Photovoltaic inverter system, control method and control device thereof, and readable storage medium

Abstract

The invention provides a photovoltaic inverter system, a control method and a control device thereof, and a readable storage medium, and relates to the field of photovoltaic technology. The photovoltaic inverter system comprises a photovoltaic power generation unit; the system controller is used for sending a query frame under the condition that the initialization of the photovoltaic inverter system is completed; determining an arc threshold value according to the receiving state of the response information corresponding to the query frame; and the energy conversion module is electrically connected with the photovoltaic power generation unit and is in communication connection with the system controller, and the energy conversion module is used for executing arc fault processing operation according to a comparison result of the arc detection value of the photovoltaic power generation unit and an arc threshold value. According to the invention, whether there is power line carrier communication interference is determined according to whether the corresponding response information is received, and the corresponding arc threshold value is dynamically set, so that arc fault false detection caused by power line carrier communication can be avoided, and the output stability of the photovoltaic inverter system is improved.

Description

Technical Field

[0001] The present application relates to the field of photovoltaic technology, and in particular to a photovoltaic inverter system and a control method, a control device, and a readable storage medium thereof. Background Art

[0002] In the relevant technology, for the scenario of photovoltaic power generation, DC arc fault is one of the main faults that affect system safety. In order to prevent arc damage, it is necessary to arrange an arc detection system in the photovoltaic inverter system. The arc detection system is based on the harmonic analysis of the DC bus current. When the arc detection value obtained by analysis is greater than the set arc strength threshold, it is judged that an arc fault has occurred.

[0003] In some photovoltaic energy systems, a photovoltaic optimizer capable of controlling the output of photovoltaic power generation units is provided. In order to monitor and control the operating data and operating status of the photovoltaic optimizer, the photovoltaic optimizer is networked by means of rectifier carrier communication, so as to collect and send data. Since the data carrier of DC carrier communication is a high-frequency current signal, its frequency overlaps with the harmonic characteristic frequency of DC arc detection. This special situation cannot effectively distinguish the DC arc, resulting in that when the current on the photovoltaic side is large, the arc detection device may calculate a large arc strength, which is greater than the set arc strength threshold, resulting in a false alarm of an arc fault, which will cause an abnormal interruption of the system output and affect the stability of the system output. Summary of the invention

[0004] The present application aims to solve at least one of the technical problems existing in the prior art or related art.

[0005] To this end, a first aspect of the present application proposes a photovoltaic inverter system.

[0006] A second aspect of the present application provides a control method for a photovoltaic inverter system.

[0007] A third aspect of the present application provides a control device for a photovoltaic inverter system.

[0008] A fourth aspect of the present application provides a readable storage medium.

[0009] In view of this, the first aspect of the present application provides a photovoltaic inverter system, including: a photovoltaic power generation unit; a system controller, the system controller is used to send a query frame when the photovoltaic inverter system is initialized; and determine the arc threshold according to the reception status of the response information corresponding to the query frame; an energy conversion module, the energy conversion module is electrically connected to the photovoltaic power generation unit and is communicatively connected to the system controller, the energy conversion module is used to perform an arc fault processing operation according to the comparison result of the arc detection value of the photovoltaic power generation unit and the arc threshold.

[0010] In this technical solution, the photovoltaic inverter system includes a photovoltaic power generation unit, a system controller and an energy conversion module. There may be multiple photovoltaic power generation units, and illustratively, multiple photovoltaic power generation units may be connected in series or in parallel. Each photovoltaic power generation unit may be a PV (photovoltaic) panel, and the photovoltaic power generation unit may utilize the photovoltaic effect to convert solar radiation energy into electrical energy.

[0011] The energy conversion module can be a photovoltaic inverter module or an energy storage hybrid inverter module. The energy conversion module receives the electric energy generated by multiple photovoltaic power generation units, and inverts this part of the DC signal to output an AC signal. This part of the AC signal can be provided to the load for use, or it can be connected to the grid and output to the grid. It can also be further rectified to charge energy storage devices such as battery components. The system controller can be a local edge controller that can collect information from all modules in the system and output control instructions. The system controller can also be integrated inside the energy conversion module.

[0012] Exemplarily, an arc fault detection unit is integrated in the energy conversion module, and the arc fault detection unit is used to detect DC arc faults in the system, that is, arc faults on the power transmission line on the input side of the inverter. Exemplarily, the arc fault detection unit collects the current signal on the power transmission line on the photovoltaic side, and performs harmonic analysis on the current signal on the power transmission line, and determines whether there is an arc fault based on the harmonic characteristics of the current signal on the power transmission line. Exemplarily, on the basis of harmonic analysis, an AI (Artificial Intelligence) algorithm can be added to improve the detection accuracy of arc faults.

[0013] The energy conversion module collects the arc detection value of the photovoltaic power generation unit through the arc fault detection unit therein. For example, the arc detection characteristic value is obtained by extracting the characteristics of the current signal on the power transmission line. After collecting the corresponding arc detection value, the energy conversion module determines whether the collected current detection value is greater than the arc threshold. If the current detection value is greater than the arc threshold, it means that an arc fault has occurred. At this time, an arc fault processing operation is performed, such as shutting down the output of the photovoltaic power generation unit to ensure system safety.

[0014] Since some modules in the photovoltaic inverter system may use power carrier communication as the communication mode, and since the data carrier of the DC power carrier communication is a high-frequency current signal, its frequency overlaps with the harmonic characteristic frequency of the DC arc detection, this special case cannot effectively distinguish the DC arc. In this regard, the system controller sends a query frame after the photovoltaic inverter system is initialized, where a query frame corresponds to a communication mode, such as query frame A for the power carrier communication mode and query frame B for the wireless communication mode.

[0015] After the system controller sends out the query frame, the system controller determines whether the response information of the corresponding query frame is received, and dynamically sets the corresponding arc threshold according to the reception status of the response information. For example, when the response information of the query frame A is received, it means that there is a functional module of power carrier communication in the system at this time. At this time, a relatively high arc threshold can be set to avoid the false detection of arc faults due to the influence of the power carrier signal. If the response information of the query frame A is not received, but the response information of the query frame B is received, it means that there is no functional module of power carrier communication in the system. At this time, the standard arc threshold is set to ensure the reliability and sensitivity of arc fault detection.

[0016] After the initialization of the photovoltaic inverter system is completed, the application sends a query frame through the system controller, and determines whether there is power carrier communication interference based on whether the corresponding response information is received, and dynamically sets the corresponding arc threshold, which can avoid false detection of arc faults caused by power carrier communication and improve the stability of the photovoltaic inverter system output.

[0017] In addition, the photovoltaic inverter system in the above technical solution provided by this application may also have the following additional technical features:

[0018] In some technical solutions of the present application, optionally, the system controller is also used to: send a second query frame when the time elapsed after sending the first query frame reaches a preset time elapsed and no response information is received; resend the first query frame and the second query frame when the time elapsed after sending the second query frame reaches a preset time elapsed and no response information is received; and determine that the arc threshold is a non-power carrier communication threshold when the number of times the first query frame and the second query frame are sent reaches a number threshold.

