A photovoltaic insulation detection fault location circuit and energy storage system

Abstract

This invention relates to the technical field of energy storage power supplies, and mainly provides a photovoltaic insulation detection fault location circuit and energy storage system. The circuit includes a detection module, a first control module, at least one second control module, and at least two location modules. The first control module and each of the second control modules are respectively connected to the detection module and the corresponding photovoltaic input source, and sequentially output control signals to connect the corresponding photovoltaic input source to the detection module. This enables a single detection module to perform insulation detection on multiple photovoltaic input sources, reducing circuit costs. When the detection module receives a drive signal, it detects the insulation impedance of the connected photovoltaic input source. When the impedance is lower than a preset range, it outputs a fault signal, responding to the fault promptly and improving circuit reliability. After receiving the corresponding control signal and fault signal, the location module outputs an indication signal to accurately locate the faulty photovoltaic input source, shortening fault diagnosis time, reducing labor costs, and improving operation and maintenance efficiency.

Description

Technical Field

[0001] This invention relates to the technical field of energy storage power supplies, and in particular to a photovoltaic insulation detection fault location circuit and energy storage system. Background Technology

[0002] During the operation of energy storage power supplies, certification requirements, operational safety, and system stability are key considerations. Insulation resistance testing of the PV input terminal to ground (PE) is a crucial step in ensuring these requirements are met. When the tested insulation resistance is less than the specified value, the power supply must promptly report an insulation fault to prevent safety issues.

[0003] In existing insulation resistance detection circuits, insulation resistance is often calculated by acquiring voltage values ​​using an MCU. To improve detection accuracy and avoid false alarms, a single-channel detection method is required. However, for photovoltaic energy storage power supplies with multiple PV inputs, this single-channel detection method requires multiple signals to control the detection sequence of each PV input to achieve individual detection control for each PV input. But in actual product design, MCU I / O port resources are often limited. If multiple control signals are added, the number of MCU pins must be increased, which will directly lead to a significant increase in product cost.

[0004] Furthermore, the commonly used insulation impedance detection circuits cannot pinpoint the specific PV input branch where the insulation impedance is abnormal when it occurs in the system. This means that on-site troubleshooting must rely on manual inspection of each branch, which is not only cumbersome but also severely delays the timeliness of fault handling. Summary of the Invention

[0005] The present invention provides a photovoltaic insulation detection fault location circuit and energy storage system, which aims to solve the technical problems of high cost of insulation detection of photovoltaic input sources and inability to locate faulty photovoltaic input sources in the prior art.

[0006] To solve the above-mentioned technical problems, one technical solution adopted in the embodiments of the present invention is: to provide a photovoltaic insulation detection fault location circuit, the photovoltaic insulation detection fault location circuit including a detection module, a first control module, at least one second control module and at least two location modules;

[0007] The first control module and at least one second control module are respectively connected to the detection module and the corresponding photovoltaic input source. The first control module is connected to each of the second control modules. The first control module and at least one second control module are also connected to a corresponding positioning module. The at least two positioning modules are also connected to the detection module.

[0008] The first control module and at least one of the second control modules are both used to output control signals for a preset time in sequence when the photovoltaic input source is connected, and to control the connected photovoltaic input source to connect to the detection module during the duration of the control signal;

[0009] The detection module is used to receive the drive signal and detect the insulation impedance of the connected photovoltaic input source based on the drive signal, and output a fault signal when the insulation impedance is less than a preset range.

[0010] The positioning module is used to output an indication signal when it receives the control signal output by the corresponding first control module or at least one second control module and the fault signal, so as to indicate that the connected photovoltaic input source is faulty.

[0011] Optionally, the positioning module includes an AND gate U2B, resistors R62 and R63, a switch Q27, and a diode LED1;

[0012] The first input terminal of the AND gate U2B is connected to the corresponding first control module, the second input terminal of the AND gate U2B is connected to the detection module, the output terminal of the AND gate U2B is connected to the control terminal of the switch Q27 through the resistor R62, the control terminal of the switch Q27 is also grounded through the resistor R63, the first terminal of the switch Q27 is connected to the cathode of the diode LED1, the second terminal of the switch Q27 is used for grounding, and the anode of the diode LED1 is connected to the first power supply.

[0013] Optionally, the photovoltaic insulation detection fault location circuit further includes at least two ground control modules;

[0014] The at least two ground control modules are connected to the first control module and at least one second control module respectively, and the at least two ground control modules are also connected to the detection module;

[0015] The at least two ground control modules are used to receive control signals output by the corresponding connected first control module or second control module, and start working based on the control signals to connect the negative terminal of the corresponding photovoltaic input source to the detection module.

[0016] Optionally, the ground control module includes a relay RLY3, a resistor R56, a resistor R59, and a switching transistor Q24;

[0017] The control terminal of the switching transistor Q24 is connected to the first control module through the resistor R56. The control terminal of the switching transistor Q24 is also grounded through the resistor R59. The first terminal of the switching transistor Q24 is used for grounding. The second terminal of the switching transistor Q24 is connected to the coil terminal of the relay RLY3. The coil terminal of the relay RLY3 is also connected to the second power supply. The connection terminals of the relay RLY3 are respectively connected to the negative terminal and the ground terminal of the corresponding photovoltaic input source.

[0018] Optionally, the detection module includes relays RLY1 and RLY2, operational amplifier U1, resistors R1, R3, R7, R10, R12, R15, R17, and switching transistors Q1 and Q2.

[0019] The coil terminal of relay RLY1 is connected to the second power supply and the first terminal of switching transistor Q1, respectively. The connection terminal of relay RLY1 is connected to resistors R3 and R7, respectively. The control terminal of switching transistor Q1 is connected to the controller. The second terminal of switching transistor Q1 is grounded. Resistor R3 is also connected to the first control module or at least one second control module through resistor R1. Resistor R3 is also connected to resistor R10. Resistor R10 is also connected to resistor R17 and the connection terminal of relay RLY2 through resistor R15, respectively. The connection terminal of relay RLY2 and resistor R17 are both grounded. The coil terminal of relay RLY2 is connected to the second power supply and the first terminal of switching transistor Q2, respectively. The control terminal of switching transistor Q2 is connected to the controller. The second terminal of switching transistor Q2 is also grounded. The first input terminal of operational amplifier U1 is connected to resistor R7. The second input terminal of operational amplifier U1 is also grounded through resistor R12. The output terminal of operational amplifier U1 is connected to the controller.

[0020] Optionally, the control signal includes a first control signal and a second control signal.

[0021] When the at least one second control module is a plurality of second control modules, the plurality of second control modules are cascaded, one second control module is connected to all the upper-level second control modules, and the plurality of second control modules are also connected to the first module;

[0022] The first control module is used to output a first control signal for a preset time when the photovoltaic input source is connected, and to control the connected photovoltaic input source to connect to the detection module during the duration of the first control signal;

[0023] Each of the second control modules is configured to stop working when it receives a first control signal and a second control signal output by any of the upper-level second control modules; and when it does not receive the first control signal and the second control signal output by any of the upper-level second control modules, it responds to the connected photovoltaic input source by outputting a second control signal for a second preset time, and controls the connected photovoltaic input source to connect to the detection module during the duration of the output second control signal.

