Photovoltaic turn-off circuit and photovoltaic turn-off device
By designing a photovoltaic shutdown circuit, the number of cables between the photovoltaic modules and the shutdown device is reduced, solving the problem of high connection costs. It enables rapid disconnection and normal operation in case of failure, thereby improving the stability and safety of the photovoltaic string.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SUZHOU HEGUANG TONGYAO INTELLIGENT TECH CO LTD
- Filing Date
- 2025-05-26
- Publication Date
- 2026-04-28
AI Technical Summary
The existing connection method between photovoltaic modules and power switches has the problem of high cost.
A photovoltaic shutdown circuit is provided, which reduces the number of cables required for connection by designing a switch module, terminals, and terminal blocks, thereby enabling control of two photovoltaic modules.
It reduces connection costs and allows for timely disconnection in case of photovoltaic module failure, avoiding disruption to the normal operation of the entire photovoltaic string and improving stability and safety.
Smart Images
Figure CN224178141U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of photovoltaic technology, and in particular to a photovoltaic shutdown circuit and a photovoltaic shutdown device. Background Technology
[0002] Photovoltaic modules typically have a three-part junction box on the back, with a cable leading out from each of the two junction boxes, serving as the positive and negative output terminals of the photovoltaic module, respectively. The ends of the cables are photovoltaic connectors, which allow for quick plugging and unplugging of the male and female connectors, enabling the connection of multiple photovoltaic modules in series or to connect photovoltaic modules to module-level power electronics (MLPE) devices.
[0003] MLPE (Multi-Layer Power Adapter) equipment mainly includes micro-inverters, shutdown devices, and power optimizers. These are sophisticated control devices in solar photovoltaic (PV) systems, capable of inverting, monitoring, optimizing power, and shutting down individual or multiple PV modules, thus achieving refined management of the PV modules. However, current connection methods between PV modules and shutdown devices suffer from high costs. Utility Model Content
[0004] The purpose of this application is to provide a photovoltaic shutdown circuit and a photovoltaic shutdown device to reduce the number of cables required to connect the photovoltaic module and the shutdown device, thereby solving the problem of high connection costs.
[0005] In a first aspect, this invention provides a photovoltaic shutdown circuit, including a switch module, a first terminal, a second terminal, and a terminal group;
[0006] One end of the switch module is connected to the first terminal, and the other end of the switch module is connected to the terminal group;
[0007] The first terminal is used to connect to the first electrode of the first photovoltaic module, and the terminal group is used to connect to the second photovoltaic module and the subsequent equipment respectively.
[0008] The second terminal is used to connect to the main terminal of the first branch cable, the first branch of the first branch cable is connected to the second pole of the first photovoltaic module, and the second branch of the first branch cable is used to connect to the previous stage equipment.
[0009] Optionally, the terminal block includes a third terminal and a fourth terminal;
[0010] The other end of the switch module is connected to the third terminal, which is also used to connect to the positive electrode of the second photovoltaic module.
[0011] The fourth terminal is used to connect to the main terminal of the second branch cable, the first branch of the second branch cable is connected to the negative terminal of the second photovoltaic module, and the second branch of the second branch cable is used to connect to the next stage equipment.
[0012] Optionally, the switching module includes a first switch, a second switch, and a bypass unit;
[0013] The first terminal of the first switch is connected to the first terminal, the second terminal of the first switch is connected to the first terminal of the second switch, and the second terminal of the second switch is connected to the third terminal.
[0014] The input terminal of the bypass unit is connected to the second terminal of the first switch, and the output terminal is connected to the second terminal, so as to bypass the first photovoltaic module when the first switch is open; or,
[0015] Alternatively, the input terminal of the bypass unit can be connected to the fourth terminal, and the output terminal can be connected to the first terminal of the second switch, so as to bypass the second photovoltaic module when the second switch is open.
[0016] Optionally, the bypass unit includes a first diode, the anode of which is connected to the second terminal of the first switch and the first terminal of the second switch, respectively, and the cathode of the first diode is connected to the second terminal.
[0017] Optionally, the switching module includes a first switch, a second switch, a second diode, and a third diode;
[0018] The first end of the first switch is connected to the first terminal, and the second end of the second switch is connected to the third terminal.
[0019] The positive terminal of the second diode is connected to the second terminal of the first switch, the first terminal of the second switch, and the negative terminal of the third diode, respectively.
[0020] The negative terminal of the second diode is connected to the second terminal, and the positive terminal of the third diode is connected to the fourth terminal.
[0021] Optionally, both the first switch and the second switch include a control terminal, which is used to receive control signals.
