Residual current monitoring device and system

Abstract

This application relates to a residual current monitoring device and system. The residual current monitoring device is applied to a power supply system and includes a power supply module, a control module, and a detection module. The power supply module is connected to the control module, and the control module is connected to the detection module. The power supply module includes a Schottky diode; the first terminal of the Schottky diode is connected to the main power supply, the second terminal is connected to a backup power supply, and the third terminal is connected to the control module. The power supply module supplies power to the control module, and the detection module acquires residual current information of the power supply system and transmits this information to the control module. The control module monitors the residual current of the power supply system based on the residual current information. The residual current monitoring device provided in this application has higher reliability.

Description

Technical Field

[0001] This application relates to the field of power grid equipment technology, and in particular to a residual current monitoring device and system. Background Technology

[0002] Three-phase four-wire and three-phase five-wire hybrid power supply (TN-CS) systems are the mainstream grounding method in low-voltage distribution networks, and their safety is crucial for the stable operation of the power grid and the guarantee of power supply for users. However, with the large-scale integration of distributed energy resources, the diversification of load types, and the aggravation of equipment aging problems, it is necessary to accurately detect the residual current of TN-CS systems.

[0003] However, traditional current monitoring devices for TN-CS systems suffer from poor reliability when performing current monitoring. Summary of the Invention

[0004] Therefore, it is necessary to provide a residual current monitoring device and system that can improve the reliability of current monitoring.

[0005] In a first aspect, one embodiment of this application provides a residual current monitoring device applied to a power supply system, comprising: a power supply module, a control module, and a detection module, wherein the power supply module is connected to the control module, and the control module is connected to the detection module;

[0006] The power supply module includes a Schottky diode. The first terminal of the Schottky diode is connected to the main power supply, the second terminal of the Schottky diode is connected to the backup power supply, and the third terminal of the Schottky diode is connected to the control module.

[0007] The power supply module supplies power to the control module, the detection module acquires the residual current information of the power supply system and transmits the residual current information to the control module; the control module monitors the residual current of the power supply system based on the residual current information.

[0008] In one embodiment, the Schottky diode includes a first diode and a second diode, the anode of the first diode being connected to the main power supply and the cathode of the first diode being connected to the power supply module, the anode of the second diode being connected to the backup power supply and the cathode of the second diode being connected to the power supply module.

[0009] In one embodiment, the power supply module further includes a first power detection circuit;

[0010] The first power supply detection circuit includes: a first resistor, a second resistor, and a first Zener diode;

[0011] The first terminal of the first resistor is grounded, the second terminal of the first resistor is connected to the first terminal of the second resistor, the second terminal of the second resistor is connected to the anode of the first Zener diode, and the cathode of the first Zener diode is connected to the first terminal of the Schottky diode.

[0012] The control module is used to detect the power supply status of the main power supply based on the voltage signal between the first resistor and the second resistor.

[0013] In one embodiment, the power supply module further includes: a second power detection circuit, which is connected to the second terminal of a Schottky diode;

[0014] The second power supply detection circuit includes a second Zener diode, a light-emitting diode, and a third resistor. The anode of the second Zener diode is connected to the second terminal of the Schottky diode, the cathode of the second Zener diode is connected to the anode of the light-emitting diode, the cathode of the light-emitting diode is connected to the first terminal of the third resistor, and the second terminal of the third resistor is grounded.

[0015] In one embodiment, the power supply module further includes an undervoltage protection circuit and an overcurrent protection circuit;

[0016] The undervoltage protection circuit is connected to the backup power supply and is used to provide undervoltage protection for the backup power supply.

[0017] The overcurrent protection circuit is connected to the backup power supply and is used to provide overcurrent protection for the backup power supply.

[0018] In one embodiment, the undervoltage protection circuit includes: a first transistor, a fourth resistor, and a fifth resistor. The base of the first transistor is connected to a first terminal of the fourth resistor, the emitter of the first transistor is connected to the negative terminal of a backup power supply, the collector of the first transistor is connected to a second terminal of the fifth resistor, the second terminal of the fourth resistor is connected to the negative terminal of the backup power supply, the first terminal of the fifth resistor is connected to the first terminal of the fourth resistor, and the second terminal of the fifth resistor is connected to the positive terminal of the backup power supply.

[0019] In one embodiment, the power supply module further includes: a field-effect transistor, a third Zener diode, a sixth resistor, a second transistor, and a seventh resistor; the overcurrent protection circuit includes: a third transistor, an eighth resistor, and a ninth resistor.

[0020] The drain of the field-effect transistor is connected to the positive terminal of the backup power supply. The gate of the field-effect transistor is connected to the collector of the second transistor and the collector of the third transistor, as well as the first terminal of the sixth resistor. The second terminal of the sixth resistor is connected to the negative terminal of the backup power supply. The anode of the third Zener diode is connected to the gate of the field-effect transistor. The cathode of the third Zener diode is connected to the source of the field-effect transistor. The base of the second transistor is connected to the first terminal of the seventh resistor. The emitter of the second transistor is connected to the second terminal of the seventh resistor and the emitter of the third transistor. The second terminal of the seventh resistor is also connected to the second terminal of the Schottky diode.

[0021] The base of the third transistor is connected to the first end of the eighth resistor, the second end of the eighth resistor is connected to the first end of the ninth resistor and the source of the field-effect transistor, and the second end of the ninth resistor is connected to the emitter of the third transistor.

[0022] In one embodiment, the power supply module further includes a pulse charging circuit connected to a backup power supply for charging the backup power supply.

[0023] In one embodiment, the pulse charging circuit includes: a capacitor, a tenth resistor, an eleventh resistor, a twelfth resistor, a thirteenth resistor, a first Schmitt trigger, a second Schmitt trigger, a third diode, and a fourth transistor;

[0024] The first terminal of the capacitor is grounded. The second terminal of the capacitor is connected to the input terminal of the first Schmitt trigger, the first terminal of the tenth resistor, and the anode of the third diode. The cathode of the third diode is connected to the second terminal of the tenth resistor and the first terminal of the eleventh resistor. The second terminal of the eleventh resistor is connected to the output terminal of the first Schmitt trigger and the input terminal of the second Schmitt trigger. The output terminal of the second Schmitt trigger is connected to the first terminal of the twelfth resistor. The second terminal of the twelfth resistor is connected to the base of the fourth transistor. The emitter of the fourth transistor is grounded. The collector of the fourth transistor is connected to the first terminal of the thirteenth resistor. The second terminal of the thirteenth resistor is connected to the backup power supply.

[0025] Secondly, one embodiment of this application provides a residual current monitoring system, including a display device, an alarm device, an input device, a communication device, and the residual current monitoring device as described in the first aspect above; the display device, alarm device, and input device are communicatively connected to the control module in the residual current monitoring device through the communication device;

[0026] The control module is used to send a trigger signal to the alarm device when it detects that the residual current information exceeds a preset threshold, so as to trigger the alarm device to generate an alarm signal.