[0024] Optionally, the first control module includes a first signal generation unit and a first switching unit;

[0025] The first signal generation unit is connected to the first switching unit and the corresponding photovoltaic input source respectively; the first switching unit is connected to the detection module and the corresponding photovoltaic input source respectively; and the first signal generation unit is also connected to a plurality of second control modules.

[0026] The first signal generation unit is configured to receive and store the input voltage of the photovoltaic input source when the photovoltaic input source is connected, and output a first control signal based on the stored voltage; and stop outputting the first control signal when the stored voltage is greater than a first preset value.

[0027] The first switching unit is configured to turn on when receiving the first control signal, so as to connect the connected photovoltaic input source to the detection module; and to turn off when not receiving the first control signal, so as to disconnect the detection circuit between the connected photovoltaic input source and the detection module.

[0028] Optionally, the second control module includes a control unit, a second signal generation unit, and a second switching unit;

[0029] The control unit is connected to the first signal generation unit and all the upper-level second control modules respectively. The control unit is also connected to the second signal generation unit and the corresponding photovoltaic input source respectively. The second signal generation unit is also connected to the second switching unit and all the lower-level second control modules respectively. The second switching unit is connected to the detection module and the corresponding photovoltaic input source respectively.

[0030] The control unit is configured to receive the first control signal and the second control signal output by any of the upper-level second control modules, and to start working when the first control signal and / or the second control signal are received to stop transmitting the input voltage of the corresponding photovoltaic input source; and to transmit the input voltage of the corresponding photovoltaic input source to the second signal generation unit when the first control signal and the second control signal are not received.

[0031] The second signal generation unit is used to receive and store the input voltage of the corresponding photovoltaic input source, and output a second control signal based on the stored voltage; and to stop outputting the second control signal when the stored voltage is greater than a second preset value;

[0032] The second switching unit is configured to turn on when receiving the second control signal, so as to connect the connected photovoltaic input source to the detection module; and to turn off when not receiving the second control signal, so as to disconnect the detection circuit between the connected photovoltaic input source and the detection module.

[0033] Optionally, the second control module further includes a delay unit;

[0034] The delay unit is connected to the corresponding photovoltaic input source and the control unit respectively;

[0035] The delay unit is used to receive the input voltage of the corresponding photovoltaic input source and input the input voltage to the control unit after delaying the input voltage by a target time.

[0036] To solve the above-mentioned technical problems, another technical solution adopted in the embodiments of the present invention is to provide an energy storage system, the energy storage system comprising:

[0037] Multiple photovoltaic input sources; and a photovoltaic insulation detection fault location circuit as described above, wherein the photovoltaic insulation detection fault location circuit is connected to the multiple photovoltaic input sources respectively.

[0038] Unlike related technologies, this invention provides a photovoltaic insulation detection fault location circuit and energy storage system. The photovoltaic insulation detection fault location circuit includes a detection module, a first control module, at least one second control module, and at least two location modules. The first control module and at least one second control module are respectively connected to the detection module and a corresponding photovoltaic input source. The first control module is connected to each of the second control modules, and the first control module and at least one second control module are also connected to a location module. The at least two location modules are also connected to the detection module. The first control module and at least one second control module are used to sequentially output control signals for a preset time when the photovoltaic input source is connected, and control the connected photovoltaic input source to connect to the detection module within the duration of the control signal. Based on this, insulation detection of multiple photovoltaic input sources can be achieved using a single detection module, effectively saving circuit costs. When the detection module receives a drive signal, it detects the insulation impedance of the connected photovoltaic input source and outputs a fault signal when the insulation impedance is less than a preset range, thus responding promptly to photovoltaic faults and improving circuit reliability. The positioning module is used to output an indication signal when it receives the control signal and the fault signal from the corresponding first control module or at least one second control module. This indicates that the connected photovoltaic input source is faulty. Based on this, the faulty photovoltaic input source can be accurately located, saving the time for troubleshooting, thereby reducing labor costs and improving operation and maintenance efficiency. Attached Figure Description

[0039] One or more embodiments are illustrated by way of example with reference to the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements having the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0040] Figure 1 This is a structural block diagram of an energy storage system provided in an embodiment of the present invention;

[0041] Figure 2 This is a structural block diagram of a photovoltaic insulation detection fault location circuit provided in an embodiment of the present invention;

[0042] Figures 3a-3b This is a circuit diagram of a detection module provided in an embodiment of the present invention;

[0043] Figure 4 This is a circuit diagram of a positioning module provided in an embodiment of the present invention;

[0044] Figure 5 This is a structural block diagram of a photovoltaic insulation detection fault location circuit provided in another embodiment of the present invention;

[0045] Figure 6 This is a circuit diagram of a photovoltaic insulation detection fault location circuit provided in an embodiment of the present invention;

[0046] Figure 7 This is a circuit diagram of a photovoltaic insulation detection fault location circuit provided in another embodiment of the present invention. Detailed Implementation

[0047] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0048] It should be noted that, unless otherwise specified, the various features in the embodiments of the present invention can be combined with each other, and all are within the protection scope of the present invention. Furthermore, although functional modules are divided in the device schematic diagram and a logical order is shown in the flowchart, in some cases, the steps shown or described may be performed in a different module division or in a different order than that shown in the device schematic diagram or the flowchart.

[0049] Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. The term "and / or" as used in this specification includes any and all combinations of one or more of the associated listed items.

[0050] Please see Figure 1 , Figure 1 This is a structural block diagram of an energy storage system provided in an embodiment of the present invention, such as... Figure 1 As shown, the energy storage system 100 includes multiple photovoltaic input sources 10 and a photovoltaic insulation detection fault location circuit 20, and all of the multiple photovoltaic input sources 10 are connected to the photovoltaic insulation detection fault location circuit 20.

[0051] Specifically, the photovoltaic insulation detection fault location circuit 20 receives the input voltage of the photovoltaic input source 10 and starts working based on the received input voltage to detect the insulation impedance of the corresponding connected photovoltaic input source 10, and determines whether the corresponding photovoltaic input source 10 is operating safely based on the insulation impedance. If the insulation impedance indicates that the corresponding photovoltaic input source 10 is faulty, the photovoltaic insulation detection fault location circuit 20 locates the faulty photovoltaic input source 10 and indicates the faulty photovoltaic input source 10. Based on this, when multiple photovoltaic input sources 10 are detected sequentially, the faulty photovoltaic input source 10 can be accurately located, thereby increasing the safety and reliability of the energy storage system 100. It should be noted that since there are multiple photovoltaic input sources 10, when the insulation impedance of multiple photovoltaic input sources 10 is measured sequentially, there may be situations where the faulty photovoltaic input source cannot be determined. Therefore, by introducing the photovoltaic insulation detection fault location circuit 20, when a faulty photovoltaic input source is detected, it is possible to intuitively indicate which photovoltaic input source 10 is faulty, thereby increasing operation and maintenance efficiency.

[0052] In some embodiments, please refer to Figure 2 , Figure 2 This is a structural block diagram of a photovoltaic insulation detection fault location circuit provided in an embodiment of the present invention, as shown below. Figure 2 As shown, the photovoltaic insulation detection fault location circuit 20 includes a detection module 21, a first control module 22, at least one second control module 23, and at least two location modules 24. Figure 2 Taking a second control module and two positioning modules as an example;

[0053] The first control module 22 and at least one second control module 23 are respectively connected to the detection module 21 and the corresponding photovoltaic input source 10. The first control module 22 is connected to each of the second control modules 23. The first control module 22 and at least one second control module 23 are also connected to a positioning module 24. The at least two positioning modules 24 are also connected to the detection module 21.

