Photovoltaic junction box and photovoltaic junction system

Abstract

This application provides a photovoltaic junction box and a photovoltaic wiring system. The photovoltaic junction box includes: a positive terminal input, a negative terminal input, a first switch assembly, a positive terminal, and a negative terminal. When the positive terminal input is unavailable, the second end of the first switch assembly is connected to the other end of the negative terminal input and one end of the negative terminal, respectively, so that the photovoltaic module is connected to the negative terminal. When the positive terminal input is connected to the positive terminal of a first adjacent photovoltaic junction box, the second end of the first switch assembly is disconnected from the other end of the negative terminal input and one end of the negative terminal, so that the photovoltaic module is connected to the positive terminal of the first adjacent photovoltaic junction box. This application solves the problem in the prior art that the odd-numbered rows of photovoltaic array components require additional extension lines and cable trays, resulting in complex wiring, by automatically switching the first switch assembly according to the positive terminal input connection state.

Description

Technical Field

[0001] This application relates to the field of photovoltaic wiring technology, and more specifically, to a photovoltaic junction box and a photovoltaic wiring system. Background Technology

[0002] With the rapid development of the photovoltaic energy industry, photovoltaic arrays, as the core power generation unit of photovoltaic power generation systems, are directly affected by the rationality and reliability of their installation and wiring, which in turn affects the system's power generation efficiency, installation costs, and ease of operation and maintenance. Photovoltaic modules achieve circuit connections between modules through their built-in junction boxes, completing the collection and transmission of electrical energy, and finally connecting to the power grid through combiner boxes and inverters. Therefore, the wiring method of the junction boxes is a key technical aspect in the installation and construction of photovoltaic arrays.

[0003] In existing photovoltaic module array wiring, modules in the same series circuit are generally connected in series using a left-right interlocking method: adjacent modules are connected to each other through the positive and negative terminals of the junction box to form a continuous series circuit. Under this wiring scheme, when the modules in the array are arranged in an even number of rows, the total positive and negative terminals of the entire string of modules can naturally rotate and converge to the same side of the array through left-right interlocking, without the need for additional adapter lines, and can be directly connected to the combiner box or inverter.

[0004] However, the existing left-right plug-in wiring technology has the following problems: when the photovoltaic array has only one row of modules, or an odd number of rows, due to the limitation of left-right plug-in series connection, the total positive and negative terminals of the entire string of modules will be located on opposite sides of the array, and cannot converge to the same side. To meet the docking requirements with the combiner box and inverter, an additional long jumper cable must be installed to lead the electrode on one side of the array to the other side to converge with the other electrode. The addition of this long jumper cable not only increases the material cost of cables and fasteners, but also requires additional cable trays or other fixing measures to limit and fix the jumper cable, significantly increasing the complexity of the installation process and construction costs. Summary of the Invention

[0005] The purpose of this application is to address the shortcomings of the prior art by providing a photovoltaic junction box and a photovoltaic wiring system to solve the problem of high cable costs in the prior art.

[0006] To achieve the above objectives, the technical solution adopted in this application is as follows:

[0007] In a first aspect, this application provides a photovoltaic junction box, the photovoltaic junction box comprising: a positive terminal input, a negative terminal input, a first switching assembly, a positive terminal, and a negative terminal;

[0008] One end of the positive terminal input is used to connect to the positive terminal of the first adjacent photovoltaic junction box or is left unused. The first end of the first switch assembly is connected to the photovoltaic module and the other end of the positive terminal input. The second end of the first switch assembly is left unused or connected to the other end of the negative terminal input and one end of the negative terminal, respectively. One end of the negative terminal input is used to connect to the negative terminal of the first adjacent photovoltaic junction box or is left unused. The other end of the negative terminal input is connected to one end of the negative terminal. One end of the positive terminal is connected to the photovoltaic module. The other end of the positive terminal is used to connect to the positive terminal input of the second adjacent photovoltaic junction box or to connect to a load. The other end of the negative terminal is used to connect to the negative terminal input of the second adjacent photovoltaic junction box or to a load.

[0009] When the positive terminal inlet is unavailable, the second end of the first switch assembly is connected to the other end of the negative terminal inlet and one end of the negative terminal, respectively, so that the photovoltaic module is connected to the negative terminal. When the positive terminal inlet is connected to the positive terminal of the first adjacent photovoltaic junction box, the second end of the first switch assembly is disconnected from the other end of the negative terminal inlet and one end of the negative terminal, so that the photovoltaic module is connected to the positive terminal of the first adjacent photovoltaic junction box.

[0010] Optionally, the first switch assembly includes a spring switch; the spring switch includes a switch trigger point and a contact component;

[0011] One end of the switch trigger point is mechanically connected to the first end of the contact component, the second end of the contact component is connected to the positive terminal inlet and the photovoltaic module respectively, and the third end of the contact component is either unused or connected to the other end of the negative terminal inlet and one end of the negative terminal respectively.

[0012] When the positive terminal of the first adjacent photovoltaic junction box is unoccupied, the third end of the contact component is connected to the other end of the negative terminal inlet and one end of the negative terminal, respectively.