[0027] The control module is also used to transmit the residual current information to the display device so that the display device can display the residual current information;

[0028] An input device used to determine a preset threshold in response to user input.

[0029] This application provides a residual current monitoring device and system. The residual current monitoring device is applied to a power supply system and includes a power supply module, a control module, and a detection module. The power supply module is connected to the control module, and the control module is connected to the detection module. The power supply module includes a Schottky diode. The first terminal of the Schottky diode is connected to the main power supply, the second terminal is connected to the backup power supply, and the third terminal is connected to the control module. The power supply module supplies power to the control module. The detection module acquires residual current information of the power supply system and transmits this information to the control module. The control module monitors the residual current of the power supply system based on the residual current information. In this embodiment, the Schottky diode U8 has low power consumption and fast response, enabling rapid and stable switching between the main power supply and the backup power supply. This avoids shutdown or data loss of the residual current monitoring device due to power supply problems, ensuring a continuous and stable power supply to the control module, allowing the residual current monitoring device to operate normally, and thus improving the reliability of the residual current monitoring device. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of this application or the conventional technology, the drawings used in the description of the embodiments or the conventional technology will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 This is a schematic diagram of the residual current monitoring device in one embodiment of this application;

[0032] Figure 2 This is a schematic diagram of the structure of a Schottky diode in one embodiment of this application;

[0033] Figure 3 This is a schematic diagram of the residual current monitoring device in another embodiment of this application;

[0034] Figure 4 This is a schematic diagram of the residual current monitoring device in another embodiment of this application;

[0035] Figure 5 This is a schematic diagram of a pulse charging circuit in one embodiment of this application;

[0036] Figure 6 This is a schematic diagram of a voltage regulator circuit in one embodiment of this application;

[0037] Figure 7This is a schematic diagram of the residual current monitoring system in one embodiment of this application;

[0038] Figure 8 This is a schematic diagram of the CAN transmission isolation circuit in one embodiment of this application;

[0039] Figure 9 This is a schematic diagram of the CAN receiver isolation circuit in one embodiment of this application;

[0040] Figure 10 This is a schematic diagram of the CAN transceiver circuit in one embodiment of this application;

[0041] Figure 11 This is a schematic diagram of the structure of a liquid crystal display circuit in one embodiment of this application;

[0042] Figure 12 This is a schematic diagram of the structure of an LED display screen in one embodiment of this application;

[0043] Figure 13 This is a schematic diagram of the LED display control circuit in one embodiment of this application;

[0044] Figure 14 This is a schematic diagram of the buzzer circuit in one embodiment of this application;

[0045] Figure 15 This is a schematic diagram of the keyboard circuit in one embodiment of this application;

[0046] Figure 16 This is a schematic diagram of the interface circuit of a printing device in one embodiment of this application. Detailed Implementation

[0047] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings, which illustrate embodiments of the present application. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of this application will be thorough and complete.

[0048] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0049] It is understood that the terms "first," "second," etc., used herein may be used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish one element from another. For example, without departing from the scope of this application, a first resistor may be referred to as a second resistor, and similarly, a second resistor may be referred to as a first resistor. Both the first resistor and the second resistor are resistors, but they are not the same resistor.

[0050] It is understood that the term "connection" in the following embodiments should be understood as "electrical connection," "communication connection," etc., if the connected circuits, modules, units, etc., have electrical signal or data transmission with each other.

[0051] When used herein, the singular forms of “a,” “an,” and “the” may also include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprising / including” or “having,” etc., specify the presence of the stated features, wholes, steps, operations, components, parts, or combinations thereof, but do not preclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof. Meanwhile, the term “and / or” as used in this specification includes any and all combinations of the associated listed items.

[0052] First, before introducing the technical solutions of the embodiments disclosed in this application, the background technology or technological evolution of the embodiments of this application is introduced. In the field of power grid equipment technology, under the background of the country's explicit proposal to "improve the intelligent level of the distribution network and strengthen the governance of electrical safety hazards", the power industry urgently needs technological innovation. The three-phase four-wire and three-phase five-wire hybrid power supply (TN-CS) system is the mainstream grounding method in the low-voltage distribution network. Its safety is crucial to the stable operation of the power grid and the power supply guarantee for users. However, with the large-scale access of distributed energy, the diversification of load types and the aggravation of equipment aging problems, it is necessary to accurately detect the residual current of the TN-CS system. The existing TN-CS system has the following shortcomings in residual current monitoring: (1) The switching of the main and backup power supplies of the existing residual current monitoring equipment is not stable enough and there may be a certain delay when it is too long. Especially in emergency situations, whether the backup power supply can be switched quickly and whether it can work stably for a long time is a key factor affecting the reliability of the system. (2) When facing sudden electrical faults, the existing residual current monitoring equipment has a slow response speed and may not be able to provide real-time feedback and quickly locate the problem, resulting in the safety hazards not being eliminated in the shortest time. To address the aforementioned issues, this application provides a residual current monitoring device.

[0053] The technical solution of this application and how the technical solution of this application solves the technical problem are described in detail below with specific embodiments.

[0054] In one embodiment, such as Figure 1 As shown, a residual current monitoring device 10 is provided. The residual current monitoring device 10 can be applied to a power supply system, such as a TN-CS system, for detecting residual current in the power supply system. The residual current monitoring device 10 includes a power supply module 100, a control module 200, and a detection module 300. The power supply module 100 is connected to the control module 200, and the control module 200 is connected to the detection module 300.

[0055] The power supply module 100 includes a Schottky diode U8. The first end of the Schottky diode U8 is connected to the main power supply 20, the second end of the Schottky diode U8 is connected to the backup power supply 30, and the third end of the Schottky diode U8 is connected to the control module 200.

[0056] The power supply module 100 is used to supply power to the control module 200, and the detection module 300 is used to acquire residual current information and transmit the residual current information to the control module 200; the control module 200 is used to monitor the residual current based on the residual current information.

[0057] The main power supply 20 can be AC ​​power, specifically a +15V DC power supply. The backup power supply can be a battery, specifically a 12Ah lead-acid battery. The Schottky diode U8 includes a first terminal, a second terminal, and a third terminal. The first terminal of the Schottky diode U8 is electrically connected to the main power supply 20, the second terminal of the Schottky diode U8 is electrically connected to the backup power supply 30, and the third terminal of the Schottky diode U8 is electrically connected to the control module 200. It can be understood that the positive terminal of the main power supply 20 is electrically connected to the first terminal of the Schottky diode U8, the positive terminal of the backup power supply 30 is connected to the second terminal of the Schottky diode U8, and the negative terminals of both the main power supply 20 and the backup power supply 30 are grounded.

[0058] In an optional embodiment, the Schottky diode U8 can be an MBR2060 chip, i.e., a 20A / 60V common cathode dual Schottky diode.

