Power supply equipment ground wire monitoring system and use method thereof

Abstract

The invention discloses a power supply equipment ground wire monitoring system and a use method thereof. The power supply equipment ground wire monitoring system comprises a ground wire monitor, a cloud server and a mobile phone APP terminal, ground wire voltage, ground wire current, zero sequence current, three-phase current, ground wire surge voltage, environment temperature, environment humidity, environment magnetic field intensity and lightning stroke frequency data are collected; obtaining a final dynamic voltage threshold value and a final dynamic current threshold value by using an environment correction factor formula, a load correction factor formula, a lightning stroke correction factor formula, a ground wire theoretical voltage threshold value formula, a ground wire theoretical current threshold value formula, an EWMA algorithm voltage threshold value formula, an EWMA algorithm current threshold value formula and threshold value amplitude limiting; according to the power supply equipment data abnormity early warning system, the false alarm rate of power supply equipment data abnormity is reduced, through early warning grading, mobile phone APP remote monitoring, ground wire monitor sound alarm, mobile phone pop-up window early warning, electric leakage switch tripping control and a lightning protection device, the convenience of equipment management and maintenance is improved, and the possibility of accident occurrence is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of ground wire monitoring, and particularly to a ground wire monitoring system for power supply equipment and its usage method. Background Art

[0002] The grounding wire is used to discharge fault current or induced charge in the power system, but its abnormal electrification (such as insulation breakage, poor contact or electromagnetic induction coupling) may lead to electric shock, equipment damage or even fire. The traditional detection means have the following problems: 1. Single-threshold alarm, the fixed voltage threshold cannot adapt to dynamic working conditions (such as instantaneous surges, environmental interference), and the false alarm rate is high; 2. Dependence on manual inspection, unable to monitor in real time, and the risk of missed inspection is large; 3. Lack of intelligent analysis, without combining environmental parameters and historical data, it is difficult to distinguish real faults from instantaneous interference.

[0003] With the development of science and technology, more advanced working methods have also emerged in the ground wire monitoring system. For example, Chinese Patent CN202411663544.6 discloses a detection method and device for grounding faults, which realizes fault detection through load switching, but does not combine environmental parameter compensation. Therefore, there is an urgent need for a high-precision and environment-adaptive ground wire monitoring method and system. Summary of the Invention

[0004] In view of this, the present invention proposes a ground wire monitoring system for power supply equipment and its usage method to solve the problems in aspects such as existing detection accuracy, environment adaptability, automation and intelligence level.

[0005] To achieve the above object, the technical solution of the present invention is realized as follows:

[0006] On the one hand, the present invention provides a ground wire monitoring system for power supply equipment, including a ground wire monitor, a cloud server and a mobile APP terminal;

[0007] The ground wire monitor is connected to the cloud server through a 4G / 5G network, and is used to collect data such as ground wire voltage, ground wire current, zero-sequence current, three-phase current, ground wire surge voltage, ambient temperature, ambient humidity, ambient magnetic field strength and the number of lightning strikes, dynamically calculate the ground wire voltage threshold and current threshold, determine the level of the ground wire abnormal warning information and take corresponding protection measures, and send real-time data and warning information to the cloud server;

[0008] The cloud server is connected to the mobile APP terminal through a 4G / 5G network, and is used to receive the real-time data and warning information sent by the ground wire monitor, store the abnormal data and warning information and forward them to the mobile APP terminal, which is convenient for equipment management personnel to query and monitor in real time, and provides a basis for equipment fault diagnosis, maintenance, repair and overhaul.

[0009] Preferably, the ground wire monitor includes a non-contact voltage sensor, a Hall current sensor, a zero-flux current sensor, a three-phase current transmitter, a temperature sensor, a humidity sensor, a three-axis magnetometer, a surge voltage detection circuit, a lightning counter, a main control unit, a leakage switch, a solid-state switch, a lightning arrester, an alarm horn, and a 4G / 5G module;

[0010] The non-contact voltage sensor is connected to the main control unit through an AD port, and is used to collect the ground wire voltage signal and send the signal to the main control unit through the AD port in the form of 0-10V or 4-20mA;

[0011] The Hall current sensor is connected to the main control unit through an AD port, and is used to collect the ground wire current signal and send the signal to the main control unit through the AD port in the form of 0-10V or 4-20mA;

[0012] The zero-flux current sensor is connected to the main control unit through an AD port, and is used to collect the zero-sequence current signal and send the signal to the main control unit through the AD port in the form of 0-10V or 4-20mA;