[0019] In this technical solution, in order to facilitate control, the system controller sends query frames corresponding to possible functional modules one by one in a polling manner. Exemplarily, after the photovoltaic inverter system completes the initialization step, the system controller first sends a first query frame through the internal network. The first query frame can be a protocol frame corresponding to the power carrier communication. If a response message is received within a preset time after the first query frame is sent, it means that there is a power carrier communication module in the system. If no response message is received within the preset time, it means that there is no power carrier communication module in the system. At this time, the second query frame continues to be sent. Exemplarily, the second query frame can be a module of other communication methods, such as wireless communication.

[0020] If no response information is received within a preset time after sending the second query frame, the first query frame and the second query frame are resent to avoid failure in receiving the response information due to module startup delay or communication packet loss.

[0021] Exemplarily, the above preset time length ranges from 500ms to 10s.

[0022] When it is detected that the number of times the first query frame and the second query frame are sent reaches the set upper limit, that is, greater than or equal to the above-mentioned number threshold, it means that there are no other modules in the system that need to communicate with the system controller, that is, there is no possibility of interference with arc detection caused by communication with other modules. At this time, the arc threshold is set to the non-power carrier communication threshold. The non-power carrier communication threshold is a threshold that can sensitively detect arc faults in the absence of external interference, thereby ensuring the sensitivity and reliability of arc fault detection.

[0023] Exemplarily, the above number threshold ranges from 4 times to 12 times.

[0024] Exemplarily, the above-mentioned non-power carrier communication threshold is the arc threshold calibrated by the photovoltaic power generation unit before leaving the factory.

[0025] In some technical solutions of the present application, optionally, the photovoltaic inverter system also includes: a photovoltaic control component, which is electrically connected to the photovoltaic power generation unit; a component monitoring module, which is communicatively connected to the energy conversion module and the photovoltaic control component, and the component monitoring module is used to control the photovoltaic control component to shut down the output of the photovoltaic power generation unit when receiving a switching signal; the energy conversion module is also used to send a switching signal to the component monitoring module when it detects that the arc detection value is greater than or equal to the arc threshold.

[0026] In this technical solution, the photovoltaic inverter system includes a photovoltaic control component. When the number of photovoltaic power generation units is multiple, the number of photovoltaic control components is the same as the number of photovoltaic power generation units in the photovoltaic control component. A photovoltaic control component is arranged on each photovoltaic power generation unit, and the photovoltaic control component can control the output of the photovoltaic power generation unit. The output ends of the multiple photovoltaic control components are connected to power transmission lines, and the multiple power transmission lines converge to the input end of the energy conversion module.

[0027] The component monitoring module is also connected to the energy conversion module and each photovoltaic control component. For example, when the energy conversion module detects that the arc detection value reaches the arc threshold value set by the system controller, it indicates that an arc fault may exist at this time. In addition to reporting the abnormal information to the communication ARM (Advanced RISC Machine, microprocessor) chip inside the inverter by communication, the arc fault detection unit in the energy conversion module can also directly send a switch signal to the component monitoring module. The switch signal is a dedicated fast switch signal.

[0028] The component monitoring module includes a dedicated communication chip. The switching signal emitted by the energy conversion module is transmitted to the dedicated communication chip. After receiving the switching signal, the dedicated communication chip sends a broadcast command signal to the corresponding photovoltaic control component, thereby controlling the photovoltaic control component to shut down the output of the photovoltaic power generation unit.

[0029] The technical solution of the present application, by setting up a component monitoring module and an independent photovoltaic control component, eliminates the need to retransmit the above-mentioned switch signal through a communication ARM chip, thereby effectively saving communication forwarding time and facilitating the realization of an arc extinguishing operation with a faster response speed.

[0030] In some technical solutions of the present application, optionally, the photovoltaic control component and the component monitoring module are communicatively connected via power carrier communication; the component monitoring module is further used to send a first response message to the system controller when a first query frame is received; the system controller is further used to determine that the arc threshold is a power carrier communication threshold when the first response message is received; wherein the power carrier communication threshold is greater than the non-power carrier communication threshold.

[0031] In this technical solution, the component monitoring module and the photovoltaic control component are connected to each other by means of power carrier communication. Exemplarily, the component monitoring module includes a dedicated communication chip, which is a power carrier communication chip. After the switch signal is transmitted to the power carrier communication chip of the component monitoring module, the power carrier communication chip sends a broadcast command signal to the photovoltaic control component through the power carrier communication protocol.

[0032] The data carrier of DC power carrier communication is a high-frequency current signal, whose frequency overlaps with the harmonic characteristic frequency of DC arc detection. This special situation cannot effectively distinguish DC arcs. When the current on the photovoltaic side is large, the arc detection in the energy conversion module may calculate a large arc detection value.

[0033] Therefore, when receiving the first response information corresponding to the first query frame, the system controller sets the arc threshold to a larger power carrier communication threshold, which is greater than the arc threshold calibrated by the photovoltaic power generation unit at the factory, that is, the first arc threshold. By appropriately increasing the arc threshold, it is possible to avoid false detection of arc faults due to the influence of power carrier communication, avoid system output interruption due to false detection of arc faults, and improve the stability of system output.

[0034] In some technical solutions of the present application, optionally, the photovoltaic control component and the component monitoring module are communicatively connected via wireless communication; the component monitoring module is further used to send a second response message to the system controller when a second query frame sent by the system controller is received; the system controller is further used to determine that the arc threshold is a non-power carrier communication threshold when the second response message is received.

[0035] In this technical solution, the photovoltaic control component and the component monitoring module are connected in communication by wireless communication. Exemplarily, the component monitoring module includes a dedicated communication chip, which is a wireless communication chip. After the switch signal is transmitted to the wireless communication chip of the component monitoring module, the wireless communication chip sends a broadcast command signal to the photovoltaic control component through a wireless communication protocol. Exemplarily, the wireless communication chip can be a Bluetooth communication chip, a Wi-Fi communication chip, a ZigBee communication chip, or a radio frequency communication chip.

[0036] If the system controller does not receive the first response information within the preset time after sending the first query frame, the system controller continues to send the second query frame. If the second query frame is received, it is determined that the photovoltaic control component and the component monitoring module are connected by wireless communication, and the wireless communication method is to transmit signals and data through radio signals. This communication method will not affect the harmonic analysis results of the DC side bus current. At this time, the arc threshold is set to the non-power carrier communication threshold to ensure the sensitivity and reliability of arc fault detection.

[0037] A second aspect of the present application provides a control method for a photovoltaic inverter system, which is applied to a photovoltaic inverter system as provided in any of the above technical solutions, and the control method includes: sending a query frame when the photovoltaic inverter system is initialized; determining an arc threshold based on a reception status of response information corresponding to the query frame; and performing an arc fault processing operation based on a comparison result between an arc detection value of a photovoltaic power generation unit and the arc threshold.

[0038] In this technical solution, the photovoltaic inverter system includes a photovoltaic power generation unit, a system controller and an energy conversion module. There may be multiple photovoltaic power generation units, and illustratively, multiple photovoltaic power generation units may be connected in series or in parallel. Each photovoltaic power generation unit may be a PV (photovoltaic) panel, and the photovoltaic power generation unit may utilize the photovoltaic effect to convert solar radiation energy into electrical energy.

[0039] The energy conversion module can be a photovoltaic inverter module or an energy storage hybrid inverter module. The energy conversion module receives the electric energy generated by multiple photovoltaic power generation units, and inverts this part of the DC signal to output an AC signal. This part of the AC signal can be provided to the load for use, or it can be connected to the grid and output to the grid. It can also be further rectified to charge energy storage devices such as battery components. The system controller can be a local edge controller that can collect information from all modules in the system and output control instructions. The system controller can also be integrated inside the energy conversion module.