[0059] The detection module 300 is installed in the power supply system. It can be understood that the detection module 300 includes multiple leakage current detectors, with a leakage current detector installed at each node (electrical connection point) in the power supply system. The detection module 300 can obtain the residual current information of the power supply system and transmit this information to the control module 200.

[0060] After receiving the residual current information sent by the detection module 300, the control module 200 will monitor the residual current of the power supply system based on this information. Understandably, the control module 200 compares the residual current value in the received residual current information with a preset threshold. If the residual current value is greater than or equal to the preset threshold, it indicates a safety hazard in the power supply system; if the residual current value is less than the preset threshold, it indicates that the power supply system is normal.

[0061] In an optional embodiment, the detection module 300 may further include a temperature detector, with a temperature detector installed at each node (electrical connection point) in the power supply system. The detection module 300 can acquire the temperature information of the TN-CS system and transmit this temperature information to the control module 200. It is understood that the control module 200 can directly monitor the residual current of the power supply system based on the received residual current information, or it can combine the received residual current information with the temperature information to perform residual current monitoring.

[0062] The residual current monitoring device 10 provided in this application embodiment is applied to a power supply system. The residual current monitoring device 10 includes a power supply module 100, a control module 200, and a detection module 300. The power supply module 100 is connected to the control module 200, and the control module 200 is connected to the detection module 300. The power supply module 100 includes a Schottky diode U8. The first terminal of the Schottky diode U8 is connected to the main power supply 20, the second terminal of the Schottky diode U8 is connected to the backup power supply 30, and the third terminal of the Schottky diode U8 is connected to the control module 200. The power supply module 100 is used to supply power to the control module 200. The detection module 300 is used to acquire the residual current information of the power supply system and transmit the residual current information to the control module 200. The control module 200 is used to monitor the residual current of the power supply system based on the residual current information. In this embodiment, the Schottky diode U8 has low power consumption and fast response, so the main power supply 20 and the backup power supply 30 can be switched quickly and stably through the Schottky diode U8, avoiding the shutdown or data loss of the residual current monitoring device 10 due to power supply problems. This ensures that the power supply module 100 can continuously and stably supply power to the control module 200, so that the residual current monitoring device 10 can work normally, thereby improving the reliability of the residual current monitoring device 10.

[0063] In addition, the residual current monitoring device 10 provided in this application embodiment can accurately measure the residual current in the power supply system in a complex electrical environment through the detection module 300, which can improve the accuracy and consistency of residual current monitoring, ensure that minute current anomalies can be detected in time, and enhance the early warning capability for safety hazards.

[0064] In one embodiment, such as Figure 2As shown, the Schottky diode U8 includes a first diode D1 and a second diode D2. The anode of the first diode D1 is connected to the main power supply 20, and the cathode of the first diode D1 is connected to the power supply module 100. The anode of the second diode D2 is connected to the backup power supply 30, and the cathode of the second diode D2 is connected to the power supply module 100.

[0065] The first terminal (PIN3) of the Schottky diode U8 is the anode of the first diode D1, the second terminal (PIN1) of the Schottky diode U8 is the anode of the second diode D2, and the third terminal (PIN2) of the Schottky diode U8 is the cathode of the first diode D1 and the cathode of the second diode D2.

[0066] When the first diode D1 in Schottky diode U8 is turned on, the +15V power supplied by the main power supply 20 reaches the power supply module 100 through the first diode D1, and the +12V power supplied by the backup power supply 30 reaches the anode of the second diode D2. The second diode D2 is reverse-biased and cut off, preventing the +12V current supplied by the backup power supply 30 from flowing through the second diode D2. At this time, the main power supply 20 supplies power to the power supply module 100. After the main power supply 20 stops supplying power, the voltage at the power supply module 100 becomes 0V, which is less than the voltage at the anode of the second diode D2 (the voltage supplied by the backup power supply 30, for example: +12V). At this time, the second diode D2 turns on, and the voltage at the power supply module 100 momentarily changes from 0V to 12V, achieving the purpose of switching from the main power supply 20 to the backup power supply 30. After the main power supply 20 resumes supplying power, the voltage at the anode of the first diode D1 (+15V) is greater than the voltage at the cathode of the second diode D2 (+12V). At this time, the first diode D1 turns on, and the second diode D2 momentarily cuts off, achieving the purpose of switching from the backup power supply 30 to the main power supply 20.

[0067] In this embodiment, the Schottky diode U8 includes a first diode D1 and a second diode D2. The anode of the first diode D1 is connected to the main power supply 20, the cathode of the second diode D2 is connected to the power supply module 100, the anode of the second diode D2 is connected to the backup power supply 30, and the cathode of the second diode D2 is connected to the power supply module 100. This Schottky diode U8 has a simple structure and low power consumption, and can realize the rapid switching between the main power supply 20 and the backup power supply 30, thereby improving the reliability of the residual current monitoring device.

[0068] In one embodiment, such as Figure 3 As shown, the power supply module 100 also includes a first power detection circuit 110. The first power detection circuit 110 is connected to the output terminal of the main power supply 20 and is used to detect the power supply status of the main power supply 20. That is, the first power detection circuit 110 can detect whether the main power supply 20 is currently in a power supply state or not.

[0069] The first power supply detection circuit 110 includes: a first resistor R1, a second resistor R2, and a first Zener diode D3.

[0070] The first end of the first resistor R1 is grounded, the second end of the first resistor R1 is connected to the first end of the second resistor R2, the second end of the second resistor R2 is connected to the anode of the first Zener diode D3, and the cathode of the first Zener diode D3 is connected to the first end of the Schottky diode U8.

[0071] The control module 200 is used to detect the power supply status of the main power supply 20 based on the voltage signal between the first resistor R1 and the second resistor R2.

[0072] The first resistor R1 includes a first terminal and a second terminal, and the second resistor R2 includes a first terminal and a second terminal. The first resistor R1, the second resistor R2, and the first Zener diode D3 are connected in series; that is, the second terminal of the first resistor R1 is electrically connected to the first terminal of the second resistor R2, and the second terminal of the second resistor R2 is electrically connected to the anode of the first Zener diode D3. The input voltage of the main power supply 20 is divided by the first Zener diode D3, the first resistor R1, and the second resistor R2. According to the voltage divider principle, the control module 200 obtains the voltage signal between the first resistor R1 and the second resistor R2 and determines the power supply state of the main power supply 20 based on this voltage signal.

[0073] In one specific embodiment, the resistance of the first resistor R1 is 5 ohms. The resistance of the second resistor R2 is 10. The first Zener diode D3 is 10V, and the voltage signal detected by the control module 200 can be expressed as: This voltage value corresponds to the high-level state in the Transistor-Transistor Logic (TTL) level standard. At this time, the main power supply 20 is supplying power normally, that is, the main power supply 20 is in the power supply state. If the voltage signal detected by the control module 200 is low-level (0V), it is determined that the main power supply 20 has failed or is interrupted, that is, the main power supply 20 is not in the power supply state.

