Power transmission line electric leakage detection system for power system

Abstract

The invention discloses a power transmission line electric leakage detection system for a power system, and relates to the technical field of power systems, and the power transmission line electric leakage detection system for the power system comprises a power supply control module, an output module, an electric leakage detection module, a temperature detection module, a timing module, a temperature difference detection module, a self-detection control module, and an abnormity judgment module. Through cooperative work of all the modules, an electric leakage signal can be automatically generated to detect whether the electric leakage detection module is abnormal or not, and when the electric leakage detection module is normal, the electric leakage detection module is reset, and when the electric leakage detection module is abnormal, electric leakage abnormity display is carried out, so that on the premise that manual participation is not needed, the electric leakage detection efficiency is greatly improved. According to the invention, electric leakage self-detection control is carried out in time, and the problems that when electric leakage self-detection control is carried out, manual control is needed, certain manpower resources need to be consumed, electric leakage self-detection control cannot be carried out in time, and certain potential safety hazards still exist when electric leakage detection is carried out are solved.

Description

Technical Field

[0001] This application relates to the field of power system technology, and in particular to a power system transmission line leakage detection system. Background Technology

[0002] In power systems, transmission lines are an indispensable component, playing a crucial role in power transmission. However, in daily operation, transmission lines are often subject to external conditions such as extreme weather and human-caused damage, which can potentially damage them and jeopardize the normal operation of the power system. To improve the safety of the power system, leakage current detection is performed on transmission lines. Related technologies for power system transmission line leakage current detection systems generally employ leakage current detection devices to detect leaks and provide leakage protection when they occur. Simultaneously, these leakage current detection devices can be self-controlled by relevant personnel (i.e., determining whether the leakage current detection device is abnormal and resetting it) to improve power system safety. However, leakage current self-control requires manual intervention, which not only consumes manpower but also cannot be performed in a timely manner, resulting in certain safety hazards during leakage current detection. Summary of the Invention

[0003] The purpose of this application is to provide a leakage current detection system for power transmission lines, which can perform timely self-detection and control of leakage current without human intervention.

[0004] To achieve the above objectives, this application provides the following solution:

[0005] In a first aspect, this application provides a power system transmission line leakage current detection system, the power system transmission line leakage current detection system comprising:

[0006] The power control module is used to receive AC power and perform step-down, rectification, filtering and voltage regulation on the AC power to obtain DC power, and output AC power and DC power.

[0007] The output module, connected to the power control module, is used to receive AC power and supply power to electrical equipment.

[0008] The leakage current detection module is connected to the power control module. It is used to receive DC power and detect leakage current in AC power. When leakage current occurs, it outputs a first protection signal to control the power control module to stop outputting AC power.

[0009] The temperature detection module is connected to the power control module. It is used to receive DC power and detect the temperature of DC power to obtain a temperature signal. When the temperature signal is greater than the temperature threshold, it outputs a first control signal. When the temperature signal is greater than the over-temperature threshold, it outputs a second protection signal to control the power control module to stop outputting AC power.

[0010] The timing module, connected to the power control module and the temperature detection module, is used to receive DC power and continuously output the second control signal when the first control signal is received, until the timing time is reached, at which point the output of the second control signal stops.

[0011] The temperature difference detection module, connected to the temperature detection module, is used to calculate the difference between the temperature signal and the temperature threshold when the first control signal is received, to obtain the temperature difference signal, and to output the third control signal when the temperature difference signal is greater than the temperature difference threshold.

[0012] The self-test control module, connected to the timing module and the temperature difference detection module, is used to output a self-test signal when simultaneously receiving the second control signal and the third control signal, so as to receive AC power and generate a leakage current signal. The power control module and the leakage current detection module are also connected to the self-test control module. The power control module is used to stop receiving the first protection signal when it receives the self-test signal. The leakage current detection module is used to output the first protection signal if it is normal when it receives the leakage current signal, and not output the first protection signal if it is abnormal.

[0013] The anomaly detection module, connected to the leakage current detection module and the self-test control module, is used to display leakage current anomalies when a self-test signal is received but a first protection signal is not received, and to output a reset signal when the first protection signal is received and the self-test signal is stopped. The leakage current detection module is also used to stop receiving DC power and output the first protection signal when the reset signal is received.

[0014] Optionally, the power control module includes: a power interface, a transformer, a rectifier, a capacitor, a Zener diode, a relay switch, a relay, a second diode, a third diode, and a second switching transistor;

[0015] The input terminal of the power interface is connected to the output terminal of the AC power supply. The first output terminal of the power interface is connected to the first terminal of the primary winding of the transformer and the first moving terminal of the relay switch. The second output terminal of the power interface is connected to the second terminal of the primary winding of the transformer and the second moving terminal of the relay switch. The first terminal of the secondary winding of the transformer is connected to the first input terminal of the rectifier. The second terminal of the secondary winding of the transformer is connected to the second input terminal of the rectifier. The first output terminal of the rectifier serves as the DC output terminal of the power control module. The first output terminal of the rectifier is connected to the first terminal of the capacitor and the cathode of the Zener diode. The second output terminal of the rectifier... The first terminal of the capacitor, the second terminal of the Zener diode, and the anode of the Zener diode are all grounded. The first stationary terminal of the relay switch serves as the first AC output terminal of the power control module, and the second stationary terminal of the relay switch serves as the second AC output terminal of the power control module. The control terminal of the relay serves as the temperature control terminal of the power control module. The control terminal of the relay is connected to the cathode of the third diode. The anode of the third diode is connected to the cathode of the second diode and the collector of the second switching transistor. The anode of the second diode serves as the leakage control terminal of the power control module. The emitter of the second switching transistor is grounded, and the base of the second switching transistor serves as the self-test control terminal of the power control module.

[0016] Optionally, the output module includes an output port;

[0017] The first input terminal of the output port serves as the first input terminal of the output module and is connected to the first AC output terminal of the power control module. The second input terminal of the output port serves as the second input terminal of the output module and is connected to the second AC output terminal of the power control module. The output terminal of the output port is connected to the input terminal of the electrical equipment.

[0018] Optionally, the leakage current detection module includes: a current transformer, a leakage current detection device, a first power transistor, a second resistor, and a first switching transistor;

[0019] The current transformer is installed on the connection line between the power control module and the output module, with the connection line passing through the current transformer. The connection line includes a power transmission line connecting the first AC output terminal of the power control module and the first input terminal of the output module, and a power transmission line connecting the second AC output terminal of the power control module and the second input terminal of the output module. The first output terminal of the current transformer is connected to the first input terminal of the leakage current detection device, and the second output terminal of the current transformer is connected to the second input terminal of the leakage current detection device. The power supply terminal of the leakage current detection device is connected to the source of the first power transistor. The output terminal of the leakage current detection device serves as the signal output terminal of the leakage current detection module and is connected to the leakage control terminal of the power control module. The drain of the first power transistor is connected to the DC output terminal of the power control module and the first terminal of the second resistor, respectively. The gate of the first power transistor is connected to the second terminal of the second resistor and the collector of the first switching transistor, respectively. The emitter of the first switching transistor is grounded, and the base of the first switching transistor serves as the reset control terminal of the leakage current detection module.