[0054] The first control module 22 and at least one of the second control modules 23 are both used to output control signals for a preset time in sequence when the photovoltaic input source 10 is connected, and to control the connected photovoltaic input source 10 to connect to the detection module 21 during the duration of the control signal;

[0055] The detection module 21 is used to receive the drive signal and detect the insulation impedance of the connected photovoltaic input source 10 based on the drive signal, and output a fault signal when the insulation impedance is less than a preset range.

[0056] The positioning module 24 is used to output an indication signal when it receives the control signal output by the corresponding first control module 22 or at least one second control module 23 and the fault signal, so as to indicate that the connected photovoltaic input source 10 is faulty.

[0057] Specifically, when the energy storage system 100 starts working, the first control module 22 and at least one second control module 23 will both start working and output control signals for a preset time based on the connected photovoltaic input source 10. During the preset time of the control signal, the first control module 22 or the second control module 23 will control the corresponding connected photovoltaic input source 10 to connect to the detection module 21 so that the detection module 21 can detect the insulation resistance of the connected photovoltaic input source 10.

[0058] When the detection module 21 receives the input voltage of the corresponding photovoltaic input source 10, it also receives a drive signal and starts working according to the drive signal. After the detection module 21 starts working, it determines the insulation impedance of the corresponding photovoltaic input source 10 based on the input voltage, and outputs a fault signal to the positioning module 24 when the insulation impedance is less than a preset range. When the positioning module 24 receives the fault signal, it determines that there is a faulty photovoltaic input source 10 among the multiple photovoltaic input sources 10. At this time, when the positioning module 24 receives the control signal output by the first control module 22 or the second control module 23, it determines that the photovoltaic input source 10 connected to the first control module 22 or the second control module 23 has a fault, and outputs an indication signal to indicate that the photovoltaic input source 10 has a fault.

[0059] In some embodiments, the energy storage system 100 further includes a controller connected to the detection module 21. When the detection module 21 detects the insulation impedance of the corresponding photovoltaic input source 10 based on the input voltage, the detection module 21 inputs the detected detection information to the controller. After receiving the detection information, the controller determines whether the corresponding photovoltaic input source 10 has malfunctioned based on the detection information, and outputs a fault signal after determining that the photovoltaic input source 10 has malfunctioned.

[0060] In another embodiment, when the detection module 21 is connected to the corresponding photovoltaic input source 10, the controller outputs a drive signal to the detection module 21 to start its operation. The drive signal includes a first drive signal and a second drive signal. When the detection module 21 receives either the first or second drive signal, it samples the input voltage of the photovoltaic input source 10 based on the first and second drive signals, thereby outputting a first sample value and a second sample value to the controller. Upon receiving the first and second sample values, the controller calculates the insulation impedance of the photovoltaic input source 10 based on the first and second sample values, and outputs a fault signal when the insulation impedance is less than a preset range. It should be noted that the method by which the controller calculates the insulation impedance based on the first and second sample values ​​is a conventional method and will not be described in detail here.

[0061] In some embodiments, please refer to Figures 3a-3b , Figures 3a-3b This is a circuit diagram of a detection module provided in an embodiment of the present invention, such as... Figures 3a-3b As shown, the detection module 21 includes relays RLY1 and RLY2, operational amplifier U1, resistors R1, R3, R7, R10, R12, R15, R17, and switching transistors Q1 and Q2.

[0062] The coil terminal of relay RLY1 is connected to the second power supply and the first terminal of switching transistor Q1, respectively. The connection terminal of relay RLY1 is connected to resistors R3 and R7, respectively. The control terminal of switching transistor Q1 is connected to the controller. The second terminal of switching transistor Q1 is grounded. Resistor R3 is also connected to the first control module 22 or at least one second control module 23 through resistor R1. Resistor R3 is also connected to resistor R10. Resistor R10 is also connected to resistor R17 and the connection terminal of relay RLY2 through resistor R15, respectively. The connection terminal of relay RLY2 and resistor R17 are both grounded. The coil terminal of relay RLY2 is connected to the second power supply and the first terminal of switching transistor Q2, respectively. The control terminal of switching transistor Q2 is connected to the controller. The second terminal of switching transistor Q2 is also grounded. The first input terminal of operational amplifier U1 is connected to resistor R7. The second input terminal of operational amplifier U1 is also grounded through resistor R12. The output terminal of operational amplifier U1 is connected to the controller.

[0063] Specifically, when the first control module 22 or the second control module 23 starts working, the detection module 21 connects to the photovoltaic input source 10 corresponding to the first control module 22 or the second control module 23 during the duration of the control signal. At this time, the controller outputs a first drive signal (RLY2 ISO) to control the switch Q1 to turn on, so that the relay RLY1 closes. When the relay RLY1 closes, the resistors R1, R3, R15, and R17 simultaneously divide the input voltage and output the first voltage divider signal (the voltage divider values ​​on resistors R15 and R17) to the first input terminal of the operational amplifier U1. When the operational amplifier U1 receives the first voltage divider signal, it outputs a first sampled value to the controller based on the first voltage divider signal. After sampling the first sampled value, the controller controls both switches Q1 and Q2 to conduct (i.e., outputs a first drive signal to switch Q1 and a second drive signal (RLY1 ISO) to switch Q2). When both switches Q1 and Q2 are conducted, both relays RLY1 and RLY2 are closed. At this time, resistor R17 is short-circuited, and resistors R1, R3, and R15 divide the input voltage, outputting a second voltage divider signal (the voltage divider value on resistor R15) to the first input terminal of operational amplifier U1, so that operational amplifier U1 outputs a second sampled value to the controller. When the controller receives the first and second sampled values, it can calculate the insulation impedance of the current photovoltaic input source 10 based on the first and second sampled values. If the insulation impedance is less than a preset range, it determines that the photovoltaic input source 10 has failed. At this time, the controller outputs a fault signal to the positioning module 24, so that the positioning module 24 indicates which photovoltaic input source has failed. Based on this, it is possible to accurately determine whether the current photovoltaic input source 10 is operating stably, thereby improving the reliability of the energy storage system 100.

[0064] In yet another embodiment, please refer to Figure 4 , Figure 4 This is a circuit diagram of a positioning module provided in an embodiment of the present invention, such as... Figure 4 As shown, the positioning module 24 includes an AND gate U2B, a resistor R62, a resistor R63, a switch Q27, and a diode LED1;

[0065] The first input terminal of the AND gate U2B is connected to the first control module 22, the second input terminal of the AND gate U2B is connected to the detection module 21, the output terminal of the AND gate U2B is connected to the control terminal of the switch Q27 through the resistor R62, the control terminal of the switch Q27 is also grounded through the resistor R63, the first terminal of the switch Q27 is connected to the cathode of the diode LED1, the second terminal of the switch Q27 is used for grounding, and the anode of the diode LED1 is connected to the first power supply.