[0040] Exemplarily, an arc fault detection unit is integrated in the energy conversion module, and the arc fault detection unit is used to detect DC arc faults in the system, that is, arc faults on the power transmission line on the input side of the inverter. Exemplarily, the arc fault detection unit collects the bus current of the DC side bus, and performs harmonic analysis on the bus current of the DC side bus, and determines whether there is an arc fault based on the harmonic characteristics of the bus current of the DC side bus. Exemplarily, on the basis of harmonic analysis, an AI algorithm can also be added to improve the detection accuracy of arc faults.

[0041] The energy conversion module collects the arc detection value of the photovoltaic power generation unit through the arc fault detection unit therein. For example, the arc detection value can be a current value or a voltage value. After collecting the corresponding arc detection value, the energy conversion module determines whether the collected current detection value is greater than the arc threshold. If the current detection value is greater than the arc threshold, it means that an arc fault has occurred. At this time, an arc fault processing operation is performed, such as shutting down the output of the photovoltaic power generation unit to ensure system safety.

[0042] Since some modules in the photovoltaic inverter system may use power carrier communication as the communication mode, and since the data carrier of the DC power carrier communication is a high-frequency current signal, its frequency overlaps with the harmonic characteristic frequency of the DC arc detection, this special case cannot effectively distinguish the DC arc. In this regard, the system controller sends a query frame after the photovoltaic inverter system is initialized, where a query frame corresponds to a communication mode, such as query frame A for the power carrier communication mode and query frame B for the wireless communication mode.

[0043] After the system controller sends out the query frame, the system controller determines whether the response information of the corresponding query frame is received, and dynamically sets the corresponding arc threshold according to the reception status of the response information. For example, when the response information of the query frame A is received, it means that there is a functional module of power carrier communication in the system at this time. At this time, a relatively high arc threshold can be set to avoid the false detection of arc faults due to the influence of the power carrier signal. If the response information of the query frame A is not received, but the response information of the query frame B is received, it means that there is no functional module of power carrier communication in the system. At this time, the standard arc threshold is set to ensure the reliability and sensitivity of arc fault detection.

[0044] After the initialization of the photovoltaic inverter system is completed, the application sends a query frame to the system communication network through the system controller, and determines whether there is power carrier communication interference based on whether the corresponding response information is received, and dynamically sets the corresponding arc threshold, which can avoid false detection of arc faults caused by power carrier communication and improve the stability of the photovoltaic inverter system output.

[0045] In some technical solutions of the present application, optionally, the arc threshold is determined according to the reception status of the response information corresponding to the query frame, including: when the time elapsed after the first query frame is sent reaches a preset time length and no response information is received, sending the second query frame; when the time elapsed after the second query frame is sent reaches a preset time length and no response information is received, resending the first query frame and the second query frame; and when the number of times the first query frame and the second query frame are sent reaches a number threshold, determining that the arc threshold is a non-power carrier communication threshold.

[0046] In this technical solution, in order to facilitate control, the system controller sends query frames corresponding to possible functional modules one by one in a polling manner. Exemplarily, after the photovoltaic inverter system completes the initialization step, the system controller first sends a first query frame through the internal network. The first query frame can be a protocol frame corresponding to the power carrier communication. If a response message is received within a preset time after the first query frame is sent, it means that there is a power carrier communication module in the system. If no response message is received within the preset time, it means that there is no power carrier communication module in the system. At this time, the second query frame continues to be sent. Exemplarily, the second query frame can be a module of other communication methods, such as wireless communication.

[0047] If no response information is received within a preset time after sending the second query frame, the first query frame and the second query frame are resent to avoid failure in receiving the response information due to module startup delay or communication packet loss.

[0048] Exemplarily, the above preset time length ranges from 500ms to 10s.

[0049] When it is detected that the number of times the first query frame and the second query frame are sent reaches the set upper limit, that is, greater than or equal to the above-mentioned number threshold, it means that there are no other modules in the system that need to communicate with the system controller, that is, there is no possibility of interference with arc detection caused by communication with other modules. At this time, the arc threshold is set to the non-power carrier communication threshold. The non-power carrier communication threshold is a threshold that can sensitively detect arc faults in the absence of external interference, thereby ensuring the sensitivity and reliability of arc fault detection.

[0050] Exemplarily, the above number threshold ranges from 4 times to 12 times.

[0051] Exemplarily, the above-mentioned non-power carrier communication threshold is the arc threshold calibrated by the photovoltaic power generation unit before leaving the factory.

[0052] In some technical solutions of the present application, optionally, the arc threshold is determined according to the reception status of the response information corresponding to the query frame, and also includes: when the first response information corresponding to the first query frame is received, the arc threshold is determined to be the power carrier communication threshold; wherein the power carrier communication threshold is greater than the non-power carrier communication threshold.

[0053] In this technical solution, the first query frame is a query frame used to identify whether there is a functional module using power carrier communication in the system. When the first response information corresponding to the first query frame is received, it is determined that there is a functional module in the system that is connected to the communication by power carrier communication. Since the data carrier of the DC power carrier communication is a high-frequency current signal, its frequency overlaps with the harmonic characteristic frequency of the DC arc detection. In this special case, the DC arc cannot be effectively distinguished. When the current on the photovoltaic side is large, the arc detection in the energy conversion module may calculate a large arc detection value.

[0054] Therefore, when receiving the first response information corresponding to the first query frame, the system controller sets the arc threshold to a larger power carrier communication threshold, which is greater than the arc threshold calibrated by the photovoltaic power generation unit at the factory, that is, the first arc threshold. By appropriately increasing the arc threshold, it is possible to avoid false detection of arc faults due to the influence of power carrier communication, avoid system output interruption due to false detection of arc faults, and improve the stability of system output.

[0055] In some technical solutions of the present application, optionally, the arc threshold is determined according to the reception status of the response information corresponding to the query frame, and also includes: when the second response information corresponding to the second query frame is received, determining that the arc threshold is a non-power carrier communication threshold.

[0056] In this technical solution, the second query frame is a query frame used to identify whether there is a functional module using wireless communication in the system. If the system controller does not receive the first response information within the preset time after sending the first query frame, the system controller continues to send the second query frame. If the second query frame is received, it is determined that the functional module in the system is connected by wireless communication, and the wireless communication method is to transmit signals and data through radio signals. This communication method will not affect the harmonic analysis results of the DC side bus current. At this time, the arc threshold is set to the non-power carrier communication threshold to ensure the sensitivity and reliability of arc fault detection.

[0057] In some technical solutions of the present application, optionally, the photovoltaic inverter system includes a photovoltaic control component, which is electrically connected to the photovoltaic power generation unit; based on the comparison result of the arc detection value of the photovoltaic power generation unit and the arc threshold, an arc fault processing operation is performed, including: when it is detected that the arc detection value is greater than or equal to the arc threshold, the photovoltaic control component is controlled to shut down the output of the photovoltaic power generation unit.

[0058] In this technical solution, the photovoltaic inverter system includes a photovoltaic control component. When the number of photovoltaic power generation units is multiple, the number of photovoltaic control components is the same as the number of photovoltaic power generation units in the photovoltaic control component. A photovoltaic control component is arranged on each photovoltaic power generation unit, and the photovoltaic control component can control the output of the photovoltaic power generation unit. The output ends of the multiple photovoltaic control components are connected to power transmission lines, and the multiple power transmission lines converge to the input end of the energy conversion module.