[0020] Optionally, the temperature detection module includes: a thermistor, a comparator, a voltage threshold device, a first resistor, a fifth resistor, a fourth diode, and a fifth diode;

[0021] The first terminal of the thermistor is connected to the DC output terminal of the power control module. The second terminal of the thermistor serves as the temperature signal output terminal of the temperature detection module. The second terminal of the thermistor is connected to the non-inverting input terminal of the comparator, the first terminal of the first resistor, and the first terminal of the fifth resistor. The inverting input terminal of the comparator is connected to the output terminal of the voltage threshold device, which provides the temperature threshold. The output terminal of the voltage threshold device serves as the threshold output terminal of the temperature detection module. The output terminal of the comparator serves as the control signal output terminal of the temperature detection module. The second terminal of the first resistor is grounded. The second terminal of the fifth resistor is connected to the cathode of the fourth diode. The anode of the fourth diode is connected to the anode of the fifth diode. The cathode of the fifth diode is connected to the temperature control terminal of the power control module.

[0022] Optionally, the timing module includes: a second power transistor and a timing control device;

[0023] The drain of the second power transistor is connected to the DC output terminal of the power control module, the gate of the second power transistor is connected to the control signal output terminal of the temperature detection module, the source of the second power transistor is connected to the input terminal of the timing control device, and the output terminal of the timing control device serves as the control signal output terminal of the timing module.

[0024] Optionally, the temperature difference detection module includes: an analog switch, a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, a tenth resistor, an operational amplifier, and a sixth diode;

[0025] Both CTRL1 and CTRL2 terminals of the analog switch are connected to the control signal output terminals of the temperature detection module. The IN1 terminal of the analog switch is connected to the threshold output terminal of the temperature detection module. The IN2 terminal of the analog switch is connected to the temperature signal output terminal of the temperature detection module. The OUT1 terminal of the analog switch is connected to the first terminal of the sixth resistor. The OUT2 terminal of the analog switch is connected to the first terminal of the seventh resistor. The second terminal of the sixth resistor is connected to the first terminal of the ninth resistor and the inverting input terminal of the operational amplifier. The second terminal of the seventh resistor is connected to the first terminal of the eighth resistor and the non-inverting input terminal of the operational amplifier. The second terminal of the eighth resistor is grounded. The second terminal of the ninth resistor is connected to the first terminal of the tenth resistor and the output terminal of the operational amplifier. The second terminal of the tenth resistor is connected to the cathode of the sixth diode. The anode of the sixth diode serves as the control signal output terminal of the temperature difference detection module.

[0026] Optionally, the self-test control module includes: a first logic chip, an optocoupler, and a third resistor;

[0027] The A terminal of the first logic chip is connected to the control signal output terminal of the temperature difference detection module, the B terminal of the first logic chip is connected to the control signal output terminal of the timing module, the Y terminal of the first logic chip serves as the signal output terminal of the self-test control module, the Y terminal of the first logic chip is connected to the self-test control terminal of the power control module and the first terminal of the optocoupler, the second terminal of the optocoupler is grounded, the third terminal of the optocoupler is connected to the first terminal of the third resistor, the fourth terminal of the optocoupler is connected to the second AC output terminal of the power control module, and the second terminal of the third resistor is connected to the first AC output terminal of the power control module.

[0028] The first logic chip is an AND gate chip.

[0029] Optionally, the anomaly detection module includes: a first inverter, a second inverter, a second logic chip, a third logic chip, a fourth logic chip, a first diode, a seventh diode, a fourth resistor, and an indicator light;

[0030] The input terminals of the first inverter are connected to the signal output terminal of the leakage current detection module and the B terminal of the second logic chip, respectively. The output terminal of the first inverter is connected to the A terminal of the third logic chip. The input terminal of the second inverter is connected to the signal output terminal of the self-test control module and the output terminal of the second inverter is connected to the A terminal of the fourth logic chip. The A terminal of the second logic chip is connected to the cathode of the first diode and the cathode of the seventh diode, respectively. The Y terminal of the second logic chip is connected to the B terminal of the fourth logic chip and the anode of the first diode, respectively. The B terminal of the third logic chip is connected to the signal output terminal of the self-test control module. The Y terminal of the third logic chip is connected to the first terminal of the fourth resistor. The Y terminal of the fourth logic chip is connected to the reset control terminal of the leakage current detection module. The anode of the seventh diode is connected to the signal output terminal of the self-test control module. The second terminal of the fourth resistor is connected to the anode of the indicator light, and the cathode of the indicator light is grounded.

[0031] Among them, the first inverter and the second inverter are both NOT gate chips, and the second logic chip, the third logic chip and the fourth logic chip are all AND gate chips.

[0032] Optionally, the leakage current detection device in the leakage current detection module uses the VG54123 chip, and the timing control device in the timing module uses the NE555 chip.

[0033] According to the specific embodiments provided in this application, this application has the following technical effects:

[0034] This application provides a leakage current detection system for power transmission lines. A temperature detection module detects the temperature of the DC power supplied by the power transmission line, obtaining a temperature signal. When the temperature signal exceeds a temperature threshold, a first control signal is output. A timing module continuously outputs a second control signal upon receiving the first control signal until a set time is reached, at which point the output of the second control signal stops. A temperature difference detection module calculates the difference between the temperature signal and the temperature threshold upon receiving the first control signal, obtaining a temperature difference signal. When the temperature difference signal exceeds the temperature difference threshold, a third control signal is output. A self-test control module outputs a self-test signal upon simultaneously receiving both the second and third control signals, in order to receive AC power. It generates a leakage current signal. When the leakage current detection module receives a leakage current signal, it outputs a first protection signal if the leakage current detection module is normal, and does not output a first protection signal if the leakage current detection module is abnormal. The abnormality judgment module displays a leakage current abnormality when it receives a self-test signal but does not receive the first protection signal, and outputs a reset signal when it receives the first protection signal and stops receiving self-test signals. It can automatically generate a self-test signal based on temperature, and further generate a leakage current signal to detect whether the leakage current detection module is abnormal. When the leakage current detection module is normal, it resets the leakage current detection module. When the leakage current detection module is abnormal, it displays a leakage current abnormality. Thus, leakage current self-detection and control can be performed in a timely manner without manual intervention. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments 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.

