Turn-off module, turn-off control method, turn-off control system and photovoltaic power generation system

Abstract

The embodiment of the invention discloses a turn-off module, a turn-off control method, a turn-off control system and a photovoltaic power generation system. According to the embodiment of the invention, the turn-off module is arranged in the photovoltaic module series circuit of the photovoltaic power generation system, and the turn-off module repeatedly sets the timing time through the timing instruction containing the timing information. In the timing process each time, the timing time is reset when a new timing instruction corresponding to itself or broadcast is received, timing is restarted, and the conducting state is kept in the timing process. And if the timing information obtained by analyzing the new timing instruction is still not received after the timing is ended, the switching device is turned off, so that the corresponding photovoltaic module is disconnected from the series connection path of the photovoltaic group string. Therefore, the disconnected photovoltaic module can be safely operated. In this way, reliable component-level turn-off is achieved, and the control has high flexibility.

Description

Technical Field

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

[0002] Photovoltaic power generation systems are used to convert solar energy into usable electrical energy. In photovoltaic power generation systems, multiple photovoltaic modules are usually connected in series to form photovoltaic strings so that the output voltage reaches the desired level. This causes DC high voltage in the system, which poses a certain safety risk to maintenance personnel. Therefore, photovoltaic power generation systems are required to have a module-level shutdown function.

[0003] There are two types of existing shutdown technologies. One is a shutdown system based on the traditional communication mechanism, where the main control unit (transmitter) sends a shutdown command to the photovoltaic string to control the photovoltaic string to shut down, so that multiple photovoltaic modules connected in series in the photovoltaic string are disconnected from each other. This technical solution can perform the shutdown and fast shutdown functions, but when the main control unit is damaged or the communication is abnormal, the photovoltaic module will continue to maintain the original shutdown or connection state, and the reliability is poor.

[0004] Another shutdown scheme is based on a periodic heartbeat mechanism, that is, the main control system periodically sends a heartbeat command to the photovoltaic string, and each photovoltaic module receives the heartbeat command independently. When the control circuit on one side of the photovoltaic module can receive the heartbeat command, the photovoltaic module remains connected. When the heartbeat command is not received after a preset time, the photovoltaic module is controlled to actively disconnect the series connection relationship. In the prior art, Chinese patent CN200880114564.0 records the relevant technical solution. Compared with the traditional communication mechanism, this technology is more reliable, but has poor flexibility and poor anti-interference ability. The control circuit on one side of the photovoltaic module may not be able to correctly receive the heartbeat signal due to interference, resulting in an erroneous shutdown. In addition, the prior art cannot achieve a fast shutdown operation.

[0005] The prior art technical solution described in US Pat. No. 8,933,321B2 has the capability of rapid shutdown under the heartbeat mechanism. However, it still realizes rapid shutdown through additional shutdown instructions, and the circuit complexity is relatively high. Summary of the invention

[0006] In view of this, the embodiments of the present invention provide a shutdown module, a shutdown control method, a system and a photovoltaic power generation system, which are expected to reliably disconnect photovoltaic components with greater flexibility as needed during maintenance or operation of the photovoltaic power generation system, reduce false shutdowns and improve equipment safety performance.

[0007] In a first aspect, a shutdown module of a photovoltaic assembly is provided, wherein the shutdown module comprises:

[0008] A signal receiving device, used to receive a timing instruction, parse the timing instruction to determine timing information, and perform timing configuration according to the timing information;

[0009] A timer, used for timing according to the timing information, and sending a shutdown instruction when the timing ends; wherein the timing information has a corresponding relationship with the timing time; and

[0010] The switch device is electrically connected to the timer and is used to trigger shutdown according to the shutdown instruction to disconnect the corresponding photovoltaic component from the series path.

[0011] In a second aspect, a shutdown control system of a photovoltaic assembly is provided, wherein the shutdown control system comprises:

[0012] A main control unit, used for sending timing instructions; and

[0013] At least one shut-off module is arranged on the series path of the photovoltaic string, and is configured to receive a timing instruction, parse the timing instruction to determine timing information, perform timing according to the timing information, and disconnect the corresponding photovoltaic component from the series path when the timing ends;

[0014] The timing information corresponds to the timing time.

[0015] In a third aspect, a photovoltaic module shutdown control method is provided, wherein the method comprises:

[0016] Receive timing instructions;

[0017] Parsing the timing instruction to determine timing information;

[0018] Perform timing according to the timing information, wherein the timing information has a corresponding relationship with the timing time;

[0019] In response to the timing ending, the corresponding photovoltaic assembly is disconnected from the series path.

[0020] According to a fourth aspect, a connection box is provided, wherein the connection box comprises the shutdown module according to the first aspect.

[0021] In a fifth aspect, a controller is provided for controlling a switching device in a shutdown module to disconnect a corresponding photovoltaic component from a series connection, wherein the controller comprises a memory and a processor, the memory being used to store one or more computer program instructions, wherein the one or more computer program instructions are executed by the processor to implement the method described in the third aspect.

