Photovoltaic connector and photovoltaic system
By using thick-film chip resistor strings connected to pads in photovoltaic connectors, combined with temperature sensing resistor units and signal processing units, efficient and accurate detection of connector temperature is achieved, solving the problem of thermal damage caused by poor connection quality and reducing detection costs and complexity.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-11
- Publication Date
- 2026-03-27
AI Technical Summary
In existing technologies, poor connection quality of photovoltaic connectors and cables leads to increased contact resistance, which generates heat and may cause the connectors and cables to melt, burn, or even cause a fire. Moreover, the detection methods are costly, inaccurate, and inefficient.
Thick-film chip resistors are directly connected to the connector conductors, and heat is conducted through the pads. The connector temperature is detected by a temperature-sensing resistor unit and a signal processing unit, which reduces the cost and complexity of the detection circuit and improves the detection accuracy and efficiency.
It reduces the cost and complexity of connector temperature detection, improves detection accuracy and efficiency, reduces the probability of connector and cable thermal fusion damage, and ensures the reliability and safety of connectors.
Smart Images
Figure CN224053570U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The embodiment of the utility model relates to the technical field of photovoltaic power generation, and particularly relates to a photovoltaic connector and a photovoltaic system. BACKGROUND
[0002] The photovoltaic inverter and the photovoltaic assembly rely on cables and photovoltaic connectors to transmit the electric energy emitted by the photovoltaic assembly to the photovoltaic inverter for inversion and grid connection. Since the photovoltaic connectors and the cables are connected at the installation site, there is a risk of poor connection quality. When the connection quality of the cables and the photovoltaic connectors is poor, the contact resistance at the connection is significantly increased compared with normal connection. When the photovoltaic assembly emits electric energy, a current flows at the connection, and the current generates a huge heating power on the abnormally increased contact resistance, thereby causing the photovoltaic connectors and the cables to be hot-melted and damaged, and even burned, and in a more serious case, even a bright fire is generated, which spreads to the inverter and the photovoltaic assembly, thereby causing serious losses to the terminal power generation customers.
[0003] In the prior art, various methods are used to detect the temperature of the photovoltaic connectors and the connection between the photovoltaic connectors and the cables, and there are problems of high material cost, complex circuit, inaccurate detection precision, and low detection efficiency. UTILITY MODEL CONTENT
[0004] The utility model provides a kind of photovoltaic connector and photovoltaic system to realize the cost of reducing temperature detection, improve the detection precision and detection efficiency of temperature detection, and simultaneously can reduce the complexity of detection circuit.
[0005] In the first aspect, the utility model embodiment provides a kind of photovoltaic connector, including connector, circuit board, temperature measurement resistance unit and signal processing unit;The circuit board is provided with pad and thick film chip resistor string, and the thick film chip resistor string includes at least one series-connected thick film chip resistor;The connecting end of the connector is connected with the pad, and the temperature measurement resistance unit is connected with at least one pad by the thick film chip resistor string, and the signal processing unit is connected with the temperature measurement resistance unit, and the temperature measurement resistance unit is used to form resistance value signal according to the temperature of the pad;The signal processing unit is used to determine the temperature of the connector according to the resistance value signal.
[0006] Optionally, each pad is connected with a temperature measurement resistance unit by a thick film chip resistor string, and at least two pads are connected with the same temperature measurement resistance unit.
[0007] Optionally, the connector includes positive connector and negative connector, and the sum of the body voltage resistance values of the thick film chip resistors in the thick film chip resistor string is greater than or equal to the voltage difference between the positive connector and the negative connector.
[0008] Optionally, the photovoltaic connector comprises a plurality of the temperature measuring resistor units; the signal processing unit comprises a multiplexer, an analog-digital conversion module and a digital signal processor;
[0009] The plurality of inputs of the multiplexer are respectively connected with one of the temperature measuring resistor units, the output of the multiplexer is connected with the input of the analog-digital conversion module, and the output of the analog-digital conversion module is connected with the input of the digital signal processor; the multiplexer is used to select one of the temperature measuring resistor units to be connected with the analog-digital conversion module in conduction, the analog-digital conversion module is used to convert the resistance value signal into a digital signal, and the signal processor is used to determine the temperature of the connector according to the digital signal.
[0010] Optionally, the signal processing unit further comprises an amplification module and a clamping module;
[0011] The input of the amplification module is connected with the output of the multiplexer, the output of the amplification module is connected with the first end of the clamping module and the input of the analog-digital conversion module, the second end of the clamping module is connected with the first reference voltage input, and the third end of the clamping module is grounded; the amplification module is used to amplify the resistance value signal output by the multiplexer to form an amplified signal; and the clamping module is used to clamp the voltage of the amplified signal to the first reference voltage provided by the first reference voltage input when the voltage of the amplified signal is greater than the first reference voltage.
[0012] Optionally, the amplification module comprises an amplifier, a filter resistor and a filter capacitor, the positive input of the amplifier is connected with the output of the multiplexer, the negative input of the amplifier and the output of the amplifier are connected with the first end of the filter resistor, the second end of the filter resistor is connected with the first pole of the filter capacitor and the first end of the clamping module, and the second pole of the filter capacitor is grounded.
