Photovoltaic surge protector

Abstract

The utility model discloses a photovoltaic surge protector, and relates to the technical field of surge protection. The device comprises a direct current protection circuit, a thermal tripping module, a reverse current protection module, a multi-stage protection module and an inversion module, the direct current protection circuit is electrically connected with photovoltaic power generation equipment, the direct current protection circuit is electrically connected with the thermal tripping module, the thermal tripping module is electrically connected with the inversion module, the reverse current protection module is electrically connected with the inversion module, and the multi-stage protection module is electrically connected with the inversion module. The reverse current protection module is electrically connected with the power supply, and the multi-stage protection module is connected with the direct current protection circuit, the thermal tripping module, the inversion module and the reverse current protection module in parallel; by integrating the direct current protection circuit, the thermal tripping module and the reverse current protection module, potential damage caused by voltage surge, overheating and reverse current is effectively prevented; through the filter circuit and the transient suppression diode, electromagnetic interference is effectively suppressed, interference of voltage spikes is prevented, and stable operation of electrical equipment and clear signal transmission are ensured.

Description

Technical Field

[0001] The utility model relates to the technical field of surge protection, in particular to a photovoltaic surge protector. Background Art

[0002] A photovoltaic surge protector is a device used to prevent damage caused by voltage surges in photovoltaic (PV) systems. Voltage surges can be caused by lightning strikes, grid fluctuations, or rapid switching of equipment. Photovoltaic surge protectors are essential for protecting inverters, controllers, and other electrical equipment in photovoltaic systems from excessive voltage. The working principle of a photovoltaic surge protector is to limit the voltage level passing through the device. When a surge overvoltage occurs in the power system, the existing photovoltaic surge protector immediately turns on within nanoseconds, limiting the amplitude of the overvoltage to the safe operating range of the equipment, and releasing the surge energy into the ground. Subsequently, the surge protector quickly trips and becomes a high-resistance state, so as not to affect the normal power supply of the power system. However, when energy reverse flow, electromagnetic interference, and voltage spikes occur during the operation of the photovoltaic system, the existing photovoltaic surge protector cannot provide effective protection, and at the same time, it cannot provide effective multi-level protection under different voltage scenarios. Utility Model Content

[0003] Based on the above-mentioned shortcomings of the prior art, the purpose of the utility model is to provide a photovoltaic surge protector to solve the above-mentioned technical problems.

[0004] To achieve the above-mentioned purpose, the utility model provides the following technical solutions: a photovoltaic surge protector, comprising a DC protection circuit, a thermal trip module, a reverse flow protection module, a multi-stage protection module and an inverter module, wherein the input end of the DC protection circuit is electrically connected to the output end of the photovoltaic power generation equipment, the output end of the DC protection circuit is electrically connected to the input end of the thermal trip module, the output end of the thermal trip module is electrically connected to the input end of the inverter module, the input end of the reverse flow protection module is electrically connected to the output end of the inverter module, the output end of the reverse flow protection module is electrically connected to a power supply, and the multi-stage protection module is connected in parallel with the DC protection circuit, the thermal trip module, the inverter module and the reverse flow protection module.

[0005] The utility model is further configured that the DC protection circuit includes a metal oxide varistor and a gas discharge tube, the metal oxide varistor and the gas discharge tube are connected in parallel, the metal oxide varistor is used to reduce the impedance of the metal oxide varistor when the voltage exceeds the voltage threshold of the metal oxide varistor, and direct the excess energy to the ground wire, and the gas discharge tube is used to ionize and conduct the gas under high voltage conditions to handle higher energy voltage shocks.

[0006] The utility model is further configured such that the thermal trip module includes a thermistor trip device, which is used to detect the internal temperature of the equipment. When the internal temperature reaches a temperature threshold, the thermal trip mechanism is triggered to automatically disconnect the circuit to prevent equipment damage due to overheating.