[0022] Optionally, the photovoltaic shutdown circuit further includes a control chip, a first current sensor, a second current sensor, a first voltage sensor, and a second voltage sensor;
[0023] The control chip is connected to the control terminal of the first switch and the control terminal of the second switch respectively. The control chip is also connected to the output terminal of the first current sensor, the output terminal of the second current sensor, the output terminal of the first voltage sensor, and the output terminal of the second voltage sensor respectively.
[0024] The sampling terminal of the first current sensor and the first sampling terminal of the first voltage sensor are both connected to the first terminal, and the second sampling terminal of the first voltage sensor is connected to the second terminal.
[0025] The sampling terminal of the second current sensor and the first sampling terminal of the second voltage sensor are both connected to the third terminal, and the second sampling terminal of the second voltage sensor is connected to the fourth terminal.
[0026] Optionally, the power supply for the control chip is the first photovoltaic module and / or the second photovoltaic module.
[0027] Optionally, the switch module includes a third switch, a fourth switch, a fourth diode, and a fifth diode, and the terminal block includes a fifth terminal, a sixth terminal, and a seventh terminal;
[0028] The first end of the third switch is connected to the first terminal, and the second end of the third switch is connected to the positive terminal of the fourth diode, the negative terminal of the fifth diode, and the fifth terminal, respectively.
[0029] The negative terminal of the fourth diode is connected to the second terminal, the positive terminal of the fifth diode is connected to the first terminal and the seventh terminal of the fourth switch, and the second terminal of the fourth switch is connected to the sixth terminal.
[0030] The fifth terminal is also used to connect to the positive electrode of the second photovoltaic module, the sixth terminal is also used to connect to the downstream equipment, and the sixth terminal is also used to connect to the negative electrode of the second photovoltaic module.
[0031] In a second aspect, this application provides a photovoltaic shutdown device, including the photovoltaic shutdown circuit as described in the first aspect.
[0032] The photovoltaic shutdown circuit and photovoltaic shutdown device provided in this application include a switch module, a first terminal and a terminal group. One end of the switch module is connected to the first terminal and the other end of the switch module is connected to the terminal group. The first terminal is used to connect to the first electrode of the first photovoltaic module, and the terminal group is used to connect to the second photovoltaic module and the next stage equipment respectively. The second terminal is used to connect to the main terminal of the first branch cable. The first branch end of the first branch cable is connected to the second electrode of the first photovoltaic module, and the second branch end of the first branch cable is used to connect to the previous stage equipment.
[0033] With the above structure, the photovoltaic shutdown circuit can connect two photovoltaic modules to the photovoltaic string and control the two photovoltaic modules. It only requires a cable to connect each photovoltaic module and does not require a separate output cable, which reduces the number of cables required for connection and thus greatly reduces costs. Attached Figure Description
[0034] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.
[0035] Figure 1 This is a schematic diagram of the structure of a conventional one-to-two switch provided in an embodiment of this application.
[0036] Figure 2 This is one of the structural schematic diagrams of the photovoltaic shut-off device provided in the embodiments of this application.
[0037] Figure 3 This is a second schematic diagram of the structure of the photovoltaic shut-off device provided in the embodiments of this application.
[0038] Figure 4 This is the third schematic diagram of the structure of the photovoltaic shut-off device provided in the embodiments of this application.
[0039] Figure 5 The fourth schematic diagram of the photovoltaic shut-off device provided in the embodiments of this application.
[0040] Figure 6 The fifth schematic diagram of the photovoltaic shut-off device provided in the embodiments of this application.
[0041] Figure 7 This is the sixth schematic diagram of the structure of the photovoltaic shut-off device provided in the embodiments of this application.
[0042] Figure 8 This is the seventh schematic diagram of the structure of the photovoltaic shut-off device provided in the embodiments of this application.
[0043] Figure 9 This is the eighth schematic diagram of the structure of the photovoltaic shut-off device provided in the embodiments of this application.
[0044] Figure 10 This is the tenth schematic diagram of the structure of the photovoltaic shut-off device provided in the embodiments of this application.
[0045] Icons: 10 - Photovoltaic shutdown circuit; 110 - Switch module; 111 - Bypass unit; 120 - First branch cable; 130 - First cable; 140 - Second cable; 150 - Second branch cable; 160 - Third cable; 170 - Fourth cable; 20 - First photovoltaic module; 30 - Second photovoltaic module; 40 - Downstream equipment; 50 - Upstream equipment; 01 - Control chip; 02 - First current sensor; 03 - Second current sensor; 04 - First voltage sensor; 05 - Second voltage sensor; Q1 - First switch; Q2 - Second switch; D1 - First diode; D2 - Second diode; D3 - Third diode; P1 - First terminal; P2 - Second terminal; PN - Terminal group; P3 - Third terminal; P4 - Fourth terminal; Q3 - Third switch; Q4 - Fourth switch; D4 - Fourth diode; D5 - Fifth diode; P5 - Fifth terminal; P6 - Sixth terminal; P7 - Seventh terminal. Detailed Implementation
[0046] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.