[0013] Optionally, the clamping module comprises a first zener diode and a second zener diode; the anode of the first zener diode is grounded, the cathode of the first zener diode and the anode of the second zener diode are connected with the output of the amplification module, and the cathode of the second zener diode is connected with the first reference voltage input.
[0014] Optionally, the signal processing unit comprises at least two multiplexers, at least two amplification modules and at least two clamping modules;
[0015] The sum of the input ends of the at least two multiplexers is greater than or equal to the number of the temperature measuring resistor units, the input end of each amplification module is connected with the output end of one multiplexer; the output end of each amplification module is connected with the first end of one clamping module and an input end of the analog-digital conversion module.
[0016] Optionally, the temperature measuring resistor unit comprises a temperature measuring resistor, a voltage dividing resistor, a first resistor and a first capacitor.
[0017] The first end of the temperature measuring resistor is connected with a second reference voltage input end, the second end of the temperature measuring resistor is connected with the first end of the voltage dividing resistor and the first end of the first resistor, and serves as an input end of the temperature measuring resistor unit; the second end of the voltage dividing resistor and the second pole of the first capacitor are grounded, the second end of the first resistor is connected with the first pole of the first capacitor, and serves as an output end of the temperature measuring resistor unit; wherein the resistance of the temperature measuring resistor changes with temperature.
[0018] In a second aspect, the utility model embodiment further provides a photovoltaic system, including the photovoltaic connector of first aspect.
[0019] The technical scheme of the utility model embodiment sets up the thick film chip resistor string to be connected directly with the conductor of the connector through the solder pad. At this time, the thick film chip resistor string can not only conduct the heat of the connector, but also can isolate the high resistance of the electrified connector, avoid setting the electrical isolation structure between the temperature measuring resistor unit and the connector or carrying out the multiple circuit conversion, can reduce the cost of the temperature detection circuit of the connector, improve the temperature detection precision of the connector, and can reduce the complexity of the temperature detection circuit of the connector. Moreover, the cost of the thick film chip resistor is low, and it is easy to obtain, and the cost of the temperature detection circuit of the connector can be further reduced. When one temperature measuring resistor unit is connected with multiple connectors, the temperature measuring resistor unit can detect the temperature of multiple connectors, so that the number of temperature measuring resistor units required can be reduced, the cost of the temperature detection circuit is further reduced, and the temperature detection efficiency is improved. BRIEF DESCRIPTION OF DRAWINGS
[0020] Figure 1 A physical structure schematic view of a photovoltaic connector is provided for the utility model embodiment;
[0021] Figure 2 A structure schematic view of a circuit board is provided for the utility model embodiment;
[0022] Figure 3 A principle structure schematic view of a photovoltaic connector is provided for the utility model embodiment;
[0023] Figure 4A circuit structure schematic diagram of a temperature measuring resistance unit is provided for the embodiment of the utility model.
[0024] Figure 5 A circuit structure schematic diagram of a thick film chip resistor string and temperature measuring resistance unit is provided for the embodiment of the utility model.
[0025] Figure 6 A principle structure schematic diagram of a thick film chip resistor string and temperature measuring resistance unit connection is provided for the embodiment of the utility model.
[0026] Figure 7 A principle structure schematic diagram of another photovoltaic connector is provided for the embodiment of the utility model.
[0027] Figure 8 A circuit structure schematic diagram of a multiplexer is provided for the embodiment of the utility model.
[0028] Figure 9 A circuit structure schematic diagram of an amplification module and clamping module is provided for the embodiment of the utility model.
[0029] Figure 10 A circuit structure schematic diagram of another multiplexer is provided for the embodiment of the utility model.
[0030] Figure 11 A circuit structure schematic diagram of another amplification module and clamping module is provided for the embodiment of the utility model. Specific embodiments
[0031] The utility model will be further explained in detail in combination with the drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the utility model, and not to limit the utility model. In addition, it should be noted that, in order to facilitate the description, only the part related to the utility model is shown in the drawings, not all structures.
[0032] Figure 1 A practical structure schematic diagram of a photovoltaic connector is provided for the embodiment of the utility model, Figure 2 A structure schematic diagram of a circuit board is provided for the embodiment of the utility model, Figure 3 A principle structure schematic diagram of a photovoltaic connector is provided for the embodiment of the utility model. As Figures 1 to 3 Indicated, the photovoltaic connector includes connector 10, circuit board 20, temperature measuring resistance unit 30 and signal processing unit 40;Circuit board 20 is provided with solder pad 21 and thick film chip resistor string 22 ( Figure 1 And Figure 2The thick film chip resistor string 22 includes at least one thick film chip resistor connected in series; a connecting end of the connector 10 is connected with the pad 21, the temperature measuring resistor unit 30 is connected with at least one pad 21 through the thick film chip resistor string 22, the signal processing unit 40 is connected with the temperature measuring resistor unit 30, and the temperature measuring resistor unit 30 is used for forming a resistance value signal according to the temperature of the pad 21; and the signal processing unit 40 is used for determining the temperature of the connector 10 according to the resistance value signal.