[0074] In this embodiment, the power supply module 100 includes a first power detection circuit 110, which includes a first resistor R1, a second resistor R2, and a first Zener diode D3. The first end of the first resistor R1 is grounded, the second end of the first resistor R1 is connected to the first end of the second resistor R2, the second end of the second resistor R2 is connected to the anode of the first Zener diode D3, and the cathode of the first Zener diode D3 is connected to the first end of the Schottky diode U8. In this way, the control module 200 can determine whether the main power supply 20 is supplying power normally through the first power detection circuit 110. Furthermore, the electronic components included in the first power detection circuit 110 have a simple structure, are easy to obtain, and have a low cost.

[0075] In one embodiment, such as Figure 3 As shown, the power supply module 100 also includes a second power detection circuit 120, which is connected to the second terminal of the Schottky diode U8. The second power detection circuit 120 is connected to the backup power supply 30 and is used to detect the power supply status of the backup power supply 30. That is, the second power detection circuit 120 can detect whether the backup power supply 30 is currently in a power supply state or not.

[0076] The second power supply detection circuit 120 includes a second Zener diode D4, a light-emitting diode D5, and a third resistor R3. The anode of the second Zener diode D4 is connected to the second terminal of the Schottky diode U8, the cathode of the second Zener diode D4 is connected to the anode of the light-emitting diode D5, the cathode of the light-emitting diode D5 is connected to the first terminal of the third resistor R3, and the second terminal of the third resistor R3 is grounded.

[0077] The second Zener diode D4, the light-emitting diode D5, and the third resistor R3 are connected in series. That is, the cathode of the second Zener diode D4 is electrically connected to the anode of the light-emitting diode D5, and the cathode of the light-emitting diode D5 is electrically connected to the first end of the third resistor R3.

[0078] When the backup power supply 30 is supplying power normally, the second terminal of the Schottky diode U8 is at a high level, and the light-emitting diode D5 is lit. When the backup power supply 30 fails or the power supply is interrupted, the second terminal of the Schottky diode U8 is at a low level, and the light-emitting diode D5 is turned off.

[0079] In an optional embodiment, the control module 200 can determine whether the backup power supply 30 is in a power supply state based on whether the light-emitting diode D5 is lit or turned off.

[0080] In another optional embodiment, the control module 200 can determine whether the backup power supply 30 is in a power supply state by detecting the voltage signal at the second terminal of the Schottky diode U8. If the voltage signal at the second terminal of the Schottky diode U8 is high, it is determined that the backup power supply 30 is in a power supply state; if the voltage signal at the second terminal of the Schottky diode U8 is low, it is determined that the backup power supply 30 is not in a power supply state.

[0081] In this embodiment, the power supply module 100 further includes a second power detection circuit 120, which is connected to the second terminal of the Schottky diode U8. The second power detection circuit 120 includes a second Zener diode D4, a light-emitting diode D5, and a third resistor R3. The anode of the second Zener diode D4 is connected to the second terminal of the Schottky diode U8, the cathode of the second Zener diode D4 is connected to the anode of the light-emitting diode D5, the cathode of the light-emitting diode D5 is connected to the first terminal of the third resistor R3, and the second terminal of the third resistor R3 is grounded. In this way, the second power detection circuit 120 can determine whether the backup power supply 30 is supplying power normally. Furthermore, the electronic components included in the second power detection circuit 120 have a simple structure, are easy to obtain, and have a low cost.

[0082] In one embodiment, such as Figure 4 As shown, the power supply module 100 also includes an undervoltage protection circuit 130 and an overcurrent protection circuit 140; the undervoltage protection circuit 130 is connected to the backup power supply 30 and is used to provide undervoltage protection for the backup power supply 30; the overcurrent protection circuit 140 is connected to the backup power supply 30 and is used to provide overcurrent protection for the backup power supply 30.

[0083] The undervoltage protection circuit 130 is electrically connected to the backup power supply 30 and provides undervoltage protection to prevent the backup power supply 30 from being depleted due to continuous discharge, thus affecting its service life. The overcurrent protection circuit 140 is also electrically connected to the backup power supply 30 and provides overcurrent protection to prevent irreversible damage to the backup power supply 30 during charging. This embodiment does not limit the specific structure of the undervoltage protection circuit 130 and the overcurrent protection circuit 140, as long as their functions are achieved.

[0084] In one embodiment, such as Figure 4 As shown, the undervoltage protection circuit 130 includes: a first transistor U1, a fourth resistor R4 and a fifth resistor R5. The base of the first transistor U1 is connected to the first end of the fourth resistor R4, the emitter of the first transistor U1 is connected to the negative terminal (BT-) of the backup power supply 30, the collector of the first transistor U1 is connected to the second end of the fifth resistor R5, the second end of the fourth resistor R4 is connected to the negative terminal (BT-) of the backup power supply 30, and the first end of the fifth resistor R5 is connected to the first end of the fourth resistor R4.

[0085] The first transistor U1 is an NPN transistor, including a base, emitter, and collector. The fourth resistor R4 includes a first terminal and a second terminal, and the fifth resistor R5 includes a first terminal and a second terminal. The first terminal of the fourth resistor R4 and the first terminal of the fifth resistor R5 are electrically connected, and both are electrically connected to the base of the first transistor U1. The emitter of the first transistor U1 and the second terminal of the fourth resistor R4 are grounded and electrically connected to the negative terminal of the backup power supply 30. The collector of the first transistor U1 and the second terminal of the fifth resistor R5 are electrically connected.

[0086] In an optional embodiment, the power supply module 100 further includes a fourteenth resistor R14, a fifteenth resistor R15, a fourth diode D11, a fourth Zener diode D12, a fifth diode D13 and a sixth diode D14, as well as a relay J1 and a switch S2. The collector of the first transistor U1 is connected to the first end of the fourteenth resistor R14. The second end of the fourteenth resistor R14 is connected to the anode of the fourth diode D11 and the first end of the coil of the relay J1. The cathode of the fourth diode D11 is connected to the cathode of the fourth Zener diode D12 and the second end of the coil of the relay J1. The anode of the fourth Zener diode D12 is electrically connected to the second end of the fifth resistor R5. The contacts of the relay J1 are connected to the switch S2. The first end of the switch S2 is connected to the positive terminal (BT+) of the backup power supply 30. The second end of the switch S2 is connected to the anode of the fifth diode D13 and the cathode of the sixth diode D14. The cathode of the fifth diode D13 is electrically connected to the anode of the sixth diode D14 and the first end of the fifteenth resistor R15. The second end of the fifteenth resistor R15 is grounded.