[0047] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.
[0048] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.
[0049] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the utility model product is in use. 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, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. In addition, the terms "first," "second," and "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.
[0050] Furthermore, terms such as "horizontal," "vertical," and "sag" do not imply that components must be absolutely horizontal or suspended, but rather that they can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal relative to "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.
[0051] In the description of this application, it should also be noted that, unless otherwise expressly specified and limited, the terms "set up," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.
[0052] The following detailed description of some embodiments of this application is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.
[0053] Reference Figure 1 This diagram illustrates a common connection between a photovoltaic (PV) module and a dual-mode circuit breaker. The dual-mode circuit breaker has two sets of input terminals and two output terminals, allowing connection to two PV modules respectively. Each set of input terminals connects to the corresponding PV module via two cables, while each of the two output terminals connects to other PV modules or devices via a separate cable. In this way, a single dual-mode circuit breaker can independently control two PV modules.
[0054] from Figure 1 As can be seen, a one-to-two circuit breaker requires six cables to connect. Photovoltaic cables account for approximately 20% of the circuit breaker's material cost, resulting in a relatively high material cost.
[0055] To address the high cost of connecting photovoltaic (PV) switches and PV modules, refer to Figure 2 This application provides a photovoltaic shutdown circuit 10, including a switch module 110, a first terminal P1, a second terminal P2, and a terminal group PN.
[0056] One end of the switch module 110 is connected to the first terminal P1, and the other end of the switch module 110 is connected to the terminal group PN.
[0057] The first terminal P1 is used to connect to the first pole of the first photovoltaic module 20, and the terminal group PN is used to connect to the second photovoltaic module 30 and the subsequent equipment 40 respectively.
[0058] The second terminal P2 is used to connect to the main terminal of the first branch cable 120. The first branch end of the first branch cable 120 is connected to the second pole of the first photovoltaic module 20. The second branch end of the first branch cable 120 is used to connect to the previous stage equipment 50.
[0059] In this system, the first electrode can be either positive or negative, and the second electrode can also be either positive or negative. For example... Figure 2 As shown, when the first electrode is negative, the second electrode is positive. Conversely, if the first electrode is positive, the second electrode is negative, and the second electrode will adjust according to the change of the first electrode.
[0060] See Figure 2 The first end of the first terminal P1 is connected to the first pole of the first photovoltaic module 20 through the first cable 130.
[0061] With the above structure, the photovoltaic shutdown circuit 10 can connect two photovoltaic modules to a photovoltaic string (a photovoltaic string is composed of multiple photovoltaic modules connected in series) and control the two photovoltaic modules. It only requires a cable to connect to each photovoltaic module and does not require a separate output cable, which reduces the number of cables required for connection and thus greatly reduces costs.
[0062] The implementation of the terminal group PN of the photovoltaic shutdown circuit 10 can be flexibly set. For example, it can be the same structure as the first terminal P1 and the second terminal P2, connecting the second photovoltaic module 30 and the downstream equipment 40 with two cables. It can also be a structure similar to the original one-to-two shutdown device. Its implementation is not limited.
[0063] To further reduce cable costs, similar to the first terminal P1 and the second terminal P2, a terminal group PN is introduced that connects to the second photovoltaic module 30 and the subsequent equipment 40 via two cables. This design follows the same principle as the first photovoltaic module 20, where the first electrode is negative and the second electrode is positive. Referring to... Figure 3 The terminal block PN includes the third terminal P3 and the fourth terminal P4.
[0064] The other end of the switch module 110 is connected to the third terminal P3, which is also used to connect to the positive terminal of the second photovoltaic module 30.
[0065] The fourth terminal P4 is used to connect to the main terminal of the second branch cable 150. The first branch of the second branch cable 150 is connected to the negative terminal of the second photovoltaic module 30. The second branch of the second branch cable 150 is used to connect to the downstream equipment 40.
[0066] Please refer to Figure 3The other end of the switch module 110 is connected to the positive terminal of the second photovoltaic module 30 via the second cable 140.