[0022] In a sixth aspect, a photovoltaic power generation system is provided, wherein the photovoltaic power generation system comprises:

[0023] at least one photovoltaic module; and

[0024] A shutdown control system for a photovoltaic assembly as described in the second aspect or a shutdown module as described in the first aspect.

[0025] In the embodiment of the present invention, a shut-off module is arranged in the series circuit of the photovoltaic modules of the photovoltaic power generation system. The shut-off module repeatedly sets the timing time through the timing instruction containing the timing information. Each time during the timing process, when a new timing instruction corresponding to itself or the broadcast is received, the timing time is reset and the timing is restarted, and the conduction state is maintained during the timing process. If the timing information obtained by parsing the new timing instruction is not received at the end of the timing, the switch device is turned off, so that the corresponding photovoltaic module is disconnected from the series path of the photovoltaic string. The disconnected photovoltaic module can be safely operated. In this way, reliable component-level shutdown is achieved, and the control has high flexibility. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The above and other objects, features and advantages of the present invention will become more apparent through the following description of the embodiments of the present invention with reference to the accompanying drawings, in which:

[0027] Figure 1 is a schematic diagram of a photovoltaic power generation system according to an embodiment of the present invention;

[0028] Figure 2 is a schematic diagram of another implementation of the photovoltaic power generation system according to an embodiment of the present invention;

[0029] Figure 3 is a schematic diagram of a shutdown module according to an embodiment of the present invention;

[0030] Figure 4 is a flow chart of a shutdown control method according to an embodiment of the present invention. DETAILED DESCRIPTION

[0031] The present application is described below based on embodiments, but the present application is not limited to these embodiments. In the detailed description of the present application below, some specific details are described in detail. It is possible for those skilled in the art to fully understand the present application without the description of these details. In order to avoid confusing the essence of the present application, known methods, processes, flows, components and circuits are not described in detail.

[0032] In addition, persons of ordinary skill in the art will appreciate that the drawings provided herein are for illustration purposes and are not necessarily drawn to scale.

[0033] At the same time, it should be understood that in the following description, "circuit" refers to a conductive loop composed of at least one element or subcircuit through electrical connection or electromagnetic connection. When an element or circuit is said to be "connected to" another element or an element / circuit is said to be "connected between" two nodes, it can be directly coupled or connected to another element or there can be an intermediate element, and the connection between the elements can be physical, logical, or a combination thereof. On the contrary, when an element is said to be "directly coupled to" or "directly connected to" another element, it means that there is no intermediate element between the two.

[0034] Unless the context clearly requires otherwise, words such as “include,” “including,” and similar terms throughout this application should be understood to mean inclusive rather than exclusive or exhaustive; that is, to mean “including but not limited to.”

[0035] In the description of this application, it should be understood that the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. In addition, in the description of this application, unless otherwise specified, the meaning of "plurality" is two or more.

[0036] Figure 1 Schematic diagram of a photovoltaic power generation system according to an embodiment of the present invention. Figure 1 As shown, the photovoltaic power generation system of this embodiment includes at least one photovoltaic string 1, an inverter 2, a power storage circuit 3 and a battery 4 at the circuit structure level. The photovoltaic string 1 includes a plurality of photovoltaic modules 11 connected in series. The photovoltaic string 1 is used to convert solar energy into a DC voltage and output it to the inverter 2 through an output port. The inverter 2 receives the input DC power and converts the DC power into AC power, which is transmitted to the power transmission network through the connected transmission port, or the AC power is converted into DC power with a suitable voltage through the power storage circuit 3 to charge the battery 4 to store electrical energy.

[0037] Among them, photovoltaic modules are usually called solar panels, which are a collection of multiple photovoltaic cells (or solar cells) connected in series or in parallel. A single solar cell is formed in a sheet shape. Usually, the specifications of the solar cell are 125mm*125mm, 156mm*156mm or 124*124mm, etc. Since the current and voltage of a single solar cell are very small, it is necessary to connect these solar cells in series to obtain a certain voltage (for example, 40V), and then connect them in parallel to obtain a certain current, and then output them through a diode (to prevent current backflow). In order to further increase the output voltage, multiple photovoltaic modules 11 are connected in series to form a photovoltaic string 1. As a result, the output voltage of each photovoltaic module 11 is accumulated and output, which is convenient for the inverter 2 to process. However, this also causes the existence of DC high voltage in the photovoltaic string. When water spraying is required for maintenance or fire fighting, the DC high voltage will cause the risk of accidental electric shock. Therefore, the photovoltaic power station has a component-level shutdown function, especially a component-level rapid shutdown function in an emergency.