[0087] Relay J1 enables the switching of the backup power supply 30 circuit, achieving electrical isolation. The fourteenth resistor, R14, limits the steady-state current of the relay J1 coil, preventing overcurrent damage to the first transistor U1. The fourth diode, D11, is a freewheeling diode used to address the reverse high voltage problem when the inductive load is disconnected; the fourth Zener diode, D12, absorbs voltage spikes and surge currents, reducing arcing when the relay J1 contacts break, and extending the lifespan of relay J1 and switch S2. The fifth diode, D13, and the sixth diode, D14, are bidirectional, preventing high voltage from flowing back into the backup power supply 30, thus protecting it. The fifteenth resistor, R15, is a pull-down / bleeder resistor, preventing the circuit from becoming energized and preventing false triggering.

[0088] When the voltage of the backup power supply 30 drops continuously due to prolonged power supply and falls to the preset undervoltage threshold, the first transistor U1 is cut off due to insufficient base voltage, the coil of relay J1 is de-energized, its contacts open, disconnecting the backup power supply 30 from the load (control module 200), and the backup power supply 30 stops supplying power, which can greatly extend the service life of the backup power supply 30.

[0089] In this embodiment, the undervoltage protection circuit 130 has a simple structure, and the electronic components therein are readily available and have low cost.

[0090] In one embodiment, such as Figure 4 As shown, the power supply module 100 also includes: a field-effect transistor Q22, a third Zener diode D6, a sixth resistor R6, a second transistor U2 and a seventh resistor R7, and the overcurrent protection circuit 140 includes: a third transistor U3, an eighth resistor R8 and a ninth resistor R9.

[0091] The drain of the field-effect transistor Q22 is connected to the positive terminal of the backup power supply 30. The gate of the field-effect transistor Q22 is connected to the collector of the second transistor U2 and the collector of the third transistor U3, as well as the first terminal of the sixth resistor R6. The second terminal of the sixth resistor R6 is connected to the negative terminal of the backup power supply 30 (i.e., grounded). The anode of the third Zener diode D6 is connected to the gate of the field-effect transistor Q22. The cathode of the third Zener diode D6 is connected to the source of the field-effect transistor Q22. The base of the second transistor U2 is connected to the first terminal of the seventh resistor R7. The emitter of the second transistor U2 is connected to the second terminal of the seventh resistor R7 and the emitter of the third transistor U3. The second terminal of the seventh resistor R7 is connected to the second terminal of the Schottky diode U8.

[0092] The base of the third transistor U3 is connected to the first end of the eighth resistor R8. The second end of the eighth resistor R8 is connected to the first end of the ninth resistor R9 and the source of the field-effect transistor Q22. The second end of the ninth resistor R9 is connected to the emitter of the third transistor U3.

[0093] When the current flowing to the backup power supply 30 exceeds the safety threshold, the voltage across the ninth resistor R9 increases significantly, driving the third transistor U3 to enter the conduction state. At this time, the third Zener diode D6 is short-circuited, and its voltage drops to 0V, causing the gate voltage of the field-effect transistor Q22 to fall below the threshold and switch from the conduction state to the cutoff state. This disconnects the charging circuit of the backup power supply 30, stopping the charging of the backup power supply 30, thereby achieving overcurrent protection.

[0094] In this embodiment, the overcurrent protection circuit 140 has a simple structure, and the electronic components therein are readily available and have low cost.

[0095] In an optional embodiment, the power supply module 100 further includes a seventh diode D15, a sixteenth resistor R16, and a fifth Zener diode D16. The anode of the seventh diode D15 is connected to the first terminal of the sixteenth resistor R16 and the drain of the field-effect transistor Q22. The second terminal of the sixteenth resistor R16 is connected to the anode of the fifth Zener diode D16, and the cathode of the fifth Zener diode D16 is connected to the first terminal of the seventh resistor R16. The sixteenth resistor R16 and the fifth Zener diode D16 are used to provide current-limiting protection for the second transistor U2. The seventh diode D15 prevents reverse current from damaging the field-effect transistor Q22.

[0096] In an optional embodiment, the power supply module 100 further includes a capacitor C21 disposed between BT+ and BT- of the backup power supply 30, and a resistor R77 and a capacitor C22 connected in parallel between the third terminal of the Schottky diode U8 and ground. The capacitor C21 is an input filter capacitor in the backup power supply 30, used to quickly provide instantaneous current when the load (control module 200) current changes abruptly, suppressing transient voltage drops in the backup power supply 30, and filtering out high-frequency ripple and electromagnetic interference in the power supply line. The parallel resistor R77 and capacitor C22 constitute an RC filter, which can filter out high-frequency noise in the output signal of the third terminal of the Schottky diode U8.

[0097] In one embodiment, such as Figure 5 As shown, the power supply module 100 also includes a pulse charging circuit 150, which is connected to the backup power supply 30 and is used to charge the backup power supply 30.

[0098] If a high-current direct charging method is used to charge the backup power supply 30, it will cause significant damage to the backup power supply 30, such as shortening its lifespan and reducing the actual power supply time. To address this, this embodiment uses a pulse charging circuit 150 to charge the backup power supply 30 with a specific current pulse waveform. This reduces the internal polarization effect of the backup power supply 30 and minimizes heat accumulation, thereby ensuring charging efficiency while reducing damage to the backup power supply 30.

[0099] In one embodiment, the pulse charging circuit 150 includes: a capacitor C23, a tenth resistor R10, an eleventh resistor R11, a twelfth resistor R12, a thirteenth resistor R13, a first Schmitt trigger U91, a second Schmitt trigger U92, a third diode D7, and a fourth transistor U4.

[0100] The first terminal of capacitor C23 is grounded. The second terminal of capacitor C23 is connected to the input terminal of the first Schmitt trigger U91, the first terminal of the tenth resistor R10, and the anode of the third diode D7. The cathode of the third diode D7 is connected to the second terminal of the tenth resistor R10 and the first terminal of the eleventh resistor R11. The second terminal of the eleventh resistor R11 is connected to the output terminal of the first Schmitt trigger U91 and the input terminal of the second Schmitt trigger U92. The output terminal of the second Schmitt trigger U92 is connected to the first terminal of the twelfth resistor R12. The second terminal of the twelfth resistor R12 is connected to the base of the fourth transistor U4. The emitter of the fourth transistor U4 is grounded. The collector of the fourth transistor U4 is connected to the first terminal of the thirteenth resistor R13. The second terminal of the thirteenth resistor R13 is connected to the backup power supply 30.

