Safety power supply management system for portable electric equipment in temporary power engineering

Abstract

The application discloses a kind of portable power utilization equipment's safety power supply management system in temporary power utilization engineering, belong to electrical safety protection technical field.Existing adaptive leakage protection scheme lacks safety constraints when adjusting protection threshold, it is difficult to take into account the safety of protection and power supply continuity.The application sets up environmental detection module to collect humidity data at each power utilization equipment side, and the dynamic correction module independently generates corresponding corrected leakage protection operating current threshold and operating time threshold according to the humidity of each equipment location, reduces the reference leakage protection operating current threshold when humidity increases, and ensures that the corrected threshold is not higher than the preset highest safety threshold, and the corrected operating time threshold does not exceed the reference value.The application realizes the precise protection of the microenvironment difference of each equipment, ensures that the threshold does not break the safety red line, takes into account the safety of leakage protection and power supply continuity, and is suitable for leakage safety power supply management of portable power utilization equipment in temporary power utilization engineering such as construction site.

Description

Technical Field

[0001] This invention relates to the field of electrical safety protection technology. More specifically, this invention relates to a safe power supply management system for portable electrical equipment in temporary power supply projects. Background Technology

[0002] In temporary power supply projects, portable electrical equipment such as handheld drills, cutting machines, welding machines, and lighting fixtures face severe challenges to power supply safety due to frequent movement, repeated cable retraction and deployment, and variable operating environments. Residual current devices (RCDs) are a crucial measure to ensure the personal safety of operators. Currently, residual current operated devices (RCDs) are commonly used to provide leakage protection for electrical equipment. Their operating current threshold and operating time threshold are set to fixed values ​​at the factory and do not change with external environmental variations during equipment use.

[0003] However, the working environment for temporary power supply projects is often harsh, with significant humidity fluctuations. For example, outdoor work may encounter rain or snow, while indoor work may face damp concrete environments or condensation. When ambient humidity increases, the insulation resistance of electrical equipment and power cables to ground decreases significantly, leading to an increase in inherent leakage current. In this situation, using a fixed-threshold leakage current device (RCD) presents two problems: first, the increased inherent leakage current may cause frequent malfunctions, resulting in unnecessary power outages and affecting construction progress; second, setting the threshold too high to prevent malfunctions may prevent timely action in the event of a real electric shock, leading to protection failure. To address this issue, some existing technologies have proposed adaptive protection schemes that dynamically adjust the leakage current protection threshold based on ambient humidity.

[0004] However, existing adaptive leakage current protection schemes often focus solely on preventing false trips by increasing the threshold when adjusting it, neglecting the fundamental purpose of leakage current protection: to ensure personal safety. The lack of safety constraints on the threshold adjustment range in existing schemes makes it easy for the threshold to be raised to over 30mA in high humidity environments. This directly violates the mandatory provision of national standard GB / T 13955-2017 regarding the rated residual operating current in direct contact electric shock protection not exceeding 30mA, posing a significant safety hazard.

[0005] In addition, most existing adaptive leakage current protection schemes make uniform adjustments based on the overall environment of a single device, ignoring the possible differences in the microenvironment of different electrical devices in the same power supply circuit, and are unable to implement differentiated and precise protection based on the actual humidity conditions of each device. Summary of the Invention

[0006] One object of the present invention is to solve at least the above-mentioned problems and to provide at least the advantages that will be described later.

[0007] Another objective of this invention is to provide a safe power supply management system for portable electrical equipment in temporary power supply projects. This system addresses the problem that existing adaptive leakage current protection schemes lack safety constraints for threshold adjustment and do not consider the micro-environmental differences of different devices in the same circuit, thus failing to balance the safety of leakage current protection with the continuity of power supply.

[0008] To achieve these objectives and other advantages according to the present invention, a safe power supply management system for portable electrical equipment in temporary power supply projects is provided, comprising:

[0009] Multiple environmental detection modules are installed on each electrical device side, and each environmental detection module is used to collect the current ambient humidity data of the location of the electrical device.

[0010] The reference parameter storage module has preset reference leakage current threshold and reference action time threshold.

[0011] The dynamic correction module is connected to the plurality of environmental detection modules and the reference parameter storage module respectively, and is used to generate the corrected leakage current threshold and the corrected action time threshold for each electrical device according to the current environmental humidity data of the location of each electrical device.

[0012] When the current ambient humidity data at the location of any electrical device increases, the dynamic correction module correspondingly reduces the reference leakage current threshold of the electrical device, and the corrected leakage current threshold of each electrical device is not higher than the preset maximum safety threshold, and the corrected action time threshold of each electrical device does not exceed the reference action time threshold.

[0013] Multiple local protection execution modules are respectively set on the side of each electrical device. Each local protection execution module is signal connected to the dynamic correction module and is used to cut off the power supply to the electrical device when the leakage current detection value of the electrical device exceeds the corrected leakage current action current threshold of the electrical device and the duration exceeds the corrected action time threshold of the electrical device.

[0014] Preferably, the preset maximum safety threshold is 30mA.

[0015] Preferably, it also includes a device identification module, which is used to identify the device type of each connected electrical device and send a parameter call instruction to the reference parameter storage module according to the identified device type;

[0016] The reference parameter storage module is pre-set with reference leakage current threshold and reference action time threshold corresponding to different equipment types.