[0059] The component monitoring module is simultaneously connected to the energy conversion module and each photovoltaic control component. Exemplarily, the photovoltaic control component and the component monitoring module are connected to each other by means of power carrier communication. Exemplarily, the component monitoring module includes a dedicated communication chip, which is a power carrier communication chip. After the switch signal is transmitted to the power carrier communication chip of the component monitoring module, the power carrier communication chip sends a broadcast command signal to the photovoltaic control component through the power carrier communication protocol.

[0060] In some possible implementations, the photovoltaic control component and the component monitoring module are connected to each other by wireless communication. Exemplarily, the component monitoring module includes a dedicated communication chip, which is a wireless communication chip. After the switch signal is transmitted to the wireless communication chip of the component monitoring module, the wireless communication chip sends a broadcast command signal to the photovoltaic control component through a wireless communication protocol. Exemplarily, the wireless communication chip can be a Bluetooth communication chip, a Wi-Fi communication chip, a ZigBee communication chip, or a radio frequency communication chip.

[0061] Exemplarily, when the energy conversion module detects that the arc detection value reaches the arc threshold set by the system controller, it indicates that an arc fault may exist at this time. In addition to reporting the abnormal information to the communication ARM (Advanced RISC Machine, microprocessor) chip inside the inverter by communication, the arc fault detection unit in the energy conversion module can also directly send a switch signal to the component monitoring module. The switch signal is a dedicated fast switching signal.

[0062] The component monitoring module includes a dedicated communication chip. The switching signal emitted by the energy conversion module is transmitted to the dedicated communication chip. After receiving the switching signal, the dedicated communication chip sends a broadcast command signal to the corresponding photovoltaic control component, thereby controlling the photovoltaic control component to shut down the output of the photovoltaic power generation unit.

[0063] The technical solution of the present application, by setting up a component monitoring module and an independent photovoltaic control component, eliminates the need to retransmit the above-mentioned switch signal through a communication ARM chip, thereby effectively saving communication forwarding time and facilitating the realization of an arc extinguishing operation with a faster response speed.

[0064] The third aspect of the present application provides a control device for a photovoltaic inverter system, comprising: a memory for storing programs or instructions; a processor for implementing the steps of the control method for the photovoltaic inverter system provided in any of the above technical solutions when executing the programs or instructions, and therefore also includes all the beneficial effects of the control method for the photovoltaic inverter system provided in any of the above technical solutions, which will not be repeated here to avoid repetition.

[0065] In a fourth aspect, the present application provides a readable storage medium having a program or instruction stored thereon. When the program or instruction is executed by a processor, the steps of the control method of the photovoltaic inverter system provided in any of the above technical solutions are implemented, and therefore all the beneficial effects of the control method of the photovoltaic inverter system provided in any of the above technical solutions are also included. To avoid repetition, they will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0066] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0067] Figure 1 A schematic diagram showing the structure of a photovoltaic inverter system in some embodiments of the present application is shown;

[0068] Figure 2 A schematic diagram showing the structure of a photovoltaic inverter system in some embodiments of the present application is shown;

[0069] Figure 3 A schematic diagram showing the structure of a photovoltaic inverter system in some embodiments of the present application is shown;

[0070] Figure 4 A flow chart showing a control method of a photovoltaic inverter system in some embodiments of the present application;

[0071] Figure 5 A flow chart showing a control method of a photovoltaic inverter system in some embodiments of the present application;

[0072] Figure 6 A structural block diagram of a control device for a photovoltaic inverter system according to some embodiments of the present application is shown.

[0073] Reference numerals:

[0074] 100 photovoltaic inverter system, 101 photovoltaic power generation unit, 102 system controller, 104 energy conversion module, 106 photovoltaic control component, 108 component monitoring module. DETAILED DESCRIPTION

[0075] In order to more clearly understand the above-mentioned purposes, features and advantages of the present application, the present application is further described in detail below in conjunction with the accompanying drawings and specific implementation methods. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

[0076] In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application may also be implemented in other ways different from those described herein. Therefore, the scope of protection of the present application is not limited to the specific embodiments disclosed below.

[0077] Refer to the following Figures 1 to 6 A photovoltaic inverter system and a control method, a control device, and a readable storage medium provided according to some embodiments of the present application are described.

[0078] In some embodiments of the present application, a photovoltaic inverter system is provided. Figure 1 , Figure 2 and Figure 3 The schematic diagram of the structure of the photovoltaic inverter system of some embodiments of the present application is shown as follows: Figure 1 , Figure 2 and Figure 3 As shown, the photovoltaic inverter system 100 includes: a photovoltaic power generation unit 101; a system controller 102, the system controller 102 is used to send a query frame when the photovoltaic inverter system 100 is initialized; and determine the arc threshold according to the reception status of the response information corresponding to the query frame; an energy conversion module 104, the energy conversion module 104 is electrically connected to the photovoltaic power generation unit 101, and is communicatively connected to the system controller 102, and the energy conversion module 104 is used to perform an arc fault processing operation according to the comparison result of the arc detection value of the photovoltaic power generation unit 101 and the arc threshold.

[0079] In this embodiment, the photovoltaic inverter system 100 includes a photovoltaic power generation unit 101, a system controller 102 and an energy conversion module 104. There may be multiple photovoltaic power generation units 101, and illustratively, multiple photovoltaic power generation units 101 may be connected in series or in parallel. Each photovoltaic power generation unit 101 may be a PV (photovoltaic) panel, and the photovoltaic power generation unit 101 may utilize the photovoltaic effect to convert solar radiation energy into electrical energy.

[0080] The energy conversion module 104 can be a photovoltaic inverter module or an energy storage hybrid inverter module. The energy conversion module 104 receives the electric energy generated by multiple photovoltaic power generation units 101, and inverts this part of the DC signal to output an AC signal. This part of the AC signal can be provided to the load for use, or it can be connected to the grid and output to the grid, and it can also be further rectified to charge energy storage devices such as battery components. The system controller 102 can be a local edge controller that can collect all module information in the system and output control instructions. The system controller 102 can also be integrated into the energy conversion module 104.

[0081] Exemplarily, an arc fault detection unit is integrated in the energy conversion module 104, and the arc fault detection unit is used to detect DC arc faults in the system, that is, arc faults on the power transmission line on the input side of the inverter. Exemplarily, the arc fault detection unit collects the current signal on the power transmission line on the photovoltaic side, and performs harmonic analysis on the current signal on the power transmission line, and determines whether there is an arc fault based on the harmonic characteristics of the current signal on the power transmission line. Exemplarily, on the basis of harmonic analysis, an AI algorithm can also be added to improve the detection accuracy of arc faults.

[0082] The energy conversion module 104 collects the arc detection value of the photovoltaic power generation unit 101 through the arc fault detection unit therein. For example, the arc detection value can be a current value or a voltage value. After collecting the corresponding arc detection value, the energy conversion module 104 determines whether the collected current detection value is greater than the arc threshold. If the current detection value is greater than the arc threshold, it means that an arc fault has occurred. At this time, an arc fault processing operation is performed, such as shutting down the output of the photovoltaic power generation unit 101 to ensure system safety.