[0067] It should be noted here that, Figure 3 This is the circuit structure when the first electrode of the first photovoltaic module 20 is the negative electrode and the second electrode of the first photovoltaic module 20 is the positive electrode. When the first electrode of the first photovoltaic module 20 is the positive electrode and the second electrode of the first photovoltaic module 20 is the negative electrode, the positive and negative electrodes of the second photovoltaic module 30 will be adjusted accordingly. That is, the third terminal P3 is connected to the negative electrode of the second photovoltaic module 30, and the first branch end of the second branch cable 150 is connected to the positive electrode of the second photovoltaic module 30.
[0068] With the above structure, the photovoltaic switch can be connected to two photovoltaic modules with four cables, and these two photovoltaic modules can be integrated into the photovoltaic string. Compared with the existing one-to-two switch which requires six cables, the number of cables is greatly reduced, thereby further reducing costs.
[0069] The aforementioned switch module 110 is used to switch the state of the first photovoltaic module 20 and the second photovoltaic module 30 connected to the photovoltaic string. If either the first photovoltaic module 20 or the second photovoltaic module 30 connected to the switch module 110 fails or is damaged, its connection will be disconnected.
[0070] The circuit structure of the switch module 110 can be flexibly configured. For example, it can be a switch circuit composed of any one or several switches, or a switch circuit composed of switches and other devices. The implemented circuit structure is unrestricted.
[0071] In order to disconnect the first photovoltaic module 20 or the second photovoltaic module 30 from the grid without affecting the connection and operation of the remaining photovoltaic modules in the event of a fault or damage, the switch module 110 is equipped with a function to disconnect and isolate the faulty or damaged photovoltaic module.
[0072] Reference Figure 4 The switch module 110 includes a first switch Q1, a second switch Q2, and a bypass unit 111.
[0073] The first terminal of the first switch Q1 is connected to the first terminal P1, the second terminal of the first switch Q1 is connected to the first terminal of the second switch Q2, and the second terminal of the second switch Q2 is connected to the third terminal P3.
[0074] The input terminal of the bypass unit 111 is connected to the second terminal of the first switch Q1, and the output terminal is connected to the second terminal P2, so as to bypass the first photovoltaic module 20 when the first switch Q1 is open.
[0075] Or, in another example, with Figure 4The difference in the provided switch module 110 is that, referring to Figure 5 The input terminal of the bypass unit 111 is connected to the fourth terminal P4, and the output terminal is connected to the first terminal of the second switch Q2, so as to bypass the second photovoltaic module 30 when the second switch Q2 is open.
[0076] When the bypass unit 111 is connected between the second terminal of the first switch Q1 and the second terminal P2 (i.e. Figure 4 When the structure shown is such that the first photovoltaic module 20 malfunctions or is damaged, the first switch Q1 will be disconnected to disconnect the first photovoltaic module 20. Under the action of the bypass unit 111, the second photovoltaic module 30 is normally connected to the photovoltaic string, allowing the photovoltaic string to function normally. When the bypass unit 111 is connected between the fourth terminal P4 and the first terminal of the second switch Q2 (i.e., ...), Figure 5 When the structure shown is such that the second photovoltaic module 30 fails or is damaged, the second switch Q2 will be disconnected to disconnect the second photovoltaic module 30. Under the action of the bypass unit 111, the first photovoltaic module 20 is normally connected to the photovoltaic string so that the photovoltaic string can work normally.
[0077] Through the aforementioned structure and the action of the photovoltaic shutdown circuit 10, only the malfunctioning photovoltaic modules can be disconnected and bypassed without affecting the entire photovoltaic string, allowing the photovoltaic string to continue operating normally. This improves the stability of the photovoltaic string and reduces power loss.
[0078] The circuit structure of the bypass unit 111 can be flexibly configured. For example, it can be a circuit composed of switching transistors such as MOSFETs and transistors, or other circuit structures, without restriction.
[0079] In order to reduce circuit complexity and cost while still achieving the bypass function, the bypass unit 111 can be a circuit composed of a single diode.
[0080] When the bypass unit 111 is a circuit composed of a single diode, and the bypass unit 111 is connected between the second terminal of the first switch Q1 and the second terminal P2 (i.e. Figure 4 When referring to the structure shown), Figure 6 The bypass unit 111 includes a first diode D1. The positive terminal of the first diode D1 (i.e., the input terminal of the bypass unit 111) is connected to the second terminal of the first switch Q1 and the first terminal of the second switch Q2, respectively. The negative terminal of the first diode D1 (i.e., the output terminal of the bypass unit 111) is connected to the second terminal P2.