[0017] In response to the parameter call command, the reference parameter storage module outputs the reference leakage current threshold and reference action time threshold corresponding to the device type to the dynamic correction module, which serve as the reference leakage current threshold and reference action time threshold for the electrical equipment, so that electrical equipment of different types can obtain differentiated leakage protection parameters that match their electrical characteristics.

[0018] Preferably, it also includes an error correction module, which is used to compensate online for the zero-point drift deviation of the detection circuit in the leakage current detection loop caused by the ambient humidity, based on the current ambient humidity data, and output the corrected leakage current value.

[0019] The corrected leakage current value is the detection loop current value after compensating for the zero-point drift deviation, and the corrected leakage current value includes the inherent leakage current component generated by the electrical equipment and power supply cable to ground; the leakage current detection value is the corrected leakage current value, and the local protection execution module performs a disconnection action based on the corrected leakage current value.

[0020] Preferably, the environmental detection module is also used to calculate the rate of change of humidity within a preset time window;

[0021] The dynamic correction module includes an amplitude correction factor and a rate correction factor. The amplitude correction factor is generated based on the current ambient humidity value and is used to perform nonlinear compensation on the reference leakage current threshold. The rate correction factor is generated based on the humidity change rate and is used to perform nonlinear compensation on the reference operating time threshold.

[0022] The dynamic correction module outputs the corrected leakage current threshold as the product of the reference leakage current protection operating current threshold and the amplitude correction factor, and outputs the corrected operating time threshold as the product of the reference operating time threshold and the rate correction factor.

[0023] Preferably, the dynamic correction module further includes a limiting unit, which is used to limit the amplitude correction factor to the range of 0.5 to 1.0 and the rate correction factor to the range of 0.5 to 1.0.

[0024] Preferably, it also includes a fault detection module, which is signal-connected to the environmental detection module and is used to output a fault shielding signal to the dynamic correction module when the current environmental humidity data exceeds the preset effective range.

[0025] After receiving the fault shielding signal, the dynamic correction module stops outputting the corrected leakage current threshold and the corrected action time threshold. The local protection execution module directly uses the reference leakage current threshold and the reference action time threshold to determine leakage protection.

[0026] Preferably, when the device identification module cannot identify the device type of the currently connected electrical device, the reference parameter storage module outputs a default reference parameter, which is the lowest leakage current threshold and the shortest operating time threshold corresponding to all device types pre-stored in the reference parameter storage module; the local protection execution module is also used to block the power supply output of the electrical device when the device identification module cannot identify the device type of the currently connected electrical device, until an external manual confirmation release signal is received.

[0027] Preferably, it also includes:

[0028] The circuit monitoring module is signal-connected to multiple local protection execution modules in the same power supply circuit, and is used to obtain the corrected leakage current value corresponding to each electrical device and calculate the current total leakage current value of the power supply circuit.

[0029] The circuit monitoring module compares the current total leakage current value with a preset first threshold and a second threshold. The first threshold is less than the second threshold, and the second threshold is less than or equal to the rated operating current value of the upstream leakage current protection device of the power supply circuit.

[0030] When the current total leakage current value exceeds the first threshold, the circuit monitoring module outputs a first-level early warning signal to each electrical device in the power supply circuit;

[0031] When the current total leakage current value exceeds the second threshold, the circuit monitoring module outputs a second-level warning signal to each electrical device in the power supply circuit, and collects the corrected leakage current value of each electrical device at the moment of outputting the second-level warning signal as a leakage snapshot before disconnection for storage.

[0032] The circuit monitoring module is also used to compare the corrected leakage current values ​​of each electrical device in the same power supply circuit with the corrected leakage current value in the leakage snapshot before the cut-off, based on the corrected leakage current value of the cut-off device in the leakage snapshot before the cut-off. The smaller the difference between the two values, the higher the suspicion of leakage fault of the electrical device.

[0033] The circuit monitoring module generates and outputs a fault investigation priority ranking of each electrical device in the power supply circuit according to the order of the suspicion of leakage fault from high to low.

[0034] Preferably, the circuit monitoring module is also used to attempt to restore the power supply to each of the uncut electrical devices in the power supply circuit in turn, according to the fault investigation priority order, after the local protection execution module cuts off the power supply to any electrical device.

[0035] The circuit monitoring module recalculates the current total leakage current value of the power supply circuit after each attempt to restore power to an electrical device.

[0036] If the current total leakage current value exceeds the second threshold, the loop monitoring module outputs a cut-off signal to the local protection execution module of the electrical equipment and continues to attempt to restore power supply to the next electrical equipment in the fault troubleshooting priority ranking.

[0037] If the current total leakage current value does not exceed the second threshold, the power supply status of the electrical equipment is maintained, and attempts are made to restore the power supply to the next electrical equipment in the fault troubleshooting priority ranking.

[0038] The present invention has at least the following beneficial effects:

[0039] By setting up environmental detection modules on each electrical device side, the dynamic correction module can independently generate corresponding corrected thresholds based on the actual humidity of each device's location. This achieves precise protection based on micro-environmental differences, avoiding the problem of different devices in the same circuit not receiving matching protection due to different humidity levels. At the same time, by setting a preset maximum safety threshold, it ensures that the corrected current threshold never exceeds this upper limit, fundamentally eliminating the hidden danger of exceeding the safety red line by adjusting the threshold. Furthermore, when the humidity increases, the current threshold is reduced accordingly, and the action time threshold is ensured not to exceed the benchmark value. This makes the protection more stringent as the environment becomes more severe, ensuring both personal safety and power supply continuity. It is suitable for leakage current safety management of portable electrical devices in temporary power supply projects such as construction sites.

