Insulation detection control circuit and energy storage system

Abstract

The invention relates to the technical field of energy storage power supplies, and mainly provides an insulation detection control circuit and an energy storage system.The circuit comprises a detection module, a plurality of second control modules and a first control module, the first control module and each second control module are connected with a corresponding photovoltaic input source, and the plurality of second control modules are arranged in a cascade manner. The first control module is used for outputting a first control signal when a photovoltaic input source is connected, so that the detection module detects the insulation resistance of the photovoltaic input source; each second control module is used for stopping working when receiving the first control signal and a second control signal output by any superior; and outputting a second control signal when the first control signal and the second control signal are not received, so that the detection module detects the insulation resistance of the photovoltaic input source. On the basis, the insulation impedance of the corresponding photovoltaic input source is sequentially detected through the detection module, so that the cost is saved.

Description

Technical Field

[0001] This invention relates to the technical field of energy storage power supplies, and more particularly to an insulation detection and control circuit and an 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. 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. In actual product design, MCU I / O resources are often limited. Adding multiple control signals necessitates increasing the number of MCU pins, which directly leads to a significant increase in product cost. Furthermore, increasing the number of MCU pins complicates MCU resource configuration and increases the design difficulty of software control logic, causing numerous inconveniences for product development and production. Summary of the Invention

[0003] The present invention provides an insulation detection control circuit and an energy storage system, which aims to solve the technical problems of high cost and complex detection of insulation of photovoltaic input sources in the prior art.

[0004] To solve the above-mentioned technical problems, one technical solution adopted in the embodiments of the present invention is to provide an insulation detection and control circuit, the circuit including a detection module, a first control module and a plurality of second control 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. Multiple second control modules are cascaded. One second control module is connected to all the upper-level second control modules. Multiple second control modules are also connected to the first module. The first control module is used to output a first control signal for a first 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.

[0005] Optionally, 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 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 The first control signal is stopped being output when the stored voltage is greater than the first preset value; The first switching unit is configured to, upon receiving the first control signal, turn on based on the first control signal to connect the connected photovoltaic input source to the detection module; and 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.

[0006] Optionally, 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 configured to receive the first control signal and a second control signal output by any of the upper-level second control modules, and to begin operation upon receiving the first control signal and / or the second control signal to stop transmitting the input voltage of the corresponding photovoltaic input source; and 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; and 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 configured to, upon receiving the second control signal, turn on based on the second control signal to connect the connected photovoltaic input source to the detection module; and 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.

[0007] Optionally, the first switching unit includes a switching transistor Q3, a switching transistor Q9, a resistor R20, a resistor R22, and a resistor R30; The switching transistor Q9 is connected to the first signal generation unit 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. 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.

[0008] Optionally, the first signal generation unit includes a switch Q5, a resistor R25, a resistor R35, a diode D5, a capacitor C9, a capacitor C10, and a capacitor C11. The first terminal of the switching transistor Q5 is connected to the corresponding photovoltaic input source. 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 and multiple second control modules respectively.

[0009] Optionally, the second control module further 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.

[0010] Optionally, the control unit includes switching transistors Q6, Q8, and Q11, resistor R29, and resistor R32; The control terminal of the switch Q11 is connected to the first signal generation unit through the resistor R32. The first terminal of the switch Q11 is connected to the corresponding photovoltaic input source 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. The second terminal of the switch Q6 is connected to the second signal generation unit.

[0011] Optionally, the delay unit includes a capacitor C7 and a resistor R28; The first terminal of capacitor C7 is connected to the corresponding photovoltaic input source 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.

[0012] Optionally, the second control module further includes a locking unit; The locking unit is connected to the first control module and any of the upper-level second control modules respectively, and the locking unit is also connected to the lower-level second control module; 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 based on the first control signal and the second control signal, so as to control the lower-level second control module to continuously stop working.

[0013] 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: Multiple photovoltaic input sources; and The insulation detection and control circuit described above is connected to multiple photovoltaic input sources.