[0013] The three-phase current transmitter is connected to the main control unit through an AD port, and is used to collect the current signals of the three phases U\V\W of the power supply equipment and send the signals to the main control unit through the AD port in the form of 0-10V or 4-20mA;

[0014] The temperature sensor is connected to the main control unit through an AD port, and is used to collect the ambient temperature signal and send the signal to the main control unit through the AD port in the form of 0-10V or 4-20mA;

[0015] The humidity sensor is connected to the main control unit through an AD port, and is used to collect the ambient humidity signal and send the signal to the main control unit through the AD port in the form of 0-10V or 4-20mA;

[0016] The three-axis magnetometer is connected to the main control unit through an AD port, and is used to collect the ambient magnetic field intensity signal and send the signal to the main control unit through the AD port in the form of 0-10V or 4-20mA;

[0017] The surge voltage detection circuit is connected to the main control unit through an AD port, and is used to collect the voltage signal when a surge occurs on the ground wire and send the signal to the main control unit through the AD port in the form of 0-10V;

[0018] The lightning counter is connected to the main control unit through an interrupt port, and is used to capture the lightning strike signal and send the signal to the main control unit through the interrupt port in the form of an electrical pulse;

[0019] The leakage switch is connected to the main control unit through the RS485 port, and is used to receive the control signal sent by the main control unit to control the on / off of all live wires and neutral wires of the power supply device;

[0020] The solid-state switch is connected to the main control unit through the I / O port, and is used to receive the high and low level signals sent by the main control unit to control the opening or closing of the lightning arrester;

[0021] The alarm horn is connected to the main control unit through the I / O port, and is used to receive the high and low level signals sent by the main control unit to control the opening or closing of the alarm horn;

[0022] The main control unit is connected to the 4G / 5G module through the TTL serial port, and is used to receive the data of the non-contact voltage sensor, Hall current sensor, zero-flux current sensor, three-phase current transmitter, temperature sensor, humidity sensor, three-axis magnetometer, surge voltage detection circuit and lightning counter, control the status information of the leakage switch, solid-state switch, lightning arrester and alarm horn, and send it to the cloud server as 4G / 5G signals.

[0023] Preferably, the surge voltage detection circuit includes a TVS diode, a trigger comparator and an optocoupler isolator; the TVS diode is connected in parallel with the ground wire and is used to collect the surge transient voltage when a surge occurs on the ground wire; the trigger comparator is used to receive the surge transient voltage and compare it with the preset voltage, and change the output state when it exceeds; the optocoupler isolator is used to receive the output signal of the trigger comparator and convert it into 0-10V and send it to the main control unit to prevent high-voltage crosstalk.

[0024] Preferably, the TVS diode in the surge voltage detection circuit uses SMBJ48CA, the trigger comparator uses TLV3501, the optocoupler isolator uses TLP281, the lightning counter is composed of an AS3935 chip and its peripheral circuit, the 4G / 5G module uses Quectel EC200T, the main control unit is composed of STM32H743 and its input conditioning circuit and output driving circuit, and is compiled and passed using the standard C language in the Keil uVision 5 software. The cloud server is compiled and passed using Python in VS Code, and the mobile APP terminal is compiled and passed using the JAVA language in Android Studio.

[0025] On the other hand, the present invention provides a method for using a power supply device ground wire monitoring system, including the following steps:

[0026] S1. The main control unit acquires the data of the ground wire voltage, ground wire current, zero-sequence current, three-phase current, ground wire surge voltage, ambient temperature, ambient humidity, ambient magnetic field intensity and the number of lightning strikes, and uses Daubechies wavelet decomposition to filter out high-frequency noise;

[0027] S2. Calculate the load intensity of the power supply equipment according to the equipment load rate formula;

[0028] S3. Select the initial values of the temperature correction coefficient, humidity correction coefficient, and magnetic field intensity correction coefficient, calculate the environment correction factor according to the environment correction factor formula, the load correction factor according to the load correction factor formula, and the lightning strike correction factor according to the lightning strike correction factor formula;

[0029] S4. Calculate the theoretical voltage threshold and theoretical current threshold according to the ground wire theoretical voltage threshold formula and the ground wire theoretical current threshold formula;

[0030] S5. Use the EWMA algorithm voltage threshold formula, EWMA algorithm current threshold formula, and threshold limiting to obtain the optimized final dynamic voltage threshold and final dynamic current threshold, and suppress threshold mutation;

[0031] S6. Use the normal historical data based on a 30-day sliding window, and use the least squares method to iteratively optimize and update the temperature correction coefficient, humidity correction coefficient, and magnetic field intensity correction coefficient;

[0032] S7. Identify abnormal data according to the real-time data of the sensor, the final dynamic voltage threshold, and the final dynamic current threshold, determine the level of the ground wire abnormal warning information, and take corresponding protection measures;

[0033] S8. The cloud server stores the real-time data and warning information, forwards the abnormal data and warning information to the mobile APP terminal, which is convenient for equipment management personnel to query, monitor, and process in real time, and provides a basis for equipment fault diagnosis, maintenance, and repair.