[0101] Both the first Schmitt trigger U91 and the second Schmitt trigger U92 are Schmitt inverters, each integrating six independent Schmitt trigger units. Their positive trigger voltage VT+ is set to 3.6V, and their negative trigger voltage VT- is set to 1.4V. The first Schmitt trigger U91 and the second Schmitt trigger U92 form a multivibrator circuit to generate a fundamental oscillation signal. Upon power-up, the voltage stored in capacitor C23 is 0V, and the first Schmitt trigger U91 outputs a high level. This charges capacitor C23 through resistors R10 and R11. When the input of the first Schmitt trigger U91 is VT+, it outputs a low level, and capacitor C23 discharges. When the capacitor discharges to VT-, it reverses direction and outputs a high level again, repeating this cycle to generate a square wave. Assume the charging time is T1, the discharging time is T2, and the period is: T = T1 + T2. , R 10 The resistance value of the tenth resistor R10 is 200. ), R 11 The resistance of the eleventh resistor, R11, is 5.1 ohms. C23 is the capacitance value of capacitor C23 (2.2). The charging cycle T = T1 + T2 = 0.183S + 0.005S = 188ms. When the output of the first Schmitt trigger U91 is high and the output of the second Schmitt trigger U92 is low, the fourth transistor U4 is cut off. The output of the pulse charging circuit 150 is connected to the seventh resistor R7 and the second transistor U2 in the power supply module 100. The second transistor U2 is cut off, and there is a 12V voltage difference across the third Zener diode D6. The turn-on voltage of the field-effect transistor Q22 is... The gate-source voltage that can be withstood is The gate-source current is .at this time When the field-effect transistor Q22 is turned on, current flows through Q22 to the backup power supply 30. The circuit path is through the ninth resistor R9, the field-effect transistor Q22, the seventh diode D15, and the sixth diode D14. When the output of the second Schmitt trigger U92 is high, the fourth transistor U4 and the second transistor U2 are turned on, the voltage of the third Zener diode D6 is 0, and the field-effect transistor Q22 is turned off, blocking the current path and stopping the charging of the backup power supply 30. With the reciprocating motion of the oscillation circuit, a pulsed power supply is formed.

[0102] In this embodiment, the pulse charging circuit 150 has a simple structure, and the electronic components therein are readily available and have low cost.

[0103] In an optional embodiment, the power supply module 100 further includes a voltage regulator circuit, the result of which is shown in the schematic diagram below. Figure 6 As shown, the voltage regulator circuit uses the LM2576 voltage regulator chip as the core control unit. This chip integrates a 52kHz fixed-frequency oscillator, thermal shutdown protection circuit, current limiting circuit, a 1.23V reference voltage source, and an internal voltage regulator module. Pin VIN of the LM2576 chip is connected to capacitor C24, with the other end of C24 grounded. Pins FB, RT, and GND are connected together to ground. Pin COMP is connected to diode D35 and inductor L2. Pin SW is connected to the other end of L2 and also to capacitor C25, one end of which is grounded. In the internal voltage regulator module, the negative terminal of the comparator is connected to the 1.23V reference voltage, and the positive terminal is connected to the voltage divider network. When the input voltage fluctuates, the output voltage of the voltage divider network is compared with the internal reference voltage. If a deviation exists, the error amplifier adjusts the output duty cycle of the internal oscillator, thereby regulating the output voltage to stabilize it at the set value. In addition, the LM2576 chip features a low-power mode and a normal operating mode, and integrates device protection functions such as thermal shutdown and current limiting, which can effectively cope with abnormal operating conditions such as overheating and overcurrent, meeting the power supply stability and reliability requirements of this design.

[0104] Please see Figure 7 One embodiment of this application provides a residual current monitoring system, including a display device 40, an alarm device 50, an input device 60, a communication device 70, and a residual current monitoring device 10 as provided in the above embodiment; the display device 40, alarm device 50, and input device 60 are communicatively connected to the control module 200 in the residual current monitoring device 10 through the communication device 70;

[0105] The control module 200 is used to send a trigger signal to the alarm device 50 when it detects that the residual current value in the residual current information exceeds a preset threshold, so as to trigger the alarm device to generate an alarm signal; the control module 200 is also used to transmit the residual current information to the display device 40 so that the display device 40 displays the residual current information; the input device 60 is used to determine the preset threshold in response to the user input operation.

[0106] After the control module 200 in the residual current monitoring device 10 obtains the residual current information in the power supply system, and determines that the residual current information exceeds a preset threshold, i.e., that there is a safety hazard in the power supply system, it sends a trigger signal to the alarm device 50. Upon receiving the trigger signal, the alarm device 50 generates an alarm signal. The alarm signal can be an alarm light, an alarm bell, or both. This embodiment does not limit the type of alarm signal generated by the alarm device 50, as long as it fulfills its function.

[0107] When the control module 200 determines that there is a safety hazard in the power supply system, it sends a trigger signal to the alarm device 50 and simultaneously sends residual current information to the display device 40 for display on the screen of the display device 40. The residual current information displayed on the display device 40 includes the address of the node in the power supply system with the safety hazard, the residual current value, and a preset threshold. The preset threshold displayed on the display device 40 can be input by the user into the control module 200 via the input device 60.

[0108] In an optional embodiment, the user can set the temperature threshold corresponding to the temperature sensor via the input device 60, and control the circuit breaker of the detection module 300 in the residual current monitoring device 10 to trip and disconnect the user's line. Simultaneously, the user can remotely reset the detection module 300 and silence the alarm device 50 via the input device 60.

[0109] In an optional embodiment, if the control module 200 determines that there are safety hazards in multiple nodes in the power supply system based on the received residual current monitoring device 10, the display device 40 will prioritize displaying the residual current information of the grounding where the safety hazard was most recently identified.

[0110] In an optional embodiment, the control module 200 can determine the alarm level based on the received residual current information and preset thresholds of different levels, and generate different trigger signals according to different alarm levels, sending them to the alarm device 50 to cause the alarm device 50 to generate alarm signals of different levels. Different levels of alarm signals can be distinguished by different colored lights or different ringtones.

[0111] This embodiment does not limit the specific structure of the display device 40, alarm device 50, input device 60, and communication device 70, as long as their functions can be realized.

[0112] In this embodiment, when the control module 200 detects that the residual current value in the residual current information exceeds a preset threshold, the alarm device 50 is immediately triggered to generate an alarm signal, and the display device 40 can display the residual current information in real time. This significantly shortens the time it takes for the user to locate the residual current value exceeding the preset threshold, improves the response speed, and effectively avoids safety hazards caused by information delays. Furthermore, the preset threshold can be remotely set via the input device, which greatly reduces the need for manual intervention, improves the intelligence level of the residual current monitoring system, reduces human error, and enhances the automated management capability of the residual current monitoring system.

[0113] In an optional embodiment, the communication device 70 is a Controller Area Network (CAN) device, including a CAN transmit isolation circuit, a CAN receive isolation circuit, a CAN transceiver circuit, and a CAN bus. The structure of the CAN transmit isolation circuit is as follows: Figure 8 As shown, the structure of the CAN receiver isolation circuit is as follows: Figure 9 As shown, the structure of the CAN transceiver circuit is as follows: Figure 10 As shown, the CAN transceiver circuit, as a key interface component between the control module 200 and the CAN bus, undertakes the core functions of signal conversion and transmission. Both the CAN transmit isolation circuit and the CAN receive isolation circuit adopt dual high-speed optocouplers 6N137 to construct an isolation protection system, which has strong anti-interference performance. Figure 8 TXCAN and RXCAN are the CAN communication ports of the control module 200, used for sending and receiving CAN frame data respectively. The CATHODE pin of the CAN receive isolation circuit is integrated into the RXD pin of the TJA1050 in the CAN transceiver circuit through resistor R20. The ENABLE / OUTPUA pin of the CAN transmit isolation circuit is integrated into the TXD pin of the TJA1050 in the CAN transceiver circuit through resistor R19. Physical isolation between the CAN bus and the back-end circuit is achieved through optocoupler principle, effectively blocking interference signals from the bus side from interfering with the normal operation of the back-end circuit. Independent power supply schemes are used on both sides of the optocoupler, avoiding the problem of a common ground loop existing when using a single power supply. Interference on the CAN bus can couple power to the front end of the optocoupler, causing isolation failure. In other words, complete decoupling of the CAN bus from the back-end circuit is achieved through electrical isolation technology.