[0081] Therefore, when the first switch Q1 is closed, both the first photovoltaic module 20 and the second photovoltaic module 30 are connected to the photovoltaic string. When the first switch Q1 is disconnected due to a fault or damage to the first photovoltaic module 20, the first photovoltaic module 20 is bypassed under the action of the first diode D1, and the second photovoltaic module 30 is normally connected to the photovoltaic string.
[0082] When the bypass unit 111 is a circuit composed of diodes, and the bypass unit 111 is located between the fourth terminal P4 and the first terminal of the second switch Q2 (i.e. Figure 5 When referring to the structure shown), Figure 7 The bypass unit 111 includes a first diode D1. The positive terminal of the first diode D1 (i.e., the input terminal of the bypass unit 111) is connected to the fourth terminal P4, and the negative terminal of the first diode D1 (i.e., the output terminal of the bypass unit 111) is connected to the first terminal of the second switch Q2.
[0083] Therefore, when the second switch Q2 is closed, both the first photovoltaic module 20 and the second photovoltaic module 30 are connected to the photovoltaic string. When the second switch Q2 is disconnected due to a fault or damage to the second photovoltaic module 30, the second photovoltaic module 30 is bypassed under the action of the first diode D1, and the first photovoltaic module 20 is normally connected to the photovoltaic string.
[0084] When switch module 110 is Figure 6 and Figure 7 In the circuit structure shown, the first electrode of the first photovoltaic module 20 is the negative electrode, and the second electrode of the first photovoltaic module 20 is the positive electrode. When the first electrode of the first photovoltaic module 20 is positive and the second electrode is negative, the polarities of the first diode D1 and the second diode D2 will be adjusted accordingly. Figure 6 The structure is adjusted as follows: the negative terminal of the first diode D1 (i.e. the input terminal of the bypass unit 111) is connected to the second terminal of the first switch Q1 and the first terminal of the second switch Q2 respectively, and the positive terminal of the first diode D1 (i.e. the output terminal of the bypass unit 111) is connected to the second terminal P2. Figure 7 The structure is adjusted as follows: the negative terminal of the first diode D1 (i.e., the input terminal of the bypass unit 111) is connected to the fourth terminal P4, and the positive terminal of the first diode D1 (i.e., the output terminal of the bypass unit 111) is connected to the first terminal of the second switch Q2.
[0085] In another example, to disconnect the connection of either the first photovoltaic module 20 or the second photovoltaic module 30 in the event of a fault or damage, without affecting the connection between the remaining photovoltaic modules, and to reduce circuit complexity and cost, a function to disconnect and isolate the faulty or damaged photovoltaic module is introduced in the switch module 110. (Refer to...) Figure 8The switch module 110 includes a first switch Q1, a second switch Q2, a second diode D2, and a third diode D3.
[0086] The first terminal of the first switch Q1 is connected to the first terminal P1, and the second terminal of the second switch Q2 is connected to the third terminal P3.
[0087] The positive terminal of the second diode D2 is connected to the second terminal of the first switch Q1, the first terminal of the second switch Q2, and the negative terminal of the third diode D3.
[0088] The negative terminal of the second diode D2 is connected to the second terminal P2, and the positive terminal of the third diode D3 is connected to the fourth terminal P4.
[0089] When both switches are closed, the first photovoltaic module 20 and the second photovoltaic module 30 are both connected to the photovoltaic string. When the first switch Q1 is opened due to a fault or damage to the first photovoltaic module 20, the first photovoltaic module 20 is bypassed under the action of the second diode D2, and the second photovoltaic module 30 is normally connected to the photovoltaic string. When the second switch Q2 is opened due to a fault or damage to the second photovoltaic module 30, the second photovoltaic module 30 is bypassed under the action of the third diode D3, and the first photovoltaic module 20 is normally connected to the photovoltaic string. When both photovoltaic modules are faulty or damaged and both the first switch Q1 and the second switch Q2 are opened, the other photovoltaic modules are normally connected under the action of the second diode D2 and the third diode D3, and the photovoltaic string is unaffected.
[0090] With the above structure, if either the first photovoltaic module 20 or the second photovoltaic module 30 fails or is damaged, the other can still be connected to the photovoltaic string normally without affecting the normal operation of the photovoltaic string, which greatly improves safety and other performance and reduces losses.
[0091] The first switch Q1 and the second switch Q2 provided above can be manually switched or automatically controlled switches, and the implementation method is not limited.