[0013] When the positive terminal of the first adjacent photovoltaic junction box is connected to the positive terminal inlet, the switch trigger point drives the contact component to move, so that the third end of the contact component is disconnected from the other end of the negative terminal inlet and one end of the negative terminal, and the photovoltaic module is connected to the positive terminal of the first adjacent photovoltaic junction box.

[0014] Optionally, the photovoltaic junction box further includes: a detection sensor and a microcontroller, wherein the first switching assembly includes an electronic switch;

[0015] The access detection sensor is connected to the first terminal of the microcontroller, and the second terminal of the microcontroller is connected to the control terminal of the electronic switch;

[0016] The access detection sensor is used to detect whether the positive terminal inlet is connected to the positive terminal of the first adjacent photovoltaic junction box. If so, it sends an access signal to the microcontroller so that the microcontroller controls the electronic switch to disconnect from the photovoltaic module and the negative terminal, and makes the photovoltaic module connected to the positive terminal of the first adjacent photovoltaic junction box.

[0017] Optionally, the photovoltaic junction box further includes: a second switching assembly, a voltage detection sensor, and a microcontroller;

[0018] The first end of the second switch assembly is connected to the first end of the first switch assembly, and the second end of the second switch assembly is used to connect to one end of the positive terminal.

[0019] The voltage detection sensor is used to detect the voltage of the photovoltaic module and output a voltage signal to the third terminal of the microcontroller. The fourth terminal of the microcontroller is connected to the control terminal of the second switching assembly.

[0020] The microcontroller determines whether the voltage value corresponding to the voltage signal is less than a preset voltage threshold. If so, it sends an on control signal to the second switch component, and the second switch component closes to make the positive terminal input and the positive terminal directly connected. If not, it sends an off control signal to the second switch component, and the second switch component opens to make the positive terminal input and the positive terminal connected through the photovoltaic module.

[0021] Optionally, the positive and negative terminals are integrated into a dual-core terminal.

[0022] Optionally, the photovoltaic junction box further includes: a bypass diode module;

[0023] The first end of the bypass diode module is connected to the first end of the first switch assembly, and the second end of the bypass diode module is connected to one end of the positive terminal.

[0024] The multiple access terminals of the bypass diode module are respectively connected to the multiple access terminals of the photovoltaic module.

[0025] Secondly, this application provides a photovoltaic wiring system, which includes at least one photovoltaic junction box as described in the first aspect above and at least one photovoltaic module.

[0026] Optionally, the photovoltaic wiring system includes multiple photovoltaic junction boxes;

[0027] In two adjacent photovoltaic junction boxes, the positive terminal of the previous photovoltaic junction box is connected to the positive terminal of the next photovoltaic junction box, and the negative terminal of the previous photovoltaic junction box is connected to the negative terminal of the next photovoltaic junction box.

[0028] The positive terminal of the photovoltaic junction box connected to the load is connected to one end of the load, and the negative terminal of the photovoltaic junction box located at the load end is connected to the other end of the load;

[0029] In a photovoltaic junction box where one end of the positive terminal input is empty, the second end of the first switching assembly is connected to the other end of the negative terminal input.

[0030] Optionally, the photovoltaic wiring system includes a photovoltaic junction box;

[0031] The second end of the first switch assembly of the photovoltaic junction box is connected to the other end of the negative terminal input and one end of the negative terminal, respectively. The positive terminal of the photovoltaic junction box is connected to one end of the load, and the negative terminal of the photovoltaic junction box is connected to the other end of the load.

[0032] Optionally, the photovoltaic junction boxes in the photovoltaic wiring system are arranged in the same row.

[0033] The beneficial effects of this application are as follows: The photovoltaic junction box includes a positive terminal inlet, a negative terminal inlet, a first switch assembly, a positive terminal, and a negative terminal. When the positive terminal inlet is unavailable, the second end of the first switch assembly is connected to the other end of the negative terminal inlet and one end of the negative terminal, respectively, so that the photovoltaic module is connected to the negative terminal. When the positive terminal inlet is connected to the positive terminal of the first adjacent photovoltaic junction box, the second end of the first switch assembly is disconnected from the other end of the negative terminal inlet and one end of the negative terminal, so that the photovoltaic module is connected to the positive terminal of the first adjacent photovoltaic junction box. This application achieves flexible switching between independent conduction in a single junction box and series conduction as an intermediate junction box by automatically switching the first switch assembly according to the connection state of the positive terminal inlet. This solves the problem in the prior art that photovoltaic arrays with odd-numbered rows of modules require additional extension lines and cable trays, resulting in complex wiring. Meanwhile, by setting the positive and negative terminals and the input ports, and in conjunction with the switching logic of the first switch assembly, the series connection can be completed by connecting adjacent junction boxes to each other. This solves the problem of incorrect insertion caused by terminal confusion when multiple junction boxes are connected in series, improves wiring reliability, and reduces the complexity of installation procedures and construction costs. Attached Figure Description

[0034] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0035] Figure 1 This is a schematic diagram of a single-row wiring diagram for a photovoltaic junction box in the prior art;

[0036] Figure 2 This is a schematic diagram of the structure of a photovoltaic junction box provided in an embodiment of this application;

[0037] Figure 3 This is a simplified circuit diagram of an embodiment of the present application with an unused positive terminal input.