[0007] The utility model is further configured that the reverse flow protection module comprises a reverse flow detection circuit, and the reverse flow detection circuit is used to prevent the energy stored in the power supply from flowing in reverse to the photovoltaic power generation equipment.

[0008] The utility model is further configured such that the reverse flow detection circuit includes a current sensor, a logic circuit and a relay, wherein the current sensor is used to monitor the direction and magnitude of the current in real time, and the logic circuit is used to receive the signal of the current sensor and make a judgment based on the direction and magnitude of the current, wherein the judgment logic includes controlling the relay to disconnect the circuit when reverse flow is detected.

[0009] The utility model is further configured such that the multi-stage protection module includes a filter circuit and a transient suppression diode, wherein the filter circuit is used to suppress electromagnetic interference, and the transient suppression diode is used to respond to voltage spikes. When the voltage exceeds the cliff voltage, the transient suppression diode is turned on within a time range of picoseconds to nanoseconds to provide a protection path to limit the voltage.

[0010] The utility model is further configured that the filtering circuit comprises a low-pass filter, and the low-pass filter is used to remove high-frequency interference from the circuit.

[0011] The utility model is further configured that the inverter module includes an inverter, and the inverter module is used to convert a DC power supply into an AC power supply.

[0012] In summary, the utility model mainly has the following beneficial effects:

[0013] 1. System safety and equipment protection: The metal oxide varistors and gas discharge tubes in the DC protection circuit can effectively prevent voltage surges from damaging the photovoltaic system, protect photovoltaic power generation equipment, and ensure the safety of other electrical equipment connected to the system; the thermal trip module monitors the temperature and automatically disconnects when the set threshold is reached, preventing equipment damage or more serious safety problems that may be caused by overheating.

[0014] 2. Energy efficiency and system efficiency: The reverse flow protection module effectively prevents the reverse flow of electric energy, improves the energy utilization efficiency of the system and prevents energy waste; the application of the inverter module optimizes the energy conversion process from DC to AC, ensures the stability and efficiency of power output, and is conducive to improving the power generation efficiency and economic benefits of the entire system.

[0015] 3. Electromagnetic compatibility and signal stability: The filtering circuit in the multi-level protection module effectively suppresses electromagnetic interference and ensures the electromagnetic compatibility of the system; the transient suppression diode is used to cope with rapid voltage changes and spikes, further improving the system's adaptability to complex electrical environments.

[0016] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. In the drawings:

[0018] Figure 1 It is a structural schematic diagram of the utility model.

[0019] In the figure: 1. DC protection circuit; 2. Thermal trip module; 3. Reverse flow protection module; 4. Multi-stage protection module; 5. Inverter module. DETAILED DESCRIPTION

[0020] The following will describe the implementation of the present invention with reference to the accompanying drawings and preferred embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific implementations, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be understood that the preferred embodiments are only for illustrating the present invention, not for limiting the scope of protection of the present invention.

[0021] It should be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present invention, and thus the drawings only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed at will, and the component layout may also be more complicated.

[0022] In the following description, a large number of details are discussed to provide a more thorough explanation of the embodiments of the present invention. However, it is obvious to those skilled in the art that the embodiments of the present invention can be implemented without these specific details. In other embodiments, well-known structures and devices are shown in the form of block diagrams rather than in detail to avoid making the embodiments of the present invention difficult to understand.

[0023] The following describes an embodiment of the utility model based on its overall structure.