[0066] When the first control module 22 outputs a control signal, the first input terminal of the AND gate U2B receives the control signal output by the first control module 22. At this time, if the controller does not output a fault signal, the AND gate U2B will output a low-level signal, the switch Q27 will be turned off, and the diode LED1 will not indicate. However, if the controller outputs a fault signal, the AND gate U2B will output a high-level signal based on the fault signal and the control signal, thereby controlling the switch Q27 to turn on. When the switch Q27 turns on, the diode LED1 also starts to work, and then outputs an indication signal. Based on this, the faulty photovoltaic input source 10 can be intuitively indicated by the positioning module 24, enabling maintenance personnel to quickly locate the problem, thereby saving time and improving maintenance efficiency.

[0067] It should be noted that the above embodiments list the positioning module 24 connected to the first control module 22. The photovoltaic insulation detection fault location circuit package 20 includes multiple positioning modules 24, and other positioning modules 24 are respectively connected to a second control module 23. In one embodiment, the multiple positioning modules 24 have the same circuit structure.

[0068] It is understood that the state of the diode LED1 is only for distinguishing whether the current photovoltaic input source 10 is faulty. Its specific indication form is not limited here. For example, it can be indicated by whether the diode LED1 is on or off, or by the color of the diode LED1.

[0069] In other embodiments, the positioning module 24 may also input the indication signal to the controller so that the controller indicates which photovoltaic input source 10 has failed.

[0070] It should be noted that the structure and working principle of each positioning module 24 are the same, so the structure and working principle of the positioning module 24 connected to at least one second control module 23 will not be described again here.

[0071] In some embodiments, the control signal includes a first control signal and a second control signal. When the at least one second control module 23 is a plurality of second control modules 23, the plurality of second control modules 23 are cascaded. One second control module 23 is connected to all the upper-level second control modules 23, and the plurality of second control modules 23 are also connected to the first module 22.

[0072] The first control module 22 is used to output a first control signal for a preset time when the photovoltaic input source 10 is connected, and to control the connected photovoltaic input source 10 to connect to the detection module 21 during the duration of the first control signal;

[0073] Each of the second control modules 23 is configured to stop working when it receives a first control signal and a second control signal output by any of the upper-level second control modules 23; and when it does not receive the first control signal and the second control signal output by any of the upper-level second control modules 23, it responds to the connected photovoltaic input source 10 by outputting a second control signal for a second preset time, and controls the connected photovoltaic input source 10 to connect to the detection module 21 during the duration of the output second control signal.

[0074] It is understood that the sum of the number of the first control module 22 and the second control module 23 is equal to the number of the photovoltaic input sources 10. The first control module 22 and the multiple second control modules 23 are connected to the multiple photovoltaic input sources 10 respectively. The number of the second control modules 23 increases as the number of photovoltaic input sources 10 increases. For example, when the number of photovoltaic input sources 10 is 5, the photovoltaic insulation detection fault location circuit 20 includes the first control module 22 and four second control modules 23.

[0075] Based on this, when multiple photovoltaic input sources 10 are connected to the photovoltaic insulation detection fault location circuit 20, the first control module 22 receives the input voltage of the connected photovoltaic input source 10 and starts working based on the input voltage to output a first control signal for a preset time. After the first control module 22 outputs the first control signal for a preset time, on the one hand, the first control module 22 controls the connected photovoltaic input source 10 to connect to the detection module 21 during the duration of the first control signal, so that the detection module 21 performs insulation detection on the photovoltaic input source 10 connected to the first control module 22 during the duration of the first control signal to determine whether the insulation impedance of the photovoltaic input source 10 connected to the first control module 22 is less than a preset range, and determines that the current photovoltaic input source 10 has a fault when the insulation impedance is less than the preset range; on the other hand, the second control module 23 also receives the first control signal and stops working during the duration of the first control signal. When the first control module 22 stops outputting the first control signal, it is considered that the photovoltaic input source 10 connected to the first control module 22 has completed the detection. At this time, if the second control module 23 is also connected to the photovoltaic input source 10, the second control module 23 will start working based on the input voltage of the connected photovoltaic input source 10 when it does not receive the first control signal, so as to output the second control signal for a preset time.

[0076] Since the second control modules 23 are cascaded, when the first second control module 23 is connected to the photovoltaic input source 10 and does not receive the first control signal, the first second control module 23 will receive the input voltage of the connected photovoltaic input source 10 and output a second control signal for a preset time based on the input voltage. At this time, on the one hand, the first second control module 23 will control the connected photovoltaic input source 10 to connect to the detection module 21 based on the second control signal, so that the detection module 21 can detect the insulation resistance of the photovoltaic input source 10 connected to the first second control module 23, thereby determining whether the photovoltaic input source 10 is operating stably based on the insulation resistance. On the other hand, the second control signal will also be output to the next-level second control module 23 of the first second control module 23, so that the next-level second control module 23 stops working based on the second control signal.

[0077] When the second control module 23 is not the first of a plurality of second control modules 23, if the second control module 23 is connected to the corresponding photovoltaic input source 10 and has not received the first control signal or any second control signal output from the upper level, the second control module 23 will output a second control signal for a preset time based on the input voltage of the corresponding connected photovoltaic input source 10. During the duration of the second control signal, the detection module 21 will be controlled to perform insulation detection on the corresponding connected photovoltaic input source 10, thereby determining whether the corresponding connected photovoltaic input source 10 is operating stably based on the detection result. Based on this, the first control module 22 and the plurality of second control modules 23 can sequentially perform insulation detection on the plurality of photovoltaic input sources 10, thereby reducing the cost of insulation detection, reducing the difficulty of detection, and improving the safety and stability of the energy storage system.

[0078] In some other embodiments, please refer to Figure 5 , Figure 5 This is a structural block diagram of a photovoltaic insulation detection fault location circuit provided in another embodiment of the present invention, as shown below. Figure 5 As shown, the first control module 22 includes a first signal generation unit 221 and a first switching unit 222;

[0079] The first signal generation unit 221 is connected to the first switch unit 222 and the corresponding photovoltaic input source 10 respectively. The first switch unit 222 is connected to the detection module 21 and the corresponding photovoltaic input source 10 respectively. The first signal generation unit 221 is also connected to a plurality of second control modules 23.

[0080] The first signal generation unit 221 is used to receive and store the input voltage of the photovoltaic input source 10 when the photovoltaic input source 10 is connected, and output a first control signal based on the stored voltage; and to stop outputting the first control signal when the stored voltage is greater than a first preset value.

[0081] The first switching unit 222 is configured to turn on based on the first control signal when receiving the first control signal, so as to connect the connected photovoltaic input source 10 to the detection module 21; and to turn off when not receiving the first control signal, so as to disconnect the detection circuit between the connected photovoltaic input source 10 and the detection module 21.

[0082] Specifically, when the first control module 22 is connected to the photovoltaic input source 10, the first signal generation unit 221 receives and stores the input voltage of the photovoltaic input source 10, and outputs the first control signal while storing the input voltage. After a preset time, if the input voltage stored by the first signal generation unit 221 is greater than a first preset value, the first signal generation unit 221 will stop outputting the first control signal.