[0038] Figure 4 This is a simplified structural diagram of a photovoltaic junction box provided in an embodiment of this application;

[0039] Figure 5 This is a schematic diagram of another photovoltaic junction box provided in an embodiment of this application;

[0040] Figure 6 This is a circuit diagram illustrating the series connection of multiple photovoltaic junction boxes according to an embodiment of this application.

[0041] Figure 7 This is a circuit diagram of a single photovoltaic junction box provided in an embodiment of this application. Detailed Implementation

[0042] 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. It should be understood that the accompanying drawings in this application are for illustrative and descriptive purposes only and are not intended to limit the scope of protection of this application. Furthermore, it should be understood that the schematic drawings are not drawn to scale. The flowcharts used in this application illustrate operations implemented according to some embodiments of this application. It should be understood that the operations in the flowcharts may not be implemented in sequence, and steps without logical contextual relationships may be reversed or implemented simultaneously. In addition, those skilled in the art, guided by the content of this application, may add one or more other operations to the flowcharts, or remove one or more operations from the flowcharts.

[0043] Furthermore, the described embodiments are merely some, not all, of the embodiments of this application. The components of the embodiments of this application described and illustrated herein can typically be arranged and designed in various different configurations. 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.

[0044] It should be noted that the term "comprising" will be used in the embodiments of this application to indicate the presence of the features declared thereafter, but does not exclude the addition of other features.

[0045] Figure 1 This is a schematic diagram of a single-row wiring in a photovoltaic junction box in existing technology. (For example...) Figure 1 As shown, in existing technologies, photovoltaic modules in the same string are connected in series by interlocking left and right. When the number of rows of modules is even, the positive and negative terminals can naturally converge on the same side, directly connecting to the combiner box / inverter, resulting in simple wiring. However, if the number of rows of modules is single or odd, the positive and negative terminals are located on both sides of the array, requiring the addition of long jumper cables for the combiner. This not only increases the cost of cables and fasteners and enhances construction complexity, but also leads to messy wiring across multiple arrays, affecting operation and maintenance, increasing safety hazards such as wear and short circuits, and reducing system reliability.

[0046] Based on this, this application proposes a photovoltaic junction box, which includes a positive terminal input, a negative terminal input, a first switch assembly, a positive terminal, and a negative terminal. When no other photovoltaic junction box's positive terminal is connected to the positive terminal input of the current photovoltaic junction box, the first switch assembly keeps the photovoltaic module connected to the negative terminal. The photovoltaic module is connected to both the positive terminal input and the positive terminal. When a photovoltaic junction box's positive terminal is connected to the positive terminal input of the current photovoltaic junction box, the first switch assembly disconnects the photovoltaic module from the negative terminal, allowing the positive terminal of an adjacent photovoltaic junction box to be connected to the photovoltaic module of the current photovoltaic junction box. This application optimizes the structure of the photovoltaic junction box, requiring only the connection between adjacent photovoltaic junction boxes. Ultimately, only the positive and negative terminals of the first photovoltaic junction box are connected to the combiner box / inverter, saving on extension cables and cable trays or conduits for fixed cables, reducing construction complexity, and improving operational reliability.

[0047] Before introducing the specific structure of the photovoltaic (PV) junction box, let's first discuss its application scenarios. In practical applications, each PV panel is equipped with a corresponding PV junction box. The direct current (DC) generated by the PV panel is connected to the corresponding junction box via leads, thus extracting the PV panel's power. When a voltage boost is needed, multiple PV panels can be connected in series through the junction box to form a PV string, and then the power is collected through the junction box. The collected DC power is first transmitted to a combiner box for initial collection, and then sent to an inverter to convert the DC power into AC power that meets usage standards. This AC power can be directly supplied to loads such as residential homes and industrial plants, meeting the power needs for daily lighting, production equipment operation, etc.

[0048] Next, refer to Figure 2 The specific structure and working process of the photovoltaic junction box are described. Figure 2 This is a structural schematic diagram of a photovoltaic junction box provided in an embodiment of this application. Wherein, Figure 2 The first switching component in the diagram is illustrated by taking a spring switch as an example.

[0049] Optionally, the photovoltaic junction box includes: a positive terminal inlet, a negative terminal inlet, a first switching assembly, a positive terminal, and a negative terminal.

[0050] The system comprises the following components: one end of the positive terminal input is used to connect to the positive terminal of the first adjacent photovoltaic junction box or is left unused; the first end of the first switching assembly is connected to the photovoltaic module and the other end of the positive terminal input; the second end of the first switching assembly is left unused or connected to the other end of the negative terminal input and one end of the negative terminal, respectively. One end of the negative terminal input is used to connect to the negative terminal of the first adjacent photovoltaic junction box or is left unused; the other end of the negative terminal input is connected to one end of the negative terminal. One end of the positive terminal is connected to the photovoltaic module. The other end of the positive terminal is used to connect to the positive terminal input of the second adjacent photovoltaic junction box or to connect a load; the other end of the negative terminal is used to connect to the negative terminal input of the second adjacent photovoltaic junction box or to a load.