[0033] Specifically, the circuit board 20 can be a printed circuit board, used for carrying the connector 10 and the thick film chip resistor string 22, and providing the pads 21 directly connected with the connector 10 and the thick film chip resistor string 22. The material of the pad 21 is metal or alloy, having good heat conduction performance. As shown in the figure, Figure 1 The connecting end of the connector 10 is welded on the circuit board 20 through the pad 21, and the other connecting end of the connector 10 can be connected with a cable, so as to realize the connection between the connector 10 and the cable. The temperature measuring resistor unit 30 is connected with at least one pad 21 through the thick film chip resistor string 22, so that the thick film chip resistor string 22 can be directly connected with the conductor of the connector 10 through the pad 21. At this time, the thick film chip resistor string 22 can not only conduct the heat of the connector 10, but also can be high-resistance isolated to the live connector 10, avoiding setting an electrical isolation structure between the temperature measuring resistor unit 30 and the connector 10 or performing multiple circuit conversions, so as to reduce the cost of the temperature detection circuit of the connector 10, improve the temperature detection precision of the connector 10, and reduce the complexity of the temperature detection circuit of the connector 10. Moreover, the thick film chip resistor string 22 includes at least one thick film chip resistor connected in series; the thick film chip resistor is printed by thick film technology, having high resistance value, which can meet the resistance value requirement of the thick film chip resistor string in the temperature detection process of the connector 10, and has good heat conduction performance, so that the thick film chip resistor string 22 can transmit the heat of the connector 10 to the temperature measuring resistor unit 30. Moreover, the thick film chip resistor has low cost and is easy to obtain, so as to further reduce the cost of the temperature detection circuit of the connector 10.
[0034] When the temperature of the connector 10 is transmitted to the temperature measuring resistor unit 30 through the solder pad 21 and the thick film patch resistor string 22, the temperature measuring resistor unit 30 forms a resistance value signal according to the received temperature, and the resistance value signal can be a voltage signal at this time, and is transmitted to the signal processing unit 40. The signal processing unit 40 determines the temperature corresponding to the temperature measuring resistor unit 30 according to the resistance value signal. The solder pad 21 and the thick film patch resistor string 22 have good heat conduction performance, so that the temperature corresponding to the temperature measuring resistor unit 30 can be equivalent to the temperature of the connector 10, so that the temperature of the connector 10 can be characterized by the temperature of the temperature measuring resistor unit 30, and the temperature detection of the connector 10 is realized. When another connection end of the connector 10 is not connected well with the cable, an excessive contact resistance is generated at the connection of the connector 10 with the cable. When the connector 10 passes through the current, a large temperature rise is generated at the place where the connection of the connector 10 with the cable is not good due to the excessive contact resistance. The temperature rise is transmitted to the solder pad 21 corresponding to the connection of the connector 10 through the conductor in the connector 10, and then is transmitted to the temperature measuring resistor unit 30 through the thick film patch resistor string 22 welded on the solder pad 21. The temperature measuring resistor unit 30 generates a change in resistance value with the change in temperature rise, and forms a resistance value signal transmitted to the signal processing unit 40. The signal processing unit 40 can determine the change in temperature by looking up a table according to the resistance value signal, so as to determine the temperature rise of the connector 10, and judge whether the connector 10 is not connected well with the cable through the temperature rise, thereby reducing the probability of thermal fusion and damage of the connector 10 and the cable.
[0035] In addition, the temperature measuring resistor unit 30 can be connected with multiple solder pads 21 through the thick film patch resistor string 22, so as to be connected with multiple connectors 10, so that the temperature measuring resistor unit 30 can detect the temperatures of the multiple connectors 10, and the number of temperature measuring resistor units 30 required can be reduced, thereby further reducing the cost of the temperature detection circuit and improving the temperature detection efficiency.
[0036] The technical scheme of the embodiment, the thick film patch resistor string is directly connected with the conductor of the connector through the solder pad. At this time, the thick film patch resistor string not only can conduct the heat of the connector, but also can perform high-resistance isolation on the live connector, so as to avoid setting an electrical isolation structure between the temperature measuring resistor unit and the connector or performing multiple circuit conversions, thereby reducing the cost of the temperature detection circuit of the connector, improving the temperature detection accuracy of the connector, and reducing the complexity of the temperature detection circuit of the connector. Moreover, the thick film patch resistor has low cost and is easy to obtain, so as to further reduce the cost of the temperature detection circuit of the connector. When one temperature measuring resistor unit is connected with multiple connectors, the temperature measuring resistor unit can detect the temperatures of the multiple connectors, so as to reduce the number of temperature measuring resistor units required, thereby further reducing the cost of the temperature detection circuit and improving the temperature detection efficiency.
[0037] In some embodiments, Figure 4The utility model provides a kind of circuit structure schematic diagram of temperature measuring resistance unit for the embodiment of the utility model. Figure 4 As shown in the drawing, the temperature measuring resistance unit includes temperature measuring resistance Rs, voltage dividing resistance Rt, first resistance R1 and first capacitor C1;The first end of temperature measuring resistance Rs is connected with second reference voltage input terminal VREF2, the second end of temperature measuring resistance Rs is connected with the first end of voltage dividing resistance Rt and the first end of first resistance R1, and serves as the input terminal of temperature measuring resistance unit 30, the second end of voltage dividing resistance Rt and the second pole of first capacitor C1 are grounded GND, the second end of first resistance R1 is connected with the first pole of first capacitor C1, and serves as the output terminal of temperature measuring resistance unit 30;Wherein, the resistance value of temperature measuring resistance Rs changes with temperature.