[0038] like Figure 1 As shown, in this embodiment, the photovoltaic string 1 also includes a plurality of shut-off modules 12 and at least one main control unit 13 for controlling the shut-off module 12. Among them, the shut-off module 12 can be formed in the form of a connection box, which is set corresponding to each photovoltaic component. That is, one connection box is set corresponding to one photovoltaic component, and the photovoltaic component 11 is connected to the series path of the photovoltaic string 1. In one example, the connection box can connect the photovoltaic component 11 to the current bus of the photovoltaic string 1. If it is necessary to disconnect one or several photovoltaic components 11 from the series path, the shut-off module 12 is controlled to disconnect the connection between the photovoltaic component and the series path. The shut-off module 12 and the corresponding main control unit 13 constitute the photovoltaic component shut-off control system of the embodiment of the present invention. Through the shutdown coordination of the two, reliable shutdown at the component level can be achieved. It should be understood that in other embodiments, multiple photovoltaic components can also be connected in series and then connected to the series path through the shut-off module, thereby making the shut-off module and the photovoltaic component not one-to-one corresponding.

[0039] like Figure 1As shown, the main control unit 13 may include a controller 131 and a signal sending device 132, and may also include a necessary human-computer interaction device (not shown in the figure). The human-computer interaction device may be a simple interaction device such as a dial switch or a button, or may be a touch screen or an interaction module with a keyboard and a liquid crystal display that is more expensive and can realize more complex interactions. The main control unit 13 is used to send a timing instruction. The timing instruction includes timing information. In this embodiment, the timing information is the time (that is, duration) required for timing. In one example, the timing information may be a floating point number or an integer, corresponding to the number of seconds of the timing duration. For example, the timing information is 30, indicating that the timing duration is 30 seconds. Alternatively, the timing information is 5, indicating that the timing duration is 5 seconds. The timing information can be configured by the maintenance personnel for the main control unit 13 according to the needs of the scene and written to the controller 131. The operation may include direct on-site operation through the human-computer interaction device, or the timing information may be set remotely through the communication circuit additionally provided in the main control unit 13 or the communication circuit integrated in the controller 131. After the main control unit 13 is set and powered on, it sends a timing instruction through the signal sending device 32. It should be understood that the timing information of the main control unit 13 can be modified during use, so as to flexibly implement shutdown control as needed.

[0040] Each shut-off module 12 is configured to receive a timing instruction, parse the timing instruction to determine the timing information, perform timing according to the timing information, and disconnect the corresponding photovoltaic component from the series path at the end of the timing. The timing instruction can be an encrypted instruction or a plain text instruction. If the shut-off module 12 receives a new timing instruction before the end of the timing and parses it to obtain new timing information, the current timing is interrupted and a new round of timing is started. The process of parsing the timing instruction is the process of decoding the coded signal suitable for communication and obtaining the timing information included therein. In other words, the shut-off module 12 will maintain the on state by the timing information received before the end of each timing, so that the corresponding photovoltaic component 11 remains connected to the series path. If the shut-off module 12 still does not receive new timing information at the end of the current timing, it enters the shut-off state and disconnects the corresponding photovoltaic component 11 from the series path.

[0041] In the shutdown control system of this embodiment, when the on state needs to be maintained, the main control unit 13 sends the next timing instruction before the timing corresponding to the previous timing instruction ends, ensuring that the shutdown module 12 can receive new timing information before its own timing ends, reset the timing, and maintain the photovoltaic assembly 11 connected to the series path. When it is necessary to shut down all photovoltaic assemblies 11 or specific photovoltaic assemblies 11 in the photovoltaic string 1, the sending of timing instructions can be stopped, which will cause the shutdown module 12 to fail to receive new timing instructions when its own current round of timing ends, and unable to perform new timing configuration, thereby entering the shutdown state and disconnecting the corresponding photovoltaic assembly 11 from the series path.

[0042] After the photovoltaic component 11 is disconnected from the series path, if it is necessary to restore the connection, that is, to reconnect the photovoltaic component 11 to the series path, the main control unit 13 can be controlled to send a timing instruction with timing information not equal to 0. The shutdown module 12 is configured to switch from a disconnected state to an on state in response to the timing information not being 0, and connect the corresponding photovoltaic component to the series path. In other words, as long as the shutdown module 12 receives a timing instruction with timing information not equal to 0, it can send a turn-on signal to the switching device. If it is already in the on state, the state is not changed. If it is currently in the off state, the switch to on is triggered. In another implementation, the main control unit 13 can also send a specially set on instruction to control the shutdown module 12 to be turned on again, and the on instruction can have a specific format and information to prevent the shutdown module from misidentifying.

[0043] In the embodiment of the present invention, a shut-off module is arranged in the series circuit of the photovoltaic modules of the photovoltaic power generation system. The shut-off module repeatedly sets the timing time through the timing instruction containing the timing information. Each time during the timing process, when a new timing instruction corresponding to itself or the broadcast is received, the timing time is reset and the timing is restarted, and the conduction state is maintained during the timing process. If the timing information obtained by parsing the new timing instruction is not received at the end of the timing, the switch device is turned off, so that the corresponding photovoltaic module is disconnected from the series path of the photovoltaic string. The disconnected photovoltaic module can be safely operated. In this way, reliable component-level shutdown is achieved, and the control has high flexibility.