[0036] Figure 1 This is a schematic diagram of a power system transmission line leakage detection system provided in Embodiment 1 of this application.

[0037] Figure 2 This is a circuit diagram of a power system transmission line leakage detection system provided in Embodiment 1 of this application.

[0038] Figure 3 This is a circuit diagram of the timing module provided in Embodiment 1 of this application.

[0039] Figure 4 This is a circuit diagram of the temperature difference detection module provided in Embodiment 1 of this application.

[0040] Figure label:

[0041] 1-Power control module; 2-Output module; 3-Leakage detection module; 4-Temperature detection module; 5-Timing module; 6-Temperature difference detection module; 7-Self-test control module; 8-Abnormal judgment module. Detailed Implementation

[0042] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0043] Example 1

[0044] This embodiment provides a power system transmission line leakage detection system, such as... Figure 1 As shown, the power system transmission line leakage detection system includes:

[0045] The power control module 1 is used to receive AC power and perform step-down, rectification, filtering and voltage regulation on the AC power to obtain DC power, and output AC power and DC power.

[0046] Output module 2 is connected to power control module 1 and is used to receive AC power to supply power to electrical equipment.

[0047] The leakage current detection module 3 is connected to the power control module 1. It is used to receive DC power and detect leakage current in AC power. When leakage current occurs, it outputs a first protection signal to control the power control module 1 to stop outputting AC power.

[0048] Temperature detection module 4 is connected to power control module 1. It is used to receive DC power and detect the temperature of DC power to obtain a temperature signal. When the temperature signal is greater than the temperature threshold, it outputs a first control signal. When the temperature signal is greater than the over-temperature threshold, it outputs a second protection signal to control power control module 1 to stop outputting AC power.

[0049] The timing module 5 is connected to the power control module 1 and the temperature detection module 4. It is used to receive DC power and continuously output the second control signal when it receives the first control signal, until the timing time is reached, at which point it stops outputting the second control signal.

[0050] The temperature difference detection module 6 is connected to the temperature detection module 4. When the first control signal is received, it calculates the difference between the temperature signal and the temperature threshold to obtain the temperature difference signal. When the temperature difference signal is greater than the temperature difference threshold, it outputs the third control signal.

[0051] The self-test control module 7, connected to the timing module 5 and the temperature difference detection module 6, outputs a self-test signal when simultaneously receiving the second and third control signals, in order to receive AC power and generate a leakage current signal. The power control module 1 and the leakage current detection module 3 are also connected to the self-test control module 7. The power control module 1 stops receiving the first protection signal upon receiving the self-test signal. The leakage current detection module 3 outputs the first protection signal if it is functioning normally, and does not output it if it is malfunctioning.

[0052] The anomaly detection module 8, connected to the leakage current detection module 3 and the self-test control module 7, is used to display a leakage current anomaly when a self-test signal is received but the first protection signal is not received, and to output a reset signal when the first protection signal is received and the self-test signal reception stops. The leakage current detection module 3 is also used to stop receiving DC power and output the first protection signal when the reset signal is received.

[0053] The following, combined with Figures 1-4 The leakage current detection system for power transmission lines provided in this embodiment will be further described in detail. The leakage current detection system for power transmission lines includes: a power control module 1, an output module 2, a leakage current detection module 3, a temperature detection module 4, a timing module 5, a temperature difference detection module 6, a self-test control module 7, and an anomaly judgment module 8.

[0054] (I) Power Control Module 1

[0055] The power control module 1 is used to receive AC power and perform step-down, rectification, filtering and voltage regulation on the AC power to obtain DC power, and output AC power and DC power. Specifically, power control module 1 is connected to output module 2, and is used to transmit AC power to output module 2. Power control module 1 is also connected to leakage current detection module 3, and is used to transmit DC power to leakage current detection module 3. When it receives the first protection signal output by leakage current detection module 3, it stops transmitting AC power to output module 2. Power control module 1 is connected to temperature detection module 4, and is used to transmit DC power to temperature detection module 4. When it receives the second protection signal output by temperature detection module 4, it stops transmitting AC power to output module 2. Power control module 1 is also connected to timing module 5, and is used to transmit DC power to timing module 5. Finally, power control module 1 is connected to self-test control module 7, and when it receives the self-test signal output by self-test control module 7, it stops receiving the first protection signal and continues to transmit AC power to output module 2 to perform abnormal detection and reset of leakage current detection module 3.

[0056] The power control module 1 can be a power control circuit composed of a power interface, transformer, rectifier, capacitor, Zener diode, relay switch, relay, diode and switching transistor, etc. It can accept AC power and control the transmission status of AC power, perform step-down, rectification, filtering and voltage regulation of AC power, and output DC power.

[0057] Specifically, such as Figure 2 As shown, the power control module 1 includes: a power interface, a transformer B1, a rectifier T1, a capacitor C1, a Zener diode VD1, a relay switch K1-1, a relay K1, a second diode D2, a third diode D3, and a second switching transistor V2. The input terminal of the power interface is connected to the output terminal of the AC power supply. The first output terminal of the power interface is connected to the first terminal of the primary winding of the transformer B1 and the first moving terminal of the relay switch K1-1. The second output terminal of the power interface is connected to the second terminal of the primary winding of the transformer B1 and the second moving terminal of the relay switch K1-1. The first terminal of the secondary winding of the transformer B1 is connected to the first input terminal of the rectifier T1, and the second terminal of the secondary winding of the transformer B1 is connected to the second input terminal of the rectifier T1. The first output terminal of the rectifier T1 serves as the DC output terminal of the power control module 1, and is subsequently connected to the leakage current detection module 3, the temperature detection module 4, and the timing module 5, providing power to these modules. The first output terminal of the rectifier T1 is connected to the first terminal of the capacitor C1 and the Zener diode VD1. The cathode of Zener diode VD1, the second output terminal of rectifier T1, the second terminal of capacitor C1, and the anode of Zener diode VD1 are all grounded. The first static terminal of relay switch K1-1 serves as the first AC output terminal of power control module 1, and the second static terminal of relay switch K1-1 serves as the second AC output terminal of power control module 1. The control terminal of relay K1 serves as the temperature control terminal of power control module 1, and is subsequently connected to temperature detection module 4 to receive the second protection signal output by temperature detection module 4. The control terminal of relay K1 is connected to the cathode of third diode D3. The anode of third diode D3 is connected to the cathode of second diode D2 and the collector of second switching transistor V2, respectively. The anode of second diode D2 serves as the leakage control terminal of power control module 1, and is subsequently connected to leakage detection module 3 to receive the first protection signal output by leakage detection module 3. The emitter of second switching transistor V2 is grounded, and the base of second switching transistor V2 serves as the self-test control terminal of power control module 1, and is subsequently connected to self-test control module 7 to receive the self-test signal output by self-test control module 7.