[0024] A photovoltaic surge protector, such as Figure 1 As shown, it includes a DC protection circuit 1, a thermal trip module 2, a reverse flow protection module 3, a multi-stage protection module 4 and an inverter module 5, the input end of the DC protection circuit 1 is electrically connected to the output end of the photovoltaic power generation equipment, the output end of the DC protection circuit 1 is electrically connected to the input end of the thermal trip module 2, the output end of the thermal trip module 2 is electrically connected to the input end of the inverter module 5, the input end of the reverse flow protection module 3 is electrically connected to the output end of the inverter module 5, the output end of the reverse flow protection module 3 is electrically connected to the power supply, and the multi-stage protection module 4 is connected in parallel with the DC protection circuit 1, the thermal trip module 2, the inverter module 5 and the reverse flow protection module 3; specifically, the DC protection circuit 1 is the first line of defense of the photovoltaic surge protector, which is responsible for processing the voltage surge of the DC power from the photovoltaic power generation equipment, and is connected to the metal oxide voltage The sensitive resistor and the gas discharge tube can effectively reduce the influence of the voltage shock on the subsequent circuit; the thermal trip module 2 is used to automatically cut off the circuit when abnormal high temperature is detected to protect the equipment from damage; the inverter module 5 is used to convert direct current into alternating current and supply it to the power grid or load; the reverse flow protection module 3 is used to prevent the current from flowing in reverse from the power grid or other power sources to the photovoltaic power generation equipment to protect the photovoltaic panels and other components from damage; the multi-level protection module 4 includes a filter circuit and a transient suppression diode to effectively suppress electromagnetic interference and respond to voltage spikes, thereby further enhancing the stability and safety of the system; the utility model can not only deal with threats from the natural environment, but also deal with problems generated by the system (including reverse flow and overheating) by arranging special modules at different protection levels, and the multi-level protection modules connected in parallel ensure that protection can still be obtained even if the main protection path fails.

[0025] The utility model is further configured that the DC protection circuit 1 includes a metal oxide varistor and a gas discharge tube, the metal oxide varistor and the gas discharge tube are connected in parallel, the metal oxide varistor is used to reduce the impedance of the metal oxide varistor when the voltage exceeds the voltage threshold of the metal oxide varistor, and guide the excess energy to the ground line, and the gas discharge tube is used to ionize and conduct the gas under high voltage conditions to handle higher energy voltage shocks; specifically, the metal oxide varistor (MOV) and the gas discharge tube (GDT) are used to achieve dual protection of the photovoltaic system, optimize the protection effect of the DC protection circuit, and ensure the stability and safety of the photovoltaic system when facing various voltage shocks, the metal oxide varistor (MOV) has a higher resistance under normal working voltage and does not affect the normal operation of the circuit, when encountering a voltage surge, the resistance of the MOV decreases rapidly, forming a low impedance path to guide the excessive voltage to the ground line, thereby protecting the circuit from damage, and the MOV is suitable for handling short-term voltage shocks that exceed its threshold but have relatively low energy levels; the gas discharge tube (GDT) is almost an open circuit to the circuit under normal conditions and will not affect the normal operation of the circuit. The GDT will only conduct when the voltage rises to a certain level, enough to ionize the gas in the tube. The ionization process creates a low-impedance path that quickly conducts current to the ground, thereby protecting the circuit when encountering extremely high voltages. GDT is suitable for handling high-energy voltage shocks that exceed the protection range of MOVs; the combination of MOVs and GDTs provides graded protection that can effectively cope with voltage shocks from medium to extremely high energy levels; MOVs can respond quickly and limit voltage shocks, while GDTs provide a safe protection threshold for the system to cope with more extreme voltage conditions.

[0026] The utility model is further configured such that the thermal trip module 2 includes a thermistor, which is used to detect the internal temperature of the equipment. When the internal temperature reaches a temperature threshold, the thermal trip mechanism is triggered to automatically disconnect the circuit to prevent equipment damage caused by overheating. Specifically, the thermal trip module 2 includes a thermistor to enhance the temperature monitoring and overheating protection capabilities of the photovoltaic system. By real-time monitoring of the internal temperature of the equipment and automatically disconnecting the circuit when the temperature reaches a preset threshold, equipment damage or more serious safety hazards that may be caused by overheating can be effectively prevented.