[0044] In this embodiment, the timing instruction can be sent by the signal sending device 132 of the main control unit 13 in different ways according to the application scenario or needs. In some implementations, the main control unit 13 and the shutdown module 12 can be connected through a dedicated data transmission cable 1a, such as a network cable, an optical fiber, etc., and the timing instruction can be sent and received in a wired manner. In some implementations, the main control unit 13 and the shutdown module 12 can also be connected through a wireless communication connection 1b, for example, a mobile communication network, a wireless local area network, Bluetooth, NB-IOT, etc., and the timing instruction can be sent and received in a wireless manner.

[0045] In some implementations, the timing signal may also be sent over the power line using power communication technology.

[0046] Figure 2 FIG. 1 is a schematic diagram of an implementation method of a photovoltaic power generation system according to an embodiment of the present invention. Figure 2 As shown, the power line 21 of the system is used as a signal transmission medium. The main control unit 13 sends a timing instruction to the shutdown module 12 through the power line communication technology. Power line communication technology (Power Line Communication, referred to as PLC) is a technology that uses existing power transmission lines to transmit data. PLC uses wires to simultaneously transmit power and digital signals. The working principle of PLC is to modulate the data signal onto a high-frequency carrier and then superimpose it on the power line for transmission. The receiving end then extracts the data signal carried from the power line and demodulates it back to the original data. As a result, there is no need to lay new communication lines, which ensures stability while reducing the cost and complexity of wiring. The main control unit 13 is connected to the power line 21, so that timing instructions can be sent to the power line 21.

[0047] Figure 2 The structure of the shutoff module 12 in a photovoltaic module is specifically shown in FIG. Specifically, the photovoltaic module 11 has a positive terminal and a negative terminal (indicated by "+" and "-" in the figure) that can be connected to the current bus. When connected to the circuit, the current from the upstream flows into the positive terminal and flows out from the negative terminal. The shutoff module 12 has a switch K. Figure 2 In the embodiment, the switch K is arranged between the positive terminal of the photovoltaic module 11 and the current busbar. When the switch K is turned off, the corresponding photovoltaic module 11 is disconnected from the series path. It should be understood that the switch K can also be arranged on the negative terminal side, or on both sides at the same time.

[0048] Optionally, in order to ensure that the series path in the photovoltaic string 1 can still remain conductive after one or a group of shutdown modules are turned off, other shutdown modules that are still in the conductive state can receive timing instructions from the power line 21. The shutdown module of this implementation can be provided with a bypass connection circuit D12. The bypass connection circuit D12 can be a diode or other type of unidirectional conductive circuit connected in parallel to the port of the shutdown module 12 on one side of the series path (that is, the current bus). When the switch device is turned off, the bypass connection circuit D12 short-circuits the port, thereby maintaining electrical connectivity between the upstream and downstream photovoltaic components. As described above, the current from the upstream flows in from the positive terminal, and when the switch K is turned off, the current will flow to the downstream via the diode D12. When the switch K is turned on, since the photovoltaic component 11 generates an active voltage, it can be regarded as having a negative resistance. In this case, the diode D12 is short-circuited and the current does not pass through the diode.

[0049] It should be understood that in order to further ensure the reliability of communication, a combination of multiple of the above-mentioned methods may be used simultaneously to send and receive timing instructions.

[0050] In order to further enhance the reliability of communication, the shutdown module 12 can also add a relay function, that is, relay and forward the received timing instruction, use itself as a relay communication node, and forward the timing instruction to other shutdown modules 12 to ensure the successful reception of the timing instruction.

[0051] It should be understood that in this embodiment, the timing instruction is not a heartbeat signal, which is reflected in two aspects. On the one hand, the timing instruction contains timing information for resetting the timing time. On the other hand, in the embodiment of the present invention, the timing instruction is not sent completely in a periodic manner. In some implementations, it is even sent completely non-periodically, which makes the reception of the timing instructions of the embodiment of the present invention more flexible and has better anti-interference performance.

[0052] In this embodiment, the main control unit 13 can regularly send a timing signal after each update setting. In one example, the timing time of the main control unit 13 is configured to be 30 seconds. If the corresponding shutdown module 12 is to be maintained in the on state, the main control unit 13 starts timing after sending a timing instruction, and sends the next timing instruction before the end of the timing time of 30 seconds. The specific timing of sending can be implemented in different ways. In one implementation, the timing instruction can be sent at a predetermined time before each timing ends, for example, 2 seconds. In another implementation, the timing of sending the timing instruction before the end of the timing can also be determined according to a fixed time length ratio. For example, the fixed time length ratio can be set to 10%. Then, if the timing information is 10, the timing instruction will be sent 1 second in advance before the end of the timing. If the timing information is modified to 30, the timing instruction will be sent 3 seconds in advance before the end of the timing. In one implementation, a time point can be randomly selected to send the timing instruction after the timing starts and before the end of the timing. For example, if the timing information is 30, then when the timing starts, a random number is selected between 0-30, and when the time point corresponding to the random number arrives, the timing instruction is triggered. When there are a large number of main control units 13 in a photovoltaic power station that control different shutdown modules 12 respectively, although different main control units 13 will avoid mutual interference through various existing means, more main control units 13 use the same frequency band for communication at the same time, which will still lead to the problem of poor communication stability. By sending timing instructions in a random manner, the timing of sending timing instructions by different main control units 13 can be staggered on the time axis, thereby minimizing mutual interference and improving communication stability.