[0034] Compared with the prior art, a power supply equipment ground wire monitoring system and its usage method provided by the present invention have the following beneficial effects:

[0035] (1) Fully consider the influence of equipment environment, load, and lightning strike factors on the ground wire abnormality, and use Daubechies wavelet decomposition to filter out high frequencies, improving the accuracy and credibility of data acquisition;

[0036] (2) Construct the environment correction factor formula, load correction factor formula, lightning strike correction factor formula, ground wire theoretical voltage threshold formula, ground wire theoretical current threshold formula, EWMA algorithm voltage threshold formula, EWMA algorithm current threshold formula, and threshold limiting method to obtain the final dynamic voltage threshold and final dynamic current threshold, reducing the false alarm rate of abnormal data of the power supply equipment;

[0037] (3) Use the normal historical data based on a 30-day sliding window, and use the least squares method to iteratively optimize and update the temperature correction coefficient, humidity correction coefficient, and magnetic field intensity correction coefficient, improving the accuracy of dynamic threshold calculation;

[0038] (4) Through early warning grading and remote monitoring via mobile APP, the convenience of power supply equipment management and maintenance services is improved. Through the sound alarm of the ground wire monitor and the pop-up warning on the mobile phone, the leakage switch is tripped and the lightning arrester is turned on, reducing the possibility of accidents. Description of the Drawings

[0039] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0040] Figure 1 It is a schematic structural diagram of a ground wire monitoring system for power supply equipment provided by the present invention;

[0041] Figure 2 It is a working flow chart of a method for using a ground wire monitoring system for power supply equipment provided by the present invention. Detailed Embodiments

[0042] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0043] Embodiment 1: As Figure 1 shown, a ground wire monitoring system for power supply equipment provided by the present invention includes a ground wire monitor, a cloud server, and a mobile APP terminal; among them, the ground wire monitor is connected to the cloud server through a 4G / 5G network, and is used to collect data such as ground wire voltage, ground wire current, zero-sequence current, three-phase current, ground wire surge voltage, ambient temperature, ambient humidity, ambient magnetic field strength, and the number of lightning strikes, dynamically calculate the ground wire voltage threshold and current threshold, determine the level of ground wire abnormal warning information and take corresponding protection measures, and send real-time data and warning information to the cloud server; the cloud server is connected to the mobile APP terminal through a 4G / 5G network, and is used to receive the real-time data and warning information sent by the ground wire monitor, store the abnormal data and warning information and forward them to the mobile APP terminal, facilitating equipment management personnel to query and monitor in real time, and providing a basis for equipment fault diagnosis, maintenance, maintenance, and repair.

[0044] This system uses a ground wire monitor, a cloud server, and a mobile APP terminal to implement a power supply device ground wire monitoring system. This system collects data such as ground wire voltage, ground wire current, zero-sequence current, three-phase current, ground wire surge voltage, ambient temperature, ambient humidity, ambient magnetic field strength, and the number of lightning strikes, dynamically calculates voltage thresholds and current thresholds, reduces the false alarm rate of abnormal data of power supply devices, and improves the convenience of power supply device management and maintenance services and reduces the possibility of accidents through early warning classification, remote monitoring via mobile APP, sound alarm of the ground wire monitor, mobile phone pop-up warning, controlling the leakage switch to trip, and lightning arrester; through design, simulation, and verification, a modular product is formed, which can be quickly transplanted between different platforms and accelerates the product development process.

[0045] Specifically, in the first embodiment, the ground wire monitor includes a non-contact voltage sensor, a Hall current sensor, a zero-flux current sensor, a three-phase current transmitter, a temperature sensor, a humidity sensor, a three-axis magnetometer, a surge voltage detection circuit, a lightning counter, a main control unit, a leakage switch, a solid-state switch, a lightning arrester, an alarm horn, and a 4G / 5G module;

[0046] Among them, the non-contact voltage sensor is connected to the main control unit through the AD port, used to collect the ground wire voltage signal, and send the signal to the main control unit through the AD port in the form of 0-10V or 4-20mA;

[0047] The Hall current sensor is connected to the main control unit through the AD port, used to collect the ground wire current signal, and send the signal to the main control unit through the AD port in the form of 0-10V or 4-20mA;