[0083] Since some modules in the photovoltaic inverter system 100 may use power carrier communication as the communication mode, and since the data carrier of the DC power carrier communication is a high-frequency current signal, its frequency overlaps with the harmonic characteristic frequency of the DC arc detection, this special case cannot effectively distinguish the DC arc. In this regard, after the photovoltaic inverter system 100 is initialized, the system controller 102 sends a query frame, where one query frame corresponds to one communication mode, such as the power carrier communication mode corresponds to the query frame A, the wireless communication mode corresponds to the query frame B, etc.

[0084] After the system controller 102 sends out the query frame, the system controller 102 determines whether the response information of the corresponding query frame is received, and dynamically sets the corresponding arc threshold according to the reception status of the response information. For example, when the response information of the query frame A is received, it means that there is a functional module of power carrier communication in the system at this time. At this time, a relatively high arc threshold can be set to avoid the false detection of arc faults due to the influence of the power carrier signal. If the response information of the query frame A is not received, but the response information of the query frame B is received, it means that there is no functional module of power carrier communication in the system. At this time, a standard arc threshold is set to ensure the reliability and sensitivity of arc fault detection.

[0085] After the photovoltaic inverter system 100 is initialized, the present application sends a query frame through the system controller 102, and determines whether there is power carrier communication interference based on whether the corresponding response information is received, and dynamically sets the corresponding arc threshold, which can avoid false detection of arc faults caused by power carrier communication and improve the stability of the output of the photovoltaic inverter system 100.

[0086] In some embodiments of the present application, optionally, the system controller 102 is also used to: send a second query frame when the time elapsed after sending the first query frame reaches a preset time elapsed and no response information is received; resend the first query frame and the second query frame when the time elapsed after sending the second query frame reaches a preset time elapsed and no response information is received; and determine that the arc threshold is a non-power carrier communication threshold when the number of times the first query frame and the second query frame are sent reaches a number threshold.

[0087] In this embodiment, for the convenience of control, the system controller 102 sends query frames corresponding to possible functional modules one by one in a polling manner. Exemplarily, after the photovoltaic inverter system 100 completes the initialization step, the system controller 102 first sends a first query frame through the internal network, and the first query frame can be a protocol frame corresponding to the power carrier communication. If a response message is received within a preset time after the first query frame is sent, it means that there is a power carrier communication module in the system. If no response message is received within the preset time, it means that there is no power carrier communication module in the system, and the second query frame continues to be sent. Exemplarily, the second query frame can be a module of other communication methods, such as wireless communication.

[0088] If no response information is received within a preset time after sending the second query frame, the first query frame and the second query frame are resent to avoid failure in receiving the response information due to module startup delay or communication packet loss.

[0089] Exemplarily, the above preset time length ranges from 500ms to 10s.

[0090] When it is detected that the number of times the first query frame and the second query frame are sent reaches the set upper limit, that is, greater than or equal to the number threshold, Figure 3 As shown, it means that there are no other modules in the system that need to communicate with the system controller 102, that is, there is no possibility that the communication of other modules will interfere with the arc detection. At this time, the arc threshold is set to the non-power carrier communication threshold. The non-power carrier communication threshold is a threshold that can sensitively detect arc faults in the absence of external interference, thereby ensuring the sensitivity and reliability of arc fault detection.

[0091] Exemplarily, the above number threshold ranges from 4 times to 12 times.

[0092] Exemplarily, the above-mentioned non-power carrier communication threshold is the arc threshold calibrated by the photovoltaic power generation unit 101 before leaving the factory.

[0093] In some embodiments of the present application, optionally, Figure 1 and Figure 2 As shown, the photovoltaic inverter system 100 also includes: a photovoltaic control component 106, which is electrically connected to the photovoltaic power generation unit 101; a component monitoring module 108, which is communicatively connected to the energy conversion module 104 and the photovoltaic control component 106, and the component monitoring module 108 is used to control the photovoltaic control component 106 to shut down the output of the photovoltaic power generation unit 101 when receiving a switch signal; the energy conversion module 104 is also used to send a switch signal to the component monitoring module 108 when it is detected that the arc detection value is greater than or equal to the arc threshold.

[0094] In this embodiment, the photovoltaic inverter system 100 includes a photovoltaic control component 106. When the number of photovoltaic power generation units 101 is multiple, the number of photovoltaic control components 106 is the same as the number of photovoltaic power generation units 101 in the photovoltaic control component 106. A photovoltaic control component 106 is set on each photovoltaic power generation unit 101. The photovoltaic control component 106 can control the output of the photovoltaic power generation unit 101. The output ends of the multiple photovoltaic control components 106 are connected to the power transmission line, and the multiple power transmission lines converge to the input end of the energy conversion module 104.

[0095] The component monitoring module 108 is simultaneously connected to the energy conversion module 104 and each photovoltaic control component 106 in communication. Exemplarily, when the energy conversion module 104 detects that the arc detection value reaches the arc threshold value set by the system controller 102, it indicates that an arc fault may exist at this time. In addition to reporting the abnormal information to the communication ARM (Advanced RISC Machine, microprocessor) chip inside the inverter in a communication manner, the arc fault detection unit in the energy conversion module 104 can also directly send a switch signal to the component monitoring module 108, and the switch signal is a dedicated fast switch signal.

[0096] The component monitoring module 108 includes a dedicated communication chip. The switching signal emitted by the energy conversion module 104 is transmitted to the dedicated communication chip. After receiving the switching signal, the dedicated communication chip sends a broadcast command signal to the corresponding photovoltaic control component 106, thereby controlling the photovoltaic control component 106 to shut down the output of the photovoltaic power generation unit 101.

[0097] The embodiment of the present application provides a component monitoring module 108 and an independent photovoltaic control component 106, which eliminates the need to retransmit the switch signal through a communication ARM chip, thereby effectively saving communication forwarding time and facilitating an arc extinguishing operation with a faster response speed.

[0098] In some embodiments of the present application, optionally, Figure 1 As shown, the photovoltaic control component 106 and the component monitoring module 108 are communicatively connected via power carrier communication; the component monitoring module 108 is further used to send a first response message to the system controller 102 upon receiving a first query frame; the system controller 102 is further used to determine that the arc threshold is a power carrier communication threshold upon receiving the first response message; wherein the power carrier communication threshold is greater than the non-power carrier communication threshold.

[0099] In this embodiment, the component monitoring module 108 and the photovoltaic control component 106 are connected to each other by means of power carrier communication. Exemplarily, the component monitoring module 108 includes a dedicated communication chip, which is a power carrier communication chip. After the switch signal is transmitted to the power carrier communication chip of the component monitoring module 108, the power carrier communication chip sends a broadcast command signal to the photovoltaic control component 106 through the power carrier communication protocol.

[0100] The data carrier of DC power carrier communication is a high-frequency current signal, and its frequency overlaps with the harmonic characteristic frequency of DC arc detection. This special situation cannot effectively distinguish DC arcs. When the current on the photovoltaic side is large, the arc detection in the energy conversion module 104 may calculate a large arc detection value.

[0101] Therefore, when receiving the first response information corresponding to the first query frame, the system controller 102 sets the arc threshold to a larger power carrier communication threshold, which is greater than the arc threshold calibrated by the photovoltaic power generation unit 101 at the factory, that is, the first arc threshold. By appropriately increasing the arc threshold, it is possible to avoid false detection of arc faults due to the influence of power carrier communication, avoid interruption of system output due to false detection of arc faults, and improve the stability of system output.