[0053] In this embodiment, the timing instruction can be sent in different ways.

[0054] In some implementations, the main control unit 13 sends the timing instruction in a broadcasting manner with a predetermined channel. As long as the shutdown module 12 is configured to receive a signal on the channel, it will receive the timing instruction, and parse it in response to receiving the timing instruction, and then perform timing control on or off operation according to the received timing information. It is easy to understand that when there are multiple main control units 13, the main control units 13 can be set to send timing instructions on different channels respectively, so that different main control units 13 can control different shutdown modules 12.

[0055] In some implementations, the main control unit 13 uses multicast to send a timing instruction, and the timing instruction includes module identification information. The module identification information corresponds to a group of shutdown modules 12 (that is, one or more shutdown modules). After receiving the timing instruction, the shutdown module 12 determines whether the module identification information corresponds to itself. If so, it parses the timing instruction to determine the timing information, and controls the on or off according to the timing information. If not, the timing instruction is not parsed, so that it is not triggered by the timing instruction to re-timing. For example, the shutdown module 12 can discard the corresponding timing instruction. Therefore, the main control unit 13 can achieve precise management of a group of shutdown modules by setting the module identification information.

[0056] As an alternative, the main control unit 13 may also use unicast to send a timing instruction to a specific shutdown module 12, which can also be achieved by including module identification information in the timing instruction, thereby achieving more precise control over the shutdown module 12.

[0057] It should be understood that in some implementations, the main control unit 13 can simultaneously have at least two of the capabilities of broadcasting, multicasting, and unicasting. Thus, the main control unit 13 can adopt different methods according to the user's settings or instructions to flexibly control all or part of the shutdown modules it covers.

[0058] In this embodiment, the timing duration corresponding to the timing information can be 0. That is to say, if an emergency occurs and the photovoltaic component 11 needs to be shut down immediately or as soon as possible, the main control unit 13 can send a timing instruction with a timing information of 0 according to the instruction. After the shutdown module 12 receives the timing instruction and parses the timing information, it still counts according to the timing information. Since the duration is 0, the timing ends immediately after it starts and triggers the shutdown operation. In this way, the photovoltaic component can be quickly shut down without adding additional instructions or signaling fields. Compared with the existing solution based on periodic heartbeat signals, a fast component-level shutdown is achieved.

[0059] It can be seen that, since the timing instruction includes a corresponding timing information with a variable timing time, in different timing processes, the main control unit 13 can be flexibly controlled to send a timing signal with a longer or shorter time according to the needs of the scene to achieve the corresponding purpose. For example, when the communication conditions are good, the sending frequency can be reduced, that is, the duration corresponding to the timing information is increased to achieve energy saving. When the communication conditions are not good, such as when the network is large or the components are installed far away, the sending frequency can be increased, that is, the duration corresponding to the timing information is reduced, so as to maintain the reliability of the connection state of the system.

[0060] At the same time, a large number of photovoltaic modules 11 are disconnected from the power grid or joined to the power grid at the same time, which may cause an impact on the power grid system. In this regard, by utilizing the characteristics of the embodiment of the present invention that the timing information is variable and can be controlled by grouping in a multicast manner, in one implementation, the main control unit 13 can set different timing information for shutdown modules of different groups according to predetermined groups, so that shutdown modules of different groups are shut down at different times, and resend the timing instructions for restoring conduction (that is, the timing instructions whose timing information is not 0) at different time points. In this way, each shutdown module 12 can be controlled to be shut down gradually, reducing the impact on the power grid and the power generation system.

[0061] Figure 3 FIG. 1 is a schematic diagram of a shutdown module according to an implementation method of an embodiment of the present invention. Figure 3 As shown, the shutoff module 12 includes a signal receiving device 121, a timer 122 and a switch device 123. The signal receiving device 121 is used to receive a timing instruction, parse the timing instruction to determine the timing information, and perform timing configuration according to the timing information. The timer 122 performs timing according to the timing information configured by the signal receiving device, and sends a shutoff instruction when the timing ends. The switch device 123 is electrically connected to the timer, and triggers the shutdown according to the shutoff instruction to disconnect the corresponding photovoltaic component from the series path.

[0062] Optionally, the shutoff module 12 may further include a first connector CON1 and a second connector CON2. The first connector CON1 is used to connect the switch device 123 and the output port of the corresponding photovoltaic assembly 11. The second connector CON2 is used to connect the switch device 123 and the upstream and downstream photovoltaic assemblies or the switch modules corresponding to the upstream and downstream photovoltaic assemblies. In the embodiment of the present invention, the upstream and downstream photovoltaic assemblies refer to other photovoltaic assemblies in a series path with the corresponding shutoff module or photovoltaic assembly. The first connector CON1 and the second connector CON2 can facilitate the installation of the shutoff module.