[0083] When the first signal generation unit 221 outputs the first control signal, on the one hand, the first switch unit 222 receives the first control signal and turns on based on the first control signal. After the first switch unit 222 turns on, the photovoltaic input source 10 connected to the first control module 22 will be connected to the detection module 21 through the first switch unit 222, so that the detection module 21 receives the input voltage of the current photovoltaic input source 10, detects the insulation resistance of the current photovoltaic input source 10 based on the input voltage, and determines whether the photovoltaic input source 10 is operating stably based on the insulation resistance. On the other hand, the first control signal will also be input to the second control module 23, so that the second control module 23 stops working during the duration of the first control signal. It should be noted that after a preset time, the first signal generation unit 221 will stop outputting the first control signal. At this time, the first switch unit 222 will turn off when it does not receive the first control signal, thereby disconnecting the connection between the corresponding photovoltaic input source 10 and the detection module 21, and thus shutting off the detection path formed by the photovoltaic input source 10 and the detection module 21.

[0084] In another embodiment, the first signal generation unit 221 is also connected to the corresponding positioning module 24. When the first signal generation unit 221 outputs a first control signal for a preset time, the positioning module 24 receives the first control signal and, upon receiving the fault signal, determines that the photovoltaic input source 10 connected to the first signal generation unit 221 has malfunctioned; otherwise, if the fault signal is not received, it determines that the connected photovoltaic input source 10 is working normally.

[0085] In some embodiments, please refer to Figure 6 , Figure 6 This is a circuit diagram of a photovoltaic insulation detection fault location circuit provided in an embodiment of the present invention, as shown below. Figure 6 As shown, the first switching unit 222 includes a switching transistor Q3, a switching transistor Q9, a resistor R20, a resistor R22, and a resistor R30; the first signal generation unit 221 includes a switching transistor Q5, a resistor R25, a resistor R35, a diode D5, a capacitor C9, a capacitor C10, and a capacitor C11.

[0086] The first terminal of the switching transistor Q5 is connected to the corresponding photovoltaic input source 10. The first terminal of the switching transistor Q5 is also connected to the control terminal of the switching transistor Q5 through the resistor R25. The control terminal of the switching transistor Q5 is also grounded through the capacitor C11. The control terminal of the switching transistor Q5 is also connected to the anode of the diode D5. The cathode of the diode D5 is also grounded through the resistor R35. The resistor R35 is also connected to the first terminal of the switching transistor Q5. The capacitor C10 is connected in parallel with the resistor R35. The second terminal of the switching transistor Q5 is grounded through the capacitor C9. The second terminal of the switching transistor Q5 is also connected to the first switching unit 222 and multiple second control modules 23 respectively.

[0087] The switching transistor Q9 is connected to the first signal generation unit 221 through the resistor R30. The first end of the switching transistor Q9 is connected to the control terminal of the switching transistor Q3 through the resistor R22. The second end of the switching transistor Q9 is used for grounding. The first end of the switching transistor Q3 is connected to the corresponding photovoltaic input source 10. The first end of the switching transistor Q3 is also connected to the control terminal of the switching transistor Q3 through the resistor R20. The second end of the switching transistor Q3 is connected to the detection module 21.

[0088] When the first control module 22 is connected to the photovoltaic input source 10, the input voltage of the photovoltaic input source 10 charges the capacitor C11 through the resistor R25. When the capacitor C11 starts charging, the voltage across the resistor R25 is greater than the forward voltage drop of the switch Q5, thereby turning on the switch Q5. After the switch Q5 is turned on, it transmits the input voltage of the photovoltaic input source 10 to the capacitor C9, causing the capacitor C9 to start charging. When the voltage of the capacitor C9 is greater than a preset threshold, a first control signal is output. During the charging process of the capacitor C11, as the voltage stored in the capacitor C11 increases, the voltage across the resistor R25 decreases. After a preset time, the voltage across the resistor R25 will be less than the forward voltage drop of the switch Q5, thereby turning off the switch Q5. When the switch Q5 is turned off, it stops outputting the input voltage. At this time, capacitor C9 begins to discharge. When the voltage of capacitor C9 is less than a preset threshold, the first control signal is stopped being output. Therefore, the time taken for the voltage of capacitor C9 to exceed the preset threshold during charging and discharging is the preset time. The charging time of capacitor C9 is the same as the conduction time of switch Q5.

[0089] When capacitor C9 outputs a first control signal for a preset time based on the stored energy, on the one hand, the first control signal is output to multiple second control modules 23, causing the multiple second control modules 23 to stop working during the duration of the first control signal. On the other hand, switch Q9 receives the first control signal through resistor R30 and turns on based on the first control signal. When switch Q9 turns on, switch Q3 also turns on, thereby connecting the connected photovoltaic input source 10 to the detection module 21, and thus enabling the detection module 21 to detect the insulation resistance of the photovoltaic input source 10. After the preset time, capacitor C9 stops outputting the first control signal, and switch Q9 no longer receives the first control signal. At this time, switch Q9 turns off, and switch Q3 also turns off, thereby cutting off the detection path between the photovoltaic input source 10 and the detection module 21. It should be noted that the photovoltaic input source 10 charges capacitor C10 on one hand and capacitor C11 on the other hand through resistor R25. Therefore, the charging time of capacitor C10 is faster than that of capacitor C11, diode D5 is in the off state, and eventually the voltages of capacitor C11 and capacitor C10 will be equal.

[0090] It can be seen that when the photovoltaic input source 10 is disconnected from the first control module 22, the capacitor C10 will discharge through the resistor R35. When the voltage stored in the capacitor C10 and the voltage stored in the capacitor C11 are greater than the forward voltage drop of the diode D5, the capacitor C11 will also begin to discharge rapidly through the resistor R35. Based on this, it can be ensured that the first signal generation unit 221 can output the first control signal normally during the next detection.

[0091] In some embodiments, such as Figure 6 As shown, the first control module 22 also includes a Zener diode DZ1. The cathode of the Zener diode DZ1 is connected to the corresponding photovoltaic input source 10, and the anode of the Zener diode DZ1 is connected to the first signal generation unit 221. The Zener diode DZ1 is used to detect the input voltage of the connected photovoltaic input source 10, so that when the input voltage is less than the Zener value of the Zener diode DZ1, the transmission of the input voltage of the photovoltaic input source 10 to the first signal generation unit 221 is stopped. Based on this, insulation testing of the photovoltaic input source 10 can be stopped when the input voltage of the photovoltaic input source 10 does not meet the requirements, thereby improving the accuracy of the detection.

[0092] In some embodiments, such as Figure 5 As shown, the second control module 23 includes a control unit 231, a second signal generation unit 232, and a second switching unit 233;

[0093] The control unit 231 is connected to the first signal generation unit 221 and all the upper-level second control modules 23 respectively. The control unit 231 is also connected to the second signal generation unit 232 and the corresponding photovoltaic input source 10 respectively. The second signal generation unit 232 is also connected to the second switch unit 233 and all the lower-level second control modules 23 respectively. The second switch unit 233 is connected to the detection module 21 and the corresponding photovoltaic input source 10 respectively.

[0094] The control unit 231 is used to receive the first control signal and the second control signal output by any of the upper-level second control modules 23, and to start working when the first control signal and / or the second control signal are received, so as to stop transmitting the input voltage of the corresponding photovoltaic input source 10; and to transmit the input voltage of the corresponding photovoltaic input source 10 to the second signal generation unit 232 when the first control signal and the second control signal are not received.