[0038] Specifically, temperature measuring resistance Rs and voltage dividing resistance Rt are connected in series between second reference voltage input terminal VREF2 and ground GND, and second reference voltage input terminal VREF2 is used to provide a fixed potential second reference voltage.Exemplarily, the second reference voltage can be 3V.Then temperature measuring resistance Rs and voltage dividing resistance Rt divide the second reference voltage, and the filtered resistance value signal is output to signal processing unit 40 through first resistance R1 and first capacitor C1.The second end of temperature measuring resistance Rs is connected with thick film chip resistor string 22, so that temperature measuring resistance Rs can receive the temperature rise of connector 10, and the resistance value of temperature measuring resistance Rs changes, which in turn changes the resistance value signal output by temperature measuring resistance Rs and voltage dividing resistance Rt after voltage division, and signal processing unit 40 can determine the change of temperature rise according to the change of resistance value signal, so as to determine the temperature rise of connector 10, and judge whether connector 10 and cable are connected poorly through temperature rise, thereby reducing the probability of thermal fusion and damage of connector 10 and cable.
[0039] Referring back to Figure 3 Each pad 21 is connected with a temperature measuring resistance unit 30 through a thick film chip resistor string 22, and at least two pads 21 are connected with the same temperature measuring resistance unit 30.
[0040] Specifically, connector 10 can include positive connector PV+ and negative connector PV-, and a positive connector PV+ and a negative connector PV- form a connector, corresponding to an input signal.A pad 21 connected with the positive connector PV+ is a first pad 211, and a pad 21 connected with the negative connector PV- is a second pad 212. Figure 3The same temperature measuring resistor unit 30 is connected to the corresponding pad 21 of the three-way connector through a thick film chip resistor string 22, so that the temperature measuring resistor unit 30 is connected to the three-way connector, and the temperature measuring resistor unit 30 can detect the temperature rise of the three-way connector. When the photovoltaic connector includes multiple input signals, the number of temperature measuring resistor units 30 can be greatly reduced, the cost of the temperature detection circuit is saved, and the number of connectors 10 to which the temperature measuring resistor unit 30 is connected can be adjusted according to requirements, so that the sampling accuracy and detection accuracy of the temperature detection circuit are maintained, and the simplicity of the temperature detection circuit is maintained.
[0041] With reference to the foregoing Figures 1 to 3 , the connector 10 includes a positive connector PV+ and a negative connector PV-, and the sum of the body voltage resistance values of the thick film chip resistors in the thick film chip resistor string 22 is greater than or equal to the voltage difference between the positive connector PV+ and the negative connector PV-.
[0042] Specifically, the thick film chip resistor string 22 includes at least one thick film chip resistor connected in series, and the sum of the body voltage resistance values of the at least one thick film chip resistor connected in series is the body voltage resistance value of the thick film chip resistor string 22. By setting the sum of the body voltage resistance values of the thick film chip resistors in the thick film chip resistor string 22 to be greater than or equal to the voltage difference between the positive connector PV+ and the negative connector PV-, that is, the body voltage resistance value of the thick film chip resistor string 22 is greater than or equal to the voltage difference between the positive connector PV+ and the negative connector PV-, it can be ensured that the thick film chip resistor string 22 can withstand the voltage between the two ends of the photovoltaic connector for a long time, and the reliability of the photovoltaic connector is improved. At the same time, according to the insulation impedance requirement from the primary circuit to the secondary circuit, the insulation impedance of the thick film chip resistor can be selected to ensure the insulation reliability of the photovoltaic connector. Exemplarily, Figure 5 A circuit structure schematic diagram of a thick film chip group string and a temperature measuring resistor unit is provided for the embodiment of the utility model. As shown in Figure 5As shown, when the maximum value of the voltage difference between the positive connector PV+ and the negative connector PV- is 1100V, and the body withstand voltage value of each thick film chip resistor RC is 250V, each thick film chip resistor string 22 includes three thick film chip resistors RC connected in series, that is, the positive connector PV+ is connected to the temperature measuring resistance unit 30 through three thick film chip resistors RC connected in series, and the negative connector PV- is connected to the temperature measuring resistance unit 30 through three thick film chip resistors RC connected in series, so that the thick film chip resistors RC between the positive connector PV+ and the negative connector PV- can withstand the photovoltaic voltage for a long time. At the same time, the resistance value of the thick film chip resistor string 22 corresponding to the connector 10 can be selected as 6MΩ. When each thick film chip resistor string 22 includes three thick film chip resistors RC connected in series, the resistance value of each thick film chip resistor RC is 2MΩ. Moreover, the thick film chip resistor string 22 is connected between the positive connector PV+ and the negative connector PV-, so that the heat generated by the voltage between the positive connector PV+ and the negative connector PV- on the thick film chip resistor string 22 is relatively small and can be ignored, thereby improving the accuracy of temperature sampling and the detection precision of temperature detection.
