic inverter side. The photovoltaic inverter can receive the optical signals during optical wireless communication using the connected photovoltaic modules, reducing the cost of introducing optical wireless communication into the photovoltaic power plant and ensuring that the photovoltaic power plant can meet the real-time requirements of grid dispatch.

[0007] In some embodiments, the photovoltaic inverter includes a photovoltaic controller, an inverter circuit, and a sampling circuit; the inverter circuit is used to connect to the photovoltaic module; the sampling circuit is connected between the photovoltaic module and the photovoltaic controller to sample the electrical signal output by the photovoltaic module; the photovoltaic controller is connected to the inverter circuit to obtain the electrical signal from the sampling circuit and adjust the output power of the inverter circuit according to the electrical signal.

[0008] In this embodiment, after the photovoltaic inverter receives the optical signal transmitted by optical wireless communication using the photovoltaic module connected to it, the photovoltaic module converts the optical signal into an electrical signal. By adding a sampling circuit at the photovoltaic inverter, the electrical signal transmitted by optical wireless communication can be collected. The modification cost on the photovoltaic inverter side is low, which is conducive to improving the communication transmission rate of the photovoltaic power station at low cost.

[0009] In some embodiments, the photovoltaic inverter further includes a filter circuit connected between the photovoltaic module and the inverter circuit. The filter circuit includes a first capacitor and a second capacitor. The first capacitor and the second capacitor are connected in parallel, and the capacitance value of the first capacitor is less than the capacitance value of the second capacitor. The sampling circuit is connected in series with the first capacitor.

[0010] In this embodiment, the first capacitor has the characteristic of passing high frequencies and blocking low frequencies, and is used to filter out high-frequency noise transmitted between the photovoltaic module and the inverter circuit. The larger the capacitance value, the better the filtering effect. The second capacitor has the characteristic of passing low frequencies and blocking high frequencies, and is used to filter out low-frequency noise transmitted between the photovoltaic module and the inverter circuit. Therefore, by utilizing the first capacitor with high-frequency and low-impedance characteristics in the filter circuit, and by connecting a sampling circuit in series with the first capacitor with a smaller capacitance value in the filter circuit, a high-pass filter branch is formed. This allows the high-frequency electrical signal generated by optical wireless communication modulation output by the photovoltaic module to pass through, thereby enabling the acquisition of optical wireless transmission signals at the sampling circuit, further reducing the modification cost on the photovoltaic inverter side when implementing optical wireless communication.

[0011] In some embodiments, the photovoltaic controller includes a first control unit and a first receiving channel. The first receiving channel is connected between the first control unit and the sampling circuit. The first receiving channel includes: a differential conversion circuit connected to the sampling circuit, used to convert the electrical signal sampled by the sampling circuit into a differential signal; and a first analog-to-digital converter connected to the differential conversion circuit and the first control unit, used to convert the differential signal into a first digital signal and send the first digital signal to the first control unit.

[0012] In this embodiment, by adding a sampling circuit and a first receiving channel to the photovoltaic inverter, the photovoltaic controller can acquire the electrical signal transmitted via optical wireless communication, reducing the modification and debugging costs on the photovoltaic inverter side when implementing optical wireless communication.

[0013] In some embodiments, the photovoltaic inverter is used to connect to a power line and to output a first power line carrier signal to the power line, the first power line carrier signal including the operating data of the photovoltaic inverter.

[0014] In this embodiment, after introducing optical wireless communication between the photovoltaic control device and the photovoltaic inverter, power line carrier communication is used to transmit uplink signals including working data, and optical wireless communication is used to transmit downlink signals including control commands. The uplink and downlink signals are isolated during transmission. When transmitting signals at high frequency between the photovoltaic control device and the photovoltaic inverter, mutual interference between the uplink and downlink signals is effectively avoided, and the probability of channel preemption events is reduced. This can improve signal transmission efficiency and transmission stability, and ensure that the communication delay is within the required range and the communication reliability is guaranteed.

[0015] In some embodiments, the photovoltaic control device is also used to output a second power line carrier signal to the power line; the photovoltaic inverter is used to adjust the output power according to the second power line carrier signal when it receives the second power line carrier signal transmitted by the power line.

[0016] In this embodiment, in some cases, such as when the signal transmission effect of optical wireless communication is poor under severe weather conditions, the transmission of downlink signals between the photovoltaic control device and the photovoltaic inverter can be switched from optical wireless communication to power line carrier communication. When the photovoltaic controller receives the second power line carrier signal transmitted by the power line, it adjusts the output power of the inverter circuit to the grid according to the second power line carrier signal, thereby ensuring the reliability of signal transmission between the photovoltaic control device and the photovoltaic inverter.

[0017] In some embodiments, the photovoltaic controller further includes a first transmitting channel, a second receiving channel, and a first coupling circuit. The first transmitting channel and the second receiving channel are coupled to the power line through the first coupling circuit. A first control unit is connected to the first transmitting channel and is used to transmit a first power line carrier signal to the power line through the first transmitting channel. The second receiving channel is connected to the first control unit and is used to receive a second power line carrier signal transmitted by the power line and transmit the second power line carrier signal to the first control unit.

[0018] In some implementations, the operating data of the photovoltaic inverter includes the inverter's voltage, current, temperature, and output power.

[0019] Secondly, this application provides a photovoltaic control device, which includes a subarray controller and a light source module; the subarray controller is connected to the light source module and controls the light source module to output light signals, the photovoltaic module receives the light signals, converts the light signals into electrical signals, and sends electrical signals to the photovoltaic inverter.

[0020] In this embodiment, on the photovoltaic control device side, when optical wireless communication is introduced into the photovoltaic power station to realize downlink communication, only a light source module needs to be added to the photovoltaic control device side to connect with the sub-array controller. The light source module can realize the transmission of optical signals for optical wireless communication transmission and work in conjunction with the photovoltaic modules connected to the photovoltaic inverter side, reducing the modification and debugging costs when realizing optical wireless communication in the photovoltaic power station.

[0021] In some implementations, the aforementioned subarray controller is coupled to the power line and receives a first power line carrier signal output from the photovoltaic inverter transmitted via the power line.

[0022] In this embodiment, after introducing optical wireless communication between the photovoltaic control device and the photovoltaic inverter, power line carrier communication is used to transmit uplink signals including working data, and optical wireless communication is used to transmit downlink signals including control commands. The uplink and downlink signals are isolated during transmission. When transmitting signals at high frequency between the photovoltaic control device and the photovoltaic inverter, mutual interference between the uplink and downlink signals is effectively avoided, and the probability of channel preemption events is reduced. This can improve signal transmission efficiency and transmission stability, and ensure that the communication delay is within the required range and the communication reliability is guaranteed.