[0095] The second signal generation unit 232 is used to receive and store the input voltage of the corresponding photovoltaic input source 10, and output a second control signal based on the stored voltage; and to stop outputting the second control signal when the stored voltage is greater than a second preset value;

[0096] The second switch unit 233 is configured to turn on based on the second control signal when receiving the second control signal, so as to connect the connected photovoltaic input source 10 to the detection module 21; and to turn off when not receiving the second control signal, so as to disconnect the detection circuit between the connected photovoltaic input source 10 and the detection module 21.

[0097] Specifically, when the second control module 23 is connected to the photovoltaic input source 10, if the control unit 231 receives the first control signal output by the first control module 22 or the second control signal output by any of the second control modules 23, the control unit 231 will start working based on the first control signal or the second control signal, thereby stopping the transmission of the input voltage to the second signal generation unit 232, causing the second signal generation unit 232 and the second switching unit 233 to stop working. Based on this, when performing insulation testing on the photovoltaic input source 10 connected to the first control module 22 or the photovoltaic input source 10 connected to the upper-level second control module 23, the current photovoltaic input source 10 can be prevented from being connected to the detection module 21, allowing multiple photovoltaic input sources 10 to be tested sequentially, thereby reducing testing costs and testing difficulty.

[0098] When the control unit 231 does not receive the first control signal and the second control signal, the control unit 231 transmits the input voltage of the photovoltaic input source 10 to the second signal generation unit 232. When the second signal generation unit 232 receives the input voltage, it stores the input voltage and outputs the second control signal based on the input voltage. After a preset time, if the voltage stored by the second signal generation unit 232 is greater than a second preset value, the second signal generation unit 232 will stop outputting the second control signal. Based on this, the second signal generation unit 232 can output the second control signal for the preset time.

[0099] When the second signal generation unit 232 outputs a second control signal for a preset time, on the one hand, the second control signal is input to the lower-level second control module 23, causing the lower-level second control module 23 to stop working during the duration of the second control signal. On the other hand, the second switch unit 233 receives the second control signal and is turned on during the duration of the second control signal. When the second switch unit 233 is turned on, the current photovoltaic input source 10 is connected to the detection module 21 through the second switch unit 233, thereby detecting the insulation impedance of the corresponding photovoltaic input source 10 based on the detection module 21. If the second switch unit 233 does not receive the second control signal, the second switch unit 233 is in the off state, thereby disconnecting the current photovoltaic input source 10 from the detection module 21, and thus breaking the detection loop between the connected photovoltaic input source 10 and the detection module 21.

[0100] In yet another embodiment, such as Figure 5 As shown, the second control module 23 also includes a delay unit 234;

[0101] The delay unit 234 is connected to the corresponding photovoltaic input source 10 and the control unit 231 respectively;

[0102] The delay unit 234 is used to receive the input voltage of the corresponding photovoltaic input source 10 and input the input voltage to the control unit 231 after delaying the input voltage by a target time.

[0103] Specifically, when the second control module 23 is connected to the photovoltaic input source 10, the delay unit 234 receives the input voltage of the photovoltaic input source 10 and inputs the input voltage to the control unit 231 after delaying it by a target time. During the target time, if the control unit 231 receives the first control signal or the second control signal, it stops transmitting the input voltage of the photovoltaic input source 10; if the control unit 231 does not receive the first or second control signal within the target time, it transmits the input voltage to the second signal generation unit 232, so that the second signal generation unit 232 generates the second control signal. It should be noted that the delay unit 234 is used to prevent the first control module 22 and the second control module 23 from operating simultaneously when connected to their respective photovoltaic input sources 10. Based on this, multiple photovoltaic input sources 10 can be sequentially tested for insulation, thereby improving the reliability of the energy storage system 100.

[0104] In some embodiments, such as Figure 6 As shown, the control unit 231 includes switching transistors Q6, Q8, and Q11, resistors R29 and R32; the delay unit 234 includes capacitor C7 and resistor R28.

[0105] The control terminal of the switch Q11 is connected to the first signal generation unit 221 through the resistor R32. The first terminal of the switch Q11 is connected to the corresponding photovoltaic input source 10 (PV2+) through the resistor R29. The first terminal of the switch Q11 is also connected to the control terminal of the switch Q8. The first terminal of the switch Q8 is connected to the control terminal of the switch Q6. The second terminals of the switch Q11 and the second terminals of the switch Q8 are both grounded. The first terminal of the switch Q6 is connected to the corresponding photovoltaic input source 10. The second terminal of the switch Q6 is connected to the second signal generation unit 232.

[0106] The first terminal of capacitor C7 is connected to the corresponding photovoltaic input source 10 through resistor R28. The first terminal of capacitor C7 is also connected to the control terminal of switch Q6. The second terminal of capacitor C7 is grounded.

[0107] Specifically, when the second control module 23 is connected to the photovoltaic input source 10, the input voltage of the photovoltaic input source 10 will charge the capacitor C7 through the resistor R28 to prevent the switch Q6 from turning on prematurely during the transmission of the first or second control signal. At this time, if the first control module 22 outputs the first control signal or the upper-level second control module 23 outputs the second control signal, the switch Q11 will receive the first or second control signal through the resistor R32 and turn on according to the first or second control signal. After the switch Q11 turns on, the switch Q8 also turns on. When the switch Q8 turns on, the control terminal voltage of the switch Q6 is pulled low, thereby turning off the switch Q6, thus cutting off the path between the photovoltaic input source 10 and the second signal generation unit 232, and stopping the transmission of the input voltage of the photovoltaic input source 10 to the second signal generation unit 232. When the switch Q11 does not receive the first and second control signals, the switch Q11 turns off, and the switch Q8 also turns off. At this time, after a target time, the switch Q6 will turn on based on the energy stored in the capacitor C7, thereby transmitting the input voltage of the photovoltaic input source 10 to the second signal generation unit 232, so that the second signal generation unit 232 generates the second control signal.

[0108] In some other embodiments, such as Figure 6 As shown, the second switching unit 233 includes a switching transistor Q4, a switching transistor Q10, a resistor R23, a resistor R21, and a resistor R31; the second signal generation unit 232 includes a switching transistor Q7, a resistor R26, a resistor R36, a diode D6, a capacitor C8, a capacitor C12, and a capacitor C13.

[0109] The first terminal of the switching transistor Q7 is connected to the control unit 231. The first terminal of the switching transistor Q7 is also connected to the control terminal of the switching transistor Q7 through the resistor R26. The control terminal of the switching transistor Q7 is also grounded through the capacitor C13. The control terminal of the switching transistor Q7 is also connected to the anode of the diode D6. The cathode of the diode D6 is also grounded through the resistor R36. The resistor R36 is also connected to the first terminal of the switching transistor Q7. The capacitor C12 is connected in parallel with the resistor R36. The second terminal of the switching transistor Q7 is grounded through the capacitor C8. The second terminal of the switching transistor Q7 is also connected to the second switching unit 233 and the lower-level second control module 23, respectively.

[0110] The control terminal of the switch Q10 is connected to the second signal generation unit 232 through the resistor R31. The first terminal of the switch Q10 is connected to the control terminal of the switch Q4 through the resistor R23. The second terminal of the switch Q10 is used for grounding. The first terminal of the switch Q4 is connected to the corresponding photovoltaic input source 10. The first terminal of the switch Q4 is also connected to the control terminal of the switch Q4 through the resistor R21. The second terminal of the switch Q4 is connected to the detection module 21.