[0058] Relay switch K1-1 can be a double-pole double-throw normally closed switch. Relay K1 controls relay switch K1-1 to open via magnetic attraction. When the control terminal of relay K1 receives the first protection signal or the second protection signal, it controls relay switch K1-1 to open and stop transmitting AC power. The second switching transistor V2 can be an NPN transistor. When the base of the second switching transistor V2 receives the self-test signal, the second switching transistor V2 is turned on. At this time, the first protection signal will be grounded through the second diode D2 and the second switching transistor V2, and will not be transmitted to relay K1 through the third diode D3.

[0059] (II) Output Module 2

[0060] Output module 2 is connected to power control module 1 and is used to receive AC power to supply power to electrical equipment.

[0061] Output module 2 can be an output circuit composed of output ports, which can receive transmitted AC power and supply power to connected electronic devices (i.e., electrical equipment).

[0062] Specifically, such as Figure 2 As shown, the output module 2 includes an output port. The first input terminal of the output port serves as the first input terminal of the output module 2 and is connected to the first AC output terminal of the power control module 1. The second input terminal of the output port serves as the second input terminal of the output module 2 and is connected to the second AC output terminal of the power control module 1. The output terminal of the output port is connected to the input terminal of the electrical equipment.

[0063] (III) Leakage Detection Module 3

[0064] The leakage current detection module 3 is connected to the power control module 1. It is used to receive DC power and detect leakage current in AC power. When leakage current occurs, it outputs a first protection signal to control the power control module 1 to stop outputting AC power. Specifically, the leakage current detection module 3 is connected to the power control module 1. The leakage current detection module 3 is used to receive the DC power output by the power control module 1. The leakage current detection module 3 is also connected to the power control module 1 and the output module 2. The leakage current detection module 3 is used to detect leakage current in the AC power transmitted by the power control module 1 and received by the output module 2. When leakage occurs, it self-locks and outputs a first protection signal. The leakage current detection module 3 is connected to the self-test control module 7. If the leakage current detection module 3 is normal, it self-locks and outputs a first protection signal when it receives a leakage signal output by the self-test control module 7. That is, the leakage current detection module 3 is connected to the self-test control module 7. When the leakage current detection module 3 receives a leakage signal, it outputs a first protection signal if it is normal and does not output a first protection signal if it is abnormal. The leakage current detection module 3 is connected to the abnormal judgment module 8. When the leakage current detection module 3 receives a reset signal output by the abnormal judgment module 8, it stops receiving DC power and outputting the first protection signal.

[0065] The leakage detection module 3 can be composed of a current transformer, a leakage detection device, a power transistor, a resistor, and a switching transistor. It can perform leakage detection and, when leakage occurs, output a high-level first protection signal. When it receives the reset signal output by the abnormal judgment module 8, it performs a self-locking reset process.

[0066] Specifically, such as Figure 2As shown, the leakage current detection module 3 includes: a current transformer ZCT1, a leakage current detection device, a first power transistor Q1, a second resistor R2, and a first switching transistor V1. The current transformer ZCT1 is installed on the connection line between the power control module 1 and the output module 2, with the connection line passing through the current transformer ZCT1. The connection line includes a power transmission line connecting the first AC output terminal of the power control module 1 and the first input terminal of the output module 2, and a power transmission line connecting the second AC output terminal of the power control module 1 and the second input terminal of the output module 2. That is, the first and second stationary terminals of the relay switch K1-1 both pass through the center of the current transformer ZCT1 and are respectively connected to the first and second input terminals of the output port. The first output terminal of the current transformer ZCT1 is connected to the first input terminal of the leakage current detection device, and the second output terminal of the current transformer ZCT1... The second input terminal of the leakage current detection device is connected. The power supply terminal of the leakage current detection device is connected to the source of the first power transistor Q1. The output terminal of the leakage current detection device serves as the signal output terminal of the leakage current detection module 3 and is connected to the leakage control terminal of the power control module 1 (i.e., connected to the anode of the second diode D2 to provide the first protection signal). The drain of the first power transistor Q1 is connected to the DC output terminal of the power control module 1 (i.e., the first output terminal of the rectifier T1, which receives DC power) and the first terminal of the second resistor R2. The gate of the first power transistor Q1 is connected to the second terminal of the second resistor R2 and the collector of the first switching transistor V1. The emitter of the first switching transistor V1 is grounded. The base of the first switching transistor V1 serves as the reset control terminal of the leakage current detection module 3 and is connected to the abnormal judgment module 8 to receive the reset signal output by the abnormal judgment module 8.

[0067] The current transformer ZCT1 can be a current transformer. The leakage current detection device can be composed of a VG54123 chip, resistors, and capacitors. It amplifies the residual current induced by the current transformer ZCT1 and outputs a high-level first protection signal when the processed signal exceeds the leakage current threshold set by the VG54123 chip. The first power transistor Q1 can be a field-effect transistor, specifically an N-channel field-effect transistor. The first switching transistor V1 can be an NPN transistor. When the base of the first switching transistor V1 does not receive a reset signal, the first switching transistor V1 is open, and DC power supplies the leakage current detection device through the first power transistor Q1. When the base of the first switching transistor V1 receives a reset signal, the first switching transistor V1 is turned on, and DC power is grounded through the second resistor R2 and the first switching transistor V1. The leakage current detection device stops receiving DC power and cannot be powered, thus stopping the output of the first protection signal.

[0068] (iv) Temperature Detection Module 4

[0069] Temperature detection module 4 is connected to power control module 1. It is used to receive DC power and detect the temperature of DC power to obtain a temperature signal. When the temperature signal is greater than a preset temperature threshold, it outputs a first control signal. When the temperature signal is greater than a preset over-temperature threshold, it outputs a second protection signal to control power control module 1 to stop outputting AC power.

[0070] The temperature detection module 4 can be a temperature detection circuit composed of a thermistor, comparator, voltage threshold device, resistor and diode, etc. It can detect the temperature of DC power supplied by the power transmission line of the power system, compare the detected temperature signal with the voltage of the preset temperature threshold, compare the temperature signal with the voltage of the preset over-temperature threshold, and the temperature threshold is less than the over-temperature threshold.