[0051] Specifically, the positive terminal inlet and the negative terminal inlet are interface structures on the photovoltaic junction box used to physically connect and conduct electricity with the positive and negative terminals of the first adjacent photovoltaic junction box. They have plug-in and plug-out dimensions and conductive contacts that are compatible with the positive and negative terminals of the adjacent junction boxes. When the positive terminal inlet is not connected to a positive terminal, it can be closed with a cover.

[0052] The positive terminal inlet is equipped with conductive terminal pieces and a trigger structure. The interface can be marked with a special shape to ensure that the positive terminal of the first adjacent photovoltaic junction box can only be inserted in the correct direction. When connected, the positive terminal of the adjacent junction box makes close contact with the conductive terminal pieces in the positive terminal inlet to achieve circuit conduction. In addition, the connection status can be fed back by mechanical pressing or electrical signal detection.

[0053] The negative terminal inlet has a conductive contact corresponding to the negative terminal inside, which is symmetrically arranged on the same side of the junction box as the positive terminal inlet to avoid confusion between the positive and negative terminals when plugged in. When the negative terminal of the first adjacent photovoltaic junction box is inserted, the circuit is connected through the physical contact of the metal contacts. When not in use, the interface can be sealed with a sealing cover to prevent the external environment from affecting the conductivity.

[0054] It is worth noting that the positions of the positive and negative terminals can be on one side of the photovoltaic junction box, arranged along the length, width, or depth. In other words, the positions of the positive and negative terminals can be set according to actual needs, and this embodiment does not impose any restrictions. Similarly, the positions of the positive and negative terminal inlets can be on the opposite side of the positions of the positive and negative terminals, or on adjacent sides, arranged along the length, width, or depth. Again, the positions of the positive and negative terminal inlets can be set according to actual needs, and this embodiment does not impose any restrictions.

[0055] The first switching assembly is used to switch the path of the photovoltaic junction box circuit and has two stable operating states: Specifically, when the positive terminal input is empty, the second end of the first switching assembly is connected to the other end of the negative terminal input and one end of the negative terminal, so that the photovoltaic module is connected to the negative terminal; when the positive terminal input is connected to the positive terminal of the first adjacent photovoltaic junction box, the second end of the first switching assembly is disconnected from the other end of the negative terminal input and one end of the negative terminal, so that the photovoltaic module is connected to the positive terminal of the first adjacent photovoltaic junction box.

[0056] Specifically, when the positive terminal input is empty, i.e., no positive terminal of the first adjacent photovoltaic junction box is inserted, the first switch assembly is in the closed state, realizing the conduction between the photovoltaic module and the negative terminal. In this state, whether the current photovoltaic junction box is working independently or in the end-component scenario of multiple photovoltaic junction boxes connected in series, there is no need to connect it in series with subsequent components. By closing the first switch assembly, the negative lead of the photovoltaic module is directly connected to the negative terminal of the current photovoltaic junction box, forming a complete working circuit from the photovoltaic module, positive terminal, load, negative terminal back to the photovoltaic module.

[0057] When the positive terminal of the first adjacent photovoltaic junction box is inserted into the positive terminal input of this junction box, the first switching component disconnects from the negative terminal input and the negative terminal. At this time, the photovoltaic module is connected to the positive terminal of the first adjacent photovoltaic junction box. Specifically, this state corresponds to the scenario of an intermediate component for multiple photovoltaic junction boxes connected in series. By switching the first switching component, the direct connection between the photovoltaic module and the negative terminal of the current photovoltaic junction box is disconnected, and the photovoltaic module is connected to the positive terminal of the first adjacent photovoltaic junction box, thereby achieving the effect of no additional extension wire when multiple components are connected in series.

[0058] Figure 3 This is a simplified circuit diagram showing an unused positive terminal input provided in an embodiment of this application. For example... Figure 3 As shown, when the positive terminal is unused, the photovoltaic module is connected to the negative terminal, and the negative and positive terminals are connected to the load respectively, thus forming a complete circuit.

[0059] The positive and negative terminals constitute the power input and output circuit of the photovoltaic junction box. They can be made of highly conductive metal materials. One end is connected to the inside of the current photovoltaic junction box, and the other end is a plug-in structure or load connection structure adapted to the input of the second adjacent photovoltaic junction box.

[0060] The first adjacent photovoltaic junction box, the current photovoltaic junction box, and the second adjacent photovoltaic junction box are connected in series. The positive and negative terminals of the first adjacent photovoltaic junction box are inserted into the corresponding terminals of the current photovoltaic junction box. The positive and negative terminals of the second adjacent photovoltaic junction box are connected to the positive and negative terminals of the current photovoltaic junction box, respectively. The first adjacent photovoltaic junction box, the current photovoltaic junction box, and the second adjacent photovoltaic junction box have the same structure.

[0061] A photovoltaic module is a core power generation unit that converts solar energy into direct current. It is usually composed of multiple photovoltaic cells connected in series and parallel. The photovoltaic module transmits electrical energy through a photovoltaic junction box. The first switching component and the positive terminal are connected to one end of the negative terminal and the positive terminal of the photovoltaic module, respectively.