[0114] The CAN transceiver circuit utilizes the TJA1050 as the CAN transceiver chip. This high-speed CAN transceiver strictly adheres to the ISO 11898 international standard, with a maximum data transmission rate of 1Mbps, meeting the demands of high-speed communication. The TJA1050 exhibits excellent electromagnetic compatibility (EMC) performance, with extremely low EME levels, effectively reducing the risk of interference to surrounding electronic equipment. Furthermore, its built-in differential receiver features a wide common-mode input range, significantly enhancing its ability to suppress electromagnetic interference (EMI) and ensuring the stability of communication signals. In addition, the TJA1050 supports low-power standby mode with extremely low standby current and integrates bus wake-up functionality and thermal protection mechanisms, extending system battery life and preventing device damage due to overheating. In the CAN transceiver circuit, the TXD and RXD pins of the TJA1050 are connected to the CAN communication ports TXCAN and RXCAN of the control module 200 via a 6N137 optocoupler isolation. The CANH and CANL pins of the TJA1050 are each connected in series with a resistor to the CAN bus, providing current limiting and protecting the TJA1050 from overcurrent surges. A 100pF capacitor, a diode, and a discharge tube are connected between CANH and ground, respectively. The capacitor filters high-frequency interference on the CAN bus and provides some electromagnetic radiation protection; the reverse-connected diode provides overvoltage protection when the CAN bus has a high negative voltage, and the discharge tube prevents instantaneous high-voltage interference on the CAN bus. A slope resistor is connected to the S pin of the TJA1050; its value can be adjusted according to the bus communication speed, typically around 16. -140 between.

[0115] In an optional embodiment, the display device 40 includes, as shown in the figure below. Figure 11 The schematic diagram of the liquid crystal display circuit shown is as follows: Figure 12 The schematic diagram of the LED display screen shown is as follows: Figure 13 The LED display control circuit shown is shown.

[0116] This LCD display circuit includes a 320×240 resolution LCD module. The core controller of this module is the ST7920, which employs a high-contrast display method with blue background and white text. It features a rich set of built-in control instructions, including screen clearing, cursor movement, and display displacement. These functions optimize the menu interface design and enhance the human-computer interaction experience. With these instructions, Chinese characters, ASCII characters, custom dot-matrix graphics, and user-defined characters can be displayed simultaneously on a single screen. The LCD module reserves 22 programmable pins for user-defined function development. The LCD-RS pin distinguishes between instruction writing and data transmission modes; LCD-RW (write operation) and LCD-RD (read operation) form a bidirectional data transmission interface; LCD-CS is the module chip select signal for multi-device addressing control; LCD-RES is the hardware reset pin, supporting system initialization; and LCD-DB0 to LCD-DB7 form an 8-bit parallel data bus, supporting single-byte data writing and effectively improving communication efficiency.

[0117] In residual current monitoring systems, LED displays serve multiple functions, primarily including indicating system status, providing alarm prompts, and assisting in the operation and maintenance of the residual current monitoring system. The specific functions of the LED display screen are as follows:

[0118] (1) Alarm. Red LED indicator: This indicator light will illuminate when an alarm signal is detected, and will turn off after "reset".

[0119] (2) Fault. Yellow LED indicator: This indicator light will illuminate when a fault occurs and will turn off after the fault is resolved.

[0120] (3) Mute. Green LED indicator: When the alarm device sounds an alarm, press the "Mute" button, the indicator light will illuminate, and the speaker will stop sounding. If a new alarm occurs, the mute indicator light will turn off, and the speaker will sound the alarm again.

[0121] (4) Main power. Green LED indicator: This indicator lights up when the main power is working.

[0122] (5) Backup power. Green LED indicator: This indicator light will illuminate when backup power is in operation.

[0123] (6) Control output. Green LED indicator: This indicator light will illuminate when the system is in operation.

[0124] (7) Main power failure. Yellow LED indicator: This indicator light will illuminate when there is a main power failure.

[0125] (8) Backup power failure. Yellow LED indicator: This indicator light will illuminate when the backup power supply fails.

[0126] (9) Shielding. Undefined function failure.

[0127] The LED display control circuit uses an 8-bit serial-input, parallel-output shift register 74HC164. It only requires two I / O ports on the microcontroller to drive eight LED indicators, significantly improving I / O resource utilization. The main function of the 74HC164 is to convert serial data into parallel data to drive the LED display. It is widely used in LED display control circuits, helping users quickly understand the real-time operating status of the monitoring terminal and promptly issue alarms for dangerous situations. The outputs of the 74HC164 (Q0 to Q7) can be directly connected to LED digital tubes or LED segment selection pins to control the on / off state of the LEDs.

[0128] In an optional embodiment, the alarm device 50 includes a buzzer, an indicator light, and a buzzer circuit. When the control module 200 detects that the residual current exceeds a preset threshold, the alarm device 50 generates an alarm signal. At this time, the buzzer in the alarm device 50 will continuously emit a high-frequency warning sound, and the indicator light will switch to a solid red state to visually alert the user to potential electrical safety risks. The alarm state will remain active until the user confirms and then deactivated. A schematic diagram of the buzzer circuit is shown below. Figure 14 As shown, after receiving an alarm signal (a square wave signal of fixed frequency), the alarm device 50 amplifies the power of the alarm signal through a buzzer circuit (power amplification unit) to drive the buzzer to sound. Specifically, the alarm signal is connected to the base of transistor Q4 through a current-limiting resistor R46. The conduction state of transistor Q4 is controlled by the LS port of the microcontroller in the alarm device 50, thereby realizing intelligent management of the entire buzzer circuit. Figure 13 The resistor R49 is a pull-down resistor to prevent the buzzer from ringing falsely.

[0129] In an optional embodiment, the input device 60 is a keyboard. A schematic diagram of the keyboard circuitry is shown below. Figure 15 As shown. Keyboard designs primarily include linear keyboards and matrix keyboards. To conserve I / O resources, this design uses a matrix keyboard with microswitches and software debouncing. The design utilizes four buttons: PUSH0, PUSH1, and PUSH2 are connected to RD3, RD4, and RD5 respectively. Pressing different buttons results in different code values ​​read from the corresponding PORTD port.