[0071] Specifically, such as Figure 2 As shown, the temperature detection module 4 includes: a thermistor NTC1, a comparator A1, a voltage threshold device, a first resistor R1, a fifth resistor R5, a fourth diode D4, and a fifth diode D5. The first terminal of the thermistor NTC1 is connected to the DC output terminal of the power control module 1 (i.e., the first output terminal of the rectifier T1, which receives DC power). The second terminal of the thermistor NTC1 serves as the temperature signal output terminal of the temperature detection module 4, connected to the temperature difference detection module 6 to provide a temperature signal. The second terminal of the thermistor NTC1 is connected to the non-inverting input terminal of the comparator A1, the first terminal of the first resistor R1, and the first terminal of the fifth resistor R5, respectively. The inverting input terminal of the comparator A1 is connected to the... The output of the voltage threshold device is used to provide the temperature threshold. The output of the voltage threshold device serves as the threshold output of the temperature detection module 4 and is connected to the temperature difference detection module 6 to provide the temperature threshold. The output of the comparator A1 serves as the control signal output of the temperature detection module 4 and is connected to the timing module 5 and the temperature difference detection module 6 to provide the first control signal. The second end of the first resistor R1 is grounded. The second end of the fifth resistor R5 is connected to the cathode of the fourth diode D4. The anode of the fourth diode D4 is connected to the anode of the fifth diode D5. The cathode of the fifth diode D5 is connected to the temperature control terminal of the power control module 1 (i.e., the control terminal of the relay K1, which provides the second protection signal).

[0072] The thermistor NTC1 can be a negative temperature coefficient thermistor, and comparator A1 can be an LM358 comparator. The voltage threshold device can be composed of a reference power supply and a resistor to provide the temperature threshold. Comparator A1 is used to compare whether the temperature signal of the thermistor NTC1 is greater than the temperature threshold (using voltage signals for comparison), and outputs a high-level first control signal when it is greater. The fifth resistor R5 and the fourth diode D4 set the over-temperature threshold. Since the resistance value of the thermistor NTC1 decreases as the temperature increases, when the current flowing through the thermistor NTC1 and the fifth resistor R5 is excessive, it is equivalent to the temperature signal being greater than the over-temperature threshold. Then the fourth diode D4 conducts, and the fifth diode D5 outputs a high-level second protection signal.

[0073] (V) Timing Module 5

[0074] The timing module 5 is connected to the power control module 1 and the temperature detection module 4. It is used to receive DC power, set the timing time, and continuously output the second control signal when the first control signal is received until the timing time is reached, that is, after the timing ends, the output of the second control signal stops.

[0075] The timing module 5 can be a timing control circuit composed of power transistors and timing control devices, which can set the timing time and output a second control signal in a high-level state when the first control signal (i.e., power is received) is received.

[0076] Specifically, such as Figure 2 and Figure 3 As shown, the timing module 5 includes: a second power transistor Q2 and a timing control device. The drain of the second power transistor Q2 is connected to the DC output terminal of the power control module 1 (i.e., the first output terminal of the rectifier T1, which receives DC power). The gate of the second power transistor Q2 is connected to the control signal output terminal of the temperature detection module 4 (i.e., the output terminal of the comparator A1, which receives the first control signal). The source of the second power transistor Q2 is connected to the input terminal of the timing control device. The output terminal of the timing control device serves as the control signal output terminal of the timing module 5 and is connected to the self-test control module 7 (i.e., the B terminal of the first logic chip J1) to provide a second control signal.

[0077] The second power transistor Q2 can be a field-effect transistor, specifically an N-channel field-effect transistor. The timing control device can be composed of an NE555 chip, diodes, capacitors, and resistors. When powered on, it can perform timing operation and output a high-level second control signal at regular intervals. After the timing period is exceeded, it stops outputting the high-level second control signal.

[0078] (vi) Temperature difference detection module 6

[0079] The temperature difference detection module 6, connected to the temperature detection module 4, is used to calculate the difference between the temperature signal and the temperature threshold when the first control signal is received. That is, the received temperature signal and the temperature threshold are subtracted to obtain the temperature difference signal. When the temperature difference signal is greater than the preset temperature difference threshold, the third control signal is output.

[0080] The temperature difference detection module 6 can be a temperature difference detection circuit composed of analog switches, resistors, operational amplifiers and diodes. When the temperature signal is greater than the temperature threshold, it can calculate the difference between the temperature signal and the temperature threshold, and output a high-level third control signal when the temperature difference signal is greater than the temperature difference threshold.

[0081] Specifically, such as Figure 2 and Figure 4 As shown, the temperature difference detection module 6 includes: analog switch IC1, sixth resistor R6, seventh resistor R7, eighth resistor R8, ninth resistor R9, tenth resistor R10, operational amplifier OP1, and sixth diode D6. The CTRL1 and CTRL2 terminals of analog switch IC1 are both connected to the control signal output terminal of temperature detection module 4 (i.e., the output terminal of comparator A1, receiving the first control signal). The IN1 terminal of analog switch IC1 is connected to the threshold output terminal of temperature detection module 4 (i.e., the output terminal of voltage threshold device, receiving the temperature threshold). The IN2 terminal of analog switch IC1 is connected to the temperature signal output terminal of temperature detection module 4 (i.e., the second terminal of thermistor NTC1, receiving the temperature signal). The OUT1 terminal of analog switch IC1 is connected to the sixth... The first end of resistor R6 is connected to the OUT2 terminal of analog switch IC1, which is connected to the first end of the seventh resistor R7. The second end of the sixth resistor R6 is connected to the first end of the ninth resistor R9 and the inverting input terminal of operational amplifier OP1. The second end of the seventh resistor R7 is connected to the first end of the eighth resistor R8 and the non-inverting input terminal of operational amplifier OP1. The second end of the eighth resistor R8 is grounded. The second end of the ninth resistor R9 is connected to the first end of the tenth resistor R10 and the output terminal of operational amplifier OP1. The second end of the tenth resistor R10 is connected to the cathode of the sixth diode D6. The anode of the sixth diode D6 serves as the control signal output terminal of the temperature difference detection module 6, which is connected to the self-test control module 7 (i.e., the A terminal of the first logic chip J1) to provide the third control signal.

[0082] The analog switch IC1 can be a CD4066 analog switch, and the operational amplifier OP1 can be an OP07 operational amplifier. Together with the sixth resistor R6, the seventh resistor R7, the eighth resistor R8, and the ninth resistor R9, they perform subtraction processing, that is, calculate the difference between the temperature signal and the temperature threshold. The tenth resistor R10 and the sixth diode D6 set the temperature difference threshold. When the current flowing through the tenth resistor R10 is excessive, it is equivalent to the temperature difference signal being greater than the temperature difference threshold. Then the sixth diode D6 conducts and outputs a high-level third control signal.

[0083] (vii) Self-test control module 7

[0084] The self-test control module 7 is connected to the timing module 5 and the temperature difference detection module 6. When the second control signal and the third control signal are received simultaneously, the self-test signal is output to receive AC power and generate a leakage signal.