[0023] In some implementations, the subarray controller is also used to send a second power line carrier signal to the power line.

[0024] In this embodiment, due to the poor signal transmission effect of optical wireless communication under severe weather conditions, the transmission of downlink signals between the photovoltaic control device and the photovoltaic inverter is switched from optical wireless communication to power line carrier communication. When the photovoltaic controller receives the second power line carrier signal transmitted by the power line, it obtains control commands based on the second power line carrier signal and adjusts the output power of the inverter circuit to the grid based on the control commands, thereby ensuring the reliability of signal transmission between the photovoltaic control device and the photovoltaic inverter.

[0025] In some embodiments, the subarray controller includes a second control unit, a second transmitting channel, a third receiving channel, and a second coupling circuit. The second transmitting channel and the third receiving channel are coupled to the power line through the second coupling circuit. The second control unit is connected to the light source module and the second transmitting channel, and is used to control the light source module to output an optical signal. Alternatively, the second control unit is used to transmit a second power line carrier signal to the power line through the second transmitting channel. The third receiving channel is connected to the second control unit and is used to receive the first power line carrier signal transmitted by the power line and transmit the first power line carrier signal to the second control unit.

[0026] In some implementations, the position of the aforementioned light source module is movable.

[0027] In this embodiment, the position of the light source module does not need to be fixed. For example, the position of the light source module can be set in the air. While ensuring that each photovoltaic module can receive the light signal emitted by the light source module, it can also be moved to different positions according to actual needs. By flexibly adjusting the illumination area of ​​the light source module, it can adapt to changes in the layout of photovoltaic modules or environmental changes, thereby improving the reliability and adaptability of optical wireless communication between the photovoltaic control device and the photovoltaic inverter.

[0028] Thirdly, this application provides a photovoltaic power station, which includes photovoltaic modules, an intelligent management system, a photovoltaic inverter as provided in the first aspect embodiment, and a photovoltaic control device as provided in the second aspect embodiment; the photovoltaic inverter is used to connect to the power grid and the photovoltaic modules, and is communicatively connected to the photovoltaic control device; the intelligent management system is connected to the photovoltaic control device, and is used to control the photovoltaic inverter through the photovoltaic control device to convert the direct current output by the photovoltaic modules into alternating current, and output the alternating current to the power grid.

[0029] In this embodiment, the beneficial effects of the second and third aspects can be referred to the description of the first aspect and any of its implementations, and will not be repeated here. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the structure of a photovoltaic power station; Figure 2 This is a schematic diagram of another type of photovoltaic power station; Figure 3 This is a schematic diagram of the structure of a photovoltaic power station provided in an embodiment of this application; Figure 4 This is a schematic diagram of the structure of a photovoltaic inverter provided in an embodiment of this application; Figure 5 This is a schematic diagram of another photovoltaic inverter provided in an embodiment of this application; Figure 6 This is a schematic diagram of the structure of a photovoltaic control device provided in an embodiment of this application; Figure 7 This is a schematic diagram of another photovoltaic control device provided in an embodiment of this application; Figure 8 This is a schematic diagram of another photovoltaic power station provided in an embodiment of this application. Detailed Implementation

[0031] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] To facilitate understanding of the technical solutions of the embodiments of this application, before introducing the solutions of the embodiments of this application, some terms or concepts that may be involved in the embodiments of this application will be introduced first.

[0033] Power line carrier communication: This method uses power lines as the transmission medium to achieve data transmission. High-frequency communication signals are modulated onto the power lines to enable data transmission within them, thus eliminating the need for additional communication cables.

[0034] Active power dispatch: Adjusting active power output according to changes in grid load and frequency. Increase active power output when the load is high or the frequency is low, and reduce output power when the frequency is high or the photovoltaic output power is excessive, in order to maintain grid frequency stability. Active power dispatch allows for a relatively long response time.

[0035] Reactive power dispatch: When the grid connection point voltage changes due to fluctuations in photovoltaic output power or sudden load changes, capacitive reactive power is output to raise the voltage when the grid connection point voltage is low, and inductive reactive power is output to lower the voltage when the grid connection point voltage is high, so as to maintain the stability of the grid connection point voltage. The response time required for reactive power dispatch is relatively short.

[0036] Retransmission mechanism: During communication, when the receiving end detects that a data frame is lost or erroneous, the sending end automatically retransmits the data frame to ensure the reliability of communication.

[0037] Carrier sense multiple access (CMSA): A media access control mechanism for shared communication channels. Each device listens to the channel to see if it is idle before sending data. When the channel is idle, the device sends data. When the channel is occupied, the device must wait for the channel to be released before trying to send data.

[0038] Optical wireless communication (OWC) is a communication method that uses optical signals to transmit data. The transmitting end transmits data by loading information onto the optical signal, and the receiving end converts the optical signal into an electrical signal through a photosensitive device (such as a photodiode, photovoltaic module, etc.) and then demodulates it to recover the data.

[0039] Please see Figure 1 , Figure 1 This is a schematic diagram of the structure of a photovoltaic power station 100. The photovoltaic power station 100 provided in this embodiment includes photovoltaic modules 110, an intelligent management system 120, a photovoltaic inverter 130, and a photovoltaic control device 140.

[0040] In this embodiment, the intelligent management system 120 connects multiple photovoltaic control devices 140, each of which is used to communicate with multiple photovoltaic inverters 130. The intelligent management system 120 serves as the centralized control core of the photovoltaic power station 100, issuing control commands to the photovoltaic control devices 140. Upon receiving the control commands, the photovoltaic control devices 140 forward them to the photovoltaic inverters 130 with which they are communicatively connected, thereby achieving unified scheduling and control of the output power of the photovoltaic inverters 130. The intelligent management system 120 may include at least one of an energy management system (EMS), automatic generator control (AGC), automatic voltage control (AVC), a fast-frequency device, a remote control device, and a station-level controller; no limitation is imposed in this application.

[0041] Photovoltaic inverter 130 is used to connect to the grid 200 and photovoltaic modules 110. Multiple photovoltaic inverters 130 can be installed in the photovoltaic power station 100, each connected to at least one photovoltaic module 110. When the photovoltaic module 110 outputs DC power, the photovoltaic inverter 130 converts the received DC power into AC power and transmits it to the grid 200. When the photovoltaic inverter 130 is connected to the grid 200, to reduce fluctuations caused by the grid connection, the intelligent management system 120, through the photovoltaic control device 140, uniformly schedules and controls the output power of the photovoltaic inverter 130. Based on the target power in the control command and the actual power at the grid connection point, the system controls the output power of the photovoltaic inverter 130.