[0014] Unlike related technologies, this invention provides an insulation detection control circuit and an energy storage system. The circuit includes a detection module, a first control module, and multiple second control modules. The first control module and each of the second control modules are respectively connected to the detection module and a corresponding photovoltaic input source. The multiple second control modules are cascaded, with one second control module connected to all upper-level second control modules, and the multiple second control modules also connected to the first control module. The first control module outputs a first control signal for a first preset time when the photovoltaic input source is connected, and controls the connected photovoltaic input source to connect to the detection module during the duration of the first control signal, so that the detection module detects the insulation impedance of the corresponding connected photovoltaic input source within the first preset time. Each of the second control modules stops working when it receives the first control signal and a second control signal output by any upper-level second control module; and when it does not receive the first control signal and the second control signal output by any upper-level second control module, it outputs a second control signal for a second preset time in response to the connected photovoltaic input source, and controls the connected photovoltaic input source to connect to the detection module during the duration of the second control signal output, so that the detection module detects the insulation impedance of the photovoltaic input source corresponding to the second control module within the second preset time. Based on this, by sequentially inputting the input voltages of multiple photovoltaic input sources to the detection module, the detection module sequentially performs insulation impedance testing on the multiple photovoltaic input sources. This eliminates the need to configure multiple I / O ports to perform insulation testing on multiple photovoltaic sources, thereby saving costs. Attached Figure Description

[0015] 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.

[0016] Figure 1 This is a structural block diagram of an energy storage system provided in an embodiment of the present invention; Figure 2 This is a structural block diagram of an insulation detection and control circuit provided in an embodiment of the present invention; Figure 3 This is a structural block diagram of an insulation detection and control circuit provided in another embodiment of the present invention; Figure 4 This is a circuit diagram of an insulation detection and control circuit provided in an embodiment of the present invention; Figure 5 This is a circuit diagram of a detection module provided in an embodiment of the present invention; Figure 6 This is a circuit diagram of an insulation detection and control circuit provided in another embodiment of the present invention; Figure 7 This is a structural block diagram of an insulation detection and control circuit provided in another embodiment of the present invention; Figures 8a-8c This is a circuit diagram of an insulation detection and control circuit provided in another embodiment of the present invention. Detailed Implementation

[0017] 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.

[0018] 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 order than the module division in the device schematic diagram or the order in the flowchart.

[0019] 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.

[0020] 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 an insulation detection and control circuit 20, and all of the multiple photovoltaic input sources 10 are connected to the insulation detection and control circuit 20.

[0021] Specifically, the insulation detection control circuit 20 receives the input voltage from the photovoltaic input source 10 and starts operating based on the received input voltage to detect the insulation impedance of the corresponding connected photovoltaic input source 10. Based on this insulation impedance, it determines whether the corresponding photovoltaic input source 10 is operating safely. Therefore, when the insulation detection control circuit 20 is connected to multiple photovoltaic input sources 10, it can sequentially perform insulation detection on multiple photovoltaic input sources 10 to determine whether the current photovoltaic input source 10 is operating safely based on the detection results. This reduces detection costs while performing insulation detection on multiple photovoltaic input sources 10, thereby improving the safety of the energy storage system 100.

[0022] In some embodiments, please refer to Figure 2 , Figure 2 This is a structural block diagram of an insulation detection and control circuit provided in an embodiment of the present invention, as shown below. Figure 2 As shown, the insulation detection and control circuit 20 includes a detection module 21, a first control module 22, and multiple second control modules 23; The first control module 22 and each of the second control modules 23 are respectively connected to the detection module 21 and the corresponding photovoltaic input source 10. Multiple second control modules 23 are cascaded. One second control module 23 is connected to all the upper-level second control modules 23. Multiple second control modules 23 are also connected to the first module 22. The first control module 22 is used to output a first control signal for a first 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; 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.

[0023] 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 plurality of second control modules 23 are connected to the plurality of photovoltaic input sources 10 respectively, and the number of 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 insulation detection control circuit 20 includes a first control module 22 and four second control modules 23.