[0085] The self-test control module 7 can use a self-test control circuit composed of logic chips, optocouplers and resistors to detect the rate of temperature change, that is, whether the temperature difference is greater than the temperature difference threshold within a time interval. If it is greater, it indicates that the rate of temperature change is too fast and a leakage signal will be generated.

[0086] Specifically, such as Figure 2 As shown, the self-test control module 7 includes: a first logic chip J1, an optocoupler IC2, and a third resistor R3. Terminal A of the first logic chip J1 is connected to the control signal output terminal of the temperature difference detection module 6 (i.e., the anode of the sixth diode D6, receiving the third control signal). Terminal B of the first logic chip J1 is connected to the control signal output terminal of the timing module 5 (i.e., the output terminal of the timing control device, receiving the second control signal). Terminal Y of the first logic chip J1 serves as the signal output terminal of the self-test control module 7. Terminal Y of the first logic chip J1 is also connected to the self-test control terminal of the power control module 1. The control terminal (i.e., the base of the second switching transistor V2, which provides a self-test signal) and the first terminal of the optocoupler IC2 are connected. The second terminal of the optocoupler IC2 is grounded. The third terminal of the optocoupler IC2 is connected to the first terminal of the third resistor R3. The fourth terminal of the optocoupler IC2 is connected to the second AC output terminal of the power control module 1 (i.e., the second stationary terminal of the relay switch K1-1, which is also the second input terminal of the output port). The second terminal of the third resistor R3 is connected to the first AC output terminal of the power control module 1 (i.e., the first stationary terminal of the relay switch K1-1, which is also the first input terminal of the output port).

[0087] The first logic chip J1 can be an AND gate chip, and the optocoupler IC2 can be an MOC3020 optocoupler. When the self-test signal is output, the optocoupler IC2 is turned on, and part of the AC power output from the power interface is transferred to the optocoupler IC2, which reduces the AC power between the power interface and the output port, generating a leakage signal. At this time, if the leakage detection device is normal, the first protection signal will be output.

[0088] (VIII) Anomaly Detection Module 8

[0089] The anomaly detection module 8 is connected to the leakage current detection module 3 and the self-test control module 7. It is used to display leakage current anomalies when a self-test signal is received but a first protection signal is not received, and to output a reset signal when the first protection signal is received and the self-test signal is stopped.

[0090] The anomaly detection module 8 can be composed of an anomaly detection circuit consisting of an inverter, a logic chip, a diode, a resistor, and an indicator light. It can display leakage current anomalies and can also reset the leakage current detection module 3 during normal leakage current detection.

[0091] Specifically, such as Figure 2 As shown, the anomaly detection module 8 includes: a first inverter INV1, a second inverter INV2, a second logic chip J2, a third logic chip J3, a fourth logic chip J4, a first diode D1, a seventh diode D7, a fourth resistor R4, and an indicator LED1. The input terminal of the first inverter INV1 is connected to the signal output terminal of the leakage current detection module 3 (i.e., the output terminal of the leakage current detection device, receiving the first protection signal) and the B terminal of the second logic chip J2. The output terminal of the first inverter INV1 is connected to the A terminal of the third logic chip J3. The input terminal of the second inverter INV2 is connected to the signal output terminal of the self-test control module 7 (i.e., the Y terminal of the first logic chip J1, receiving the self-test signal). The output terminal of the second inverter INV2 is connected to the A terminal of the fourth logic chip J4. The second logic chip J2... Terminal A of the first logic chip J2 is connected to the cathode of the first diode D1 and the cathode of the seventh diode D7. Terminal Y of the second logic chip J2 is connected to terminal B of the fourth logic chip J4 and the anode of the first diode D1. Terminal B of the third logic chip J3 is connected to the signal output terminal of the self-test control module 7 (i.e., the Y terminal of the first logic chip J1, which receives the self-test signal). Terminal Y of the third logic chip J3 is connected to the first terminal of the fourth resistor R4. Terminal Y of the fourth logic chip J4 is connected to the reset control terminal of the leakage current detection module 3 (i.e., the base of the first switching transistor V1, which provides the reset signal). The anode of the seventh diode D7 is connected to the signal output terminal of the self-test control module 7 (i.e., the Y terminal of the first logic chip J1, which receives the self-test signal). Terminal Y of the fourth resistor R4 is connected to the anode of the indicator LED1. The cathode of the indicator LED1 is grounded.

[0092] The first inverter INV1 and the second inverter INV2 can both be NOT gate chips. The second logic chip J2, the third logic chip J3 and the fourth logic chip J4 can all be AND gate chips. The second logic chip J2, together with the first diode D1 and the seventh diode D7, can perform high-level self-locking. The indicator LED1 can be an LED.

[0093] The working process of the power system transmission line leakage detection system provided in this embodiment is as follows: AC power is connected to the power interface, and the relay switch K1-1 transmits the AC power to the output port. The transformer B1, rectifier T1, capacitor C1 and voltage regulator VD1 perform voltage reduction, rectification, filtering and voltage regulation on the AC power to output DC power. The current transformer ZCT1 performs leakage detection on the transmitted AC power. When residual current is detected in the AC power, the leakage detection device will make a leakage judgment and output a high-level first protection signal when leakage occurs, which controls the relay K1 to be energized. The relay K1 controls the relay switch K1-1 to be disconnected to perform power outage protection.During the period when leakage is not detected, the thermistor NTC1 and the first resistor R1 detect the temperature of the power system transmission line and output a temperature signal. When the temperature signal exceeds the temperature threshold set by the voltage threshold device, the comparator A1 outputs a high-level first control signal, controlling the second power transistor Q2 to conduct. The timing control device starts timing operation and outputs a high-level second control signal. At the same time, the CTRL1 and CTRL2 terminals of the analog switch IC1 become high-level, the IN1 and OUT1 terminals of the analog switch IC1 conduct, and the IN2 and OUT2 terminals conduct, supplying power to the operational amplifier. Operational amplifier OP1 transmits the temperature signal and temperature threshold. OP1, in conjunction with resistors R6, R7, R8, and R9, subtracts the temperature signal from the temperature threshold, outputting a temperature difference signal. During the timing control device's output of the second control signal, if the temperature difference signal exceeds the temperature difference threshold set by resistor R10 and diode D6, it indicates a rapid temperature change rate. Diode D6 then outputs a high-level third control signal. At this time, the Y-terminal of the first logic chip J1 outputs a high-level self-test signal, controlling the second switching transistor V2. When the circuit is turned on, the optocoupler IC2 is activated, generating a leakage signal in conjunction with the third resistor R3. This leakage signal is detected by the current transformer ZCT1 and assessed by a leakage detection device. If the leakage detection device performs its leakage assessment correctly, it will output a first protection signal, causing the B terminal of the second logic chip J2 to go high. This, combined with the first diode D1 and the seventh diode D7, triggers a self-locking mechanism, causing the Y terminal of the second logic chip J2 to go high. This ensures that after the timing is complete, the second inverter INV2 outputs a high level, and the Y terminal of the fourth logic chip J3 outputs a high-level reset signal. The first switch V1 is turned on, the first power transistor Q1 is turned off, the leakage current detection device is powered off and reset, and the output of the first protection signal stops. The second logic chip J2, the first diode D1, and the seventh diode D7 stop self-locking, and the first power transistor Q1 is turned on again so that the leakage current detection device can resume leakage current detection. If the leakage current detection device does not output the first protection signal at this time, it indicates that the leakage current detection device has an abnormality. The first inverter INV1 will output a high-level signal, causing the Y terminal of the third logic chip J3 to output a high-level signal, and controlling the indicator LED1 to be lit. In addition, when the temperature signal is greater than the over-temperature threshold set by the fifth resistor R5 and the fourth diode D4, the relay K1 will also be energized, which in turn controls the relay switch K1-1 to open.