[0048] The zero-flux current sensor is connected to the main control unit through the AD port, used to collect the zero-sequence current signal, and send the signal to the main control unit through the AD port in the form of 0-10V or 4-20mA;

[0049] The three-phase current transmitter is connected to the main control unit through the AD port, used to collect the current signals of the three phases U\V\W of the power supply device, and send the signals to the main control unit through the AD port in the form of 0-10V or 4-20mA;

[0050] The temperature sensor is connected to the main control unit through the AD port, used to collect the ambient temperature signal, and send the signal to the main control unit through the AD port in the form of 0-10V or 4-20mA;

[0051] The humidity sensor is connected to the main control unit through the AD port, used to collect the ambient humidity signal, and send the signal to the main control unit through the AD port in the form of 0-10V or 4-20mA;

[0052] The three-axis magnetometer is connected to the main control unit through the AD port, which is used to collect the environmental magnetic field intensity signal and send the signal to the main control unit through the AD port in the form of 0-10V or 4-20mA;

[0053] The surge voltage detection circuit is connected to the main control unit through the AD port, which is used to collect the voltage signal when a surge occurs on the ground wire and send the signal to the main control unit through the AD port in the form of 0-10V;

[0054] The lightning counter is connected to the main control unit through the interrupt port, which is used to capture the lightning strike signal and send the signal to the main control unit through the interrupt port in the form of electrical pulses;

[0055] The leakage switch is connected to the main control unit through the RS485 port, which is used to receive the control signal sent by the main control unit and control the on-off of all live wires and neutral wires of the power supply equipment;

[0056] The solid-state switch is connected to the main control unit through the I / O port, which is used to receive the high and low level signals sent by the main control unit and control the opening or closing of the lightning arrester;

[0057] The alarm horn is connected to the main control unit through the I / O port, which is used to receive the high and low level signals sent by the main control unit and control the opening or closing of the alarm horn;

[0058] The main control unit is connected to the 4G / 5G module through the TTL serial port, which is used to receive the data of the non-contact voltage sensor, Hall current sensor, zero-flux current sensor, three-phase current transmitter, temperature sensor, humidity sensor, three-axis magnetometer, surge voltage detection circuit and lightning counter, control the status information of the leakage switch, solid-state switch, lightning arrester and alarm horn, and send it to the cloud server in the form of 4G / 5G signals.

[0059] Specifically, in the first embodiment, the surge voltage detection circuit includes a TVS diode, a trigger comparator and an opto-isolator; among them, the TVS diode is connected in parallel with the ground wire, which is used to collect the surge transient voltage when a surge occurs on the ground wire; the trigger comparator is used to receive the surge transient voltage and compare it with the preset voltage, and change the output state when it exceeds; the opto-isolator is used to receive the output signal of the trigger comparator and convert it into 0-10V and send it to the main control unit to prevent high-voltage crosstalk.

[0060] A ground wire monitoring system for a power supply device in this embodiment uses a ground wire monitor, a cloud server, and a mobile APP terminal to implement a ground wire monitoring system for a power supply device. This system collects data such as ground wire voltage, ground wire current, three-phase current, ground wire surge voltage, ambient temperature, ambient humidity, ambient magnetic field strength, and the number of lightning strikes, dynamically calculates voltage thresholds and current thresholds, reduces the false alarm rate of abnormal data of the power supply device, and improves the convenience of the management and maintenance service of the power supply device and reduces the possibility of accidents through early warning classification, remote monitoring by mobile APP, sound alarm of the ground wire monitor, mobile phone pop-up warning, controlling the leakage switch to trip, and lightning arrester; through design, simulation, and verification, a modular product is formed, which can be quickly transplanted between different platforms and accelerates the product development process.

[0061] Embodiment 2: A method for using a ground wire monitoring system for a power supply device is provided. It uses the ground wire monitoring system for a power supply device as described in Embodiment 1, and specifically includes the following steps:

[0062] S1. The main control unit obtains data such as ground wire voltage, ground wire current, zero-sequence current, three-phase current, ground wire surge voltage, ambient temperature, ambient humidity, ambient magnetic field strength, and the number of lightning strikes, and uses Daubechies wavelet decomposition to filter out high-frequency noise;

[0063] S2. Calculate the load intensity of the power supply device according to the device load rate formula;

[0064] S3. Select the initial values of the temperature correction coefficient, humidity correction coefficient, and magnetic field strength correction coefficient, calculate the environmental correction factor according to the environmental correction factor formula, calculate the load correction factor according to the load correction factor formula, and calculate the lightning strike correction factor according to the lightning strike correction factor formula;