[0040] Other advantages, objectives and features of the present invention will become apparent in part from the following description, and in part from those skilled in the art through study and practice of the invention. Detailed Implementation

[0041] The present invention will be further described in detail below with reference to embodiments, so that those skilled in the art can implement it based on the description.

[0042] This invention provides a safe power supply management system for portable electrical equipment in temporary power supply projects, comprising:

[0043] Multiple environmental detection modules are installed on each electrical device side, and each environmental detection module is used to collect the current ambient humidity data of the location of the electrical device.

[0044] The reference parameter storage module has preset reference leakage current threshold and reference action time threshold.

[0045] The dynamic correction module is connected to the plurality of environmental detection modules and the reference parameter storage module respectively, and is used to generate the corrected leakage current threshold and the corrected action time threshold for each electrical device according to the current environmental humidity data of the location of each electrical device.

[0046] When the current ambient humidity data at the location of any electrical device increases, the dynamic correction module correspondingly reduces the reference leakage current threshold of the electrical device, and the corrected leakage current threshold of each electrical device is not higher than the preset maximum safety threshold, and the corrected action time threshold of each electrical device does not exceed the reference action time threshold.

[0047] Multiple local protection execution modules are respectively set on the side of each electrical device. Each local protection execution module is signal connected to the dynamic correction module and is used to cut off the power supply to the electrical device when the leakage current detection value of the electrical device exceeds the corrected leakage current action current threshold of the electrical device and the duration exceeds the corrected action time threshold of the electrical device.

[0048] In the above technical solution, the safe power supply management system, in actual implementation, mainly includes an environmental detection module, a reference parameter storage module, a dynamic correction module, and a local protection execution module. Multiple environmental detection modules are respectively installed on the side of each electrical device. Each environmental detection module can use a capacitive humidity sensor or a resistive humidity sensor. During specific installation, the humidity sensor can be installed inside the power plug housing of the electrical device, inside the insulating shell of the power cord inlet, or at the air inlet or vent of the electrical device to obtain the most representative humidity data of the microenvironment in which the device is located. Each humidity sensor is connected to the dynamic correction module via shielded cable or wireless communication, transmitting the collected current environmental humidity data to the dynamic correction module in real time.

[0049] The reference parameter storage module can use non-volatile memory, such as electrically erasable programmable read-only memory or flash memory, which internally has preset reference leakage current threshold and reference action time threshold. The current threshold can be set to 15mA, 20mA, or 30mA according to the type and power level of the electrical equipment, and the action time threshold can be set to 0.04s, 0.1s, or 0.3s. For example, for equipment with direct contact operation such as handheld electric drills, the reference current threshold can be set to 15mA to provide more stringent protection; for equipment with indirect contact operation such as welding machines, the reference current threshold can be set to 30mA. The dynamic correction module can use a digital signal processor or microcontroller, which maintains signal connection with each environmental detection module and the reference parameter storage module through signal lines or communication buses.

[0050] The dynamic correction module acquires the current ambient humidity data of each electrical device's location via signal connection, and retrieves the corresponding baseline leakage current threshold and baseline operating time threshold for each device from the baseline parameter storage module. Then, based on the humidity data of each device, it generates the corrected leakage current threshold and corrected operating time threshold for each device. When the current ambient humidity at any electrical device's location increases, the dynamic correction module correspondingly lowers the baseline leakage current threshold for that device. This reduction process can employ a piecewise linear relationship; for example, the baseline value remains unchanged when the humidity is between 0 and 60%, it is reduced linearly when the humidity is between 60% and 80%, and it is reduced to 50% to 80% of the baseline value when the humidity exceeds 80%. Alternatively, this reduction process can employ a functional relationship; for example, the corrected current threshold equals the baseline current threshold multiplied by an amplitude correction factor, which decreases as the humidity increases, and its value can range from 0.5 to 1.0. The correction coefficient table corresponding to different humidity ranges can be pre-written into the reference parameter storage module, and the dynamic correction module can obtain the correction coefficient corresponding to the current humidity by looking up the table.

[0051] For correcting the action time threshold, the dynamic correction module processes the baseline action time threshold based on the current ambient humidity data to ensure that the corrected action time threshold does not exceed the baseline action time threshold. In practice, this correction can be similar to that used for the current threshold. For example, the corrected action time threshold can be equal to the baseline action time threshold multiplied by a rate correction factor. This rate correction factor decreases as the humidity increases, ranging from 0.5 to 1.0, so that the action time threshold shortens or remains unchanged as humidity increases. Similarly, a rate correction coefficient table corresponding to different humidity ranges can be pre-written into the baseline parameter storage module, and the dynamic correction module retrieves the rate correction coefficient corresponding to the current humidity by looking up the table. It should be noted that regardless of the correction method used, the corrected leakage current threshold for each electrical device will not exceed the preset maximum safety threshold, which can be set to 30mA to ensure that this safety limit is not exceeded under any humidity conditions. Simultaneously, the corrected action time threshold for each electrical device will not exceed the device's baseline action time threshold. The dynamic correction module can perform correction calculations according to a preset time period, which can be set to 1s, 5s, or 10s.