[0042] In addition, such as Figure 1 As shown, the photovoltaic control device 140 includes a subarray controller 141, which is used to realize functions such as interface aggregation, protocol conversion, data storage, centralized detection, and centralized maintenance of various devices in the photovoltaic power station 100. For example, the subarray controller 141 can be a communication cabinet for outdoor applications, which is equipped with a data acquisition unit and communication components to realize functions such as control of the photovoltaic inverter 130 and data acquisition.

[0043] In this embodiment, after the intelligent management system 120 establishes a communication connection with the photovoltaic control device 140, the photovoltaic control device 140 establishes a communication connection with the photovoltaic inverter 130 using power line carrier communication. When the photovoltaic control device 140 sends a downlink signal to the photovoltaic inverter 130, it outputs a power line carrier signal containing control commands to the photovoltaic inverter 130 to adjust the output power of the photovoltaic inverter 130. When the photovoltaic inverter 130 sends an uplink signal to the photovoltaic control device 140, it feeds back a power line carrier signal containing operating data to the photovoltaic control device 140. The operating data includes the voltage, current, temperature, and output power of the photovoltaic inverter 130.

[0044] When photovoltaic power plant 100 is connected to grid 200, to ensure the power supply stability of grid 200 during unified dispatch and control, a reactive power dispatch delay of 30ms and an active power dispatch delay of 60ms are required for the process from the issuance of control commands to the response of photovoltaic inverter 130 and the completion of power adjustment. After removing non-communication delays such as decision delay and execution feedback delay, the communication delay requirement for the power line carrier channel is within 10ms.

[0045] However, when the photovoltaic control device 140 and the photovoltaic inverter 130 share the power line carrier channel for both downlink and uplink communication, the photovoltaic inverter 130 generates electromagnetic noise on the power line during operation, interfering with the transmission of the power line carrier signal. When a communication frame is lost, a retransmission mechanism is triggered, increasing communication latency. Furthermore, the power line transmission process causes significant attenuation of high-frequency signals, limiting the available bandwidth of the power line carrier communication and thus restricting the communication rate and increasing latency. In addition, when the photovoltaic control device 140 and the photovoltaic inverter 130 share the same channel for uplink and downlink communication, multiple photovoltaic inverters 130 connected to the photovoltaic control device 140 use carrier sense multiple access (CSMA) to compete for the channel, leading to channel conflicts and further increasing communication latency. Therefore, the actual communication latency between the photovoltaic control device 140 and the photovoltaic inverter 130 is too high, making it difficult to meet the latency requirements for unified scheduling and control of the photovoltaic inverters.

[0046] In some implementations, such as Figure 2 As shown, Figure 2 This is a schematic diagram of another photovoltaic power station 100. The photovoltaic power station 100 provided in this embodiment also includes a radio frequency transmitter 150 and a radio frequency receiver 160.

[0047] In this embodiment, the RF transmitter 150 is connected to the photovoltaic inverter 130, and the RF receiver 160 is connected to the photovoltaic control device 140. When the photovoltaic control device 140 sends a downlink signal to the photovoltaic inverter 130, it outputs a power line carrier signal containing control commands to the photovoltaic inverter 130 to adjust the output power of the photovoltaic inverter 130. When the photovoltaic inverter 130 sends an uplink signal to the photovoltaic control device 140, it outputs an RF signal including operating data through the RF transmitter 150, and the photovoltaic control device 140 receives the RF signal through the RF receiver 160.

[0048] The photovoltaic control device 140 and the photovoltaic inverter 130 use both power line carrier communication and wireless radio frequency communication to transmit signals. Uplink signal transmission and downlink signal transmission achieve channel isolation. When transmitting signals at high frequency between the photovoltaic control device 140 and the photovoltaic inverter 130, the signal transmission efficiency can be improved and the communication delay can be reduced.

[0049] However, introducing wireless radio frequency (RF) communication to achieve dual-channel communication presents several challenges. First, to transmit RF signals, modules for modulation and demodulation of RF signals need to be added to both the photovoltaic inverter 130 and the photovoltaic inverter 130. Additionally, RF transceivers and communication antennas need to be added between the photovoltaic control device 140 and the photovoltaic inverter 130. Furthermore, there are additional construction and debugging costs associated with on-site antenna debugging and frequency planning, resulting in high costs for introducing wireless RF communication. Second, since the antennas at the RF transmitter 150 and RF receiver 160 are typically lower than the photovoltaic modules, the RF signal needs to penetrate multiple layers of photovoltaic panels during transmission. This not only leads to significant signal attenuation but also exposes the RF signal to interference from signals in the same frequency band when transmitted in open environments. Moreover, the multipath effect and fading of the RF channel cause signal strength to fluctuate over time, further affecting communication stability.

[0050] Thus, in order to reduce the communication delay between the photovoltaic control device 140 and the photovoltaic inverter 130, the introduction of wireless radio frequency communication has the problems of low signal transmission reliability and high communication cost. It is difficult to meet the real-time and stability requirements of the power grid for active power dispatch and reactive power dispatch. At the same time, it will significantly increase the hardware investment cost of the photovoltaic power station 100 and the complexity of on-site construction.

[0051] To address the aforementioned issues, this application provides a photovoltaic inverter, a photovoltaic control device, and a photovoltaic power station, which are used to introduce optical wireless communication in a photovoltaic power station at low cost to meet latency requirements during the communication process.

[0052] The specific embodiments involved in this application are described in detail below with reference to the accompanying drawings.

[0053] Please see Figure 3 , Figure 3 This is a schematic diagram of the structure of a photovoltaic power station 300 provided in an embodiment of this application. The photovoltaic power station 300 provided in this embodiment includes a photovoltaic module 310, an intelligent management system 320, a photovoltaic inverter 330, and a photovoltaic control device 340.

[0054] In this embodiment, the photovoltaic inverter 330 is used to connect to the power grid 200 and the photovoltaic module 310, and is communicatively connected to the photovoltaic control device 340. One photovoltaic inverter 330 can connect to multiple photovoltaic modules 310. The intelligent management system 320 is connected to the photovoltaic control device 340 and is used to control the photovoltaic inverter 330 to convert the DC power output from the photovoltaic module 310 into AC power and output AC power to the power grid 200.

[0055] When the intelligent management system 320 is connected to the photovoltaic control device 340, it serves as the centralized control core in the photovoltaic power station 300, and is used to send control commands to the photovoltaic control device 340. The photovoltaic control device 340 includes a subarray controller 341 and a light source module 342. The subarray controller 341 is connected to the light source module 342 and is used to control the light source module 342 to output a light signal including the control command to the photovoltaic module 310 according to the control command sent by the intelligent management system 320, so as to realize optical wireless communication.