[0065] S4. Calculate the theoretical voltage threshold and theoretical current threshold according to the ground wire theoretical voltage threshold formula and the ground wire theoretical current threshold formula;

[0066] S5. Use the EWMA algorithm voltage threshold formula, the EWMA algorithm current threshold formula, and threshold limiting to obtain the optimized final dynamic voltage threshold and final dynamic current threshold, and suppress threshold mutation;

[0067] S6. Use the normal historical data based on a 30-day sliding window, and use the least squares method to iteratively optimize the temperature correction coefficient, humidity correction coefficient, and magnetic field strength correction coefficient and update them;

[0068] S7. According to the real-time data of the sensor, the final dynamic voltage threshold, and the final dynamic current threshold, identify abnormal data, determine the level of the ground wire abnormal warning information, and take corresponding protection measures;

[0069] The cloud server stores real-time data and warning information, and forwards abnormal data and warning information to the mobile APP terminal, facilitating real-time query, monitoring, and processing by equipment management personnel, and providing a basis for equipment fault diagnosis, maintenance, and repair.

[0070] Specifically, in step S2, the formula for the equipment load rate is as follows:

[0071]

[0072] Where L represents the equipment load rate, in %; I u represents the current of phase U, in A; I v represents the current of phase V, in A; I w represents the current of phase W, in A; I0 represents the rated current, in A.

[0073] Specifically, in step S3, the formula for the environmental correction factor is as follows:

[0074] K e = 1 + α(T - 25) + β(H - 50%) + γ(B - 10) (2)

[0075] Where K e represents the environmental correction factor; T represents the environmental temperature, in °C; H represents the environmental humidity, in %; B represents the environmental magnetic field strength, in mT; α represents the temperature correction coefficient, with an initial value of 0.01; β represents the humidity correction coefficient, with an initial value of 0.005; γ represents the magnetic field strength correction coefficient, with an initial value of 0.003.

[0076] Specifically, in step S3, the formula for the load correction factor is as follows:

[0077]

[0078] Where K l represents the load correction factor; L represents the equipment load rate, in %.

[0079] Specifically, in step S3, the formula for the lightning strike correction factor is as follows:

[0080]

[0081] Where K g represents the lightning strike correction factor.

[0082] Specifically, in step S4, the formula for the theoretical voltage threshold is as follows:

[0083] U r = U b × K e × K l × Kg (5)

[0084] Among them, U r represents the theoretical voltage threshold, with the unit of V; U b represents the basic voltage threshold, generally taken as 10V; K e represents the environmental correction factor; K l represents the load correction factor; K g represents the lightning strike correction factor.

[0085] Specifically, in step S4, the formula for the theoretical current threshold is as follows:

[0086] I r = I b × K e × K l × K g (6)

[0087] Among them, I r represents the theoretical current threshold, with the unit of mA; I b represents the basic voltage threshold, generally taken as 30mA; K e represents the environmental correction factor; K l represents the load correction factor; K g represents the lightning strike correction factor.

[0088] Specifically, in step S5, the formula for the EWMA algorithm voltage threshold is as follows:

[0089] U0 = 0.7 × U t + 0.3 × U r (7)

[0090] Among them, U0 represents the calculated dynamic voltage threshold; U t represents the previous final dynamic voltage threshold; U r represents the theoretical voltage threshold, and the units are all V.

[0091] Specifically, in step S5, the formula for the EWMA algorithm current threshold is as follows:

[0092] I0 = 0.7 × I t + 0.3 × I r (8)

[0093] Among them, I0 represents the calculated dynamic current threshold; I t represents the previous final dynamic current threshold; I r represents the theoretical current threshold, and the units are all mA.

[0094] Specifically, in step S5, the threshold clipping is to compare the calculated dynamic voltage threshold to make it meet the range of [5V, 20V] as the final dynamic voltage threshold, and compare the calculated dynamic current threshold to make it meet the range of [10mA, 50mA] as the final dynamic current threshold.

[0095] Specifically, in step S7, the abnormal data refers to the surge voltage exceeding the final dynamic voltage threshold, the sum of zero-sequence currents not being zero, the ground wire voltage fluctuation exceeding 1KHz, the ground wire voltage or ground wire current reaching more than 80% of the final dynamic threshold, and lightning strike with the ground wire voltage or ground wire current exceeding the final dynamic threshold.