[0102] In some embodiments of the present application, optionally, Figure 2 As shown, the photovoltaic control component 106 and the component monitoring module 108 are connected in communication via wireless communication; the component monitoring module 108 is further used to send a second response message to the system controller 102 when a second query frame sent by the system controller 102 is received; the system controller 102 is further used to determine that the arc threshold is a non-power carrier communication threshold when the second response message is received.

[0103] In this embodiment, the photovoltaic control component 106 and the component monitoring module 108 are connected in communication by wireless communication. Exemplarily, the component monitoring module 108 includes a dedicated communication chip, which is a wireless communication chip. After the switch signal is transmitted to the wireless communication chip of the component monitoring module 108, the wireless communication chip sends a broadcast command signal to the photovoltaic control component 106 through a wireless communication protocol. Exemplarily, the wireless communication chip can be a Bluetooth communication chip, a Wi-Fi communication chip, a ZigBee communication chip, or a radio frequency communication chip.

[0104] If the system controller 102 does not receive the first response information within the preset time after sending the first query frame, the system controller 102 continues to send the second query frame. If the second query frame is received, it is determined that the photovoltaic control component 106 and the component monitoring module 108 are connected in communication through wireless communication, and the wireless communication method is to transmit signals and data through radio signals. This communication method will not affect the harmonic analysis results of the DC side bus current. At this time, the arc threshold is set to the non-power carrier communication threshold to ensure the sensitivity and reliability of arc fault detection.

[0105] In some embodiments of the present application, a control method for a photovoltaic inverter system is provided. The control method is applied to a photovoltaic inverter system provided in any of the above embodiments. Figure 4 A flow chart showing a control method for a photovoltaic inverter system in some embodiments of the present application is shown. Figure 4 As shown, the control method includes:

[0106] Step 402, when the photovoltaic inverter system is initialized, a query frame is sent;

[0107] Step 404, determining an arc threshold value according to a reception status of a response message corresponding to the query frame;

[0108] Step 406 , performing arc fault processing operations according to the comparison result between the arc detection value of the photovoltaic power generation unit and the arc threshold value.

[0109] In this embodiment, the photovoltaic inverter system includes a photovoltaic power generation unit, a system controller and an energy conversion module. There may be multiple photovoltaic power generation units, and illustratively, multiple photovoltaic power generation units may be connected in series or in parallel. Each photovoltaic power generation unit may be a PV (photovoltaic) panel, and the photovoltaic power generation unit may utilize the photovoltaic effect to convert solar radiation energy into electrical energy.

[0110] The energy conversion module can be a photovoltaic inverter module or an energy storage hybrid inverter module. The energy conversion module receives the electric energy generated by multiple photovoltaic power generation units, and inverts this part of the DC signal to output an AC signal. This part of the AC signal can be provided to the load for use, or it can be connected to the grid and output to the grid. It can also be further rectified to charge energy storage devices such as battery components. The system controller can be a local edge controller that can collect information from all modules in the system and output control instructions. The system controller can also be integrated inside the energy conversion module.

[0111] Exemplarily, an arc fault detection unit is integrated in the energy conversion module, and the arc fault detection unit is used to detect DC arc faults in the system, that is, arc faults on the power transmission line on the input side of the inverter. Exemplarily, the arc fault detection unit collects the bus current of the DC side bus, and performs harmonic analysis on the bus current of the DC side bus, and determines whether there is an arc fault based on the harmonic characteristics of the bus current of the DC side bus. Exemplarily, on the basis of harmonic analysis, an AI algorithm can also be added to improve the detection accuracy of arc faults.

[0112] The energy conversion module collects the arc detection value of the photovoltaic power generation unit through the arc fault detection unit therein. For example, the arc detection value can be a current value or a voltage value. After collecting the corresponding arc detection value, the energy conversion module determines whether the collected current detection value is greater than the arc threshold. If the current detection value is greater than the arc threshold, it means that an arc fault has occurred. At this time, an arc fault processing operation is performed, such as shutting down the output of the photovoltaic power generation unit to ensure system safety.

[0113] Since some modules in the photovoltaic inverter system may use power carrier communication as the communication mode, and since the data carrier of the DC power carrier communication is a high-frequency current signal, its frequency overlaps with the harmonic characteristic frequency of the DC arc detection, this special case cannot effectively distinguish the DC arc. In this regard, the system controller sends a query frame after the photovoltaic inverter system is initialized, where a query frame corresponds to a communication mode, such as query frame A for the power carrier communication mode and query frame B for the wireless communication mode.

[0114] After the system controller sends out the query frame, the system controller determines whether the response information of the corresponding query frame is received, and dynamically sets the corresponding arc threshold according to the reception status of the response information. For example, when the response information of the query frame A is received, it means that there is a functional module of power carrier communication in the system at this time. At this time, a relatively high arc threshold can be set to avoid the false detection of arc faults due to the influence of the power carrier signal. If the response information of the query frame A is not received, but the response information of the query frame B is received, it means that there is no functional module of power carrier communication in the system. At this time, the standard arc threshold is set to ensure the reliability and sensitivity of arc fault detection.

[0115] After the initialization of the photovoltaic inverter system is completed, the application sends a query frame to the system communication network through the system controller, and determines whether there is power carrier communication interference based on whether the corresponding response information is received, and dynamically sets the corresponding arc threshold, which can avoid false detection of arc faults caused by power carrier communication and improve the stability of the photovoltaic inverter system output.

[0116] In some embodiments of the present application, optionally, the arc threshold is determined based on the reception status of the response information corresponding to the query frame, including: sending a second query frame when the time elapsed after sending the first query frame reaches a preset time elapsed and no response information is received; resending the first query frame and the second query frame when the time elapsed after sending the second query frame reaches a preset time elapsed and no response information is received; and determining that the arc threshold is a non-power carrier communication threshold when the number of times the first query frame and the second query frame are sent reaches a number threshold.

[0117] In this embodiment, for the convenience of control, the system controller sends query frames corresponding to possible functional modules one by one in a polling manner. Exemplarily, after the photovoltaic inverter system completes the initialization step, the system controller first sends a first query frame through the internal network, and the first query frame can be a protocol frame corresponding to the power carrier communication. If a response message is received within a preset time after the first query frame is sent, it means that there is a power carrier communication module in the system. If no response message is received within the preset time, it means that there is no power carrier communication module in the system, and the second query frame continues to be sent. Exemplarily, the second query frame can be a module of other communication methods, such as wireless communication.

[0118] If no response information is received within a preset time after sending the second query frame, the first query frame and the second query frame are resent to avoid failure in receiving the response information due to module startup delay or communication packet loss.

[0119] Exemplarily, the above preset time length ranges from 500ms to 10s.

[0120] When it is detected that the number of times the first query frame and the second query frame are sent reaches the set upper limit, that is, greater than or equal to the above-mentioned number threshold, it means that there are no other modules in the system that need to communicate with the system controller, that is, there is no possibility of interference with arc detection caused by communication with other modules. At this time, the arc threshold is set to the non-power carrier communication threshold. The non-power carrier communication threshold is a threshold that can sensitively detect arc faults in the absence of external interference, thereby ensuring the sensitivity and reliability of arc fault detection.

[0121] Exemplarily, the above number threshold ranges from 4 times to 12 times.

[0122] Exemplarily, the above-mentioned non-power carrier communication threshold is the arc threshold calibrated by the photovoltaic power generation unit before leaving the factory.