[0130] The truth table for the keyboard circuit keys is shown below:

[0131]

[0132] Please continue reading Figure 7In an optional embodiment, the residual current monitoring system further includes a printing device 80. The user can print the residual current information displayed on the display device as needed. A schematic diagram of the interface circuit of the printing device 80 is shown below. Figure 16 As shown, the thermal printhead integrates 384 heating units on its 48mm substrate, divided into 6 groups (STB1-STB6) with 64 units per group. During operation, the power supply module 100 provides a 7.6V (VH) drive voltage. Printing data is serially input to the shift register via pin DI under the synchronization of pin CLK. After 384 clock cycles of data loading, the CPU sets pin / LAT low to lock the data and then sets pin STB high to trigger heating. A data bit of "1" indicates that the heating unit is working, forming a dot matrix on the thermal paper. After each line is printed, a stepper motor advances the paper. For a 24×24 dot matrix Chinese character, 24 consecutive lines need to be printed, with a spacing of 1 dot between each line, ultimately forming a complete character. This circuit module achieves high-precision printing output through precise timing control and mechanical transmission.

[0133] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0134] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these modifications and improvements all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A residual current monitoring device, characterized in that, Applied to a power supply system, it includes: a power supply module, a control module, and a detection module, wherein the power supply module is connected to the control module, and the control module is connected to the detection module; The power supply module includes a Schottky diode, the first end of which is connected to the main power supply, the second end of which is connected to the backup power supply, and the third end of which is connected to the control module. The power supply module is used to supply power to the control module, and the detection module is used to acquire the residual current information of the power supply system and transmit the residual current information to the control module; the control module is used to monitor the residual current of the power supply system based on the residual current information.

2. The residual current monitoring device according to claim 1, characterized in that, The Schottky diode includes a first diode and a second diode. The anode of the first diode is connected to the main power supply, and the cathode of the first diode is connected to the power supply module. The anode of the second diode is connected to the backup power supply, and the cathode of the second diode is connected to the power supply module.

3. The residual current monitoring device according to claim 1 or 2, characterized in that, The power supply module also includes a first power detection circuit; The first power supply detection circuit includes: a first resistor, a second resistor, and a first Zener diode; The first terminal of the first resistor is grounded, the second terminal of the first resistor is connected to the first terminal of the second resistor, the second terminal of the second resistor is connected to the anode of the first Zener diode, and the cathode of the first Zener diode is connected to the first terminal of the Schottky diode. The control module is used to detect the power supply status of the main power supply based on the voltage signal between the first resistor and the second resistor.

4. The residual current monitoring device according to claim 1 or 2, characterized in that, The power supply module further includes: a second power detection circuit, which is connected to the second terminal of the Schottky diode; The second power supply detection circuit includes a second Zener diode, a light-emitting diode, and a third resistor. The anode of the second Zener diode is connected to the second terminal of the Schottky diode, the cathode of the second Zener diode is connected to the anode of the light-emitting diode, the cathode of the light-emitting diode is connected to the first terminal of the third resistor, and the second terminal of the third resistor is grounded.

5. The residual current monitoring device according to claim 1 or 2, characterized in that, The power supply module also includes an undervoltage protection circuit and an overcurrent protection circuit; The undervoltage protection circuit is connected to the backup power supply and is used to provide undervoltage protection for the backup power supply. The overcurrent protection circuit is connected to the backup power supply and is used to provide overcurrent protection for the backup power supply.

6. The residual current monitoring device according to claim 5, characterized in that, The undervoltage protection circuit includes a first transistor, a fourth resistor, and a fifth resistor. The base of the first transistor is connected to the first end of the fourth resistor, the emitter of the first transistor is connected to the negative terminal of the backup power supply, the collector of the first transistor is connected to the second end of the fifth resistor, the second end of the fourth resistor is connected to the negative terminal of the backup power supply, the first end of the fifth resistor is connected to the first end of the fourth resistor, and the second end of the fifth resistor is connected to the positive terminal of the backup power supply.

7. The residual current monitoring device according to claim 5, characterized in that, The power supply module also includes: a field-effect transistor, a third Zener diode, a sixth resistor, a second transistor, and a seventh resistor; the overcurrent protection circuit includes: a third transistor, an eighth resistor, and a ninth resistor. The drain of the field-effect transistor is connected to the positive terminal of the backup power supply. The gate of the field-effect transistor is connected to the collector of the second transistor and the collector of the third transistor, as well as the first terminal of the sixth resistor. The second terminal of the sixth resistor is connected to the negative terminal of the backup power supply. The anode of the third Zener diode is connected to the gate of the field-effect transistor. The cathode of the third Zener diode is connected to the source of the field-effect transistor. The base of the second transistor is connected to the first terminal of the seventh resistor. The emitter of the second transistor is connected to the second terminal of the seventh resistor and the emitter of the third transistor. The second terminal of the seventh resistor is also connected to the second terminal of the Schottky diode. The base of the third transistor is connected to the first end of the eighth resistor, the second end of the eighth resistor is connected to the first end of the ninth resistor and the source of the field-effect transistor, and the second end of the ninth resistor is connected to the emitter of the third transistor.

8. The residual current monitoring device according to claim 1 or 2, characterized in that, The power supply module also includes a pulse charging circuit, which is connected to the backup power supply and is used to charge the backup power supply.

9. The residual current monitoring device according to claim 8, characterized in that, The pulse charging circuit includes: a capacitor, a tenth resistor, an eleventh resistor, a twelfth resistor, a thirteenth resistor, a first Schmitt trigger, a second Schmitt trigger, a third diode, and a fourth transistor; The first terminal of the capacitor is grounded. The second terminal of the capacitor is connected to the input terminal of the first Schmitt trigger, the first terminal of the tenth resistor, and the anode of the third diode. The cathode of the third diode is connected to the second terminal of the tenth resistor and the first terminal of the eleventh resistor. The second terminal of the eleventh resistor is connected to the output terminal of the first Schmitt trigger and the input terminal of the second Schmitt trigger. The output terminal of the second Schmitt trigger is connected to the first terminal of the twelfth resistor. The second terminal of the twelfth resistor is connected to the base of the fourth transistor. The emitter of the fourth transistor is grounded. The collector of the fourth transistor is connected to the first terminal of the thirteenth resistor. The second terminal of the thirteenth resistor is connected to the backup power supply.

10. A residual current monitoring system, characterized in that, It includes a display device, an alarm device, an input device, a communication device, and a residual current monitoring device according to any one of claims 1-9; the display device, the alarm device, and the input device are communicatively connected to the control module in the residual current monitoring device through the communication device; The control module is used to send a trigger signal to the alarm device when it detects that the residual current information exceeds a preset threshold, so as to trigger the alarm device to generate an alarm signal. The control module is further configured to transmit the remaining current information to the display device so that the display device displays the remaining current information; The input device is used to determine the preset threshold in response to user input.

Images