[0024] Based on this, when multiple photovoltaic input sources 10 are connected to the insulation detection and control 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 first preset time. After the first control module 22 outputs the first control signal for the first 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 photovoltaic input source 10 connected to the first control module 22 is operating stably; 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. The method to stop operation can be as follows: During the duration of the first control signal, the input terminal of the second control module 23 can be bypassed, so that the second control module 23 does not work, meaning it will not receive the input voltage from the connected photovoltaic input source 10, and correspondingly, the second control module 23 will not output the second control signal; alternatively, during the duration of the first control signal, the second control module 23 can be disconnected from the photovoltaic input source 10, thus preventing it from working. After the first control module 22 stops outputting the first control signal, it is considered that the detection of the photovoltaic input source 10 connected to the first control module 22 is complete. If the second control module 23 is also connected to the photovoltaic input source 10 at this time, 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, and output the second control signal for a second preset time.

[0025] 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 second 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.

[0026] 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 second 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, insulation detection of multiple photovoltaic input sources 10 can be performed sequentially using the first control module 22 and the plurality of second control modules 23, thereby reducing the cost and difficulty of insulation detection and improving the safety and stability of the energy storage system.

[0027] In some other embodiments, please refer to Figure 3 , Figure 3 This is a structural block diagram of an insulation detection and control circuit provided in another embodiment of the present invention, as shown below. Figure 3 As shown, the first control module 22 includes a first signal generation unit 221 and a first switching unit 222; 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. 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 The first control signal is stopped being output when the stored voltage is greater than the first preset value; The first switching unit 222 is configured to, upon receiving the first control signal, turn on based on the first control signal to connect the connected photovoltaic input source 10 to the detection module 21; and When the first control signal is not received, the circuit is turned off to disconnect the detection loop between the connected photovoltaic input source 10 and the detection module 21.

[0028] 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 first 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.

[0029] 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 first 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.

[0030] In some embodiments, please refer to Figure 4 , Figure 4 This is a circuit diagram of an insulation detection and control circuit provided in an embodiment of the present invention, such as... Figure 4 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. 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.

[0031] 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.

[0032] 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 first 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 transmitting the input voltage. At this time, the 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 the charging and discharging process is the first preset time. The charging time of capacitor C9 is the same as the conduction time of the switch Q5.

[0033] When capacitor C9 outputs a first control signal for a first 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 first preset time, capacitor C9 stops outputting 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.

[0034] It is known that when the photovoltaic input source 10 is disconnected from the first control module 22, the capacitor C10 will discharge through the resistor R35. Furthermore, when the voltage difference between the voltage stored in capacitor C10 and the voltage stored in capacitor C11 is greater than the forward voltage drop of diode D5, 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.

[0035] In some embodiments, such as Figure 4 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.

[0036] In some embodiments, the energy storage system 100 further includes a controller connected to the detection module 31. See also... Figure 5 , Figure 5This is a circuit diagram of a detection module provided in an embodiment of the present invention, such as... Figure 5 As shown, the detection module 21 includes relays RLY1 and RLY2, operational amplifier U1, resistors R1, R3, R7, R12, R10, R15, R17, and switching transistors Q1 and Q2. The coil terminal of relay RLY1 is connected to the power supply (+5V) 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 used to connect to the controller, and the second terminal of switching transistor Q1 is grounded. Resistor R3 is also connected to the first control module 22 or multiple second control modules 23 through resistor R1. Resistor R3 is also connected to resistor R15 through resistor R10. Resistor R15 is also connected to resistor R17 and the connection terminal of relay RLY2, respectively. The connection terminal of relay RLY2 and resistor R17 are both grounded. The coil terminal of relay RLY2 is connected to the power supply and the first terminal of switching transistor Q2, respectively. The control terminal of switching transistor Q2 is connected to the controller, and the second terminal of switching transistor Q2 is also grounded. The first input terminal of operational amplifier U1 is connected to resistor R7, and the second input terminal of operational amplifier U1 is grounded through resistor R12. The output of operational amplifier U1 is connected to the controller.

[0037] Specifically, when the first switching unit 222 is turned on, the detection module 21 connects to the photovoltaic input source 10 through the first switching unit 222. At this time, the controller outputs a first drive signal (RLY2 ISO) to control the switching transistor Q1 to turn on, so that the relay RLY1 closes. When the relay RLY1 closes, the resistors R1, R3, R10, 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.