[0062] A load refers to an electrical device or power transmission equipment that receives electrical energy from the photovoltaic junction box, including combiner boxes, inverters, energy storage devices, etc. The photovoltaic junction box is connected to the load through positive and negative terminals to transmit the direct current generated by the photovoltaic module to the load.

[0063] In this embodiment, the photovoltaic junction box includes a positive terminal inlet, a negative terminal inlet, a first switch assembly, a positive terminal, and a negative terminal. When the positive terminal inlet is unavailable, the second end of the first switch assembly is connected to the other end of the negative terminal inlet and one end of the negative terminal, respectively, so that the photovoltaic module is connected to the negative terminal. When the positive terminal inlet is connected to the positive terminal of the first adjacent photovoltaic junction box, the second end of the first switch assembly is disconnected from the other end of the negative terminal inlet and one end of the negative terminal, so that the photovoltaic module is connected to the positive terminal of the first adjacent photovoltaic junction box. This embodiment achieves flexible switching between independent conduction in a single junction box and series conduction as an intermediate junction box by automatically switching the first switch assembly according to the positive terminal inlet connection state. This solves the problem of the need for additional extension lines and cable trays and complex wiring in the prior art for odd-numbered rows of photovoltaic array components. Meanwhile, by setting the positive and negative terminals and the input ports, and in conjunction with the switching logic of the first switch assembly, the series connection can be completed by connecting adjacent junction boxes to each other. This solves the problem of incorrect insertion caused by terminal confusion when multiple junction boxes are connected in series, improves wiring reliability, and reduces the complexity of installation procedures and construction costs.

[0064] The following describes the structures of two types of first switch components.

[0065] As an optional implementation method, continue to refer to Figure 2 The first switch assembly includes a spring switch. The spring switch includes a switch trigger point and contact components.

[0066] Specifically, one end of the switch trigger point is mechanically connected to the first end of the contact component, the second end of the contact component is connected to the positive terminal inlet and the photovoltaic module respectively, and the third end of the contact component is either unused or connected to the other end of the negative terminal inlet and one end of the negative terminal respectively.

[0067] When the positive terminal of the first adjacent photovoltaic junction box is unused, the third end of the contact component is connected to the other end of the negative terminal inlet and one end of the negative terminal, respectively.

[0068] When the positive terminal of the first adjacent photovoltaic junction box is connected to the positive terminal input, the switch trigger point drives the contact component to move, so that the third end of the contact component is disconnected from the other end of the negative terminal input and one end of the negative terminal, and the photovoltaic module is connected to the positive terminal of the first adjacent photovoltaic junction box.

[0069] Specifically, from a structural connection perspective, the switch trigger point is mechanically connected to the contact component, and the movement of the switch trigger point can drive the movement of the contact component.

[0070] From the perspective of working logic, there are two adaptation scenarios: The contact component includes a spring structure. When the switch trigger point is not subjected to external force, the elasticity of the spring structure keeps the third end of the contact component connected to the other end of the negative terminal input and one end of the negative terminal, so that the photovoltaic module is connected to the negative terminal through the contact component to form a complete independent working circuit.

[0071] When the positive terminal of the first adjacent photovoltaic junction box is connected to the positive terminal input of this junction box, the connected terminal head will press against the switch trigger point. After the switch trigger point is subjected to force, it will cause the contact component to move, so that its third end is disconnected from the other end of the negative terminal input and one end of the negative terminal. Since the positive terminal of the first adjacent photovoltaic junction box is connected to the positive terminal input of the current photovoltaic junction box, the second end of the contact component is connected to the positive terminal of the first adjacent photovoltaic junction box and the photovoltaic module, thus realizing the series connection of the photovoltaic module and the first adjacent photovoltaic junction box. The automatic switching of the series circuit can be completed without manual intervention.

[0072] In this embodiment, the spring switch includes a switch trigger point and a contact component. The spring switch enables automatic switching of the circuit state, which can adapt to both scenarios of a single photovoltaic junction box working independently and multiple photovoltaic junction boxes connected in series without manual intervention.

[0073] As another alternative implementation, the photovoltaic junction box also includes: access detection sensors and a microcontroller, and the first switching assembly includes an electronic switch.

[0074] The access detection sensor is used to detect whether the positive terminal of the first adjacent photovoltaic junction box is inserted into the access port, and converts the access status into a transmittable signal. The access detection sensor can be a pressure sensor, a photoelectric sensor, etc. The pressure sensor is triggered to output an access signal by the pressure of the terminal insertion, and the photoelectric sensor is triggered to output an access signal by the terminal blocking light.

[0075] The microcontroller can generate control commands based on the received access signals, and then transmit the control commands to the control terminal of the electronic switch to drive the electronic switch to perform circuit switching actions, ensuring the timeliness and accuracy of circuit switching.

[0076] Electronic switches are controlled circuit switching switches that can quickly switch circuit paths according to external control commands.