[0092] When switch module 110 is Figure 8 In the circuit structure shown, the first electrode of the first photovoltaic module 20 is the negative electrode, and the second electrode of the first photovoltaic module 20 is the positive electrode. When the first electrode of the first photovoltaic module 20 is positive and the second electrode is negative, the polarities of the first diode D1 and the second diode D2 will be adjusted accordingly. Figure 8 The structure is adjusted as follows: the negative terminal of the second diode D2 is connected to the second terminal of the first switch Q1, the first terminal of the second switch Q2, and the positive terminal of the third diode D3, respectively; the positive terminal of the second diode D2 is connected to the second terminal P2; and the negative terminal of the third diode D3 is connected to the fourth terminal P4.
[0093] To facilitate the automatic opening and closing of the switches, both the first switch Q1 and the second switch Q2 include a control terminal, which is used to receive control signals.
[0094] The control signal can be input from an external device to the first switch Q1 and the second switch Q2, or it can be input from an internal device to the first switch Q1 and the second switch Q2; the implementation method is not limited.
[0095] To automate the monitoring of photovoltaic (PV) module conditions and promptly disconnect modules in case of failure or damage, thus preventing collateral damage to other PV modules and reducing risk costs, a concept is introduced into the PV shutdown circuit 10 to automatically detect the voltage and current status of the PV modules and control the switching on and off accordingly. (Refer to...) Figure 9 The photovoltaic shutdown circuit 10 also includes a control chip 01, a first current sensor 02, a second current sensor 03, a first voltage sensor 04, and a second voltage sensor 05.
[0096] The control chip 01 is connected to the control terminal of the first switch Q1 and the control terminal of the second switch Q2 respectively. The control chip 01 is also connected to the output terminal of the first current sensor 02, the output terminal of the second current sensor 03, the output terminal of the first voltage sensor 04 and the output terminal of the second voltage sensor 05 respectively.
[0097] The sampling terminal of the first current sensor 02 and the first sampling terminal of the first voltage sensor 04 are both connected to the first terminal P1, and the second sampling terminal of the first voltage sensor 04 is connected to the second terminal P2.
[0098] The sampling terminal of the second current sensor 03 and the first sampling terminal of the second voltage sensor 05 are both connected to the third terminal P3, and the second sampling terminal of the second voltage sensor 05 is connected to the fourth terminal P4.
[0099] With the above structure, the first current sensor 02 is used to collect the output current of the first photovoltaic module 20, the first voltage sensor 04 is used to collect the output voltage of the first photovoltaic module 20, the second current sensor 03 is used to collect the output current of the second photovoltaic module 30, and the second voltage sensor 05 is used to collect the output voltage of the second photovoltaic module 30. Furthermore, the control chip 01 determines whether the first photovoltaic module 20 is faulty based on its output voltage and output current (e.g., a fault occurs when both are zero), and controls the first switch Q1 to open when a fault is determined. Similarly, the control chip 01 determines whether the second photovoltaic module 30 is faulty based on its output voltage and output current, and controls the second switch Q2 to open when a fault is determined.
[0100] In another example, there may be only one current sensor. In this case, the sampling terminal of the current sensor is set at any position in the switch module 110, and the number and setting position of the voltage sensors remain unchanged. Based on this, the control chip 01 determines whether the first photovoltaic module 20 is faulty (if both are zero, it is a fault) based on the output voltage of the first photovoltaic module 20 and the current value collected by the current sensor, and controls the first switch Q1 to open when a fault is determined. Similarly, the control chip 01 determines whether the second photovoltaic module 30 is faulty based on the output voltage of the second photovoltaic module 30 and the current value collected by the current sensor, and controls the second switch Q2 to open when a fault is determined.
[0101] It should be noted that, Figure 9 merely in Figure 8 The corresponding solution provides a connection diagram, in Figures 4 to 7 The above-mentioned concept of automatically detecting the status of photovoltaic modules and controlling the switch accordingly also applies to the corresponding solution. The specific connection method can be adjusted adaptively, and will not be elaborated here.
[0102] The above structure enables real-time detection of photovoltaic module status and automatic control of the switch, thereby allowing for timely switching and bypassing when photovoltaic modules are damaged or malfunction, greatly reducing losses and improving safety.
[0103] The power supply of the control chip 01 provided above can be flexibly set. For example, it can be an external storage battery or a lithium battery, and its implementation method is not limited.
[0104] To reduce costs, in one example, the control chip 01 is powered by the first photovoltaic module 20 and / or the second photovoltaic array. That is, the control chip 01 draws power directly from the photovoltaic module, thus eliminating the need for an additional power supply and saving on power costs, further reducing costs.