[0038] In some embodiments, after the controller receives the first sampled value and the second sampled value, it can calculate the insulation impedance of the current photovoltaic input source 10 based on the first sampled value and the second sampled value. When the insulation impedance is less than a preset range, it determines that the corresponding photovoltaic input source 10 has failed, and the controller will output a fault signal. 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.

[0039] In some embodiments, such as Figure 3 As shown, the second control module 23 includes a control unit 231, a second signal generation unit 232, and a second switching unit 233; 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. The control unit 231 is used to receive the first control signal and a second control signal output by any of the upper-level second control modules 23, and to start working upon receiving the first control signal and / or the second control signal to stop transmitting the input voltage of the corresponding photovoltaic input source 10; and When the first control signal and the second control signal are not received, the input voltage of the corresponding photovoltaic input source 10 is transmitted to the second signal generation unit 232; 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 The output of the second control signal is stopped when the stored voltage is greater than the second preset value; The second switching unit 233 is configured to, upon receiving the second control signal, turn on based on the second control signal to connect the connected photovoltaic input source 10 to the detection module 21; and When the second control signal is not received, the circuit is turned off to disconnect the detection loop between the connected photovoltaic input source 10 and the detection module 21.

[0040] 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, thus 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 sequentially tested for insulation, thereby reducing both testing costs and testing difficulty.

[0041] 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 second 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 second preset time.

[0042] When the second signal generation unit 232 outputs a second control signal for a second preset time, on the one hand, the second control signal is input to the lower-level second control module 23, so that the lower-level second control module 23 stops 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.

[0043] In yet another embodiment, such as Figure 3 As shown, the second control module 23 also includes a delay unit 234; The delay unit 234 is connected to the corresponding photovoltaic input source 10 and the control unit 231 respectively; 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.

[0044] 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.

[0045] In some embodiments, such as Figure 4As 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. 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.

[0046] 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.

[0047] 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, causing the switch Q6 to turn off, thereby 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.

[0048] In some other embodiments, such as Figure 4As 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. 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.

[0049] 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.

[0050] 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.

[0051] In some embodiments, such as Figure 4 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.

[0052] In some embodiments, the first preset time and the second preset time may be the same time or different times. The first preset time and the second preset time can be adjusted by adjusting the capacitance values ​​of capacitors C8, C9, C16, etc.

[0053] 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). 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; 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.

[0054] 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 its stopped working state. Based on this, 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 can be 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.

[0055] In some embodiments, such as Figure 4 As shown, the locking unit is capacitor C14; 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.

[0056] In some embodiments, please refer to Figure 6 , Figure 6 This is a circuit diagram of an insulation detection and control circuit provided in another embodiment of the present invention, as shown below. Figure 6 As shown, taking three sets of photovoltaic input sources as an example, Figure 6 It includes a first control module 22 and two second control modules 23; When the first control module 22 and the two second control modules 23 are respectively connected to the three photovoltaic input sources 10, the capacitor C11 begins charging, the switch Q5 turns on according to the input voltage of PV1+, and simultaneously the capacitor C7 receives the input voltage of PV2+, and the capacitor C15 receives the input voltage of PV3+, to prevent the switches Q6 and Q13 from turning on. When the switch Q5 turns on, the input voltage of PV1+ is input to the capacitor C9 through the switch Q5 to charge the capacitor C9. As the voltage stored in the capacitor C11 gradually increases, the switch Q5 turns off, the capacitor C9 stops charging, and the first control signal is output based on the stored voltage. At this time, the first control signal is input to the switch Q9 to turn on the switch Q9, and the switch Q3 also turns on, so that the input voltage of PV1+ is transmitted to the detection module 21 through the switch Q3, thereby enabling the detection module 21 to detect the insulation resistance of PV1+. Secondly, the first control signal is input to the control terminal of switch Q11 to turn on switch Q11, and switch Q8 also turns on, thereby turning off switch Q6 and preventing the transmission of the PV2+ input voltage. Thirdly, the first control signal is input to capacitor C14 and switch Q17, so that capacitor C14 stores the first control signal while controlling switch Q13 to turn off. After a first preset time, capacitor C9 stops outputting the first control signal, switch Q9 turns off, and detection module 21 stops detecting the insulation resistance of PV1+. At the same time, switches Q11 and Q17 do not receive the first control signal, switch Q11 turns off, but at this time capacitor C14 begins to discharge, thereby keeping switch Q17 in a conducting state. When switch Q11 turns off, switch Q6 turns on, capacitor C13 begins to charge based on the PV2+ input voltage, and switch Q7 is also in a conducting state, thereby charging capacitor C8. After a second preset time, the voltage stored in capacitor C13 exceeds the second preset value, causing switch Q7 to turn off and capacitor C8 to begin discharging, thus outputting a second control signal for the second preset time. At this time, switches Q10 and Q4 are both turned on, allowing detection module 21 to detect the insulation resistance of PV2+. Simultaneously, switch Q17 receives the second control signal and turns on based on it, causing switch Q13 to turn off. After the second preset time, the second control signal disappears, switches Q17 and Q15 turn off, Q13 turns on, and Q14 turns off after the second preset time, outputting the second control signal, which in turn causes detection module 21 to detect the insulation resistance of PV3+. Based on this, insulation testing of the photovoltaic input source 10 can be performed sequentially, reducing testing costs while improving testing reliability.