[0094] This embodiment provides a leakage current detection system for power transmission lines, relating to the field of power system technology. It includes a power control module 1 for power input, transmission, and conversion processing, and for output module 2 to receive power; a leakage current detection module 3 for receiving power and detecting leakage current, and controlling the power control module 1 to cut off power when leakage occurs; a temperature detection module 4 for temperature detection, temperature comparison, and over-temperature judgment; a timing module 5 for setting a timing period and providing a high-level second control signal to a self-test control module 7 at regular intervals; a temperature difference detection module 6 for providing a high-level third control signal to the self-test control module 7 when the difference between the temperature difference signal and the temperature threshold exceeds the temperature difference threshold; a self-test control module 7 for generating a leakage current signal; and an anomaly judgment module 8 for displaying leakage current anomalies and controlling the reset of the leakage current detection module 3. The leakage current detection system for power transmission lines provided in this embodiment can improve the safety of power transmission lines, reduce the risk of leakage current anomalies, and reduce manpower requirements.

[0095] Compared with the prior art, the beneficial effects of this embodiment are as follows: The power system transmission line leakage detection system provided in this embodiment can use the leakage detection module 3 to judge the leakage of the transmission line between the power control module 1 and the output module 2, and perform power-off protection when leakage occurs. At the same time, the temperature detection module 4 performs temperature detection and over-temperature detection, and performs power-off protection when over-temperature occurs. When the detected temperature signal is greater than the set temperature threshold, the temperature difference detection module 6 will detect the degree of temperature change, and cooperate with the timing module 5 to detect the rate of temperature change. When the temperature changes rapidly, the self-test control module 7 controls the leakage detection module 3 to perform leakage self-detection. When the leakage detection module 3 does not judge leakage, the anomaly judgment module 8 will display the leakage protection anomaly. When the leakage detection module 3 judges leakage, it will perform reset control, thereby improving the safety of the power system transmission line, reducing the risk of leakage detection anomalies, and reducing manpower.

[0096] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. Furthermore, those skilled in the art will recognize that, based on the ideas of this application, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A power transmission line leakage current detection system for power systems, characterized in that, The power system transmission line leakage detection system includes: The power control module is used to receive AC power and perform step-down, rectification, filtering and voltage regulation on the AC power to obtain DC power, and output AC power and DC power. The output module, connected to the power control module, is used to receive AC power and supply power to electrical equipment. The leakage current detection module is connected to the power control module. It is used to receive DC power and detect leakage current in AC power. When leakage current occurs, it outputs a first protection signal to control the power control module to stop outputting AC power. The temperature detection module is connected to the power control module. It is used to receive DC power and detect the temperature of DC power to obtain a temperature signal. When the temperature signal is greater than the temperature threshold, it outputs a first control signal. When the temperature signal is greater than the over-temperature threshold, it outputs a second protection signal to control the power control module to stop outputting AC power. The timing module, connected to the power control module and the temperature detection module, is used to receive DC power and continuously output the second control signal when the first control signal is received, until the timing time is reached, at which point the output of the second control signal stops. The temperature difference detection module, connected to the temperature detection module, is used to calculate the difference between the temperature signal and the temperature threshold when the first control signal is received, to obtain the temperature difference signal, and to output the third control signal when the temperature difference signal is greater than the temperature difference threshold. The self-test control module, connected to the timing module and the temperature difference detection module, is used to output a self-test signal when simultaneously receiving the second control signal and the third control signal, so as to receive AC power and generate a leakage current signal. The power control module and the leakage current detection module are also connected to the self-test control module. The power control module is used to stop receiving the first protection signal when it receives the self-test signal. The leakage current detection module is used to output the first protection signal if it is normal when it receives the leakage current signal, and not output the first protection signal if it is abnormal. The anomaly detection module, connected to the leakage current detection module and the self-test control module, is used to display leakage current anomalies when a self-test signal is received but a first protection signal is not received, and to output a reset signal when the first protection signal is received and the self-test signal is stopped. The leakage current detection module is also used to stop receiving DC power and output the first protection signal when the reset signal is received.

2. The power system transmission line leakage detection system according to claim 1, characterized in that, The power control module includes: a power interface, a transformer, a rectifier, a capacitor, a Zener diode, a relay switch, a relay, a second diode, a third diode, and a second switching transistor; The input terminal of the power interface is connected to the output terminal of the AC power supply. The first output terminal of the power interface is connected to the first terminal of the primary winding of the transformer and the first moving terminal of the relay switch. The second output terminal of the power interface is connected to the second terminal of the primary winding of the transformer and the second moving terminal of the relay switch. The first terminal of the secondary winding of the transformer is connected to the first input terminal of the rectifier. The second terminal of the secondary winding of the transformer is connected to the second input terminal of the rectifier. The first output terminal of the rectifier serves as the DC output terminal of the power control module. The first output terminal of the rectifier is connected to the first terminal of the capacitor and the cathode of the Zener diode. The second output terminal of the rectifier... The first terminal of the capacitor, the second terminal of the Zener diode, and the anode of the Zener diode are all grounded. The first stationary terminal of the relay switch serves as the first AC output terminal of the power control module, and the second stationary terminal of the relay switch serves as the second AC output terminal of the power control module. The control terminal of the relay serves as the temperature control terminal of the power control module. The control terminal of the relay is connected to the cathode of the third diode. The anode of the third diode is connected to the cathode of the second diode and the collector of the second switching transistor. The anode of the second diode serves as the leakage control terminal of the power control module. The emitter of the second switching transistor is grounded, and the base of the second switching transistor serves as the self-test control terminal of the power control module.