[0077] Specifically, the detection sensor is connected to the first end of the microcontroller, and the second end of the microcontroller is connected to the control end of the electronic switch.

[0078] The access detection sensor is used to detect whether the positive terminal input is connected to the positive terminal of the first adjacent photovoltaic junction box. If so, it sends an access signal to the microcontroller, so that the microcontroller controls the electronic switch to disconnect from the photovoltaic module and the negative terminal, and makes the photovoltaic module conduct with the positive terminal of the first adjacent photovoltaic junction box.

[0079] Specifically, the access detection sensor monitors the access status of the positive terminal inlet in real time, that is, it determines whether the positive terminal of the first adjacent photovoltaic junction box has been inserted.

[0080] When the positive terminal is unavailable, the detection sensor has no input signal output, the microcontroller maintains the initial control state, and the electronic switch maintains the conduction circuit between the photovoltaic module and the negative terminal, ensuring that the independent photovoltaic junction box or the photovoltaic junction box at the end of the series can work normally.

[0081] When the positive terminal of the first adjacent photovoltaic junction box is connected to the positive terminal input, the connection detection sensor immediately identifies the connection status and sends a connection signal to the microcontroller. After receiving the connection signal, the microcontroller generates a control command through preset control logic and transmits it to the control terminal of the electronic switch. This drives the electronic switch to disconnect the photovoltaic module from the negative terminal and connect the circuit between the photovoltaic module and the positive terminal of the first adjacent photovoltaic junction box. This automatically completes the circuit switching required for connecting multiple photovoltaic junction boxes in series, achieving loop connection without manual intervention.

[0082] In this embodiment, by connecting detection sensors, microcontrollers, and electronic switches, the circuit switching is automated and precise. It can adapt to scenarios where a single photovoltaic junction box works independently or multiple photovoltaic junction boxes are connected in series without manual intervention. This solves the problems of slow switching response and easy wear of traditional mechanical switches, and improves the working stability and service life of the junction box.

[0083] It should be understood that a photovoltaic (PV) panel is composed of multiple PV cells connected in series and parallel. Under normal operation, the impedance of each cell is consistent, and the current and voltage are evenly distributed. When some PV cells are shaded, such as by leaves, dust, or shadows, the shaded cells cannot absorb light energy to generate electricity, and their impedance increases sharply. The high-impedance shaded cells will generate abnormal voltage division, causing the overall output voltage of the entire PV module to drop sharply. The large current passing through the high-impedance shaded area will generate a lot of heat, forming hot spots. If not intervened in time, hot spots will burn out the PV cells, damage the PV panel, and even cause a fire. Therefore, as an optional implementation, the PV junction box also includes: a second switching component, a voltage detection sensor, and a microcontroller.

[0084] The second switching component can be an electronic switch, which can be turned on and off based on control signals sent by the microcontroller. A voltage detection sensor is used to acquire the operating voltage of the photovoltaic module in real time and convert the voltage physical quantity into a transmittable voltage signal. The microcontroller receives the operating voltage sent by the voltage detection sensor and outputs control signals based on the operating voltage to control the on and off of the second switching component.

[0085] Specifically, the first end of the second switch assembly is connected to the first end of the first switch assembly, and the second end of the second switch assembly is used to connect to one end of the positive terminal.

[0086] The voltage detection sensor is used to detect the voltage of the photovoltaic module and outputs a voltage signal to the third terminal of the microcontroller. The fourth terminal of the microcontroller is connected to the control terminal of the second switching component.

[0087] The microcontroller determines whether the voltage value corresponding to the voltage signal is less than a preset voltage threshold. If so, it sends an on control signal to the second switching component, and the second switching component closes to make the positive terminal input and the positive terminal directly connected. If not, it sends an off control signal to the second switching component, and the second switching component opens to make the positive terminal input and the positive terminal connected through the photovoltaic module.

[0088] The preset voltage threshold can be set based on the minimum voltage required for the photovoltaic module to operate normally. Once a hot spot appears on the photovoltaic module, the voltage will inevitably fall below this threshold.

[0089] If a hot spot appears in the current photovoltaic junction box, the operating voltage of the photovoltaic module corresponding to that junction box is lower than a preset voltage threshold. The microcontroller sends a connection control signal to the second switching component to directly connect the positive terminal input and the positive terminal, short-circuiting the photovoltaic module. If the detected voltage value of the photovoltaic module is not lower than the preset voltage threshold, the positive terminal input and the positive terminal are connected through the photovoltaic module, and the photovoltaic module supplies power normally.

[0090] Figure 4 This is a simplified structural diagram of a photovoltaic junction box provided in an embodiment of this application. Figure 4 As shown, the second switch assembly is closed to directly connect the positive terminal inlet and the positive terminal, preventing current from flowing through the abnormal photovoltaic module and causing hot spots to form.

[0091] In this embodiment, the hot spots are avoided from affecting the photovoltaic wiring system by means of a second switching component, a voltage detection sensor, and a microcontroller.

[0092] As an optional implementation, the positive and negative terminals are integrated into a dual-core terminal.