[0096] Specifically, in step S7, the ground wire abnormal warning information level means that when the surge voltage exceeds the final dynamic voltage threshold and the duration does not exceed 5S, or the ground wire voltage fluctuation exceeds 1KHz and the duration does not exceed 5S, a level-three warning information is triggered; when the surge voltage exceeds the final dynamic voltage threshold and the duration exceeds 5S, the ground wire voltage fluctuation exceeds 1KHz and the duration exceeds 5S, the sum of zero-sequence currents is not zero, the ground wire voltage or ground wire current reaches 80% of the final dynamic threshold and is less than the final dynamic threshold, a level-two warning information is triggered; when there is a lightning strike and the ground wire voltage or ground wire current exceeds the final dynamic threshold, a level-one warning information is triggered.

[0097] Specifically, in step S7, the corresponding protection measures include forwarding to the equipment management personnel for query in case of level-three warning and formulating a short-term maintenance plan; starting a mobile APP pop-up notification for equipment management personnel and formulating a diagnostic inspection plan for the day in case of level-two warning; starting a sound alarm of the ground wire monitor, controlling the leakage switch to trip and the lightning arrester to turn on, generating a maintenance work order, and sending a continuous vibration notification through the APP pop-up window for the equipment management personnel to query on the mobile phone and immediately repair in case of level-one warning.

[0098] As Figure 2 shown, the usage method of the power supply equipment ground wire monitoring system provided by the present invention specifically includes the following steps: first, obtain data of ground wire voltage, ground wire current, zero-sequence current, three-phase current, ground wire surge voltage, ambient temperature, ambient humidity, ambient magnetic field intensity, and the number of lightning strikes, and filter out high-frequency noise; then calculate the load intensity of the power supply equipment, ambient correction factor, load correction factor, and lightning strike correction factor, and substitute them into the ground wire theoretical voltage threshold formula and ground wire theoretical current threshold formula to calculate the theoretical voltage threshold and theoretical current threshold; then use the EWMA algorithm and threshold clipping to obtain the optimized final dynamic voltage threshold and final dynamic current threshold, and use the least squares method to iteratively optimize the coefficients. Subsequently, based on the real-time data of the sensor, the final dynamic voltage threshold, and the final dynamic current threshold, identify abnormal data, determine the ground wire abnormal warning information level, and take corresponding protection measures; finally, store the real-time data and warning information through the cloud server and forward them to the mobile APP terminal for the convenience of the equipment management personnel to query, monitor, and process in real time.

[0099] The usage method of the power supply equipment ground wire monitoring system in this embodiment adopts a modular design method. A power supply equipment ground wire monitoring system is implemented using a ground wire monitor, a cloud server, and a mobile APP terminal. This system collects data such as ground wire voltage, ground wire current, three-phase current, ground wire surge voltage, ambient temperature, ambient humidity, ambient magnetic field strength, and the number of lightning strikes, dynamically calculates voltage thresholds and current thresholds, reduces the false alarm rate of abnormal data of power supply equipment, and improves the convenience of power supply equipment management and maintenance services and reduces the possibility of accidents by means of early warning classification, remote monitoring via mobile APP, sound alarm of the ground wire monitor, mobile phone pop-up warning, controlling the leakage switch to trip, and lightning arrester.

[0100] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A ground wire monitoring system for a power supply device, characterized in that: It includes a ground wire monitor, a cloud server, and a mobile APP terminal; The ground wire monitor is connected to the cloud server through a 4G / 5G network, and is used to collect data such as ground wire voltage, ground wire current, zero-sequence current, three-phase current, ground wire surge voltage, ambient temperature, ambient humidity, ambient magnetic field strength, and the number of lightning strikes, dynamically calculate the ground wire voltage threshold and current threshold, determine the level of the ground wire anomaly warning information and take corresponding protection measures, and send real-time data and warning information to the cloud server; The cloud server is connected to the mobile APP terminal through a 4G / 5G network, and is used to receive the real-time data and warning information sent by the ground wire monitor, store the abnormal data and warning information and forward them to the mobile APP terminal.