[0056] The photovoltaic module 310 is capable of responding to light signals in specific wavelengths (such as visible light, infrared light, or ultraviolet light). When operating, the photovoltaic module 310 receives natural light and converts this light energy into electrical energy, which is then output to the photovoltaic inverter 330. Furthermore, without adding additional photosensitive devices to the photovoltaic inverter 330, the photovoltaic module 310 can also receive light signals used for optical wireless communication, thus completing a hybrid function of natural light energy harvesting and light signal reception.

[0057] Furthermore, to ensure that all photovoltaic controllers 331 connected to the photovoltaic control device 340 can achieve optical wireless communication, the light source module 342 is positioned within the common visible area of ​​all photovoltaic modules 310 connected to the photovoltaic controller 331. This ensures that the light signal output by the light source module 342 can cover the light-receiving surface of each photovoltaic module 310 without obstruction. For example, when the photovoltaic power station 300 is located in the Northern Hemisphere, with the photovoltaic modules 310 facing south, the light source module 342 in the photovoltaic control device 340 can be placed on the south side of all photovoltaic modules 310, with a height higher than all photovoltaic modules 310, ensuring no obstruction between it and all photovoltaic modules 310, so that each photovoltaic module 310 can receive the light signal emitted by the light source module 342.

[0058] In addition, since the spectrum of natural light received by the photovoltaic module 310 is mainly concentrated in a relatively stable and slowly changing frequency range, while in the process of optical wireless communication, the optical signal carries information through rapid frequency changes. The frequency changes of the optical signal are significantly different from the frequency changes of natural light, and the interference of natural light on the optical signal transmitted during optical wireless communication can be almost ignored, resulting in high reliability.

[0059] In this embodiment, the photovoltaic module 310 connected to the photovoltaic inverter 330 is used to receive the optical signal output by the photovoltaic control device 340, convert the optical signal into an electrical signal, and then send the electrical signal to the photovoltaic inverter 330. When the photovoltaic module 310 outputs a DC electrical signal, the photovoltaic inverter 330 converts the DC power into AC power and transmits it to the power grid 200. Furthermore, when the electrical signal output by the photovoltaic module 310 includes optical wireless communication data, the photovoltaic inverter 330 can also, upon receiving the electrical signal output by the photovoltaic module 310, obtain the control command forwarded by the photovoltaic control device 340 based on the electrical signal, and thereby adjust the output power of the photovoltaic inverter 330 to the power grid 200 based on the control command.

[0060] Based on this, in the process of introducing optical wireless communication between the photovoltaic control device 340 and the photovoltaic inverter 330 to reduce communication delay, since a light source module 342 that converts electrical signals into optical signals is added to the photovoltaic control device 340 side, there is no need to add a photosensitive device to the photovoltaic inverter 330 side. The photovoltaic module 310 connected to the photovoltaic inverter 330 can be used to receive the optical signal, thereby reducing the cost of introducing optical wireless communication in the photovoltaic power station 300 and ensuring that the photovoltaic power station 300 can meet the real-time requirements of the power grid 200 for active power dispatch and reactive power dispatch.

[0061] Furthermore, in this embodiment, the photovoltaic inverter 330 is used to connect to the power line 350. The photovoltaic inverter 330 is used to output a first power line carrier signal to the power line 350 during operation. The first power line carrier signal includes the operating data of the photovoltaic inverter 330, such as the voltage, current, temperature and output power of the photovoltaic inverter 330, which are not limited in this application.

[0062] The subarray controller 341 in the photovoltaic control device 340 is coupled to the power line 350 and is used to receive the first power line carrier signal output by the photovoltaic inverter 330 transmitted through the power line 350 to obtain the operating data of the photovoltaic inverter 330. The subarray controller 341 is also used to feed back the operating data of the photovoltaic inverter 330 to the intelligent management system 320, so that the intelligent management system 320 can perform unified scheduling and control on the output power of each photovoltaic inverter 330 based on the operating data of each photovoltaic inverter 330 in the photovoltaic power plant 300, based on the grid 200 dispatching requirements and the goal of optimal power plant power generation efficiency, so as to ensure that the power generation performance of the photovoltaic power plant 300 is compatible with the operation stability of the grid 200, while maximizing the utilization rate of photovoltaic energy.

[0063] In this embodiment, after introducing optical wireless communication between the photovoltaic control device 340 and the photovoltaic inverter 330, power line carrier communication is used to transmit uplink signals, and optical wireless communication is used to transmit downlink signals. Uplink and downlink signals are isolated during transmission, effectively avoiding mutual interference and reducing the probability of channel preemption. When transmitting high-frequency signals between the photovoltaic control device 340 and the photovoltaic inverter 330, signal transmission efficiency and stability are improved, ensuring communication latency is within the required range and communication reliability is maintained. Furthermore, when the photovoltaic inverter 330 receives optical signals using the connected photovoltaic module 310, the introduction of optical wireless communication in the photovoltaic power station 300 eliminates the need for additional photosensitive devices, resulting in low construction and commissioning costs. This ensures low-cost and efficient signal transmission between the photovoltaic control device 340 and the photovoltaic inverter 330.

[0064] Furthermore, when the photovoltaic control device 340 sends a downlink signal including control commands to the photovoltaic inverter 330, the inverter 330 needs to respond to the control commands within a very short time. For example, when the grid voltage fluctuates, the inverter needs to quickly adjust its output power according to the control commands to ensure the stability, safety, and control accuracy of the system operation. Therefore, compared to the uplink signal from the photovoltaic inverter 330 to the photovoltaic control device 340 that feeds back operating data, the downlink signal from the photovoltaic control device 340 to the photovoltaic inverter 330 has a higher time delay requirement.

[0065] Therefore, when optical signals are not easily affected by electromagnetic interference and channel attenuation, and the frequency of optical signals is much higher than that of power line carrier signals, the available bandwidth in optical wireless communication is larger, and higher data transmission rates can be supported. In this application, when optical wireless communication is used to transmit downlink signals, it not only does not need to compete for the channel with uplink signals using power line carrier communication, but also fully utilizes the advantages of low latency and high bandwidth of optical wireless communication in high-speed transmission scenarios, ensuring the real-time performance and reliability of control actions.

[0066] In some situations, such as in severe weather, if optical wireless communication is used between the photovoltaic control device 340 and the photovoltaic inverter 330, there may be problems with poor transmission performance. For example, fog, rain, snow, dust, etc., can cause scattering and absorption of the light beam during optical signal transmission, resulting in power attenuation of the light signal. Uneven temperature and humidity can cause changes in the air refractive index, leading to jitter, spread, and flicker of the light beam, as well as instability in the intensity and phase of the light signal, resulting in an increased bit error rate.