[0057] It is understood that, since the energy storage system 100 includes multiple photovoltaic input sources 10, and these multiple photovoltaic input sources 10 sequentially pass through the detection module 21 for insulation resistance detection and input the detection results to the controller, when the detection module 21 sequentially detects multiple photovoltaic input sources 10 and inputs the detection results to the controller, if a photovoltaic input source 10 malfunctions, it may be impossible to accurately determine which photovoltaic input source 10 is faulty. This results in the inability to promptly address the faulty photovoltaic input source 10, thereby reducing the reliability and safety of the energy storage system. Based on this, please refer to... Figure 7 , Figure 7 This is a structural block diagram of an insulation detection and control circuit provided in another embodiment of the present invention, as shown below. Figure 7 As shown, taking two fault location modules 24 as an example, the insulation detection and control circuit 20 also includes at least two fault location modules 24; The at least two fault location modules 24 are respectively connected to the first control module 22 and a plurality of second control modules 23, and the at least two fault location modules 24 are also connected to the detection module 21; The fault location module 24 is used to output an indication signal when it receives the first control signal output by the corresponding first control module 22 or the second control signal output by the second control module 23 and the fault signal, so as to indicate that the connected photovoltaic input source 10 is faulty.

[0058] When the controller determines that the photovoltaic input source 10 has malfunctioned based on the first and second sampled values, the controller outputs a fault signal. At least two fault location modules 24 will also receive the fault signal. If a fault location module 24 receives a first control signal output by the first control module 22 or a second control signal output by the second control module 23, the corresponding fault location module 24 will output an indication signal based on the fault signal and the first / second control signal to indicate that the photovoltaic input source 10 corresponding to the first / second control module 22 has malfunctioned. Based on this, when a fault is detected in the photovoltaic input source 10, the faulty photovoltaic input source 10 can be quickly identified, thereby improving the safety and reliability of the energy storage system 100.

[0059] In some embodiments, please refer to Figures 8a-8c , Figures 8a-8c This is a circuit diagram of an insulation detection and control circuit provided in another embodiment of the present invention, as shown below. Figure 8a As shown, the fault location module 24 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 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.

[0060] When the first control module 22 outputs the first control signal, the first input terminal of the AND gate U2B receives the first control signal. At this time, if the controller does not output a fault signal (ISO Fault), the AND gate U2B outputs a low-level signal, the switch Q27 is turned off, and the diode LED1 does not indicate. If the controller outputs a fault signal, the AND gate U2B outputs a high-level signal, the switch Q27 is turned on, and the diode LED1 outputs an indicator signal.

[0061] It is understood that the state of the diode LED1 is only for distinguishing whether the current photovoltaic input source 10 is faulty, and 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.

[0062] In other embodiments, the fault location module 24 may also input the indication signal to the controller so that the controller indicates which photovoltaic input source 10 has failed.