2. The power supply equipment ground wire monitoring system according to claim 1, wherein: The ground wire monitor includes a non-contact voltage sensor, a Hall current sensor, a zero-flux current sensor, a three-phase current transmitter, a temperature sensor, a humidity sensor, a three-axis magnetometer, a surge voltage detection circuit, a lightning counter, a main control unit, a leakage switch, a solid-state switch, a lightning arrester, an alarm horn, and a 4G / 5G module; The non-contact voltage sensor is connected to the main control unit through an AD port, and is used to collect the ground wire voltage signal and send the signal to the main control unit through the AD port in the form of 0-10V or 4-20mA; The Hall current sensor is connected to the main control unit through an AD port, and is used to collect the ground wire current signal and send the signal to the main control unit through the AD port in the form of 0-10V or 4-20mA; The zero-flux current sensor is connected to the main control unit through an AD port, and is used to collect the zero-sequence current signal and send the signal to the main control unit through the AD port in the form of 0-10V or 4-20mA; The three-phase current transmitter is connected to the main control unit through an AD port, and is used to collect the current signals of the three phases U\V\W of the power supply equipment and send the signals to the main control unit through the AD port in the form of 0-10V or 4-20mA; The temperature sensor is connected to the main control unit through an AD port, and is used to collect the ambient temperature signal and send the signal to the main control unit through the AD port in the form of 0-10V or 4-20mA; The humidity sensor is connected to the main control unit through an AD port, and is used to collect the ambient humidity signal and send the signal to the main control unit through the AD port in the form of 0-10V or 4-20mA; The three-axis magnetometer is connected to the main control unit through an AD port, and is used to collect the ambient magnetic field strength signal and send the signal to the main control unit through the AD port in the form of 0-10V or 4-20mA; The surge voltage detection circuit is connected to the main control unit through an AD port, and is used to collect the voltage signal when a surge occurs on the ground wire and send the signal to the main control unit through the AD port in the form of 0-10V; The lightning counter is connected to the main control unit through an interrupt port, and is used to capture the lightning strike signal and send the signal to the main control unit through the interrupt port in the form of an electrical pulse; The leakage switch is connected to the main control unit through the RS485 port, and is used to receive the control signal sent by the main control unit to control the on-off of all live wires and neutral wires of the power supply equipment; The solid-state switch is connected to the main control unit through the I / O port, and is used to receive the high and low level signals sent by the main control unit to control the opening or closing of the lightning arrester; The alarm horn is connected to the main control unit through the I / O port, and is used to receive the high and low level signals sent by the main control unit to control the opening or closing of the alarm horn; The main control unit is connected to the 4G / 5G module through the TTL serial port, and is used to receive the data of the non-contact voltage sensor, Hall current sensor, zero-flux current sensor, three-phase current transmitter, temperature sensor, humidity sensor, three-axis magnetometer, surge voltage detection circuit and lightning counter, control the status information of the leakage switch, solid-state switch, lightning arrester and alarm horn, and send it to the cloud server as 4G / 5G signals.

3. The power supply equipment ground wire monitoring system according to claim 2, characterized in that: The surge voltage detection circuit includes a TVS diode, a trigger comparator and an opto-isolator. The TVS diode is connected in parallel with the ground wire and is used to collect the surge transient voltage when a surge occurs on the ground wire; the trigger comparator is used to receive the surge transient voltage and compare it with a preset voltage, and change the output state when it exceeds; the opto-isolator is used to receive the output signal of the trigger comparator and convert it into 0-10V and send it to the main control unit.

4. A method for using a power supply device ground wire monitoring system according to any one of claims 1-3, characterized in that, It includes the following steps: S1. The main control unit obtains the data of the ground wire voltage, ground wire current, zero-sequence current, three-phase current, ground wire surge voltage, ambient temperature, ambient humidity, ambient magnetic field intensity and the number of lightning strikes, and uses Daubechies wavelet decomposition to filter out high-frequency noise; S2. Calculate the load intensity of the power supply equipment according to the equipment load rate formula; S3. Select the initial values of the temperature correction coefficient, humidity correction coefficient and magnetic field intensity correction coefficient, calculate the environment correction factor according to the environment correction factor formula, the load correction factor according to the load correction factor formula, and the lightning strike correction factor according to the lightning strike correction factor formula; S4. Calculate the theoretical voltage threshold and theoretical current threshold according to the ground wire theoretical voltage threshold formula and the ground wire theoretical current threshold formula; S5. Use the EWMA algorithm voltage threshold formula, EWMA algorithm current threshold formula and threshold limiting to obtain the optimized final dynamic voltage threshold and final dynamic current threshold to suppress threshold mutation; S6. Use the normal historical data of a 30-day sliding window, and use the least squares method to iteratively optimize and update the temperature correction coefficient, humidity correction coefficient and magnetic field intensity correction coefficient; S7. According to the real-time data of the sensor, the final dynamic voltage threshold and the final dynamic current threshold, identify abnormal data, determine the level of the ground wire abnormal warning information, and take corresponding protection measures; S8. The cloud server stores the real-time data and warning information, forwards the abnormal data and warning information to the mobile APP terminal, which is convenient for equipment management personnel to query, monitor and process in real time, and provides a basis for equipment fault diagnosis, maintenance, maintenance and overhaul.