[0123] In some embodiments of the present application, optionally, determining the arc threshold based on the reception status of the response information corresponding to the query frame also includes: when the first response information corresponding to the first query frame is received, determining the arc threshold as the power carrier communication threshold; wherein the power carrier communication threshold is greater than the non-power carrier communication threshold.

[0124] In this embodiment, the first query frame is a query frame for identifying whether there is a functional module using power carrier communication in the system. When the first response information corresponding to the first query frame is received, it is determined that there is a functional module in the system that is connected to the communication by power carrier communication. Since the data carrier of the DC power carrier communication is a high-frequency current signal, its frequency overlaps with the harmonic characteristic frequency of the DC arc detection. In this special case, the DC arc cannot be effectively distinguished. When the current on the photovoltaic side is large, the arc detection in the energy conversion module may calculate a large arc detection value.

[0125] Therefore, when receiving the first response information corresponding to the first query frame, the system controller sets the arc threshold to a larger power carrier communication threshold, which is greater than the arc threshold calibrated by the photovoltaic power generation unit at the factory, that is, the first arc threshold. By appropriately increasing the arc threshold, it is possible to avoid false detection of arc faults due to the influence of power carrier communication, avoid system output interruption due to false detection of arc faults, and improve the stability of system output.

[0126] In some embodiments of the present application, optionally, determining the arc threshold according to a reception status of response information corresponding to the query frame also includes: when second response information corresponding to a second query frame is received, determining that the arc threshold is a non-power carrier communication threshold.

[0127] In this embodiment, the second query frame is a query frame for identifying whether there is a functional module using wireless communication in the system. If the system controller does not receive the first response information within the preset time after sending the first query frame, the system controller continues to send the second query frame. If the second query frame is received, it is determined that the functional module in the system is connected by wireless communication, and the wireless communication method is to transmit signals and data through radio signals. This communication method will not affect the harmonic analysis results of the DC side bus current. At this time, the arc threshold is set to the non-power carrier communication threshold to ensure the sensitivity and reliability of arc fault detection.

[0128] In some embodiments of the present application, optionally, the photovoltaic inverter system includes a photovoltaic control component, which is electrically connected to the photovoltaic power generation unit; based on the comparison result of the arc detection value of the photovoltaic power generation unit and the arc threshold, an arc fault processing operation is performed, including: when it is detected that the arc detection value is greater than or equal to the arc threshold, the photovoltaic control component is controlled to shut down the output of the photovoltaic power generation unit.

[0129] In this embodiment, the photovoltaic inverter system includes a photovoltaic control component. When the number of photovoltaic power generation units is multiple, the number of photovoltaic control components is the same as the number of photovoltaic power generation units in the photovoltaic control component. A photovoltaic control component is arranged on each photovoltaic power generation unit, and the photovoltaic control component can control the output of the photovoltaic power generation unit. The output ends of the multiple photovoltaic control components are connected to power transmission lines, and the multiple power transmission lines converge to the input end of the energy conversion module.

[0130] The component monitoring module is simultaneously connected to the energy conversion module and each photovoltaic control component. Exemplarily, the photovoltaic control component and the component monitoring module are connected to each other by means of power carrier communication. Exemplarily, the component monitoring module includes a dedicated communication chip, which is a power carrier communication chip. After the switch signal is transmitted to the power carrier communication chip of the component monitoring module, the power carrier communication chip sends a broadcast command signal to the photovoltaic control component through the power carrier communication protocol.

[0131] In some possible implementations, the photovoltaic control component and the component monitoring module are connected to each other by wireless communication. Exemplarily, the component monitoring module includes a dedicated communication chip, which is a wireless communication chip. After the switch signal is transmitted to the wireless communication chip of the component monitoring module, the wireless communication chip sends a broadcast command signal to the photovoltaic control component through a wireless communication protocol. Exemplarily, the wireless communication chip can be a Bluetooth communication chip, a Wi-Fi communication chip, a ZigBee communication chip, or a radio frequency communication chip.

[0132] Exemplarily, when the energy conversion module detects that the arc detection value reaches the arc threshold set by the system controller, it indicates that an arc fault may exist at this time. In addition to reporting the abnormal information to the communication ARM (Advanced RISC Machine, microprocessor) chip inside the inverter by communication, the arc fault detection unit in the energy conversion module can also directly send a switch signal to the component monitoring module. The switch signal is a dedicated fast switching signal.

[0133] The component monitoring module includes a dedicated communication chip. The switching signal emitted by the energy conversion module is transmitted to the dedicated communication chip. After receiving the switching signal, the dedicated communication chip sends a broadcast command signal to the corresponding photovoltaic control component, thereby controlling the photovoltaic control component to shut down the output of the photovoltaic power generation unit.

[0134] The embodiment of the present application sets up a component monitoring module and an independent photovoltaic control component, which eliminates the need to retransmit the above-mentioned switch signal through a communication ARM chip, thereby effectively saving communication forwarding time and facilitating an arc extinguishing operation with a faster response speed.

[0135] In some embodiments of the application, Figure 5 A flow chart showing a control method for a photovoltaic inverter system in some embodiments of the present application is shown. Figure 5 As shown, the method includes:

[0136] Step 502, system initialization;

[0137] Step 504, determine whether the number of query frame transmissions exceeds a threshold; if yes, proceed to step 514B, otherwise proceed to step 506;

[0138] Step 506, sending a first query frame;

[0139] Step 508, determine whether the first response message is received; if yes, proceed to step 514A, otherwise proceed to step 510;

[0140] Step 510, sending a second query frame;

[0141] Step 512, determine whether the second response message is received; if yes, proceed to step 514B, otherwise return to step 504;

[0142] Step 514A, setting a non-power carrier communication threshold;

[0143] Step 514B, setting the power carrier communication threshold.

[0144] The photovoltaic inverter system includes an energy concentration conversion module, a component control module, a component monitoring module and a system controller. The component control module is directly connected to the component and has component-level MPPT (Maximum power point tracking), component-level shutdown and component-level monitoring functions. The component monitoring module controls the component controller and collects information through a power carrier communication chip or a wireless communication chip.

[0145] All power transmission lines of the entire photovoltaic inverter system are collected in the energy concentration conversion module, which may be a photovoltaic inverter or a hybrid inverter with both inverter and energy storage functions, and integrated DC arc detection function. The system controller is a local edge controller that can collect information from all modules in the system and output control instructions.

[0146] The energy concentration conversion module contains a DC arc detection function. When the DC detection function detects an abnormality, in addition to reporting the abnormal information to the communication ARM chip inside the inverter by communication, it directly outputs a fast switching signal to the outside, and this switching signal is connected to the system controller.

[0147] After receiving the switch signal output due to abnormal DC arc, the system controller sends a component shutdown command to the component monitoring module to quickly shut down the power output of the component. In addition, the system controller can automatically identify which component monitoring module is connected according to different 485 communication protocols, such as power carrier communication, wireless communication or no connection, and set the arc strength threshold of the DC arc detection inside the energy concentration conversion module according to the identified component monitoring module type.

[0148] The component monitoring module contains a dedicated communication chip for the component controller, such as a power carrier communication chip or a wireless communication chip. After receiving the component shutdown command issued by the system controller, it sends a dedicated broadcast command signal to the component control module.

[0149] After receiving the above-mentioned dedicated broadcast command signal, the component control module turns off the component power output and resumes the output after receiving the start-up command.