[0111] It should be noted that the working principle of the second signal generation unit 232 and the second switching unit 233 is similar to that of the first signal generation unit 221 and the first switching unit 222, and will not be described again here.

[0112] In some embodiments, such as Figure 6 As shown, the second control module 23 also includes a Zener diode DZ2. The cathode of the Zener diode DZ2 is connected to the corresponding photovoltaic input source 10, and the anode of the Zener diode DZ2 is connected to the control unit 231. The Zener diode DZ2 is used to detect the input voltage of the connected photovoltaic input source 10, so that when the input voltage is less than the Zener value of the Zener diode DZ2, the transmission of the input voltage of the photovoltaic input source 10 to the control unit 231 is stopped. Based on this, insulation testing of the photovoltaic input source 10 can be stopped when the input voltage of the photovoltaic input source 10 does not meet the requirements, thereby improving the accuracy of the detection.

[0113] In some embodiments, the preset duration of the first control signal and the preset duration of the second control signal may be the same or different. The duration of the first and second control signals can be adjusted by adjusting the capacitance values ​​of capacitors C8, C9, C16, etc.

[0114] In another embodiment, when the second control module 23 is not the first of a plurality of second control modules 23, the second control module 23 further includes a locking unit (not shown).

[0115] The locking unit is connected to the first control module 22 and any upper-level second control module 23 respectively, and the locking unit is also connected to the lower-level second control module 23;

[0116] The locking unit is used to receive the first control signal and the second control signal, and output a locking signal to the lower-level second control module 23 based on the first control signal and the second control signal, so as to control the lower-level second control module 23 to continuously stop working.

[0117] Specifically, when the first control module 22 outputs a first control signal or the second control module 23 outputs a second control signal, the locking unit receives the first or second control signal and outputs a locking signal to the lower-level second control module 23 based on the first or second control signal, thereby locking the lower-level second control module 23 to maintain a stopped working state. This means that after the first control module 22 / second control module 23 completes its detection but before the current second control module 23 begins its detection, the lower-level second control module 23 is locked into a stopped working state, thus avoiding false detections and allowing multiple photovoltaic input sources 10 to be detected sequentially, thereby improving the reliability of the energy storage system.

[0118] In some embodiments, such as Figure 6 As shown, the locking unit is capacitor C14;

[0119] The capacitor C14 is connected to both the first signal generation unit 221 and the second signal generation unit 232, and is also used for grounding. The capacitor C14 is used to receive and store the first control signal or the second control signal, and to output a locking signal based on the first control signal and / or the second control signal, thereby preventing the lower-level second control module 23 from starting prematurely when the first control module 22 / second control module 23 switches to the current second control module 23.

[0120] In another embodiment, when a photovoltaic input source 10 fails, to prevent that photovoltaic input source 10 from affecting other photovoltaic input sources, such as... Figure 2 As shown, the photovoltaic insulation detection fault location circuit 20 also includes at least two ground control modules 25;

[0121] The at least two ground control modules 25 are connected to the first control module 22 and at least one second control module 23 respectively, and the at least two ground control modules 25 are also connected to the detection module 21;

[0122] The at least two ground control modules 25 are used to receive control signals output by the corresponding connected first control module 22 or second control module 23, and start working based on the control signals so that the negative terminal of the corresponding photovoltaic input source 10 is connected to the detection module 21.

[0123] Specifically, when the first control module 22 or the second control module 23 operates, it outputs a control signal for a preset time to connect the corresponding photovoltaic input source 10 to the detection module 21. Simultaneously, the control signal is also input to the corresponding ground control module 25. Upon receiving the control signal, the ground control module 25 starts operating based on it, connecting the negative terminal of the connected photovoltaic input source 10 to the grounding terminal of the detection module 21 during operation. When the control signal disappears, the ground control module 25 stops operating, thus disconnecting the negative terminal of the photovoltaic input source 10 from the grounding terminal of the detection module 21. Based on this, when an insulation test is performed on a photovoltaic input source 10, the negative terminal of that photovoltaic input source 10 is connected to the detection module 21; the negative terminal of a photovoltaic input source 10 that is not undergoing insulation testing is not connected to the detection module 21, effectively avoiding the impact of a common ground and thus improving the reliability of the energy storage system 100.

[0124] In some embodiments, please refer to Figure 7 , Figure 7 This is a circuit diagram of a photovoltaic insulation detection fault location circuit provided in another embodiment of the present invention, combined with... Figures 6-7 The ground control module 25 includes a relay RLY3, a resistor R56, a resistor R59, and a switching transistor Q24;

[0125] The control terminal of the switching transistor Q24 is connected to the first control module 22 through the resistor R56. The control terminal of the switching transistor Q24 is also connected to the ground terminal of the detection module 21 through the resistor R59. The first terminal of the switching transistor Q24 is connected to the ground terminal of the detection module 21, and the second terminal of the switching transistor Q24 is connected to the coil terminal of the relay RLY3. The coil terminal of the relay RLY3 is also connected to the power supply. The connection terminals of the relay RLY3 are respectively connected to the negative terminal of the corresponding photovoltaic input source 10 and the ground terminal of the detection module 21.

[0126] Specifically, when the first control module 22 outputs the first control signal, the first control signal is also input to the control terminal of the switching transistor Q24 through the resistor R56, so that the switching transistor Q24 is turned on. When the switching transistor Q24 is turned on, the coil terminal of the relay RLY3 is energized, and at this time the relay RLY3 is closed, and the negative terminal of the photovoltaic input source 10 is connected to the ground terminal of the detection module 21.

[0127] It should be noted that the structure and working principle of each ground control module 25 are the same, so the structure and working principle of the ground control module 25 connected to at least one second control module 23 will not be described again here.

[0128] This invention provides a photovoltaic insulation detection fault location circuit, comprising a detection module, a first control module, at least one second control module, and at least two location modules. The first control module and at least one second control module are respectively connected to the detection module and a corresponding photovoltaic input source. The first control module is connected to each of the second control modules, and the first control module and at least one second control module are also connected to a location module. The at least two location modules are also connected to the detection module. The first control module and at least one second control module are used to sequentially output control signals for a preset time when the photovoltaic input source is connected, and control the connected photovoltaic input source to connect to the detection module within the duration of the control signals. Based on this, insulation detection of multiple photovoltaic input sources can be achieved using a single detection module, effectively saving circuit costs. When the detection module receives a drive signal, it detects the insulation impedance of the connected photovoltaic input source and outputs a fault signal when the insulation impedance is less than a preset range, thereby responding promptly to photovoltaic faults and improving circuit reliability. The positioning module is used to output an indication signal when it receives the control signal and the fault signal from the corresponding first control module or at least one second control module. This indicates that the connected photovoltaic input source is faulty. Based on this, the faulty photovoltaic input source can be accurately located, saving the time for troubleshooting, thereby reducing labor costs and improving operation and maintenance efficiency.