[0067] In some embodiments, the subarray controller 341 in the photovoltaic control device 340 is also used to send a second power line carrier signal to the power line 350. The second power line carrier signal includes control commands. The photovoltaic inverter 330 is used to obtain control commands based on the second power line carrier signal when it receives the second power line carrier signal transmitted by the power line 350, and adjust its output power to the grid 200 based on the control commands.

[0068] Based on this, when the photovoltaic control device 340 sends downlink signals including control commands to the photovoltaic inverter 330, it can prioritize optical wireless communication when the weather conditions are good to improve the efficiency of downlink signal transmission. When the weather conditions are bad and the optical wireless communication effect is poor, the downlink signal transmission can be switched to power line carrier communication to ensure the reliability of signal transmission between the photovoltaic control device 340 and the photovoltaic inverter 330.

[0069] Please see Figure 4 , Figure 4 This is a schematic diagram of the structure of a photovoltaic inverter 400 provided in an embodiment of this application. The photovoltaic inverter 400 provided in this embodiment includes a photovoltaic controller 410, an inverter circuit 420, and a sampling circuit 430.

[0070] In this embodiment, the photovoltaic module 310 receives natural light and light signals including control commands when it is working, and converts the natural light and light signals into electrical signals when they are superimposed, and then outputs them to the photovoltaic inverter 400. The inverter circuit 420 is used to connect the photovoltaic module 310 and the power grid, and includes a DC-AC converter for converting the DC power output by the photovoltaic module 310 into AC power for output to the power grid.

[0071] The irradiance of natural light is mainly caused by cloud cover, slow changes in the sun's position, and temperature changes. Its frequency is relatively stable and changes slowly. It appears as a low-frequency DC signal (such as 0Hz-1Hz) at the output of the photovoltaic module 310. In contrast, the optical signal transmitted by optical wireless transmission carries information through rapid frequency changes. It appears as a high-frequency AC signal (such as above 45kHz) at the output of the photovoltaic module 310 and is superimposed on the low-frequency DC signal. The electrical signal transmitted during power line carrier communication is generally in the bandwidth range of 50kHz-150kHz and is superimposed on the AC signal transmitted by the three-phase power line 350. In order to extract the optical wireless communication transmission signal from the mixed electrical signal output by the photovoltaic module 310, taking advantage of the frequency difference between the optical wireless communication transmission signal and the natural light signal in the electrical signal output by the photovoltaic module 310, a sampling circuit 430 is set in the photovoltaic inverter 400 and connected between the photovoltaic module 310 and the photovoltaic controller 410. The sampling circuit 430 is used to sample the electrical signal output by the photovoltaic module 310 including the control command, that is, to separate the high-frequency electrical signal part from the mixed electrical signal output by the photovoltaic module 310.

[0072] The photovoltaic controller 410 is connected to the inverter circuit 420 and the sampling circuit 430. After the sampling circuit 430 samples an electrical signal including a control command, the controller 410 can obtain the electrical signal from the sampling circuit 430, derive the control command based on the electrical signal, and adjust the output power of the inverter circuit 420 based on the control command. Furthermore, the photovoltaic controller 410 can also collect operating data of the photovoltaic inverter 400 during the operation of the inverter circuit 420, such as the voltage, current, temperature, and output power of the photovoltaic inverter 400. Based on the operating data, it generates a first power line carrier signal and transmits the first power line carrier signal to the power line 350.

[0073] In some implementations, such as under severe weather conditions, the transmission of downlink signals between the photovoltaic control device and the photovoltaic inverter 400 is switched from optical wireless communication to power line carrier communication. When the photovoltaic controller 410 receives the second power line carrier signal transmitted by the power line 350, it obtains control commands based on the second power line carrier signal and adjusts the output power of the inverter circuit 420 to the grid based on the control commands, thereby ensuring the reliability of signal transmission between the photovoltaic control device and the photovoltaic inverter 400.

[0074] In some implementations, such as Figure 5 As shown, Figure 5 This is a schematic diagram of another photovoltaic inverter 400 provided in an embodiment of this application. The photovoltaic inverter 400 provided in this embodiment also includes a filter circuit 440.

[0075] In this embodiment, a filter circuit 440 is connected between the photovoltaic module 310 and the inverter circuit 420. The filter circuit 440 includes a first capacitor C1 and a second capacitor C2. The first capacitor C1 and the second capacitor C2 are connected in parallel, and the sampling circuit is connected in series with the first capacitor C1. That is, one end of the first capacitor C1 in the filter circuit 440 is connected to one end of the second capacitor C2, and the sampling circuit is connected between the other ends of the first capacitor C1 and the other ends of the second capacitor C2. Furthermore, the capacitance value of the first capacitor C1 is smaller than the capacitance value of the second capacitor C2. The first capacitor C1 has the characteristic of passing high frequencies and blocking low frequencies, and is used to filter out high-frequency noise transmitted between the photovoltaic module 310 and the inverter circuit 420 (such as high-frequency harmonics generated by the switching action of the inverter circuit 420). A larger capacitance value results in better filtering. The second capacitor C2 has the characteristic of passing low frequencies and blocking high frequencies. It is used to filter out low-frequency noise transmitted between the photovoltaic module 310 and the inverter circuit 420 (such as low-frequency fluctuations in the output electrical signal of the photovoltaic module 310 caused by the influence of the environment on natural light). The smaller the capacitance value, the better the filtering effect. The combined use of the first capacitor C1 and the second capacitor C2 can improve the noise filtering effect in the photovoltaic inverter 400 and ensure the stable operation of the inverter circuit 420.

[0076] The sampling circuit includes a sampling resistor R. Specifically, a sampling resistor R is connected in series with a first capacitor C1 (which has a relatively small capacitance) in the filter circuit 440. The sampling resistor R and the first capacitor C1 form a high-pass filter branch. By designing the resistance value of the sampling resistor R, the cutoff frequency of this high-pass filter branch is matched with the frequency of the electrical signal transmitted via optical wireless communication output from the photovoltaic module 310. This allows the high-frequency electrical signal generated by optical signal modulation in the output of the photovoltaic module 310 to pass through and be acquired by the photovoltaic controller 410 after passing through the sampling resistor R.

[0077] For example, in the light source module, the bandwidth of the electrical signal modulated by the light source is 200kHz, allowing the intensity of the output optical signal to vary with the frequency of the electrical signal. In this case, the light source driver module can effectively amplify and transmit modulated electrical signals with frequencies above 45kHz for wireless optical transmission, thus ensuring good modulation quality and communication performance of the output optical signal. A high-pass filter branch with a sampling resistor R has a cutoff frequency of 45kHz for the electrical signal, enabling the high-pass filter branch to effectively transmit electrical signals with frequencies above 45kHz, thereby achieving signal acquisition for wireless optical transmission at the sampling resistor R.