3. The power system transmission line leakage detection system according to claim 1, characterized in that, The output module includes output ports; The first input terminal of the output port serves as the first input terminal of the output module and is connected to the first AC output terminal of the power control module. The second input terminal of the output port serves as the second input terminal of the output module and is connected to the second AC output terminal of the power control module. The output terminal of the output port is connected to the input terminal of the electrical equipment.

4. The power system transmission line leakage detection system according to claim 1, characterized in that, The leakage current detection module includes: a current transformer, a leakage current detection device, a first power transistor, a second resistor, and a first switching transistor; The current transformer is installed on the connection line between the power control module and the output module, with the connection line passing through the current transformer. The connection line includes a power transmission line connecting the first AC output terminal of the power control module and the first input terminal of the output module, and a power transmission line connecting the second AC output terminal of the power control module and the second input terminal of the output module. The first output terminal of the current transformer is connected to the first input terminal of the leakage current detection device, and the second output terminal of the current transformer is connected to the second input terminal of the leakage current detection device. The power supply terminal of the leakage current detection device is connected to the source of the first power transistor. The output terminal of the leakage current detection device serves as the signal output terminal of the leakage current detection module and is connected to the leakage control terminal of the power control module. The drain of the first power transistor is connected to the DC output terminal of the power control module and the first terminal of the second resistor, respectively. The gate of the first power transistor is connected to the second terminal of the second resistor and the collector of the first switching transistor, respectively. The emitter of the first switching transistor is grounded, and the base of the first switching transistor serves as the reset control terminal of the leakage current detection module.

5. The power system transmission line leakage detection system according to claim 1, characterized in that, The temperature detection module includes: a thermistor, a comparator, a voltage threshold device, a first resistor, a fifth resistor, a fourth diode, and a fifth diode; The first terminal of the thermistor is connected to the DC output terminal of the power control module. The second terminal of the thermistor serves as the temperature signal output terminal of the temperature detection module. The second terminal of the thermistor is connected to the non-inverting input terminal of the comparator, the first terminal of the first resistor, and the first terminal of the fifth resistor. The inverting input terminal of the comparator is connected to the output terminal of the voltage threshold device, which provides the temperature threshold. The output terminal of the voltage threshold device serves as the threshold output terminal of the temperature detection module. The output terminal of the comparator serves as the control signal output terminal of the temperature detection module. The second terminal of the first resistor is grounded. The second terminal of the fifth resistor is connected to the cathode of the fourth diode. The anode of the fourth diode is connected to the anode of the fifth diode. The cathode of the fifth diode is connected to the temperature control terminal of the power control module.

6. The power system transmission line leakage detection system according to claim 1, characterized in that, The timing module includes: a second power transistor and a timing control device; The drain of the second power transistor is connected to the DC output terminal of the power control module, the gate of the second power transistor is connected to the control signal output terminal of the temperature detection module, the source of the second power transistor is connected to the input terminal of the timing control device, and the output terminal of the timing control device serves as the control signal output terminal of the timing module.

7. The power system transmission line leakage detection system according to claim 1, characterized in that, The temperature difference detection module includes: an analog switch, a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, a tenth resistor, an operational amplifier, and a sixth diode; Both CTRL1 and CTRL2 terminals of the analog switch are connected to the control signal output terminals of the temperature detection module. The IN1 terminal of the analog switch is connected to the threshold output terminal of the temperature detection module. The IN2 terminal of the analog switch is connected to the temperature signal output terminal of the temperature detection module. The OUT1 terminal of the analog switch is connected to the first terminal of the sixth resistor. The OUT2 terminal of the analog switch is connected to the first terminal of the seventh resistor. The second terminal of the sixth resistor is connected to the first terminal of the ninth resistor and the inverting input terminal of the operational amplifier. The second terminal of the seventh resistor is connected to the first terminal of the eighth resistor and the non-inverting input terminal of the operational amplifier. The second terminal of the eighth resistor is grounded. The second terminal of the ninth resistor is connected to the first terminal of the tenth resistor and the output terminal of the operational amplifier. The second terminal of the tenth resistor is connected to the cathode of the sixth diode. The anode of the sixth diode serves as the control signal output terminal of the temperature difference detection module.

8. The power system transmission line leakage detection system according to claim 1, characterized in that, The self-test control module includes: a first logic chip, an optocoupler, and a third resistor; The A terminal of the first logic chip is connected to the control signal output terminal of the temperature difference detection module, the B terminal of the first logic chip is connected to the control signal output terminal of the timing module, the Y terminal of the first logic chip serves as the signal output terminal of the self-test control module, the Y terminal of the first logic chip is connected to the self-test control terminal of the power control module and the first terminal of the optocoupler, the second terminal of the optocoupler is grounded, the third terminal of the optocoupler is connected to the first terminal of the third resistor, the fourth terminal of the optocoupler is connected to the second AC output terminal of the power control module, and the second terminal of the third resistor is connected to the first AC output terminal of the power control module. The first logic chip is an AND gate chip.

9. The power system transmission line leakage detection system according to claim 1, characterized in that, The anomaly detection module includes: a first inverter, a second inverter, a second logic chip, a third logic chip, a fourth logic chip, a first diode, a seventh diode, a fourth resistor, and an indicator light; The input terminals of the first inverter are connected to the signal output terminal of the leakage current detection module and the B terminal of the second logic chip, respectively. The output terminal of the first inverter is connected to the A terminal of the third logic chip. The input terminal of the second inverter is connected to the signal output terminal of the self-test control module and the output terminal of the second inverter is connected to the A terminal of the fourth logic chip. The A terminal of the second logic chip is connected to the cathode of the first diode and the cathode of the seventh diode, respectively. The Y terminal of the second logic chip is connected to the B terminal of the fourth logic chip and the anode of the first diode, respectively. The B terminal of the third logic chip is connected to the signal output terminal of the self-test control module. The Y terminal of the third logic chip is connected to the first terminal of the fourth resistor. The Y terminal of the fourth logic chip is connected to the reset control terminal of the leakage current detection module. The anode of the seventh diode is connected to the signal output terminal of the self-test control module. The second terminal of the fourth resistor is connected to the anode of the indicator light, and the cathode of the indicator light is grounded. Among them, the first inverter and the second inverter are both NOT gate chips, and the second logic chip, the third logic chip and the fourth logic chip are all AND gate chips.

10. The power system transmission line leakage detection system according to claim 1, characterized in that, The leakage current detection device in the leakage current detection module uses the VG54123 chip, and the timing control device in the timing module uses the NE555 chip.

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