[0052] Multiple local protection execution modules are respectively installed on the side of each electrical device. Each local protection execution module includes a leakage current detection element and a switching actuator. The leakage current detection element can be a zero-sequence current transformer, which is installed at the power supply line input terminal of the electrical device to detect the leakage current value of the electrical device in real time. The switching actuator can be an electromagnetic relay or a solid-state relay, which is installed on the power input line of the electrical device, located after the zero-sequence current transformer. Each local protection execution module is connected to the dynamic correction module via a signal connection, receiving the corrected leakage current threshold and the corrected operating time threshold corresponding to the electrical device, and using them as the current protection setting value.

[0053] In operation, the leakage current detection element in each local protection execution module monitors the leakage current value of the electrical equipment in real time. When the leakage current value exceeds the corrected leakage protection operating current threshold, the timer built into the local protection execution module starts counting. If the leakage current value falls below the threshold during the counting period, the timer is reset and monitoring restarts. If the leakage current value continues to exceed the threshold and the counting time reaches the corrected operating time threshold, the local protection execution module drives the switch actuator to cut off the power supply to the electrical equipment. The local protection execution module can also be equipped with an anti-jitter circuit to prevent false triggering of the cut-off due to transient interference signals. In actual use, the signal connection between the modules can be wired, such as RS485 bus or CAN bus, or wirelessly, such as Bluetooth or ZigBee. The power supply for each module can be provided by the power supply line of the electrical equipment or by an independently set DC power supply module.

[0054] This system features an independent environmental detection module on each piece of electrical equipment. This allows the dynamic correction module to generate corresponding corrected thresholds based on the actual humidity at each device's location, achieving differentiated leakage current protection for each device based on its own microenvironment. By lowering the current threshold when humidity increases while ensuring the corrected threshold does not exceed the preset maximum safety threshold, and by ensuring the corrected action time threshold does not exceed the baseline action time threshold, the protection becomes more stringent when ambient humidity rises. This effectively avoids unnecessary power outages while ensuring personal safety, balancing the safety and construction efficiency of temporary power supply projects.

[0055] In another technical solution, the preset maximum safety threshold is 30mA.

[0056] In the above technical solution, the preset maximum safety threshold can be set to 30mA. This value is selected based on the provisions of the national standard GB / T 13955-2017 regarding protection against direct contact electric shock, namely, the rated residual operating current of residual current operated protective devices used for protection against direct contact electric shock should not exceed 30mA.

[0057] In practical implementation, the 30mA threshold can be written into the reference parameter storage module during system initialization as an upper limit constraint value. After the dynamic correction module corrects the reference leakage current threshold of any electrical device, it compares the corrected current threshold with the 30mA. If the corrected value is higher than 30mA, it is forcibly limited to 30mA; if it is lower than or equal to 30mA, the corrected value remains unchanged. This ensures that the corrected leakage current threshold of each electrical device does not exceed the safety limit of 30mA under any environmental humidity conditions.

[0058] In another technical solution, a device identification module is also included. The device identification module is used to identify the device type of each connected electrical device and send a parameter call instruction to the reference parameter storage module according to the identified device type.

[0059] The reference parameter storage module is pre-set with reference leakage current threshold and reference action time threshold corresponding to different equipment types.

[0060] In response to the parameter call command, the reference parameter storage module outputs the reference leakage current threshold and reference action time threshold corresponding to the device type to the dynamic correction module, which serve as the reference leakage current threshold and reference action time threshold for the electrical equipment, so that electrical equipment of different types can obtain differentiated leakage protection parameters that match their electrical characteristics.

[0061] In the above technical solutions, the device identification module can identify the type of electrical equipment in various ways during actual implementation. The device identification module can be located at the power plug of the electrical equipment or the input end of the power supply line, maintaining a signal connection with each electrical device. In one embodiment, the device identification module can identify the device type by reading the device type code stored internally by the electrical equipment. The electrical equipment may have a storage chip storing parameters such as the device type code, rated power, and rated voltage. The device identification module reads the information from the storage chip via a single-bus protocol or an I2C bus protocol. In another embodiment, the device identification module can identify the device type by detecting the waveform characteristics of the starting current of the electrical equipment. Different types of electrical equipment have different current waveform characteristics during startup; for example, motor-type equipment has a large starting inrush current, while resistive load equipment experiences a steady rise in current during startup. In yet another embodiment, the device identification module can obtain the device type through manual input; that is, after the electrical equipment is connected to the system, the operator selects the currently connected device type via buttons or a touchscreen.

[0062] The reference parameter storage module is pre-loaded with reference leakage current thresholds and reference action time thresholds corresponding to different device types. This module can use non-volatile memory and internally establishes a parameter index table according to device type, with each device type corresponding to a set of reference parameters. For example, for handheld power tools such as handheld drills, the reference leakage current threshold can be set to 15mA and the reference action time threshold to 0.04s. For fixed or semi-fixed installed equipment such as welding machines, the reference leakage current threshold can be set to 30mA and the reference action time threshold to 0.1s. For benchtop power tools such as cutting machines, the reference leakage current threshold can be set to 20mA and the reference action time threshold to 0.04s. For lighting fixtures, the reference leakage current threshold can be set to 10mA and the reference action time threshold to 0.04s. This parameter index table can be pre-written at the system factory or modified and updated on-site using configuration tools.