[0063] As mentioned above, for Figure 3 For the shutdown module shown, the timing instruction can be a signal instruction sent non-periodically. Further, the timing instruction is sent at a randomly selected time before the timing corresponding to the previous timing instruction ends.

[0064] The signal receiving device 121 may be configured to receive the timing instruction through at least one of a wireless connection, a dedicated data transmission cable, or a power line. Furthermore, the signal receiving device 121 may have the ability to parse module identification information from the timing instruction. The module identification information is used to identify one or a group of shutdown modules. Thus, the signal receiving device 121 is configured to determine the timing information in response to the module identification information corresponding to the shutdown module to which it belongs, and perform timing configuration according to the timing information; and, in response to the module identification information not corresponding to the shutdown module to which it belongs, no timing configuration is performed. Thus, the signal receiving device 121 can selectively determine whether to reset its own timer 122 according to the module identification information specified in the timing instruction, thereby realizing selective operation based on the timing instruction.

[0065] In this embodiment, the timer 122 performs timing configuration in response to the timing information received from the signal receiving device 121, starts timing, and at the end of the timing, if it is not reconfigured to start a new timing, sends a shutdown signal to control the switch device 123 to shut down. If new timing information is received, the current timing is interrupted and a new round of timing is started, and the switch device 123 is not operated, so that it remains turned on. The timing of the new round of timing corresponds to the new timing information.

[0066] In one example, the signal receiving device 121 receives a timing instruction at time t0, and the timing information obtained by parsing is an integer "30". The signal receiving device 121 sends the timing information "30" to the timer 122. At this time, the timer 122 is counting down the previous timing information "10". In response to receiving the new timing information "30", the timer 122 restarts a new round of timing and re-times according to a period of 30 seconds. If new timing information is received during this round of timing, a new round of timing is restarted again. If no new timing information is received at the end of this round of timing, a shutdown signal is sent to the switch device 123 to control the switch device 123 to disconnect the corresponding photovoltaic component from the series path.

[0067] After the photovoltaic component 11 is disconnected from the series path, if it is necessary to restore the connection, that is, to reconnect the photovoltaic component 11 to the series path. In response to the timing information being not 0, the signal receiving device 121 sends a connection instruction to trigger the switch device to switch from off to on. In other words, as long as the signal receiving device 121 receives a timing instruction whose timing information is not 0, it can send a conduction signal to the switch device 123. Alternatively, as long as the timer 122 receives a timing information that is not 0, it sends a conduction signal to the switch device 123. If the switch device 123 is currently in the on state, the state is not changed. If it is currently in the off state, the switch is triggered to be turned on. In another implementation, the main control unit 13 can also send a specially set conduction instruction to control the shutdown module 12 to be turned on again. The conduction instruction can have a specific format and information to prevent the shutdown module from misidentifying.

[0068] It can be seen that, since the timing instruction includes a corresponding timing information with a variable timing time, in different timing processes, the main control unit 13 can be flexibly controlled to send a timing signal with a longer or shorter time according to the needs of the scene to achieve the corresponding purpose. For example, when the communication conditions are good, the sending frequency can be reduced, that is, the duration corresponding to the timing information is increased to achieve energy saving. When the communication conditions are not good, such as when the network is large or the components are installed far away, the sending frequency can be increased, that is, the duration corresponding to the timing information is reduced, so as to maintain the reliability of the connection state of the system.

[0069] In order to ensure that after a shutdown module or a group of shutdown modules are shut down, the series path of the photovoltaic string can still remain conductive, so that other shutdown modules that are still in the conductive state can receive timing instructions from the power line. Figure 3 The shutdown module can be provided with a bypass connection circuit D12 (indicated by a dotted line in the figure). The bypass connection circuit D12 can be a diode or a unidirectional conduction circuit connected in parallel to the port of the shutdown module 12 on one side of the series path (i.e., the current busbar). When the switch device is turned off, the bypass connection circuit D12 short-circuits the port, thereby maintaining electrical connectivity between upstream and downstream photovoltaic components. Therefore, even if one photovoltaic component in the photovoltaic string is disconnected, the entire photovoltaic string is still connected in series and can continue to work or transmit signals through the power line.

[0070] It should be understood that the signal receiving device and the timer of the shutdown module of this embodiment can be implemented in various ways. The two can be integrated in the same integrated circuit, or formed as independent integrated circuits, or formed independently on a printed circuit board. At the same time, the signal receiving device and the timer can be implemented by a general data processing circuit or chip, for example, by running a computer program on a DSP, a single-chip microcomputer or a general terminal device with communication capabilities, such as a Raspberry Pi, etc. to implement related functions.

[0071] Figure 4 FIG. 1 is a flow chart of a shutdown control method according to an embodiment of the present invention. Figure 4 As shown, the method of this embodiment includes:

[0072] Step S100, receiving a timing instruction.

[0073] Step S200, parsing the timing instruction to determine timing information.

[0074] Step S300: timing according to the timing information, wherein the timing information corresponds to the timing time.

[0075] Step S400, in response to the timing ending, disconnecting the corresponding photovoltaic module from the series path.