[0027] The utility model is further configured that the reverse flow protection module 3 includes a reverse flow detection circuit, and the reverse flow detection circuit is used to prevent the energy stored in the power supply from flowing back into the photovoltaic power generation equipment. Specifically, the reverse flow protection module 3 includes a reverse flow detection circuit to enhance the protection capability of the photovoltaic system against reverse flow phenomenon. The reverse flow phenomenon usually occurs when the photovoltaic system is connected to the power grid or has battery storage. When the power flow direction of the system is opposite to the normal situation, that is, when it flows from the power grid or battery to the photovoltaic panel, it may cause damage to the photovoltaic panel or other system components.

[0028] The utility model is further configured such that the reverse flow detection circuit includes a current sensor, a logic circuit and a relay, wherein the current sensor is used to monitor the direction and magnitude of the current in real time, and the logic circuit is used to receive the signal of the current sensor and make a judgment based on the direction and magnitude of the current, wherein the judgment logic includes controlling the relay to disconnect the circuit when reverse flow is detected; specifically, the current sensor is used to monitor the direction and magnitude of the current in real time, and can quickly identify the current reverse flow situation; the logic circuit: receives the signal of the current sensor, and analyzes the direction and magnitude of the current to determine whether there is a reverse flow phenomenon; according to the judgment of the logic circuit, the relay is responsible for the actual disconnection control. When reverse flow is detected, the relay acts to disconnect the circuit to prevent further reverse flow from occurring.

[0029] The utility model is further configured such that the multi-stage protection module 4 includes a filter circuit and a transient suppression diode, wherein the filter circuit is used to suppress electromagnetic interference, and the transient suppression diode is used to respond to voltage spikes. When the voltage exceeds the cliff voltage, the transient suppression diode is turned on within a time of picoseconds to nanoseconds, providing a protection path to limit the voltage; specifically, the filter circuit includes a low-pass filter, and the low-pass filter is used to remove high-frequency interference from the circuit; the low-pass filter effectively removes high-frequency interference on the power line or signal line through a combination of capacitors, inductors and resistors, allowing low-frequency signals to pass through, while blocking or weakening high-frequency noise, thereby ensuring the normal operation of the photovoltaic system; the transient suppression diode (TVS diode) is quickly turned on when the voltage suddenly exceeds its designed cliff voltage (i.e., the protection voltage threshold), providing a low-impedance path to quickly guide the excess voltage to the ground or reverse to the source, thereby protecting sensitive electronic components from damage caused by instantaneous high voltage shocks, and the fast response time of the TVS diode (usually in the range of picoseconds to nanoseconds) makes the TVS diode suitable for resisting voltage spikes caused by lightning strikes, power switching or other emergencies.

[0030] The utility model is further configured that the inverter module 5 includes an inverter, and the inverter module 5 is used to convert a DC power supply into an AC power supply; specifically, the inverter module 5 is used to convert a DC power supply into an AC power supply, ensuring that the electricity generated by the photovoltaic power generation equipment can be effectively supplied to the power grid or directly used in various electrical equipment.

[0031] The working principle of the utility model is as follows: when the DC current generated by the photovoltaic panel flows to the inverter module, the DC protection circuit first monitors and protects the current; if the voltage exceeds the threshold of the metal oxide varistor (MOV), the impedance of the MOV drops sharply, and the excess electric energy is quickly directed to the ground wire to prevent the voltage surge from causing damage to subsequent equipment; when encountering a higher voltage shock, the gas discharge tube (GDT) is activated, and the gas inside it is ionized and conducted to form a low-impedance path, which quickly directs the excess current to the ground wire to handle the high-energy voltage shock; the thermal release module monitors the internal temperature of the system in real time through the built-in thermistor release. Once the internal temperature exceeds the preset safety threshold, the thermistor release is automatically triggered to disconnect the circuit to prevent equipment damage or fire risks caused by overheating. The reverse flow detection circuit in the reverse flow protection module uses a current sensor to monitor the direction and size of the current in real time. If the reverse flow of current is detected, the logic circuit judges and instructs the relay to disconnect the circuit, preventing the reverse energy flow from the power grid or energy storage device to the photovoltaic panel, and protecting the photovoltaic power generation equipment; the multi-stage protection module includes a filter circuit and a transient suppression diode (TVS diode), in which the filter circuit suppresses electromagnetic interference through a low-pass filter to ensure the stable operation of the system; when the voltage experiences a spike that exceeds the cliff voltage of the TVS diode, the TVS diode quickly turns on and limits the voltage in a very short time (picosecond to nanosecond level) to protect the system from transient overvoltages; the inverter module includes an inverter, which is used to convert the direct current generated by the photovoltaic panel into alternating current, which is used by the power grid or directly drives various AC loads.