[0063] Once the device identification module identifies the device type of the currently connected electrical equipment, it sends a parameter call command to the reference parameter storage module based on the identified device type. This parameter call command contains the device type code or device type identifier information. Upon receiving the call command, the reference parameter storage module uses the device type code as an index to search its internally stored parameter index table for the reference residual current protection operating current threshold and reference operating time threshold corresponding to that device type. In response to the parameter call command, the reference parameter storage module outputs the reference residual current protection operating current threshold and reference operating time threshold corresponding to the current device type to the dynamic correction module, which serve as the reference residual current protection operating current threshold and reference operating time threshold for that electrical equipment.

[0064] After receiving the reference parameters corresponding to the electrical equipment, the dynamic correction module corrects the reference parameters based on the current ambient humidity data of the equipment's location, as described above, to generate the corrected leakage current threshold and the corrected operating time threshold for the electrical equipment. These corrected thresholds are related to both the equipment type and the humidity of its location, achieving precise protection that considers both the differences in the equipment's own electrical characteristics and the differences in the humidity of its microenvironment.

[0065] After receiving the corrected leakage current threshold and corrected operating time threshold for the corresponding electrical device from the dynamic correction module, the local protection execution module uses these two corrected thresholds as the current protection setting for the electrical device. When the leakage current detection value of the electrical device exceeds the corrected leakage current threshold and the duration exceeds the corrected operating time threshold, the local protection execution module cuts off the power supply to the electrical device.

[0066] Through the above method, the system can automatically call up the benchmark leakage current protection parameters that match the electrical characteristics of the connected electrical equipment. Then, it corrects the benchmark parameters based on the current ambient humidity of the equipment's location, so that different types of electrical equipment obtain differentiated leakage current protection parameters that match their electrical characteristics. For example, when a handheld electric drill and a welding machine are connected to the same power supply circuit, the equipment identification module identifies the types of the two devices and calls up the corresponding benchmark parameters for each. Then, it generates corrected thresholds based on the humidity of their respective locations. The handheld electric drill receives a more stringent action threshold, while the welding machine receives a relatively lenient action threshold. Each device obtains a protection level that is adapted to its own safety requirements, avoiding the safety risks of insufficient protection for direct contact equipment and the frequent power outages caused by excessive protection for indirect contact equipment, thus balancing electrical safety and construction efficiency.

[0067] In another technical solution, an error correction module is also included. The error correction module is used to compensate online for the zero-point drift deviation of the detection circuit in the leakage current detection loop caused by the ambient humidity, based on the current ambient humidity data, and output the corrected leakage current value.

[0068] The corrected leakage current value is the detection loop current value after compensating for the zero-point drift deviation, and the corrected leakage current value includes the inherent leakage current component generated by the electrical equipment and power supply cable to ground; the leakage current detection value is the corrected leakage current value, and the local protection execution module performs a disconnection action based on the corrected leakage current value.

[0069] In the above technical solution, the error correction module can achieve online compensation for the zero-point drift of the detection circuit using either hardware or software compensation methods. This error correction module can be integrated into the local protection execution module or set as an independent functional module between the local protection execution module and the leakage current detection element. The zero-point drift deviation of the detection circuit itself due to ambient humidity mainly originates from the parameter drift of analog circuit components such as operational amplifiers, analog-to-digital converters, and external resistor voltage divider networks when humidity changes. When humidity increases, a weak water film may form on the circuit board surface, causing a change in the equivalent resistance of the resistor network, resulting in a non-zero output offset when there is no leakage current input. This zero-point drift deviation can be handled by temperature compensation. In specific implementation, a thermistor or integrated temperature and humidity sensor can be set in the detection circuit at the same location as the humidity sensor, and the humidity data can be simultaneously sent to the error correction module as the compensation basis.

[0070] In the hardware compensation method, the error correction module can include an adjustable reference voltage source. This adjustable reference voltage source outputs a compensation voltage opposite to the zero-point drift direction based on the current ambient humidity data. This compensation voltage is superimposed on the output of the detection circuit, so that the output of the detection circuit is zero when there is no leakage current input. This adjustable reference voltage source can be constructed using a digital potentiometer and an operational amplifier. The dynamic correction module outputs the compensation voltage value corresponding to the current humidity data to the control terminal of the digital potentiometer through a digital-to-analog converter, thereby adjusting the output value of the adjustable reference voltage source. In the software compensation method, a table showing the correspondence between humidity and zero-point drift can be pre-stored in the reference parameter storage module. For example, the zero-point drift is 0.5mA at 40% humidity, 1.2mA at 60% humidity, and 2.5mA at 80% humidity. After reading the current humidity data, the error correction module obtains the zero-point drift corresponding to the current humidity by looking up a table. Then, it subtracts this zero-point drift from the original leakage current detection value output by the detection circuit to obtain the corrected leakage current value. This software compensation process can be completed in the dynamic correction module, or it can be executed by the microcontroller in the local protection execution module after receiving the original detection value.