[0093] Specifically, in this embodiment, the originally independently set positive and negative terminals are integrated into an integrated dual-core structure component, that is, they share a terminal base or shell, and the two cores correspond to the positive conductive channel and the negative conductive channel, respectively.

[0094] In this embodiment, the junction box structure is simplified by integrating the positive and negative terminals into a dual-core terminal, which reduces the installation space and material cost of individual terminals. Furthermore, it avoids the insertion errors caused by the dispersion of positive and negative terminals when multiple sets are connected in series, thereby improving wiring efficiency.

[0095] As an optional implementation method, Figure 5 This is a schematic diagram of another photovoltaic junction box provided in an embodiment of this application. Figure 5 As shown, the photovoltaic junction box also includes a bypass diode module.

[0096] The first terminal of the bypass diode module is connected to the first terminal of the first switching assembly, and the second terminal of the bypass diode module is connected to one end of the positive terminal.

[0097] The multiple access terminals of the bypass diode module are connected to the multiple access terminals of the photovoltaic module, respectively.

[0098] The bypass diode module is used to prevent hot spot effects caused by partial shading or malfunction of the photovoltaic modules, ensuring the safety of the overall circuit. A single or multiple photovoltaic modules can be connected to the photovoltaic module, enabling power collection when multiple modules are connected in parallel. The photovoltaic modules can be photovoltaic panels.

[0099] When one or more photovoltaic modules are shaded or malfunction, that module becomes a load in the photovoltaic wiring system, causing current from the normal modules to flow through the faulty module and generate hot spots. At this time, the bypass diode module will conduct in reverse, directly bypassing the faulty module to form a bypass loop, preventing current from flowing through the high-impedance faulty module, preventing hot spots from forming, and ensuring normal power transmission to other normal modules.

[0100] The bypass diode module, together with the aforementioned second switching component, prevents the generation of hot spots, ensuring the normal power transmission of other normal components and providing double protection for the photovoltaic wiring system.

[0101] Next, a photovoltaic wiring system consisting of the aforementioned photovoltaic junction box will be introduced. Specifically, the photovoltaic wiring system includes at least one photovoltaic junction box as described above and at least one photovoltaic module.

[0102] Figure 6 This is a circuit diagram illustrating the series connection of multiple photovoltaic junction boxes according to an embodiment of this application. Figure 6 As shown, the photovoltaic wiring system includes multiple photovoltaic junction boxes.

[0103] In two adjacent photovoltaic junction boxes, the positive terminal of the previous photovoltaic junction box is connected to the positive terminal of the next photovoltaic junction box, and the negative terminal of the previous photovoltaic junction box is connected to the negative terminal of the next photovoltaic junction box.

[0104] The positive terminal of the photovoltaic junction box connected to the load is connected to one end of the load, and the negative terminal of the photovoltaic junction box located at the load end is connected to the other end of the load.

[0105] In a photovoltaic junction box where one end of the positive terminal input is empty, the second end of the first switching assembly is connected to the other end of the negative terminal input.

[0106] This embodiment is applicable to medium and large-scale photovoltaic power generation systems that require increased generation voltage. Therefore, multiple photovoltaic modules and corresponding photovoltaic junction boxes need to be connected in series to form a photovoltaic string. By superimposing the voltage, the input voltage requirements of subsequent combiner boxes, inverters, etc. are met.

[0107] Figure 7 This is a circuit diagram of a single photovoltaic junction box provided in an embodiment of this application. Figure 7 As shown, the photovoltaic wiring system includes a photovoltaic junction box.

[0108] The second end of the first switch assembly of the photovoltaic junction box is connected to the other end of the negative terminal input and one end of the negative terminal, respectively. The positive terminal of the photovoltaic junction box is connected to one end of the load, and the negative terminal of the photovoltaic junction box is connected to the other end of the load.

[0109] This embodiment is applicable to small electrical devices such as small portable photovoltaic devices, small photovoltaic systems for home balconies, and monitoring equipment powered by a single photovoltaic module. This device does not require series voltage boosting; a single photovoltaic module directly powers the load, resulting in lower power and voltage requirements.

[0110] As an optional implementation, the photovoltaic junction boxes in the photovoltaic wiring system are arranged in the same row.

[0111] Specifically, all photovoltaic junction boxes are installed in the same position for each photovoltaic module, and all photovoltaic modules are arranged in the same row. For photovoltaic modules arranged in the same row, the illumination received is more consistent, which can avoid the situation where the lower row of modules is blocked due to the installation of photovoltaic modules in the front and back rows.

[0112] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application.