[0032] Although an embodiment of the utility model has been shown and described, this specific embodiment is merely an explanation of the utility model and is not a limitation of the utility model. The specific features, structures, materials or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. After reading this specification, those skilled in the art may make modifications, substitutions and variations to the embodiments without creative contributions as needed without departing from the principles and purpose of the utility model. However, as long as they are within the scope of the claims of the utility model, they are protected by patent law.

Claims

1. A photovoltaic surge protector, comprising a DC protection circuit (1), a thermal trip module (2), a reverse flow protection module (3), a multi-stage protection module (4) and an inverter module (5), characterized in that: The input end of the DC protection circuit (1) is electrically connected to the output end of the photovoltaic power generation equipment, the output end of the DC protection circuit (1) is electrically connected to the input end of the thermal trip module (2), the output end of the thermal trip module (2) is electrically connected to the input end of the inverter module (5), the input end of the reverse flow protection module (3) is electrically connected to the output end of the inverter module (5), the output end of the reverse flow protection module (3) is electrically connected to a power supply, and the multi-stage protection module (4) is connected in parallel with the DC protection circuit (1), the thermal trip module (2), the inverter module (5) and the reverse flow protection module (3).

2. A photovoltaic surge protector according to claim 1, characterized in that: The DC protection circuit (1) comprises a metal oxide varistor and a gas discharge tube, wherein the metal oxide varistor and the gas discharge tube are connected in parallel, the metal oxide varistor is used to reduce the impedance of the metal oxide varistor when the voltage exceeds the voltage threshold of the metal oxide varistor, and to guide the excess energy to the ground line, and the gas discharge tube is used to ionize and conduct the gas under high voltage conditions, and to handle voltage shocks with higher energy.

3. A photovoltaic surge protector according to claim 1, characterized in that: The thermal release module (2) comprises a thermistor release, which is used to detect the internal temperature of the device. When the internal temperature reaches a temperature threshold, the thermal release mechanism is triggered to automatically disconnect the circuit to prevent damage to the device due to overheating.

4. A photovoltaic surge protector according to claim 1, characterized in that: The reverse flow protection module (3) comprises a reverse flow detection circuit, which is used to prevent the energy stored in the power supply from flowing in reverse into the photovoltaic power generation equipment.

5. A photovoltaic surge protector according to claim 4, characterized in that: The reverse flow detection circuit includes a current sensor, a logic circuit and a relay. The current sensor is used to monitor the direction and magnitude of the current in real time. The logic circuit is used to receive the signal of the current sensor and make a judgment based on the direction and magnitude of the current, wherein the judgment logic includes controlling the relay to disconnect the circuit when reverse flow is detected.

6. A photovoltaic surge protector according to claim 1, characterized in that: The multi-stage protection module (4) comprises a filter circuit and a transient suppression diode, wherein the filter circuit is used to suppress electromagnetic interference, and the transient suppression diode is used to respond to voltage spikes. When the voltage exceeds the cliff voltage, the transient suppression diode is turned on within a time of picoseconds to nanoseconds, providing a protection path to limit the voltage.

7. A photovoltaic surge protector according to claim 6, characterized in that: The filtering circuit includes a low pass filter for removing high frequency interference from the circuit.

8. A photovoltaic surge protector according to claim 1, characterized in that: The inverter module (5) comprises an inverter, and the inverter module (5) is used to convert a direct current power source into an alternating current power source.

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