[0078] In this way, by utilizing the first capacitor C1 in the filter circuit 440, which has high-frequency and low-impedance characteristics, only a sampling resistor R needs to be connected in series at the first capacitor C1 to extract the electrical signal of optical wireless communication transmission, thereby reducing the modification cost of the photovoltaic inverter 400 side when realizing optical wireless communication.

[0079] In this embodiment, the filter circuit 440 further includes an inductor L, a first switch Q1, a second switch Q2, and a third capacitor C3. One end of the inductor L is connected to one end of the second capacitor C2, and the other end of the inductor L is connected to one end of the first switch Q1. The other end of the first switch Q1 is connected to the other end of the second capacitor C2. The inductor L is used to suppress current surges and works with the second capacitor C2 to improve the noise filtering effect.

[0080] One end of the second switch Q2 is connected to the other end of the inductor L, and the other end of the second switch Q2 is connected to one end of the third capacitor C3. The other end of the third capacitor C3 is connected to the other end of the first switch Q1. The photovoltaic controller 410 controls the switching action of the second switch Q2 to control the conduction and disconnection between the photovoltaic module 310 and the filter circuit 440. The third capacitor C3 is used to work with the second capacitor C2 to improve the noise filtering effect, and at the same time to alleviate the voltage surge when the first switch Q1 switches.

[0081] In this embodiment, as Figure 5 As shown, the photovoltaic controller 410 in the photovoltaic inverter 400 includes a first control unit 411 and a first receiving channel 412. The first receiving channel 412 is connected between the first control unit 411 and the sampling circuit, and is used to receive the electrical signal sampled by the sampling circuit and send the electrical signal to the first control unit 411. The first control unit 411 is connected to the inverter circuit 420. Figure 5 The connection between the first control unit 411 and the inverter circuit 420 is not shown in the diagram. It is used to control the output power of the inverter circuit 420.

[0082] The first receiving channel 412 includes a differential conversion circuit 4121 and a first analog-to-digital converter 4122. The differential conversion circuit 4121 is connected to the sampling circuit and converts the electrical signal sampled by the sampling circuit into a differential signal. The first analog-to-digital converter 4122 is connected to the differential conversion circuit 4121 and a first control unit 411 and converts the differential signal into a first digital signal, which is then sent to the first control unit 411. When the differential conversion circuit 4121 is connected across the sampling circuit, a weak voltage signal proportional to the current is generated across the sampling resistor R. The differential conversion circuit 4121 amplifies, reduces noise, and performs common-mode rejection on the voltage signal, converting the sampled voltage signal into a differential signal to meet the input requirements of subsequent analog-to-digital conversion.

[0083] Furthermore, the photovoltaic controller 410 also includes a first transmitting channel 413, a second receiving channel 414, and a first coupling circuit 415. The first transmitting channel 413 and the second receiving channel 414 are coupled to the power line 350 through the first coupling circuit 415. The first control unit 411 is connected to the first transmitting channel 413 and is used to transmit a first power line carrier signal to the power line 350 through the first transmitting channel 413. The second receiving channel 414 is connected to the first control unit 411 and is used to receive the second power line carrier signal transmitted from the power line 350 and transmit the second power line carrier signal to the first control unit 411.

[0084] Specifically, the first coupling circuit 415 can be composed of capacitors, inductors, transformers, etc., and is used to isolate the photovoltaic controller 410 on the low-voltage side from the power line 350 on the high-voltage side, and to enable the photovoltaic controller 410 and the power line 350 to be safely and efficiently coupled. That is, it can prevent the high-voltage electrical signal transmitted by the power line 350 from entering the photovoltaic controller 410, while realizing the coupling transmission of the power line carrier signal between the photovoltaic controller 410 and the power line 350.

[0085] In some implementations, such as Figure 5 As shown, the first transmission channel 413 includes a digital-to-analog converter DAC1 and a line driver LD1. The digital-to-analog converter DAC1 is used to convert the digital signal output by the first control unit 411 into an analog signal, and the line driver LD1 is used to amplify the power of the analog signal to compensate for the attenuation of the signal during transmission and coupling, and to ensure the transmission effect of the signal in the power line 350.

[0086] In addition, the second receiving channel 414 includes an analog-to-digital converter ADC1 and a band pass filter BPF1. The band pass filter BPF1 is used to filter the second power line carrier signal received from the power line 350, that is, to suppress low-frequency power frequency interference and high-frequency electromagnetic noise, and improve the signal-to-noise ratio. The analog-to-digital converter ADC1 is used to convert the second power line carrier signal (analog signal) into a digital signal that can be received by the first control unit 411 and transmitted to the first control unit 411.

[0087] When the first control unit 411 is connected to the first transmitting channel 413, the first receiving channel 412, and the second receiving channel 414, the first control unit 411 is configured to prioritize processing signals obtained from the first receiving channel 412, i.e., signals including control commands transmitted via optical wireless communication. This reduces the queuing and processing delays of control commands within the first control unit 411, enabling it to control the inverter circuit 420 to adjust its output power more quickly based on the control commands. This ensures that the photovoltaic inverter 400 responds rapidly to power regulation demands issued by the grid dispatching or intelligent management system, thereby improving the power control accuracy and dynamic response performance of the photovoltaic power plant.

[0088] On the photovoltaic inverter 400 side, when optical wireless communication is introduced into the photovoltaic power station to realize downlink communication, there is no need to add photosensitive devices on the photovoltaic inverter 400 side. The photovoltaic module 310 connected to the photovoltaic inverter 400 can realize the reception of optical signals. Furthermore, after adding a sampling circuit and a first receiving channel 412 in the photovoltaic inverter 400, the photovoltaic controller 410 can realize the acquisition of optical signals transmitted by optical wireless communication, which reduces the modification and debugging costs of the photovoltaic inverter 400 side when realizing optical wireless communication.

[0089] In some implementations, such as Figure 6 As shown, Figure 6 This is a schematic diagram of a photovoltaic control device 500 provided in an embodiment of this application. The photovoltaic control device 500 provided in this embodiment includes a subarray controller 510 and a light source module 520.

[0090] In this embodiment, the subarray controller 510 is connected to the light source module 520 and includes a second control unit 511, a second transmitting channel 512, a third receiving channel 513, and a second coupling circuit 514. The second transmitting channel 512 and the third receiving channel 513 are coupled to the power line 350 through the second coupling circuit 514. The second control unit 511 is connected to the light source module 520 and the second transmitting channel 512. The second control unit 511 is used to control the light source module 520 to output an optical signal when the photovoltaic control device 500 and the photovoltaic inverter transmit downlink signals using optical wireless communication. The second control unit 511 is also used to send a second power line carrier signal to the power line 350 through the second transmitting channel 512 when the photovoltaic control device 500 and the photovoltaic inverter transmit downlink signals using power line carrier communication. The third receiving channel 513 is connected to the second control unit 511 and is used to receive the first power line carrier signal transmitted from the power line 350 and transmit the first power line carrier signal to the second control unit 511.