[0071] Regardless of whether hardware or software compensation is used, the corrected leakage current value output by the error correction module is the detection loop current value after compensating for the zero-point drift deviation of the detection circuit itself. This corrected leakage current value includes the inherent leakage current component generated by the electrical equipment and power supply cables to ground. That is, the error correction module only deducts the zero-point drift deviation of the detection circuit itself, and does not deduct the inherent leakage current generated by the insulation of the equipment and the distributed capacitance of the cables. In practical implementation, when the electrical equipment is operating normally in a dry environment, its inherent leakage current is usually 2mA to 8mA. This leakage current increases as the equipment insulation ages or the cables become damp. Since the error correction module does not deduct this inherent leakage current component, when the local protection execution module performs a disconnection action based on the corrected leakage current value, this inherent leakage current component is always included as part of the leakage current in the protection judgment.

[0072] The local protection execution module receives the corrected leakage current value as the leakage current detection value, i.e., the leakage current detection value is the corrected leakage current value. The local protection execution module performs a disconnection action based on this corrected leakage current value. In specific operation, the local protection execution module receives the corrected leakage current value output by the error correction module in real time and compares this value with the corrected leakage protection operating current threshold output by the dynamic correction module. When the corrected leakage current value exceeds the corrected leakage protection operating current threshold and the duration exceeds the corrected operating time threshold, the power supply to the electrical equipment is cut off. Since the error correction module does not deduct the inherent leakage current component of the electrical equipment itself, when humidity increases, the increase in inherent leakage current caused by moisture absorption of the equipment insulation will be fully reflected by the corrected leakage current value. This, combined with the corrected current threshold lowered due to increased humidity, makes the system more likely to trigger protection actions when humidity rises, thus providing more sensitive safety protection when the equipment insulation performance deteriorates.

[0073] In this technical solution, the error correction module compensates online for the zero-point drift deviation of the detection circuit itself, avoiding deviations in protection threshold judgment caused by detection circuit drift, thus improving the accuracy of leakage current detection and the reliability of protection action. Since the corrected leakage current value retains the inherent leakage current component generated by the electrical equipment and power supply cables to ground, the system can incorporate the increase in inherent leakage current into the protection judgment criteria when the insulation of the equipment deteriorates due to increased ambient humidity. Combined with the dynamic correction module's strategy of lowering the current threshold when humidity increases, a two-way tightening effect is formed, with both the detection value increasing and the threshold decreasing. This makes the protection action more sensitive in humid environments, further improving the level of electrical safety.

[0074] In another technical solution, the environmental detection module is also used to calculate the rate of change of humidity within a preset time window;

[0075] The dynamic correction module includes an amplitude correction factor and a rate correction factor. The amplitude correction factor is generated based on the current ambient humidity value and is used to perform nonlinear compensation on the reference leakage current threshold. The rate correction factor is generated based on the humidity change rate and is used to perform nonlinear compensation on the reference operating time threshold.

[0076] The dynamic correction module outputs the corrected leakage current threshold as the product of the reference leakage current protection operating current threshold and the amplitude correction factor, and outputs the corrected operating time threshold as the product of the reference operating time threshold and the rate correction factor.

[0077] In the above technical solution, the environmental monitoring module collects the current ambient humidity data of each electrical device's location and also calculates the humidity change rate within a preset time window. This preset time window can be set according to the actual needs of the temporary power supply project; for example, it can be set to 10s, 30s, or 60s, or even longer, such as 5min or 10min. In practical implementation, the environmental monitoring module continuously collects humidity data and records it at a certain sampling frequency, which can be set to 1Hz, 0.5Hz, or 0.2Hz, meaning it collects humidity values ​​once per second or every two seconds.

[0078] The environmental monitoring module can be equipped with a data buffer, which stores all humidity data collected within a preset time window. When the latest humidity data is collected, the environmental monitoring module stores the latest data in the buffer and automatically removes the oldest data from the buffer, so that the buffer always contains a complete sequence of humidity data within the preset time window.

[0079] The humidity change rate can be calculated by dividing the difference between the latest and earliest humidity values ​​collected in the buffer by the duration of a preset time window. For example, if the preset time window is 60 seconds, the humidity at the start of the window is 55%, and the humidity at the end of the window is 70%, then the humidity change rate is (70% - 55%) / 60 seconds = 0.25% / second.

[0080] The dynamic correction module includes an amplitude correction factor and a rate correction factor. The amplitude correction factor is generated based on the current ambient humidity level and is used for nonlinear compensation of the reference leakage current protection operating current threshold. This nonlinear compensation refers to a nonlinear correspondence between humidity and the current threshold correction amount. In practice, a piecewise nonlinear approach can be used. For example, when the humidity is between 0% and 50%, the amplitude correction factor is 1.0; when the humidity is between 50% and 70%, the amplitude correction factor linearly decreases from 1.0 to 0.85; when the humidity is between 70% and 90%, the amplitude correction factor linearly decreases from 0.85 to 0.6; and when the humidity exceeds 90%, the amplitude correction factor is 0.5. The dynamic correction module multiplies the reference leakage current protection operating current threshold by this amplitude correction factor to obtain the corrected leakage current protection operating current threshold, thereby achieving the effect of nonlinearly reducing the current threshold as humidity increases.