[0076] In some embodiments, the timing instruction is a signal instruction sent aperiodically. Further, the timing instruction is sent at a randomly selected time before the timing corresponding to the previous timing instruction ends.

[0077] In some embodiments, the method further comprises:

[0078] The system is configured to interrupt the current timing and start a new round of timing in response to obtaining the new timing information through parsing.

[0079] In some embodiments, the timing time corresponding to the timing information is variable.

[0080] In some implementations, in response to the timing information corresponding to the timing instruction being 0, the corresponding photovoltaic component is directly disconnected from the series path.

[0081] In some embodiments, in response to the timing information not being 0, a connection instruction is sent to trigger the switch device to switch from off to on.

[0082] In some embodiments, the timing instruction further includes module identification information, and the module identification information is used to identify one or a group of shutdown modules;

[0083] In some embodiments, the timing instruction further includes module identification information, and the module identification information is used to identify one or a group of shutdown modules;

[0084] Before parsing the timing instruction to determine the timing information, the method further includes: determining module identification information;

[0085] The determining the timing information by parsing the timing instruction comprises:

[0086] In response to the module identification information corresponding to the shutdown module itself, determining timing information; and

[0087] In response to the module identification information not corresponding to the shutdown module itself, no timing configuration is performed.

[0088] In some embodiments, the method further comprises:

[0089] The relay forwards the timing instruction.

[0090] In the embodiment of the present invention, a shut-off module is arranged in the series circuit of the photovoltaic modules of the photovoltaic power generation system. The shut-off module repeatedly sets the timing time through the timing instruction containing the timing information. Each time during the timing process, when a new timing instruction corresponding to itself or the broadcast is received, the timing time is reset and the timing is restarted, and the conduction state is maintained during the timing process. If the timing information obtained by parsing the new timing instruction is not received at the end of the timing, the switch device is turned off, so that the corresponding photovoltaic module is disconnected from the series path of the photovoltaic string. The disconnected photovoltaic module can be safely operated. In this way, reliable component-level shutdown is achieved, and the control has high flexibility.

[0091] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, devices (equipment) or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment or an embodiment combining software and hardware. Moreover, the present application may adopt a computer program product implemented on one or more computer-readable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0092] The present application is described with reference to flowcharts of methods, apparatuses (devices) and computer program products according to embodiments of the present application. It should be understood that each process in the flowchart can be implemented by computer program instructions.

[0093] These computer program instructions may be stored in a computer-readable memory that can direct a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture including an instruction device that implements the process Figure 1 A function specified in a process or multiple processes.

[0094] These computer program instructions may also be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device produce the instructions for implementing the process Figure 1 A device that specifies functions in a process or multiple processes.

[0095] Another embodiment of the present invention relates to a non-volatile storage medium for storing a computer-readable program, wherein the computer-readable program is used for a computer to execute part or all of the above method embodiments.

[0096] That is, those skilled in the art can understand that all or part of the steps in the above-mentioned embodiment method can be completed by specifying relevant hardware through a program, and the program is stored in a storage medium, including several instructions for a device (which can be a single-chip microcomputer, chip, etc.) or a processor (processor) to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk and other media that can store program codes.

[0097] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A photovoltaic module shutdown module, characterized in that: The shutdown module comprises: A signal receiving device, used to receive a timing instruction, parse the timing instruction to determine timing information, and perform timing configuration according to the timing information; A timer, used for timing according to the timing information, and sending a shutdown instruction when the timing ends; wherein the timing information has a corresponding relationship with the timing time; and The switch device is electrically connected to the timer and is used to trigger shutdown according to the shutdown instruction to disconnect the corresponding photovoltaic component from the series path.

2. The shutdown module according to claim 1, characterized in that: The timing instruction is a signal instruction sent non-periodically.

3. The shutdown module according to claim 2, characterized in that: The timing instruction is sent at a randomly selected time before the timing corresponding to the previous timing instruction ends.

4. The shutdown module according to claim 2, characterized in that: The signal receiving device is configured to send the timing information to the timer for timing configuration; The timer is configured to interrupt current timing and start a new round of timing in response to receiving new timing information.

5. The shutdown module according to claim 2, characterized in that: The timing time corresponding to the timing information is variable.

6. The shutdown module according to claim 1, characterized in that: The timer is configured to directly control the switching device to turn off in response to the timing information being 0.

7. The shutdown module according to claim 1, characterized in that: The timer is configured to send a connection instruction in response to the timing information not being 0, thereby triggering the switch device to switch from off to on.

8. The shutdown module according to claim 1, characterized in that: The timing instruction further includes module identification information, and the module identification information is used to identify one or a group of shutdown modules; The signal receiving device is configured to determine timing information in response to the module identification information corresponding to the shutdown module to which the module belongs, and perform timing configuration according to the timing information; In response to the module identification information not corresponding to the shutdown module to which the module belongs, no timing configuration is performed.

9. The shutdown module according to claim 1, characterized in that: The signal receiving device is also configured to relay and forward the received timing instruction.