[0105] In the above Figure 2 Based on the illustrated scheme, in order to reduce the number of cables and to disconnect the first photovoltaic module 20 and the second photovoltaic module 30 without affecting the connection between the remaining photovoltaic modules in the event of a fault or damage, so that the photovoltaic string can still operate normally, a function to disconnect and isolate the faulty or damaged photovoltaic module is introduced into the switch module 110. (Refer to...) Figure 10 The switch module 110 includes a third switch Q3, a fourth switch Q4, a fourth diode D4, and a fifth diode D5. The terminal block PN includes a fifth terminal P5, a sixth terminal P6, and a seventh terminal P7.
[0106] The first terminal of the third switch Q3 is connected to the first terminal P1, and the second terminal of the third switch Q3 is connected to the positive terminal of the fourth diode D4, the negative terminal of the fifth diode D5, and the fifth terminal P5.
[0107] The cathode of the fourth diode D4 is connected to the second terminal P2, the anode of the fifth diode D5 is connected to the first terminal and the seventh terminal P7 of the fourth switch Q4, and the second terminal of the fourth switch Q4 is connected to the sixth terminal P6.
[0108] The fifth terminal P5 is also used to connect to the positive terminal of the second photovoltaic module 30, the sixth terminal P6 is also used to connect to the downstream equipment 40, and the sixth terminal P6 is also used to connect to the negative terminal of the second photovoltaic module 30.
[0109] The fourth switch Q4, the fourth diode D4, and the fifth diode D5 here can also be replaced by other switching transistors such as MOSFETs and transistors. This is just an example and not the only limitation.
[0110] Therefore, when the first photovoltaic module 20 fails and turns off the third switch Q3, the remaining photovoltaic modules are normally connected under the bypassing effect of the fourth diode D4, and the operation of the photovoltaic string is not affected. Similarly, when the second photovoltaic module 30 fails and turns off the fourth switch Q4, the remaining photovoltaic modules are normally connected under the bypassing effect of the fifth diode D5, and the operation of the photovoltaic string is not affected.
[0111] Furthermore, in the above structure, the first terminal P1 is connected to the negative terminal of the first photovoltaic module 20 via a first cable 130; the second terminal P2 is connected to the positive terminal of the first photovoltaic module 20 and the upstream device 50 via a first branch cable 120; the fifth terminal P5 is connected to the positive terminal of the second photovoltaic module 30 via a second cable 140; the sixth terminal P6 is connected to the negative terminal of the second photovoltaic module 30 via a third cable 160; and the seventh terminal P7 is connected to the downstream device 40 via a fourth cable 170. That is, the photovoltaic shutdown circuit 10 only requires five cables to connect the two photovoltaic modules to the photovoltaic string. Figure 1 Compared to the single-to-two switch shown, the number of cables is reduced, resulting in a decrease in cost.
[0112] Similar to the principle of the aforementioned switch module 110, when the switch module 110 is Figure 10 In the circuit structure shown, the first electrode of the first photovoltaic module 20 is the negative electrode, and the second electrode of the first photovoltaic module 20 is the positive electrode. When the first electrode of the first photovoltaic module 20 is positive and the second electrode of the first photovoltaic module 20 is negative, the positive and negative electrodes of the fourth diode D4 and the fifth diode D5 will be adjusted accordingly, that is, the positive and negative electrodes will be reversed, which will not be elaborated here.
[0113] Based on the same concept as the photovoltaic shutdown circuit 10 described above, this application embodiment also provides a photovoltaic shutdown device, which includes any of the photovoltaic shutdown circuits 10 provided above. The specific implementation and effects of the photovoltaic shutdown circuit 10 are described above and will not be repeated here.
[0114] The photovoltaic shutdown device may also include a housing and multiple junction boxes. The circuit board of the photovoltaic shutdown circuit 10 is housed inside the housing, and the junction boxes are mounted on the housing, each corresponding to a terminal of the photovoltaic shutdown circuit 10. The junction boxes are used to lead out cables, which include any of the following: the first cable 130, the second cable 140, the first branch cable 120, and the second branch cable 150. The specific number and type of cables are determined by the photovoltaic shutdown circuit 10.
[0115] For ease of installation and use, the length of the lead cable can be any specification such as 0.5m, 0.8m, 1.2m, or 1.5m, and the size of the photovoltaic switch shall not exceed 15cm × 20cm.
[0116] The photovoltaic shutdown device described above can reduce the number of cables used for connection, thereby significantly reducing the material cost of the shutdown device. In addition, when shutting down a faulty photovoltaic module, it can maintain the connection between the remaining faulty photovoltaic modules, improving risk resistance and reducing losses caused by failure.
[0117] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.