[0081] The rate correction factor, generated based on the humidity change rate, is used for nonlinear compensation of the baseline action time threshold. This factor reflects the impact of the rate of change in ambient humidity on the action time threshold. In practice, the rate correction factor can be set to be negatively correlated with the absolute value of the humidity change rate; that is, the larger the absolute value of the humidity change rate, the smaller the rate correction factor, thus shortening the action time threshold accordingly. For example, when the humidity change rate is 0 to 0.1% / s, the rate correction factor can be 1.0; when the humidity change rate is 0.1% / s to 0.5% / s, the rate correction factor can linearly decrease from 1.0 to 0.7; when the humidity change rate exceeds 0.5% / s, the rate correction factor can be 0.5. It should be noted that the rate correction factor value cannot exceed 1.0 and cannot be lower than 0.5. The dynamic correction module multiplies the baseline action time threshold by this rate correction factor to obtain the corrected action time threshold, thereby achieving the effect of shortening the action time threshold when humidity changes rapidly.

[0082] After the dynamic correction module calculates the amplitude correction factor and the rate correction factor, it outputs the corrected leakage current threshold by multiplying the reference leakage current protection operating current threshold by the amplitude correction factor, and the corrected operating time threshold by multiplying the reference operating time threshold by the rate correction factor. For example, if the reference leakage current threshold for a certain electrical device is 30mA, the current humidity is 75%, and the amplitude correction factor is 0.7, then the corrected current threshold is 30mA × 0.7 = 21mA. Simultaneously, if the reference operating time threshold for this device is 0.1s, the current humidity change rate is 0.3% / s, and the rate correction factor is 0.8, then the corrected operating time threshold is 0.1s × 0.8 = 0.08s. Upon receiving these corrected current thresholds and operating time thresholds, the local protection execution module uses 21mA and 0.08s as the current protection settings for leakage protection judgment.

[0083] By setting an amplitude correction factor to perform nonlinear compensation of the current threshold based on the current humidity value, and setting a rate correction factor to perform nonlinear compensation of the action time threshold based on the humidity change rate, the system can not only adjust the protection sensitivity according to the current humidity level, but also adjust the protection action speed according to the rate of humidity change. This makes the protection characteristics match the dynamic process of humidity change, avoiding the response lag problem that may be caused by simply relying on the current humidity value for correction.

[0084] In another technical solution, the dynamic correction module further includes a limiting unit, which is used to limit the amplitude correction factor to the range of 0.5 to 1.0 and the rate correction factor to the range of 0.5 to 1.0.

[0085] In the above technical solution, the limiting unit can be integrated into the digital signal processor or microcontroller used in the dynamic correction module as a software module, or it can be set as a hardware circuit at the output of the dynamic correction module. In the software implementation, after the dynamic correction module calculates the value of the amplitude correction factor, the limiting unit first compares the value with 1.0. If it is greater than 1.0, the value is limited to 1.0; then it compares the value with 0.5. If it is less than 0.5, the value is limited to 0.5; if the value is between 0.5 and 1.0, the original value is maintained and output.

[0086] The rate correction factor is limited in the same way: when it is greater than 1.0, it is limited to 1.0; when it is less than 0.5, it is limited to 0.5; and when it is between 0.5 and 1.0, it retains its original value. In the hardware implementation, the limiting unit can use a clamping circuit composed of an operational amplifier and a diode to clamp the voltage value corresponding to the correction factor in the analog voltage signal output by the dynamic correction module within the voltage range of 0.5 to 1.0.

[0087] The function of this limiting unit is to prevent the dynamic correction module from exceeding the reasonable range due to humidity sensor malfunction, communication interference, or algorithm calculation abnormalities. It avoids the correction factor from being greater than 1.0, which would cause the action time threshold to exceed the baseline value, and also avoids the correction factor from being less than 0.5, which would cause the protection threshold to be too low and trigger frequent malfunctions.

[0088] In another technical solution, a fault detection module is also included. The fault detection module is signal-connected to the environmental detection module and is used to output a fault shielding signal to the dynamic correction module when the current environmental humidity data exceeds the preset effective range.

[0089] After receiving the fault shielding signal, the dynamic correction module stops outputting the corrected leakage current threshold and the corrected action time threshold. The local protection execution module directly uses the reference leakage current threshold and the reference action time threshold to determine leakage protection.

[0090] In the above technical solution, the fault diagnosis module can be integrated with the dynamic correction module in the same digital signal processor or microcontroller, or it can be set as an independent comparison circuit in the signal path between the environmental detection module and the dynamic correction module. This fault diagnosis module maintains a signal connection with the environmental detection module, receiving the current ambient humidity data collected by the environmental detection module in real time and comparing this data with a preset effective range. The preset effective range can be set according to the performance parameters of the selected humidity sensor, for example, it can be set to 0 to 100%RH, or it can be set to 0 to 95%RH according to the actual environmental conditions of the temporary power supply project. When the humidity sensor outputs humidity data exceeding this range due to moisture, condensation, aging, or damage—for example, a short circuit outputting a value below 0%RH or an open circuit outputting a value above 100%RH—the fault diagnosis module determines that the current humidity data is abnormal.