[0043] In some embodiments, the number of thick film chip resistors in different thick film chip resistor strings 22 is equal.
[0044] Specifically, the number of thick film chip resistors in different thick film chip resistor strings 22 is equal, so that the heat transfer paths of different thick film chip resistor strings 22 are the same, thereby improving the accuracy of temperature rise transmission of different connectors 10 to the temperature measuring resistance unit 30 and improving the detection precision of temperature detection. For example, continuing to refer to Figure 5 As shown, when the maximum value of the voltage difference between the positive connector PV+ and the negative connector PV- is 1100V, and the body withstand voltage value of each thick film chip resistor RC is 250V, each thick film chip resistor string 22 includes three thick film chip resistors RC connected in series, that is, the positive connector PV+ is connected to the temperature measuring resistance unit 30 through three thick film chip resistors RC connected in series, and the negative connector PV- is connected to the temperature measuring resistance unit 30 through three thick film chip resistors RC connected in series, so that the thick film chip resistors RC between the positive connector PV+ and the negative connector PV- can withstand the photovoltaic voltage for a long time. At the same time, the resistance value of the thick film chip resistor string 22 corresponding to the connector 10 can be selected as 6MΩ. When each thick film chip resistor string 22 includes three thick film chip resistors RC connected in series, the resistance value of each thick film chip resistor RC is 2MΩ. Moreover, the thick film chip resistor string 22 is connected between the positive connector PV+ and the negative connector PV-, so that the heat generated by the voltage between the positive connector PV+ and the negative connector PV- on the thick film chip resistor string 22 is relatively small and can be ignored, thereby improving the accuracy of temperature sampling and the detection precision of temperature detection.
[0045] Figure 6 A schematic diagram of the principle structure of the connection between the thick film chip resistor string and the temperature measuring resistance unit is provided for the embodiments of the present application. As shown, Figure 6 The circuit board 20 is also provided with wires 23, and the thick film chip resistor string 22 is connected to the temperature measuring resistance unit 30 through the wires 23.
[0046] Specifically, the material of the wire 23 can be copper foil. The copper foil has good heat conduction, so that the temperature rise on the thick film chip resistor string 22 is conducted to the temperature measuring resistor unit 30 through the wire 23, ensuring the accuracy of the temperature collected by the temperature measuring resistor unit 30. In addition, the wire 23 has heat dissipation. When one temperature measuring resistor unit 30 is connected to a plurality of thick film chip resistor strings 22 through the wire 23, the number of thick film chip resistor strings 22 corresponding to the temperature measuring resistor unit 30 can be limited according to the heat dissipation of the wire 23, so that the length of the wire between the temperature measuring resistor unit 30 and the thick film chip resistor string 22 is relatively short, so that the heat dissipation of the wire 23 is relatively small, avoiding the distortion of the temperature rise received by the temperature measuring resistor unit 30, ensuring the accuracy of the temperature sampling, and improving the detection precision of the temperature detection. For example, as shown in the figure, Figure 6 one temperature measuring resistor unit 30 can be connected to a three-way connector, which can ensure that the length of the wire between the thick film chip resistor string 22 and the temperature measuring resistor unit 30 is relatively short, ensuring the accuracy of the temperature sampling and improving the detection precision of the temperature detection.
[0047] Figure 7 Another principle structure diagram of a photovoltaic connector is provided for the embodiment of the utility model. As shown in the figure, Figure 7 The photovoltaic connector includes a plurality of temperature measuring resistor units 30, and the signal processing unit 40 includes a multiplexer 41, an analog-to-digital conversion module 42 and a digital signal processor 43. A plurality of input ends of the multiplexer 41 are respectively connected to a temperature measuring resistor unit 30, an output end of the multiplexer 41 is connected to an input end of the analog-to-digital conversion module 42, and an output end of the analog-to-digital conversion module 42 is connected to an input end of the digital signal processor 43. The multiplexer 41 is used to select a temperature measuring resistor unit 30 and the analog-to-digital conversion module 42 to be connected in conduction, the analog-to-digital conversion module 42 is used to perform analog-to-digital conversion on the resistance value signal to form a digital signal, and the signal processor 43 is used to determine the temperature of the connector 10 according to the digital signal.