Claims

1. A photovoltaic junction box, characterized in that, The photovoltaic junction box includes: a positive terminal input, a negative terminal input, a first switch assembly, a positive terminal, and a negative terminal; One end of the positive terminal input is used to connect to the positive terminal of the first adjacent photovoltaic junction box or is left unused. The first end of the first switch assembly is connected to the photovoltaic module and the other end of the positive terminal input. The second end of the first switch assembly is left unused or connected to the other end of the negative terminal input and one end of the negative terminal, respectively. One end of the negative terminal input is used to connect to the negative terminal of the first adjacent photovoltaic junction box or is left unused. The other end of the negative terminal input is connected to one end of the negative terminal. One end of the positive terminal is connected to the photovoltaic module. The other end of the positive terminal is used to connect to the positive terminal input of the second adjacent photovoltaic junction box or to connect to a load. The other end of the negative terminal is used to connect to the negative terminal input of the second adjacent photovoltaic junction box or to a load. When the positive terminal inlet is unavailable, the second end of the first switch assembly is connected to the other end of the negative terminal inlet and one end of the negative terminal, respectively, so that the photovoltaic module is connected to the negative terminal. When the positive terminal inlet is connected to the positive terminal of the first adjacent photovoltaic junction box, the second end of the first switch assembly is disconnected from the other end of the negative terminal inlet and one end of the negative terminal, so that the photovoltaic module is connected to the positive terminal of the first adjacent photovoltaic junction box.

2. The photovoltaic junction box according to claim 1, characterized in that, The first switch assembly includes a spring switch; the spring switch includes a switch trigger point and a contact component; One end of the switch trigger point is mechanically connected to the first end of the contact component, the second end of the contact component is connected to the positive terminal inlet and the photovoltaic module respectively, and the third end of the contact component is either unused or connected to the other end of the negative terminal inlet and one end of the negative terminal respectively. When the positive terminal of the first adjacent photovoltaic junction box is unoccupied, the third end of the contact component is connected to the other end of the negative terminal inlet and one end of the negative terminal, respectively. When the positive terminal of the first adjacent photovoltaic junction box is connected to the positive terminal inlet, the switch trigger point drives the contact component to move, so that the third end of the contact component is disconnected from the other end of the negative terminal inlet and one end of the negative terminal, and the photovoltaic module is connected to the positive terminal of the first adjacent photovoltaic junction box.

3. The photovoltaic junction box according to claim 1, characterized in that, The photovoltaic junction box further includes: a detection sensor and a microcontroller, and the first switch assembly includes an electronic switch; The access detection sensor is connected to the first terminal of the microcontroller, and the second terminal of the microcontroller is connected to the control terminal of the electronic switch; The access detection sensor is used to detect whether the positive terminal inlet is connected to the positive terminal of the first adjacent photovoltaic junction box. If so, it sends an access signal to the microcontroller so that the microcontroller controls the electronic switch to disconnect from the photovoltaic module and the negative terminal, and makes the photovoltaic module connected to the positive terminal of the first adjacent photovoltaic junction box.

4. The photovoltaic junction box according to claim 1, characterized in that, The photovoltaic junction box also includes: a second switching assembly, a voltage detection sensor, and a microcontroller; The first end of the second switch assembly is connected to the first end of the first switch assembly, and the second end of the second switch assembly is used to connect to one end of the positive terminal. The voltage detection sensor is used to detect the voltage of the photovoltaic module and output a voltage signal to the third terminal of the microcontroller. The fourth terminal of the microcontroller is connected to the control terminal of the second switching assembly. The microcontroller determines whether the voltage value corresponding to the voltage signal is less than a preset voltage threshold. If so, it sends an on control signal to the second switch component, and the second switch component closes to make the positive terminal input and the positive terminal directly connected. If not, it sends an off control signal to the second switch component, and the second switch component opens to make the positive terminal input and the positive terminal connected through the photovoltaic module.

5. The photovoltaic junction box according to claim 1, characterized in that, The positive and negative terminals are integrated into a dual-core terminal.

6. The photovoltaic junction box according to claim 1, characterized in that, The photovoltaic junction box also includes: a bypass diode module; The first end of the bypass diode module is connected to the first end of the first switch assembly, and the second end of the bypass diode module is connected to one end of the positive terminal. The multiple access terminals of the bypass diode module are respectively connected to the multiple access terminals of the photovoltaic module.

7. A photovoltaic wiring system, characterized in that, The photovoltaic wiring system includes at least one photovoltaic junction box as described in any one of claims 1-6 and at least one photovoltaic module.

8. The photovoltaic wiring system according to claim 7, characterized in that, The photovoltaic wiring system includes multiple photovoltaic junction boxes; In two adjacent photovoltaic junction boxes, the positive terminal of the previous photovoltaic junction box is connected to the positive terminal of the next photovoltaic junction box, and the negative terminal of the previous photovoltaic junction box is connected to the negative terminal of the next photovoltaic junction box. The positive terminal of the photovoltaic junction box connected to the load is connected to one end of the load, and the negative terminal of the photovoltaic junction box located at the load end is connected to the other end of the load; In a photovoltaic junction box where one end of the positive terminal input is empty, the second end of the first switching assembly is connected to the other end of the negative terminal input.

9. The photovoltaic wiring system according to claim 7, characterized in that, The photovoltaic wiring system includes a photovoltaic junction box; The second end of the first switch assembly of the photovoltaic junction box is connected to the other end of the negative terminal input and one end of the negative terminal, respectively. The positive terminal of the photovoltaic junction box is connected to one end of the load, and the negative terminal of the photovoltaic junction box is connected to the other end of the load.

10. The photovoltaic wiring system according to claim 7, characterized in that, In the photovoltaic wiring system, all photovoltaic junction boxes are arranged in the same row.

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