Claims
1. A photovoltaic turn-off circuit, characterized in that, Includes a switch module, a first terminal, a second terminal, and a terminal block; One end of the switch module is connected to the first terminal, and the other end of the switch module is connected to the terminal group; The first terminal is used to connect to the first electrode of the first photovoltaic module, and the terminal group is used to connect to the second photovoltaic module and the subsequent equipment respectively. The second terminal is used to connect to the main terminal of the first branch cable, the first branch of the first branch cable is connected to the second pole of the first photovoltaic module, and the second branch of the first branch cable is used to connect to the previous stage equipment.
2. The photovoltaic shutdown circuit according to claim 1, characterized in that, The first electrode of the first photovoltaic module is the negative electrode, the second electrode of the first photovoltaic module is the positive electrode, and the terminal group includes a third terminal and a fourth terminal. The other end of the switch module is connected to the third terminal, which is also used to connect to the positive electrode of the second photovoltaic module. The fourth terminal is used to connect to the main terminal of the second branch cable, the first branch of the second branch cable is connected to the negative terminal of the second photovoltaic module, and the second branch of the second branch cable is used to connect to the next stage equipment.
3. The photovoltaic shutdown circuit according to claim 2, characterized in that, The switching module includes a first switch, a second switch, and a bypass unit; The first terminal of the first switch is connected to the first terminal, the second terminal of the first switch is connected to the first terminal of the second switch, and the second terminal of the second switch is connected to the third terminal. The input terminal of the bypass unit is connected to the second terminal of the first switch, and the output terminal is connected to the second terminal, so as to bypass the first photovoltaic module when the first switch is open; or, The input terminal of the bypass unit is connected to the fourth terminal, and the output terminal is connected to the first terminal of the second switch, so as to bypass the second photovoltaic module when the second switch is open.
4. The photovoltaic shutdown circuit according to claim 3, characterized in that, The bypass unit includes a first diode, the positive terminal of which is connected to the second terminal of the first switch and the first terminal of the second switch, respectively, and the negative terminal of the first diode is connected to the second terminal.
5. The photovoltaic shutdown circuit according to claim 2, characterized in that, The switching module includes a first switch, a second switch, a second diode, and a third diode; The first end of the first switch is connected to the first terminal, and the second end of the second switch is connected to the third terminal. The positive terminal of the second diode is connected to the second terminal of the first switch, the first terminal of the second switch, and the negative terminal of the third diode, respectively. The negative terminal of the second diode is connected to the second terminal, and the positive terminal of the third diode is connected to the fourth terminal.
6. The photovoltaic shutdown circuit according to any one of claims 3 to 5, characterized in that, Both the first switch and the second switch include a control terminal, which is used to receive control signals.
7. The photovoltaic shutdown circuit according to any one of claims 3 to 5, characterized in that, The photovoltaic shutdown circuit also includes a control chip, a first current sensor, a second current sensor, a first voltage sensor, and a second voltage sensor. The control chip is connected to the control terminal of the first switch and the control terminal of the second switch respectively. The control chip is also connected to the output terminal of the first current sensor, the output terminal of the second current sensor, the output terminal of the first voltage sensor, and the output terminal of the second voltage sensor respectively. The sampling terminal of the first current sensor and the first sampling terminal of the first voltage sensor are both connected to the first terminal, and the second sampling terminal of the first voltage sensor is connected to the second terminal. The sampling terminal of the second current sensor and the first sampling terminal of the second voltage sensor are both connected to the third terminal, and the second sampling terminal of the second voltage sensor is connected to the fourth terminal.
8. The photovoltaic shutdown circuit according to claim 7, characterized in that, The control chip is powered by the first photovoltaic module and / or the second photovoltaic module.
9. The photovoltaic shutdown circuit according to claim 1, characterized in that, The switch module includes a third switch, a fourth switch, a fourth diode, and a fifth diode, and the terminal block includes a fifth terminal, a sixth terminal, and a seventh terminal; The first end of the third switch is connected to the first terminal, and the second end of the third switch is connected to the positive terminal of the fourth diode, the negative terminal of the fifth diode, and the fifth terminal, respectively. The negative terminal of the fourth diode is connected to the second terminal, the positive terminal of the fifth diode is connected to the first terminal and the seventh terminal of the fourth switch, and the second terminal of the fourth switch is connected to the sixth terminal. The fifth terminal is also used to connect to the positive electrode of the second photovoltaic module, the sixth terminal is also used to connect to the downstream equipment, and the sixth terminal is also used to connect to the negative electrode of the second photovoltaic module.
10. A photovoltaic switch, characterized in that, Includes the photovoltaic shutdown circuit as described in any one of claims 1 to 9.