5. The method for using the power supply equipment ground wire monitoring system according to claim 4, characterized in that, In step S2, the equipment load rate formula is specifically as follows: Among them, L represents the device load rate, unit: %; I u represents the current of phase U, unit: A; I v represents the current of phase V, unit: A; I w represents the current of phase W, unit: A; I0 represents the rated current, unit: A.

6. The method for using the power supply device ground wire monitoring system according to claim 4, characterized in that, In step S3: The environment correction factor formula is specifically as follows: K e = 1 + α(T - 25) + β(H - 50%) + γ(B - 10) (2) Among them, K e represents the environmental correction factor; T represents the environmental temperature, with the unit of °C; H represents the environmental humidity, with the unit of %; B represents the environmental magnetic field strength, with the unit of mT; α represents the temperature correction coefficient, and the initial value is taken as 0.01; β represents the humidity correction coefficient, and the initial value is taken as 0.005; γ represents the magnetic field strength correction coefficient, and the initial value is taken as 0.003; The formula for the load correction factor is as follows: Among them, K l represents the load correction factor; L represents the equipment load rate, in %; The formula for the lightning strike correction factor is as follows: Among them, K g represents the lightning strike correction factor.

7. The method of using the power supply device ground wire monitoring system according to claim 4, characterized in that In step S4: The formula for the theoretical voltage threshold is as follows: U r = U b × K e × K l × K g (4) Among them, U r represents the theoretical voltage threshold, with the unit of V. U b represents the basic voltage threshold, generally taken as 10V. K e represents the environmental correction factor. K l represents the load correction factor. K g represents the lightning strike correction factor; The formula for the theoretical current threshold is as follows: I r = I b × K e × K l × K g (5) Among them, I r represents the theoretical current threshold, in mA; I b represents the voltage base threshold, generally taken as 30 mA; K e represents the environmental correction factor; K l represents the load correction factor; K g represents the lightning strike correction factor.

8. The method of using the power supply equipment ground wire monitoring system according to claim 4, characterized in that, In step S5: The formula for the voltage threshold of the EWMA algorithm is as follows: U0 = 0.7×U t + 0.3×U r (6) Among them, U0 represents the calculated dynamic voltage threshold; U t represents the previous final dynamic voltage threshold; U r represents the theoretical voltage threshold, and the unit of all is V; The formula for the current threshold of the EWMA algorithm is as follows: I0 = 0.7×I t + 0.3×I r (7) Among them, I0 represents the calculated dynamic current threshold; I t represents the previous final dynamic current threshold; I r represents the theoretical current threshold, and the unit of all is mA; The threshold limiting means comparing the calculated dynamic voltage threshold to make it satisfy between [5V, 20V] as the final dynamic voltage threshold, and comparing the calculated dynamic current threshold to make it satisfy between [10mA, 50mA] as the final dynamic current threshold.

9. The method for using the power supply equipment ground wire monitoring system according to claim 4, characterized in that, In step S7: The abnormal data refers to the surge voltage exceeding the final dynamic voltage threshold, the sum of zero-sequence currents not being 0, the ground wire voltage fluctuating exceeding 1KHz, the ground wire voltage or ground wire current reaching more than 80% of the final dynamic threshold, lightning strike and the ground wire voltage or ground wire current exceeding the final dynamic threshold; The level of the ground wire abnormal warning information refers to that when the surge voltage exceeds the final dynamic voltage threshold and the duration does not exceed 5S or the ground wire voltage fluctuates exceeding 1KHz and the duration does not exceed 5S, a level-three warning information is triggered; when the surge voltage exceeds the final dynamic voltage threshold and the duration exceeds 5S, the ground wire voltage fluctuates exceeding 1KHz and the duration exceeds 5S, the sum of zero-sequence currents is not 0, the ground wire voltage or ground wire current reaches 80% of the final dynamic threshold and is less than the final dynamic threshold, a level-two warning information is triggered; Lightning strike and the ground wire voltage or ground wire current exceeding the final dynamic threshold trigger a level-one warning information; The corresponding protective measures include forwarding to the equipment management personnel for query and formulating a short-term maintenance plan for level-three warning; For level-two warning, a pop-up notification on the mobile APP of the equipment management personnel is initiated and a diagnostic inspection plan for the day is formulated; for level-one warning, a sound alarm of the ground wire monitor is initiated, the leakage switch is controlled to trip and the lightning arrester is turned on, a maintenance work order is generated, and a continuous vibration notification with a pop-up on the mobile APP of the equipment management personnel is used for mobile query and immediate maintenance.

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