[0063] 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 7 As shown, taking two ground control modules 25 as an example, the insulation detection and control circuit 20 also includes at least two ground control modules 25; The at least two ground control modules 25 are respectively connected to the first control module 22 and a plurality of second control modules 23, and the at least two ground control modules 25 are also connected to the detection module 21; The at least two ground control modules 25 are used to receive the first control signal output by the first control module 22 or the second control signal output by the second control module 23 connected to them, and start working based on the first control signal or the second control signal so that the negative terminal of the corresponding photovoltaic input source 10 is connected to the detection module 21.

[0064] In some embodiments, such as Figures 8b-8cAs shown, the ground control module 25 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 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.

[0065] 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 the relay RLY3 is closed, so that the negative terminal of the photovoltaic input source 10 is connected to the ground terminal of the detection module 21.

[0066] This invention provides an insulation detection control circuit, comprising a detection module, a first control module, and multiple second control modules. The first control module and each of the second control modules are respectively connected to the detection module and a corresponding photovoltaic input source. The multiple second control modules are cascaded, with one second control module connected to all upper-level second control modules, and the multiple second control modules also connected to the first module. The first control module outputs a first control signal for a first preset time when the photovoltaic input source is connected, and controls the connected photovoltaic input source to connect to the detection module during the duration of the first control signal, so that the detection module detects the insulation impedance of the corresponding connected photovoltaic input source within the first preset time. Each of the second control modules stops operating upon receiving the first control signal and a second control signal output by any upper-level second control module; and when neither the first control signal nor the second control signal output by any upper-level second control module is received, 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 second control signal output, thereby enabling the detection module to detect the insulation impedance of the photovoltaic input source corresponding to the second control module within the second preset time. Based on this, by sequentially inputting the input voltages of multiple photovoltaic input sources to the detection module, the detection module sequentially performs insulation impedance testing on the multiple photovoltaic input sources. This eliminates the need to configure multiple I / O ports to perform insulation testing on multiple photovoltaic sources, thereby saving costs.

[0067] 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. An insulation detection and control circuit, characterized in that, The circuit includes a detection module, a first control module, and multiple second control 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. Multiple second control modules are cascaded. One second control module is connected to all the upper-level second control modules. Multiple second control modules are also connected to the first module. The first control module is used to output a first control signal for a first 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 insulation detection and control circuit according to claim 1, 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.

3. The insulation detection and control circuit according to claim 2, 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.

4. The insulation detection and control circuit according to claim 2 or 3, characterized in that, The first switching unit includes a switching transistor Q3, a switching transistor Q9, a resistor R20, a resistor R22, and a resistor R30; The switching transistor Q9 is connected to the first signal generation unit 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. 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.

5. The insulation detection and control circuit according to claim 4, characterized in that, The first signal generation unit includes a switch Q5, a resistor R25, a resistor R35, a diode D5, a capacitor C9, a capacitor C10, and a capacitor C11; The first terminal of the switching transistor Q5 is connected to the corresponding photovoltaic input source. 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 and multiple second control modules respectively.

6. The insulation detection and control circuit according to claim 3, 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.

7. The insulation detection and control circuit according to claim 6, characterized in that, The control unit includes switching transistors Q6, Q8, and Q11, resistor R29, and resistor R32; The control terminal of the switch Q11 is connected to the first signal generation unit through the resistor R32. The first terminal of the switch Q11 is connected to the corresponding photovoltaic input source 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. The second terminal of the switch Q6 is connected to the second signal generation unit.

8. The insulation detection and control circuit according to claim 7, characterized in that, The delay unit includes a capacitor C7 and a resistor R28; The first terminal of capacitor C7 is connected to the corresponding photovoltaic input source 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.

9. The insulation detection and control circuit according to claim 3, characterized in that, The second control module also includes a locking unit; The locking unit is connected to the first control module and any of the upper-level second control modules respectively, and the locking unit is also connected to the lower-level second control module; 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 based on the first control signal and the second control signal, so as to control the lower-level second control module to continuously stop working.

10. An energy storage system, characterized in that, The energy storage system includes: Multiple photovoltaic input sources; and The insulation detection and control circuit according to any one of claims 1-9 is connected to the plurality of photovoltaic input sources respectively.

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