[0150] For a component monitoring module using DC carrier communication, the 485 protocol frame that obtains its SN (Serial Number) code is the first query frame, and its factory-calibrated DC arc detection threshold is the non-power carrier communication threshold.

[0151] For a component monitoring module using wireless communication, the 485 protocol frame for obtaining its SN code is the second query frame, and its factory-calibrated DC arc detection threshold is the power carrier communication threshold.

[0152] For systems that do not use component monitoring modules and component control modules, the default DC arc detection threshold is set to the power carrier communication threshold.

[0153] In some embodiments of the present application, a control device for a photovoltaic inverter system is provided. Figure 6 The structure block diagram of the control device of the photovoltaic inverter system of some embodiments of the present application is shown as follows: Figure 6As shown, the control device 600 of the photovoltaic inverter system includes: a memory 602, which is used to store programs or instructions; a processor 604, which is used to implement the steps of the control method of the photovoltaic inverter system provided in any of the above embodiments when executing the programs or instructions, and therefore also includes all the beneficial effects of the control method of the photovoltaic inverter system provided in any of the above embodiments, which will not be repeated here to avoid repetition.

[0154] In some embodiments of the present application, a readable storage medium is provided, on which a program or instruction is stored. When the program or instruction is executed by a processor, the steps of the control method of the photovoltaic inverter system provided in any of the above embodiments are implemented, and therefore all the beneficial effects of the control method of the photovoltaic inverter system provided in any of the above embodiments are also included. To avoid repetition, they are not repeated here.

[0155] The methods may be implemented in various ways according to specific features and / or example applications. For example, the methods may be implemented by a combination of hardware, firmware, and / or software. For example, in a hardware implementation, the processor may be implemented in one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), controllers, microcontrollers, microprocessors, electronic devices, other equipment units for performing the above functions, and / or combinations thereof.

[0156] A computer readable storage medium may be a tangible device that can retain and store instructions for use by an instruction execution device. A computer readable storage medium may be an electronic storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination of the above devices, but is not limited thereto. A non-exhaustive list of more specific examples of computer readable storage media includes: a portable computer floppy disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM) or flash memory, a static random access memory (SRAM), a portable compact disc read-only memory (CD-ROM), a digital versatile disk (DVD), a memory card, a floppy disk, a coding mechanical device (such as a punch card or a groove with a raised structure with instructions recorded thereon), and any suitable combination of the above devices. The computer-readable storage medium used herein should not be understood as a transmission signal itself, such as radio waves or other freely propagating electromagnetic waves, electromagnetic waves propagated through wave guides or other transmission media, or electrical signals transmitted through wires.

[0157] In the description of this application, the term "plurality" refers to two or more than two. Unless otherwise clearly defined, the terms "upper" and "lower" indicate positions or positional relationships based on the positions or positional relationships described in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on this application. The terms "connect", "install", "fixed", etc. should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0158] In the description of the present application, the description of the terms "one embodiment", "some embodiments", "specific embodiments", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In the present application, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0159] The above description is only the 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 inverter system, characterized in that: include: Photovoltaic power generation unit; A system controller, wherein the system controller is used to send a query frame when the photovoltaic inverter system is initialized; and determining an arc threshold value according to a reception status of a response message corresponding to the query frame; An energy conversion module, the energy conversion module is electrically connected to the photovoltaic power generation unit and is communicatively connected to the system controller, the energy conversion module is used to perform an arc fault processing operation according to a comparison result of an arc detection value of the photovoltaic power generation unit and the arc threshold.

2. The photovoltaic inverter system according to claim 1, characterized in that: The system controller is further configured to: When the time after sending the first query frame reaches the preset time and the response information is not received, sending a second query frame; When the time after sending the second query frame reaches the preset time and the response information is not received, resending the first query frame and the second query frame; as well as When the number of times the first query frame and the second query frame are sent reaches a number threshold, the arc threshold is determined to be a non-power carrier communication threshold.

3. The photovoltaic inverter system according to claim 2, characterized in that: Also includes: A photovoltaic control component, the photovoltaic control component is electrically connected to the photovoltaic power generation unit; A component monitoring module, the component monitoring module is in communication with the energy conversion module and the photovoltaic control component, and the component monitoring module is used to control the photovoltaic control component to shut down the output of the photovoltaic power generation unit when receiving a switch signal; The energy conversion module is further configured to send the switch signal to the component monitoring module when it is detected that the arc detection value is greater than or equal to the arc threshold.

4. The photovoltaic inverter system according to claim 3, characterized in that: The photovoltaic control component and the component monitoring module are communicatively connected via power carrier communication; The component monitoring module is further configured to send a first response message to the system controller when receiving the first query frame; The system controller is further configured to determine, upon receiving the first response information, that the arc threshold is a power carrier communication threshold; The power carrier communication threshold is greater than the non-power carrier communication threshold.

5. The photovoltaic inverter system according to claim 3, characterized in that: The photovoltaic control component and the component monitoring module are connected to each other by wireless communication; The component monitoring module is further configured to send second response information to the system controller upon receiving a second query frame sent by the system controller; The system controller is further configured to determine, upon receiving the second response information, that the arc threshold is the non-power carrier communication threshold.

6. A control method for a photovoltaic inverter system, characterized in that: The control method is applied to the photovoltaic inverter system according to any one of claims 1 to 5, and the control method comprises: When the PV inverter system is initialized, a query frame is sent; determining an arc threshold value according to a reception status of a response message corresponding to the query frame; An arc fault processing operation is performed according to a comparison result between the arc detection value of the photovoltaic power generation unit and the arc threshold value.

7. The control method according to claim 6, characterized in that: The step of determining the arc threshold according to a reception status of the response information corresponding to the query frame includes: When the time after sending the first query frame reaches the preset time and the response information is not received, sending a second query frame; When the time after sending the second query frame reaches the preset time and the response information is not received, resending the first query frame and the second query frame; and When the number of times the first query frame and the second query frame are sent reaches a number threshold, the arc threshold is determined to be a non-power carrier communication threshold.

8. The control method according to claim 7, characterized in that: The step of determining the arc threshold according to the reception status of the response information corresponding to the query frame further includes: Upon receiving the first response information corresponding to the first query frame, determining that the arc threshold is a power carrier communication threshold; The power carrier communication threshold is greater than the non-power carrier communication threshold.

9. The control method according to claim 7, characterized in that: The step of determining the arc threshold according to the reception status of the response information corresponding to the query frame further includes: When the second response information corresponding to the second query frame is received, the arc threshold is determined to be the non-power carrier communication threshold.

10. The control method according to any one of claims 6 to 9, characterized in that: The photovoltaic inverter system includes a photovoltaic control component, and the photovoltaic control component is electrically connected to the photovoltaic power generation unit; The performing of arc fault processing operation according to the comparison result between the arc detection value of the photovoltaic power generation unit and the arc threshold value comprises: When it is detected that the arc detection value is greater than or equal to the arc threshold, the photovoltaic control component is controlled to shut down the output of the photovoltaic power generation unit.

11. A control device for a photovoltaic inverter system, characterized in that: include: Memory, used to store programs or instructions; A processor, configured to implement the steps of the method according to any one of claims 6 to 10 when executing the program or instruction.

12. A readable storage medium having a program or instruction stored thereon, characterized in that: When the program or instruction is executed by a processor, the steps of the method according to any one of claims 6 to 10 are implemented.

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