[0048] Specifically, the multiplexer 41 has a plurality of input terminals, each of which is connected with an output terminal of a temperature measurement resistor unit 30 through a signal conditioning 50 for receiving the resistance value signal output by the temperature measurement resistor unit 30. The output terminal of the multiplexer 41 is connected with an input terminal of an analog-digital conversion module 42. When the multiplexer 41 selects one of the input terminals to be connected with the output terminal, the resistance value signal received by the input terminal is output to the analog-digital conversion module 42 through the multiplexer 41. The analog-digital conversion module 42 can be integrated on the signal processor 43. The analog-digital conversion module 42 performs analog-digital conversion on the input resistance value signal to form a corresponding digital signal and transmits the digital signal to the signal processor 43. The signal processor 43 compares the resistance value corresponding to the resistance value signal with a resistance-temperature curve stored in the signal processor 43 in advance to determine the temperature corresponding to the current resistance value signal, so that the temperature of the connector 10 connected with the current temperature measurement resistor unit 30 can be determined to realize temperature detection of the connector 10. By connecting the multiplexer 41 with the temperature measurement resistor unit 30, the number of analog-digital conversion modules 42 and the number of channels of the signal processor 43 can be reduced, so that the cost of the photovoltaic connector can be further reduced. Moreover, the temperature of the connector 10 changes slowly, for example, at a rate of one thousandth of a second, and the channel switching process of the multiplexer 41 can meet the sampling requirements of the temperature change. Exemplarily, Figure 8 A circuit structure schematic diagram of a multiplexer provided by the embodiment of the utility model is shown in Figure 8 The multiplexer 41 includes eight input terminals, namely NTC1 to NTC8, which are respectively connected with output terminals of temperature measurement resistor units 30. Meanwhile, the multiplexer 41 includes an output terminal NTC_CH1 which is used to be connected with an input terminal of an analog-digital conversion module 42. During the working process of the signal processing unit 40, the multiplexer 41 can select one of the eight input terminals NTC1 to NTC8 to be connected with the output terminal NTC_CH1 according to requirements, so that the resistance value signal provided by the temperature measurement resistor unit 30 connected with the selected input terminal can be output to the output terminal NTC_CH1 and transmitted to the analog-digital conversion module 42 to perform analog-digital conversion.
[0049] Figure 9 An amplification module and a clamping module provided by the embodiment of the utility model are shown in Figure 9As shown, the signal processing unit 40 further includes an amplification module 44 and a clamping module 45; the input terminal of the amplification module 44 is connected to the output terminal of the multiplexer 41, the output terminal of the amplification module 44 is connected to the first terminal of the clamping module 45 and the input terminal of the analog-to-digital conversion module 42, the second terminal of the clamping module 45 is connected to the first reference voltage input terminal VREF1, and the third terminal of the clamping module 45 is grounded to GND; the amplification module 44 is used to amplify the resistance signal output by the multiplexer 41 to form an amplified signal; the clamping module 45 is used to clamp the voltage of the amplified signal to the first reference voltage when the voltage of the amplified signal is greater than the first reference voltage provided by the first reference voltage input terminal VREF1.
[0050] Specifically, the input terminal of the amplification module 44 is connected to the output terminal of the multiplexer 41. The amplification module 44 amplifies and conditions the resistance signal output by the multiplexer 41 to form an amplified signal, which is then output to the analog-to-digital converter 42, thereby improving the conversion accuracy of the analog-to-digital converter 42. Furthermore, the signal processing unit 40 also includes a clamping module 45. When the photovoltaic processor malfunctions, if the amplified signal output by the amplification module 44 exceeds a first reference voltage (the first reference voltage is a protection threshold voltage set according to the voltage at which the photovoltaic processor malfunctions), the clamping module 45 can clamp the amplified signal output by the amplification module 44, clamping the voltage of the amplified signal to the first reference voltage, thus preventing damage to the analog-to-digital converter 42 due to excessive voltage. For example, the first reference voltage can be 3V. When the voltage clamp of the amplified signal is the first reference voltage, the signal processor 43 can perform shutdown protection based on the voltage of the amplified signal, causing the power of the device connected to the photovoltaic connector to drop to 0, thus disconnecting the device connected to the photovoltaic connector from the grid. Simultaneously, it disconnects the DC isolation switch on the photovoltaic module side and sends fault information to the host computer, such as "abnormal photovoltaic connector temperature." The device connected to the photovoltaic connector can be an inverter or an energy storage converter, etc.
[0051] For details, please refer to Figure 8 and Figure 9 The input terminal of the amplification module 44 is connected to the output terminal NTC_CH1 of the multiplexer 41. The amplification module 44 can perform voltage following and signal conditioning on the resistance signal to form an amplified signal, which is then output to one input terminal ADC_A3 of the analog-to-digital converter module 42 for analog-to-digital conversion to form a digital signal. Then, the signal processor 43 determines the temperature based on the digital signal, that is, the temperature value corresponding to the current resistance signal. Figure 10 A schematic diagram of another multiplexer circuit structure provided in this embodiment of the utility model is shown below. Figure 10 As shown, the multiplexer 41 includes four input terminals, NTC9 to NTC12, and one output terminal, NTC_CH2.Figure 11 Another circuit structure schematic diagram of the amplification module and the clamping module is provided for the embodiments of the utility model. The input end of the amplification module 44 is connected with the output end NTC_CH2 of another multiplexer 41, and the output end of the amplification module 44 is connected with another input end ADC_A0 of the analog-digital conversion module 42, so that the analog-digital conversion module 42 carries out analog-digital conversion according to the inputted amplified signal, and forms a digital signal. Then, the signal processor 43 determines the temperature according to the digital signal, that is, the temperature value corresponding to the current resistance value signal.
[0052] In some embodiments, continuing to refer to Figure 9 , the amplification module 44 comprises an amplifier 441, a filter resistor R2 and a filter capacitor C2, the positive input end + of the amplifier 441 is connected with the output end of the multiplexer 41, the negative input end - of the amplifier 441 and the output end OUT of the amplifier 441 are connected with the first end of the filter resistor R2, the second end of the filter resistor R2 is connected with the first pole of the filter capacitor C2, and is connected with the first end of the clamping module 45, and the second pole of the filter capacitor C2 is grounded GND.