[0091] Specifically, the second coupling circuit 514 is used to isolate the subarray controller 510 on the low-voltage side from the power line 350 on the high-voltage side, and to enable the subarray controller 510 and the power line 350 to be safely and efficiently coupled together. That is, it can prevent the high-voltage electrical signal transmitted by the power line 350 from entering the subarray controller 510, while realizing the coupling transmission of the power line carrier signal between the subarray controller 510 and the power line 350.

[0092] The second transmission channel 512 includes a digital-to-analog converter DAC2 and a line driver LD2. The digital-to-analog converter DAC2 is used to convert the digital signal output by the second control unit 511 into an analog signal, and the line driver LD2 is used to amplify the power of the analog signal to compensate for the attenuation of the signal during transmission and coupling, and to ensure the transmission effect of the signal in the power line 350.

[0093] In addition, the third receiving channel 513 includes an analog-to-digital converter ADC2 and a bandpass filter BPF2. The bandpass filter BPF2 is used to filter the first power line carrier signal received from the power line 350. The analog-to-digital converter ADC2 is used to convert the first power line carrier signal (analog signal) into a digital signal that can be received by the second control unit 511 and transmitted to the second control unit 511.

[0094] In one implementation, the light source module 520 is electrically connected to the subarray controller 510, and the position of the light source module 520 is movable. For example, the light source module 520 is connected to the subarray controller 510 via a cable of a certain length, and its base is movable. The light source module 520 includes a light source driving module 521 and a light source 522. The light source driving module 521 is connected to the light source 522 and is used to drive the light source 522 to output an optical signal under the control of the subarray controller 510. The light source 522 includes, but is not limited to, a laser light source 522 and a light-emitting diode. Since infrared light is not in the visible light range, it is not easily interfered with by visible light in natural light, thus maintaining a high signal-to-noise ratio. Therefore, infrared light is preferentially selected as the optical signal output by the light source 522. For example, the light source 522 is an array of light-emitting diodes with an output light wavelength of 850nm.

[0095] In this embodiment, the second transmission channel 512 further includes a switch K, which is connected between the digital-to-analog converter and the line driver of the second transmission channel 512. The light source driving module 521 is connected to the second control unit 511 and the digital-to-analog converter of the second transmission channel 512.

[0096] When the photovoltaic control device 500 and the photovoltaic inverter transmit downlink signals via optical wireless communication, switch K disconnects the connection between the digital-to-analog converter and the line driver. The second control unit 511 sends an enable signal to the light source drive module 521. With the enable of the second control unit 511, the light source drive module 521 drives the light source 522 to output a light signal including control commands based on the signal received from the second transmission channel 512.

[0097] When the photovoltaic control device 500 and the photovoltaic inverter transmit downlink signals via power line carrier communication, switch K connects the digital-to-analog converter and the line driver, the second control unit 511 stops sending enable signals to the light source drive module 521, and the second transmission channel 512 sends the second power line carrier signal, which includes control commands, to the power line 350.

[0098] As one implementation method, such as Figure 7 As shown, Figure 7 This is a schematic diagram of another photovoltaic control device 500 provided in an embodiment of this application. The light source module 520 provided in this embodiment is communicatively connected to the subarray controller 510, and the position of the light source module 520 is movable.

[0099] For example, the light source module 520 is installed on aerial mobile platforms such as drones and airships, and the subarray controller 510 communicates with the light source module 520 via wireless communication, laser communication, or other means. While ensuring that each photovoltaic module can receive the light signal emitted by the light source module 520, the light source module 520 can be moved to different locations according to actual needs. By flexibly adjusting the illumination area of ​​the light source module 520, it can adapt to changes in photovoltaic module layout or environment, thereby improving the reliability and adaptability of the optical wireless communication between the photovoltaic control device 500 and the photovoltaic inverter.

[0100] In this embodiment, the second control unit 511 is used to send an enable signal to the light source driving module 521. When enabled by the second control unit 511, the light source driving module 521 drives the light source 522 to output a light signal including the control command based on the signal including the control command received from the second control unit 511.

[0101] On the photovoltaic control device 500 side, when optical wireless communication is introduced into the photovoltaic power station to realize downlink communication, only a light source module 520 needs to be added to the photovoltaic control device 500 side to connect with the sub-array controller 510. The light source module 520 can realize the transmission of optical signals for optical wireless communication transmission and work in conjunction with the photovoltaic modules connected to the photovoltaic inverter side, reducing the modification and debugging costs when realizing optical wireless communication in the photovoltaic power station.

[0102] Please see Figure 8 , Figure 8This is a schematic diagram of another photovoltaic power station 300 provided in an embodiment of this application. The photovoltaic power station 300 provided in this embodiment includes a photovoltaic module 310, an intelligent management system 320, a photovoltaic inverter 330, and a photovoltaic control device 340.

[0103] In this embodiment, the photovoltaic inverter 330 is used to connect to the photovoltaic module 310 and to communicate with the photovoltaic control device 340 via optical wireless communication and power line carrier communication. One photovoltaic inverter 330 can connect to multiple photovoltaic modules 310. The photovoltaic inverter 330 includes a photovoltaic controller 331, an inverter circuit 332, and an AC output connector 333. The photovoltaic controller 331 is connected to the inverter circuit 332 and the AC output connector 333. The inverter circuit 332 converts the DC power output from the photovoltaic module 310 into three-phase AC power and outputs it to the AC output connector 333. The photovoltaic controller 331, connected to the inverter circuit 332 and the AC output connector 333, controls the output power of the photovoltaic inverter 330.

[0104] The photovoltaic inverter 330 also includes a differential-mode inductor 334 and a common-mode inductor 335. The differential-mode inductor 334 is connected between the inverter circuit 332 and the common-mode inductor 335. The common-mode inductor 335 is connected to the AC output connector 333. The differential-mode inductor 334 and the common-mode inductor 335 work together to suppress the differential-mode interference and common-mode interference generated by the inverter circuit 332, and reduce the impact of electromagnetic interference on the power grid 200. The AC output connector 333 serves as the physical connection interface between the photovoltaic inverter 330 and the external power grid 200 or distribution cabinet, realizing the safe output of three-phase AC power.