10. The shutdown module according to claim 1, characterized in that: The signal receiving device is configured to receive the timing instruction via at least one of a wireless connection, a dedicated data transmission cable, or a power line.

11. A photovoltaic module shutdown control system, characterized in that: The shutdown control system comprises: A main control unit, used for sending timing instructions; and At least one shut-off module is arranged on the series path of the photovoltaic string, and is configured to receive a timing instruction, parse the timing instruction to determine timing information, perform timing according to the timing information, and disconnect the corresponding photovoltaic component from the series path when the timing ends; The timing information corresponds to the timing time.

12. The system according to claim 11, characterized in that The main control unit is configured to send the timing instruction non-periodically.

13. The system according to claim 12, characterized in that The main control unit is configured to send the timing instruction at a randomly selected time before the timing corresponding to the previous timing instruction ends.

14. The system according to claim 12, characterized in that The shutdown module is configured to interrupt the current timing and start a new round of timing in response to obtaining new timing information through parsing.

15. The system according to claim 12, characterized in that The main control unit is configured to set the timing information corresponding to the timing instruction according to pre-configuration information or a received control instruction, and the timing time corresponding to the timing information is variable.

16. The system according to claim 11, characterized in that The shut-off module is configured to directly disconnect the corresponding photovoltaic component from the series connection path in response to the timing information corresponding to the timing instruction being 0.

17. The system according to claim 11, characterized in that The shut-off module is configured to switch from an off state to an on state in response to the timing information not being 0, so as to reconnect the corresponding photovoltaic assembly to the series connection path.

18. The system according to claim 11, characterized in that The main control unit is configured to set module identification information in the timing instruction, and the module identification information is used to identify one or a group of shutdown modules; The shutdown module is configured to determine the timing information in response to the module identification information of the timing instruction corresponding to itself, and re-time according to the timing information; and not re-time in response to the module identification information not corresponding to itself.

19. The system according to claim 11, characterized in that The shutdown module is configured to receive the timing instruction via at least one of a wireless connection, a dedicated data transmission cable, or a power line.

20. The system according to claim 11, characterized in that The shutdown module comprises: A signal receiving device, used to receive a timing instruction, parse the timing instruction to determine timing information, and perform timing configuration according to the timing information; a timer, which counts according to the timing information configured by the signal receiving device, and sends a shutdown instruction when the timing ends; and A switch device is electrically connected to the timer and is used to trigger the disconnection of the corresponding photovoltaic assembly from the series path according to the shutdown instruction.

21. The system according to claim 11, characterized in that The shutdown module is configured to relay and forward the timing instruction.

22. The system according to claim 18, characterized in that The main control unit is configured to set different timing information for different groups of shutdown modules, so that the shutdown modules of different groups are shut down at different times.

23. A photovoltaic module shutdown control method, characterized in that: The method comprises: Receive timing instructions; Parsing the timing instruction to determine timing information; Perform timing according to the timing information, wherein the timing information has a corresponding relationship with the timing time; In response to the timing ending, the corresponding photovoltaic assembly is disconnected from the series path.

24. The method according to claim 23, characterized in that Timing instructions are signal instructions that are sent non-periodically.

25. The method according to claim 24, characterized in that The timing instruction is sent at a randomly selected time before the timing corresponding to the previous timing instruction ends.

26. The method according to claim 24, characterized in that The method further comprises: In response to obtaining the new timing information through parsing, the current timing is interrupted and a new round of timing is started.

27. The method according to claim 24, characterized in that The timing time corresponding to the timing information is variable.

28. The method according to claim 27, characterized in that In response to the timing information corresponding to the timing instruction being 0, the corresponding photovoltaic component is directly disconnected from the series connection path.

29. The method according to claim 23, characterized in that In response to the timing information not being 0, the control switches from the disconnected state to the conductive state, and the corresponding photovoltaic assembly is reconnected to the series path.

30. The method according to claim 23, characterized in that The timing instruction further includes module identification information, and the module identification information is used to identify one or a group of shutdown modules; Before parsing the timing instruction to determine the timing information, the method further includes: determining module identification information; The determining the timing information by parsing the timing instruction comprises: In response to the module identification information corresponding to the shutdown module to which the module belongs, determining timing information; and In response to the module identification information not corresponding to the shutdown module to which the module belongs, no timing configuration is performed.

31. The method according to claim 23, characterized in that The method further comprises: The relay forwards the timing instruction.

32. A connection box, characterized in that: The connection box comprises a shutdown module according to any one of claims 1-10.

33. A controller for controlling a switch device in a shutdown module to disconnect a corresponding photovoltaic module from a series connection, characterized in that: The controller comprises a memory and a processor, the memory being used to store one or more computer program instructions, wherein the one or more computer program instructions are executed by the processor to implement the method according to any one of claims 23-31.

34. A photovoltaic power generation system, characterized in that: The photovoltaic power generation system comprises: at least one photovoltaic module; and A shutdown control system for a photovoltaic assembly as described in any one of claims 11 to 20 or a shutdown module as described in any one of claims 1 to 10.

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