[0053] Specifically, the amplifier 441 is in a voltage following connection mode, and the voltage of the resistance value signal does not change after passing through the amplifier 441. At the same time, the filter resistor R2 and the filter capacitor C2 constitute an RC filter circuit, and the signal output by the amplifier 441 is filtered and then output to an input end of the analog-digital conversion module 42 for analog-digital conversion, forming a digital signal. Then, the signal processor 43 determines the temperature according to the digital signal, that is, the temperature value corresponding to the current resistance value signal.
[0054] In some embodiments, continuing to refer to Figure 9 , the clamping module 45 comprises a first zener diode D1 and a second zener diode D2; the anode of the first zener diode D1 is grounded GND, the cathode of the first zener diode D1 and the anode of the second zener diode D2 are connected with the output end of the amplification module 44, and the cathode of the second zener diode D2 is connected with the first reference voltage input end REF1.
[0055] Specifically, when the photovoltaic processor is normal, the amplified signal output by the amplification module 44 is greater than the zero voltage provided by the ground end GND, and at the same time is less than the first reference voltage provided by the first reference voltage input end REF1, at this time, the first zener diode D1 and the second zener diode D2 are both in the cut-off state, and the analog-digital conversion module 42 receives the amplified signal output by the amplification module 44, so that the temperature can be determined according to the amplified signal. When the photovoltaic processor is faulty, the amplified signal output by the amplification module 44 is greater than the first reference voltage, at this time, the second zener diode D2 is turned on, so that the first end potential of the clamping module 45 is clamped to the first reference voltage, avoiding damage to the analog-digital conversion module 42 caused by the voltage of the amplified signal being too large.
[0056] In some embodiments, the signal processing unit 40 comprises at least two multiplexers 41, at least two amplification modules 44 and at least two clamping modules 45; the sum of the input ends of the at least two multiplexers 41 is greater than or equal to the number of the temperature measuring resistor units 30, the input end of each amplification module 44 is connected with the output end of a multiplexer 41; the output end of each amplification module 44 is connected with the first end of a clamping module 45 and an input end of the analog-to-digital conversion module 42.
[0057] Specifically, the number of input ends of the multiplexer 41 is relatively fixed. When the photovoltaic connector comprises a plurality of temperature measuring resistor units 30 and the number of the temperature measuring resistor units 30 is greater than the number of input ends of one multiplexer 41, the signal processing unit 40 can comprise a plurality of multiplexers 41, so that the sum of the number of input ends of the plurality of multiplexers 41 is greater than or equal to the number of the temperature measuring resistor units 30, thereby making the resistance value signal provided by each temperature measuring resistor unit 30 can be output to the analog-to-digital conversion module 42 through the multiplexer 41. When the signal processing unit 40 comprises a plurality of multiplexers 41, each multiplexer 41 is correspondingly connected with one amplification module 44 and one clamping module 45, so that each amplification module 44 and clamping module 45 can respectively perform signal conditioning and clamping on the resistance value signal provided by different multiplexers 41, thereby ensuring the reliability of the photovoltaic connector.
[0058] For example, as shown in Figures 8 to 11 When the photovoltaic connector comprises 12 temperature measuring resistor units 30, the signal processing unit 40 can comprise two multiplexers 41, as shown in Figure 8 and Figure 10 respectively, an 8-input-end multiplexer and a 4-input-end multiplexer, so that the number of input ends of the multiplexer 41 is equal to the number of the temperature measuring resistor units 30. At this time, the signal processing unit 40 can comprise two amplification modules 44 and two clamping modules 45. As shown in Figure 9 and Figure 11As shown, one amplification module 44 and one clamping module 45 are connected with the output terminal NTC_CH1 of one multiplexer 41, the output terminal of the amplification module 44 is connected with one input terminal ADC_A3 of the analog-digital conversion module 42. Another amplification module 44 and another clamping module 45 are connected with the output terminal NTC_CH2 of another multiplexer 41, the output terminal of the amplification module 44 is connected with another input terminal ADC_A0 of the analog-digital conversion module 42. During the working process of the signal processing unit 40, one of the two multiplexers 41 selects one input terminal and the output terminal to provide the resistance value signal to the amplification module 44, and then the resistance value signal is output to one input terminal of the analog-digital conversion module 42 after being processed by the amplification module 44, the analog-digital conversion module 42 outputs the digital signal to the signal processor 43 after performing analog-digital conversion according to the amplified signal provided by the input terminal, so that the signal processor 43 determines the temperature value corresponding to the resistance value signal according to the input digital signal.
[0059] The utility model embodiment further provides a photovoltaic system. The photovoltaic system includes the photovoltaic connector provided by any embodiment of the utility model. Since the photovoltaic system includes the photovoltaic connector provided by any embodiment of the utility model, it has the same beneficial effects as the photovoltaic connector provided by any embodiment of the utility model, which will not be repeated here. Illustratively, the photovoltaic system includes a photovoltaic assembly and can further include at least one of a photovoltaic inverter and an energy storage converter. The photovoltaic connector can be connected between the photovoltaic assembly and the photovoltaic inverter or between the photovoltaic assembly and the energy storage converter, which is not limited here.