[0129] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; under the concept of the present invention, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of different aspects of the present invention as described above, which are not provided in detail for the sake of brevity; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A photovoltaic insulation detection fault location circuit, characterized in that, The photovoltaic insulation detection fault location circuit includes a detection module, a first control module, at least one second control module, and at least two location modules. The first control module and at least one second control module are respectively connected to the detection module and the corresponding photovoltaic input source. The first control module is connected to each of the second control modules. The first control module and at least one second control module are also connected to a corresponding positioning module. The at least two positioning modules are also connected to the detection module. Wherein, when the at least one second control module is multiple second control modules, the multiple second control modules are cascaded, one second control module is connected to all the upper-level second control modules, and the multiple second control modules are also connected to the first module; The first control module and at least one of the second control modules are both used to output control signals for a preset time in sequence when the photovoltaic input source is connected, and to control the connected photovoltaic input source to connect to the detection module during the duration of the control signal; The detection module is used to receive the drive signal and detect the insulation impedance of the connected photovoltaic input source based on the drive signal, and output a fault signal when the insulation impedance is less than a preset range. The positioning module is used to output an indication signal when it receives the control signal output by the corresponding first control module or at least one second control module and the fault signal, so as to indicate that the connected photovoltaic input source is faulty. The photovoltaic insulation detection fault location circuit also includes at least two ground control modules; The at least two ground control modules are connected to the first control module and at least one second control module respectively, and the at least two ground control modules are also connected to the detection module; The at least two ground control modules are used to receive control signals output by the corresponding connected first control module or second control module, and start working based on the control signals so that the negative terminal of the corresponding photovoltaic input source is connected to the detection module; The control signal includes a first control signal and a second control signal. The first control module is used to output a first control signal for a preset time when the photovoltaic input source is connected, and to control the connected photovoltaic input source to connect to the detection module during the duration of the first control signal; Each of the second control modules is configured to stop working when it receives a first control signal and a second control signal output by any of the upper-level second control modules; and when it does not receive the first control signal and the second control signal output by any of the upper-level second control modules, it responds to the connected photovoltaic input source by outputting a second control signal for a second preset time, and controls the connected photovoltaic input source to connect to the detection module during the duration of the output second control signal.

2. The photovoltaic insulation detection fault location circuit according to claim 1, characterized in that, The positioning module includes an AND gate U2B, a resistor R62, a resistor R63, a switch Q27, and a diode LED1; The first input terminal of the AND gate U2B is connected to the corresponding first control module, the second input terminal of the AND gate U2B is connected to the detection module, the output terminal of the AND gate U2B is connected to the control terminal of the switch Q27 through the resistor R62, the control terminal of the switch Q27 is also grounded through the resistor R63, the first terminal of the switch Q27 is connected to the cathode of the diode LED1, the second terminal of the switch Q27 is used for grounding, and the anode of the diode LED1 is connected to the first power supply.

3. The photovoltaic insulation detection fault location circuit according to claim 2, characterized in that, The ground control module includes a relay RLY3, a resistor R56, a resistor R59, and a switching transistor Q24; The control terminal of the switching transistor Q24 is connected to the first control module through the resistor R56. The control terminal of the switching transistor Q24 is also grounded through the resistor R59. The first terminal of the switching transistor Q24 is used for grounding. The second terminal of the switching transistor Q24 is connected to the coil terminal of the relay RLY3. The coil terminal of the relay RLY3 is also connected to the second power supply. The connection terminals of the relay RLY3 are respectively connected to the negative terminal and the ground terminal of the corresponding photovoltaic input source.

4. The photovoltaic insulation detection fault location circuit according to claim 1, characterized in that, The detection module includes relays RLY1 and RLY2, operational amplifier U1, resistors R1, R3, R7, R10, R12, R15, R17, and switching transistors Q1 and Q2. The coil terminal of relay RLY1 is connected to the second power supply and the first terminal of switching transistor Q1, respectively. The connection terminal of relay RLY1 is connected to resistors R3 and R7, respectively. The control terminal of switching transistor Q1 is connected to the controller. The second terminal of switching transistor Q1 is grounded. Resistor R3 is also connected to the first control module or at least one second control module through resistor R1. Resistor R3 is also connected to resistor R10. Resistor R10 is also connected to resistor R17 and the connection terminal of relay RLY2 through resistor R15, respectively. The connection terminal of relay RLY2 and resistor R17 are both grounded. The coil terminal of relay RLY2 is connected to the second power supply and the first terminal of switching transistor Q2, respectively. The control terminal of switching transistor Q2 is connected to the controller. The second terminal of switching transistor Q2 is also grounded. The first input terminal of operational amplifier U1 is connected to resistor R7. The second input terminal of operational amplifier U1 is also grounded through resistor R12. The output terminal of operational amplifier U1 is connected to the controller.

5. The photovoltaic insulation detection fault location circuit according to any one of claims 1-4, characterized in that, The first control module includes a first signal generation unit and a first switching unit; The first signal generation unit is connected to the first switching unit and the corresponding photovoltaic input source respectively; the first switching unit is connected to the detection module and the corresponding photovoltaic input source respectively; and the first signal generation unit is also connected to a plurality of second control modules. The first signal generation unit is used to receive and store the input voltage of the photovoltaic input source when the photovoltaic input source is connected, and output a first control signal based on the stored voltage; as well as The first control signal is stopped being output when the stored voltage is greater than the first preset value; The first switching unit is used to turn on based on the first control signal when it receives the first control signal, so as to connect the connected photovoltaic input source to the detection module; as well as The system shuts off when the first control signal is not received, thereby disconnecting the connected photovoltaic input source from the detection circuit of the detection module.

6. The photovoltaic insulation detection fault location circuit according to claim 5, characterized in that, The second control module includes a control unit, a second signal generation unit, and a second switching unit; The control unit is connected to the first signal generation unit and all the upper-level second control modules respectively. The control unit is also connected to the second signal generation unit and the corresponding photovoltaic input source respectively. The second signal generation unit is also connected to the second switching unit and all the lower-level second control modules respectively. The second switching unit is connected to the detection module and the corresponding photovoltaic input source respectively. The control unit is used to receive the first control signal and the second control signal output by any of the upper-level second control modules, and to start working when it receives the first control signal and / or the second control signal to stop transmitting the input voltage of the corresponding photovoltaic input source; as well as When neither the first control signal nor the second control signal is received, the input voltage of the corresponding photovoltaic input source is transmitted to the second signal generation unit. The second signal generation unit is used to receive and store the input voltage of the corresponding photovoltaic input source, and output a second control signal based on the stored voltage; as well as The output of the second control signal is stopped when the stored voltage is greater than the second preset value; The second switching unit is used to turn on based on the second control signal when it receives the second control signal, so as to connect the connected photovoltaic input source to the detection module; as well as The system shuts off when the second control signal is not received, thereby disconnecting the connected photovoltaic input source from the detection circuit of the detection module.

7. The photovoltaic insulation detection fault location circuit according to claim 6, characterized in that, The second control module also includes a delay unit; The delay unit is connected to the corresponding photovoltaic input source and the control unit respectively; The delay unit is used to receive the input voltage of the corresponding photovoltaic input source and input the input voltage to the control unit after delaying the input voltage by a target time.

8. An energy storage system, characterized in that, The energy storage system includes: Multiple photovoltaic input sources; and The photovoltaic insulation detection fault location circuit according to any one of claims 1-7 is connected to a plurality of photovoltaic input sources respectively.

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