[0105] Furthermore, the photovoltaic power station 300 also includes a low-voltage distribution cabinet 360 and a high-voltage cabinet 370. The AC output connector 333 of each photovoltaic inverter 330 is connected to the input terminal of the low-voltage distribution cabinet 360 via three-phase power lines 350. After current collection and preliminary power distribution, the output is sent from the low-voltage distribution cabinet 360 to the high-voltage cabinet 370. The high-voltage cabinet 370 steps up the low-voltage AC power to meet the high-voltage AC power requirements of the grid 200 before connecting it to the grid 200 or a substation, thereby realizing grid-connected power generation of the photovoltaic power station 300.

[0106] The intelligent management system 320 connects multiple photovoltaic control devices 340. Each photovoltaic control device 340 is communicatively connected to multiple photovoltaic inverters 330. The photovoltaic control device 340 is coupled to the three-phase power line 350 of the low-voltage distribution cabinet 360 of the transformer substation. The intelligent management system 320 is used to issue control commands to the photovoltaic control devices 340, and the photovoltaic control devices 340, acting as a central coordinator, forward the commands to the photovoltaic inverters 330 with which they are communicatively connected.

[0107] In this embodiment, after introducing optical wireless communication into the photovoltaic power station 300, power line carrier communication is used to transmit uplink signals including working data, and optical wireless communication is used to transmit downlink signals including control commands. Uplink and downlink signals are isolated during transmission. When transmitting high-frequency signals between the photovoltaic control device 340 and the photovoltaic inverter 330, mutual interference between uplink and downlink signals is effectively avoided, and the probability of channel preemption events is reduced. This improves signal transmission efficiency and stability, ensuring communication latency is within the required range and communication reliability. Furthermore, when optical wireless communication is ineffective, the transmission of downlink signals between the photovoltaic control device 340 and the photovoltaic inverter 330 switches back to power line carrier communication, ensuring the reliability of signal transmission between the two devices.

[0108] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any changes or substitutions within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A photovoltaic inverter, characterized in that, The photovoltaic inverter is used to communicate with the photovoltaic control device, the photovoltaic control device is used to output light signals to the photovoltaic module, and the photovoltaic module is used to convert the light signals into electrical signals. The photovoltaic inverter is used to connect to the photovoltaic module and to adjust the output power according to the electrical signal output by the photovoltaic module when it receives the electrical signal.

2. The photovoltaic inverter according to claim 1, characterized in that, The photovoltaic inverter includes a photovoltaic controller, an inverter circuit, and a sampling circuit; The inverter circuit is used to connect the photovoltaic module; The sampling circuit is connected between the photovoltaic module and the photovoltaic controller, and is used to sample the electrical signal output by the photovoltaic module; The photovoltaic controller is connected to the inverter circuit and is used to obtain the electrical signal from the sampling circuit and adjust the output power of the inverter circuit according to the electrical signal.

3. The photovoltaic inverter according to claim 2, characterized in that, The photovoltaic inverter also includes a filter circuit, which is connected between the photovoltaic module and the inverter circuit, and the filter circuit includes a first capacitor and a second capacitor. The first capacitor and the second capacitor are connected in parallel, and the capacitance of the first capacitor is less than the capacitance of the second capacitor. The sampling circuit is connected in series with the first capacitor.

4. The photovoltaic inverter according to claim 2, characterized in that, The photovoltaic controller includes a first control unit and a first receiving channel. The first receiving channel is connected between the first control unit and the sampling circuit. The first receiving channel includes: A differential conversion circuit, connected to the sampling circuit, is used to convert the electrical signal sampled by the sampling circuit into a differential signal; A first analog-to-digital converter, connected to the differential conversion circuit and the first control unit, is used to convert the differential signal into a first digital signal and send the first digital signal to the first control unit.

5. The photovoltaic inverter according to any one of claims 1 to 4, characterized in that, The photovoltaic inverter is used to connect to the power line and to output a first power line carrier signal to the power line, the first power line carrier signal including the operating data of the photovoltaic inverter.

6. The photovoltaic inverter according to claim 5, characterized in that, The photovoltaic control device is also used to output a second power line carrier signal to the power line; The photovoltaic inverter is used to adjust its output power according to the second power line carrier signal when it receives the second power line carrier signal transmitted by the power line.

7. The photovoltaic inverter according to claim 6, characterized in that, The photovoltaic controller further includes a first transmitting channel, a second receiving channel, and a first coupling circuit, wherein the first transmitting channel and the second receiving channel are coupled to the power line through the first coupling circuit; The first control unit is connected to the first transmission channel and is used to transmit the first power line carrier signal to the power line through the first transmission channel. The second receiving channel is connected to the first control unit and is used to receive the second power line carrier signal transmitted by the power line and transmit the second power line carrier signal to the first control unit.

8. The photovoltaic inverter according to any one of claims 5 to 7, characterized in that, The operating data of the photovoltaic inverter includes the inverter's voltage, current, temperature, and output power.

9. A photovoltaic control device, characterized in that, The photovoltaic control device includes a subarray controller and a light source module; The subarray controller is connected to the light source module and controls the light source module to output light signals. The photovoltaic module receives the light signals, converts the light signals into electrical signals, and sends the electrical signals to the photovoltaic inverter.

10. The photovoltaic control device according to claim 9, characterized in that, The subarray controller is coupled to the power line and receives the first power line carrier signal output by the photovoltaic inverter transmitted through the power line.

11. The photovoltaic control device according to claim 10, characterized in that, The subarray controller is also used to send a second power line carrier signal to the power line.

12. The photovoltaic control device according to claim 11, characterized in that, The subarray controller includes a second control unit, a second transmitting channel, a third receiving channel, and a second coupling circuit. The second transmitting channel and the third receiving channel are coupled to the power line through the second coupling circuit. The second control unit is connected to the light source module and the second emission channel, and is used to control the light source module to output the light signal; or, The second control unit is used to transmit the second power line carrier signal to the power line through the second transmission channel; The third receiving channel is connected to the second control unit and is used to receive the first power line carrier signal transmitted by the power line and transmit the first power line carrier signal to the second control unit.

13. The photovoltaic control device according to any one of claims 9 to 12, characterized in that, The position of the light source module is movable.

14. A photovoltaic power station, characterized in that, The photovoltaic power station includes photovoltaic modules, an intelligent management system, a photovoltaic inverter as described in any one of claims 1 to 8, and a photovoltaic control device as described in any one of claims 9 to 13; The photovoltaic inverter is used to connect to the power grid and the photovoltaic modules, and is communicatively connected to the photovoltaic control device. The intelligent management system is connected to the photovoltaic control device and is used to control the photovoltaic inverter to convert the direct current output by the photovoltaic module into alternating current and output the alternating current to the power grid.

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