[0060] It should be noted that the above are only preferred embodiments of the utility model and the technical principles applied. Those skilled in the art will understand that the utility model is not limited to the specific embodiments described herein, and those skilled in the art can make various obvious changes, readjustments and substitutions without departing from the protection scope of the utility model. Therefore, although the utility model has been described in more detail through the above embodiments, the utility model is not limited to the above embodiments, and can include more other equivalent embodiments without departing from the utility model concept, and the scope of the utility model is determined by the appended claims.
Claims
1. A photovoltaic connector, characterized by, The photovoltaic connector comprises a connector, a circuit board, a temperature measuring resistance unit and a signal processing unit; the circuit board is provided with a solder pad and a thick film chip resistor string, the thick film chip resistor string comprises at least one thick film chip resistor connected in series; the connecting end of the connector is connected with the solder pad, the temperature measuring resistance unit is connected with at least one solder pad through the thick film chip resistor string, the signal processing unit is connected with the temperature measuring resistance unit, and the temperature measuring resistance unit is used for forming a resistance value signal according to the temperature of the solder pad; and the signal processing unit is used for determining the temperature of the connector according to the resistance value signal.
2. The photovoltaic connector of claim 1, wherein, Each solder pad is connected with a temperature measuring resistance unit through a thick film chip resistor string, and at least two solder pads correspond to the same temperature measuring resistance unit.
3. The photovoltaic connector of claim 2, wherein, The connector comprises a positive electrode connector and a negative electrode connector, and the sum of the body voltage resistance values of the thick film chip resistors in the thick film chip resistor string is greater than or equal to the voltage difference between the positive electrode connector and the negative electrode connector.
4. The photovoltaic connector according to any of claims 1-3, characterized in that, The photovoltaic connector comprises a plurality of temperature measuring resistance units; the signal processing unit comprises a multiplexer, an analog-to-digital conversion module and a digital signal processor; A plurality of input ends of the multiplexer are respectively connected with a temperature measuring resistance unit, the output end of the multiplexer is connected with the input end of the analog-to-digital conversion module, and the output end of the analog-to-digital conversion module is connected with the input end of the digital signal processor; the multiplexer is used for selecting a temperature measuring resistance unit to be connected in conduction with the analog-to-digital conversion module, the analog-to-digital conversion module is used for performing analog-to-digital conversion on the resistance value signal to form a digital signal, and the signal processor is used for determining the temperature of the connector according to the digital signal.
5. The photovoltaic connector of claim 4, wherein, The signal processing unit further comprises an amplification module and a clamping module; The input end of the amplification module is connected with the output end of the multiplexer, the output end of the amplification module is connected with the first end of the clamping module and the input end of the analog-to-digital conversion module, the second end of the clamping module is connected with a first reference voltage input end, and the third end of the clamping module is grounded; the amplification module is used for amplifying the resistance value signal output by the multiplexer to form an amplified signal; and the clamping module is used for clamping the voltage of the amplified signal to be a first reference voltage provided by the first reference voltage input end when the voltage of the amplified signal is greater than the first reference voltage.
6. The photovoltaic connector of claim 5, wherein, The amplification module comprises an amplifier, a filter resistor and a filter capacitor, the positive input end of the amplifier is connected with the output end of the multiplexer, the negative input end of the amplifier and the output end of the amplifier are connected with the first end of the filter resistor, the second end of the filter resistor is connected with the first pole of the filter capacitor and the first end of the clamping module, and the second pole of the filter capacitor is grounded.
7. The photovoltaic connector of claim 5, wherein, The clamping module comprises a first zener diode and a second zener diode; the anode of the first zener diode is grounded, the cathode of the first zener diode and the anode of the second zener diode are connected with the output end of the amplification module, and the cathode of the second zener diode is connected with the first reference voltage input end.
8. The photovoltaic connector of claim 5, wherein, The signal processing unit comprises at least two multiplexers, at least two amplification modules and at least two clamping modules; The sum of the input ends of the at least two multiplexers is greater than or equal to the number of the temperature measurement resistance units, the input end of each amplification module is connected with the output end of one multiplexer, the output end of each amplification module is connected with the first end of one clamping module and one input end of the analog-digital conversion module.
9. The photovoltaic connector of claim 1, wherein, The temperature measurement resistance unit comprises a temperature measurement resistance, a voltage division resistance, a first resistance and a first capacitor; The first end of the temperature measurement resistance is connected with a second reference voltage input end, the second end of the temperature measurement resistance is connected with the first end of the voltage division resistance and the first end of the first resistance, and serves as an input end of the temperature measurement resistance unit; the second end of the voltage division resistance and the second pole of the first capacitor are grounded, the second end of the first resistance is connected with the first pole of the first capacitor, and serves as an output end of the temperature measurement resistance unit; wherein the resistance value of the temperature measurement resistance changes with temperature.
10. A photovoltaic system characterized by, A photovoltaic connector comprising the signal processing unit according to any one of claims 1-9.