[0091] After determining that the current ambient humidity data exceeds the preset effective range, the fault detection module outputs a fault shielding signal to the dynamic correction module. This fault shielding signal can be a high-level or low-level active digital signal. Upon receiving this signal, the dynamic correction module stops outputting the corrected leakage current threshold and the corrected operating time threshold. At this time, the output of the dynamic correction module can be set to a high-impedance state, or it can output a specific invalid value, such as 0 or the same value as the reference parameter. Simultaneously, the dynamic correction module sends a status flag to the local protection execution module, informing it that it is currently in a fault shielding state.

[0092] Upon receiving this status flag, the local protection execution module no longer waits for the corrected threshold output by the dynamic correction module. Instead, it directly reads the reference leakage current threshold and reference action time threshold of the electrical equipment from the reference parameter storage module and uses these reference parameters as the current protection setting value for leakage protection determination. In other words, the fault diagnosis module does not change the hardware configuration of the humidity sensor, nor does it alter the normal data acquisition of the environmental detection module. It only triggers the system to switch from correction mode to hard protection mode by outputting a fault shielding signal when the humidity data is abnormal.

[0093] By configuring a fault detection module, the system can automatically exit dynamic correction mode and directly use baseline parameters for protection determination when the humidity sensor malfunctions. This avoids protection malfunctions or failures caused by incorrect correction factor calculations due to sensor abnormalities. For example, if the humidity sensor outputs an abnormally high humidity value due to a short circuit caused by water ingress, the dynamic correction module might lower the corrected current threshold to an extremely low value without a fault detection module, leading to frequent false shutdowns of the equipment during normal operation. With the fault detection module configured, the system automatically switches back to baseline parameters when the humidity data exceeds the effective measurement range, ensuring basic leakage protection for the equipment during sensor failures and improving the system's fault tolerance and reliability in harsh temporary power environments. Simultaneously, the fault detection module can also issue a fault alarm to the external management terminal or operator while outputting a fault shielding signal, prompting them to check or replace the humidity sensor.

[0094] In another technical solution, when the device identification module cannot identify the device type of the currently connected electrical device, the reference parameter storage module outputs a default reference parameter, which is the lowest leakage current threshold and the shortest action time threshold corresponding to all device types pre-stored in the reference parameter storage module; the local protection execution module is also used to block the power supply output of the electrical device when the device identification module cannot identify the device type of the currently connected electrical device, until an external manual confirmation release signal is received.

[0095] In the above technical solutions, the device identification module encounters several situations where it cannot identify the device type during actual operation. For example, if the connected electrical equipment does not have a storage chip containing the device type code, the device identification module cannot obtain the device type by reading it. Similarly, when the device identification module identifies the device type by detecting the starting current waveform, if the starting current waveform characteristics of the currently connected device do not match any pre-stored waveform templates, identification will also fail. Furthermore, when the device identification module relies on manual input, if the operator fails to select the device type within the specified input time or inputs an invalid device type identifier, identification will also fail.

[0096] When the device identification module cannot identify the device type of the currently connected electrical equipment, it sends a default parameter call command to the reference parameter storage module. Upon receiving this command, the reference parameter storage module compares the reference leakage current threshold values ​​corresponding to all device types stored internally, selecting the lowest value as the default reference leakage current threshold value. Simultaneously, it compares the reference action time threshold values ​​corresponding to all device types, selecting the shortest value as the default reference action time threshold value. The combination of these two values ​​is then output to the dynamic correction module as the default reference parameter for the unknown type of electrical equipment. For example, if the reference parameter storage module stores reference parameters for four types of equipment—handheld drill (15mA, 0.04s), welding machine (30mA, 0.1s), cutting machine (20mA, 0.04s), and lighting fixture (10mA, 0.04s)—then the default reference parameter is the combination of the lowest current threshold of 10mA and the shortest action time threshold of 0.04s.

[0097] After receiving the default reference parameters, the dynamic correction module corrects them according to the current ambient humidity data of the device's location, generating corrected leakage current thresholds and corrected operating time thresholds. Since the default reference parameters are selected as the lowest current threshold and shortest operating time threshold among all device types, even after humidity correction, the corrected thresholds still represent the most stringent protection level in the system. This design is based on the principle of safety first; that is, when the specific device type is unknown, the most stringent standard is applied for protection, avoiding safety risks caused by using mismatched, lenient thresholds.

[0098] When the device identification module fails to identify the device type, the local protection execution module also locks the power supply output to the device. This locking function is implemented through the switch actuator in the local protection execution module. Specifically, after receiving an identification failure signal from the device identification module, the local protection execution module keeps the switch actuator in the open state and does not output power voltage to the device. In this locked state, even if the dynamic correction module has generated a corrected protection threshold, the local protection execution module will not perform a closing power supply operation. The locked state will continue until the local protection execution module receives an external manual confirmation release signal. This manual confirmation release signal can be generated in the following ways: after the operator confirms the safety status of the device on-site, they can input a confirmation command through the confirmation button located at the power socket or distribution box; or they can send a communication command to the local protection execution module to release the lock via a handheld terminal or upper management platform.

[0099] The introduction of manual confirmation of the cancellation signal allows operators to perform necessary safety checks on the equipment or manually input equipment parameters when equipment identification fails. Power can be restored only after safety is confirmed. This preserves a safe channel for manual intervention when the system's automatic identification capability is insufficient, ensuring electrical safety and providing a way for the system to resume normal operation under boundary conditions.

[0100] Another technical solution also includes:

[0101] The circuit monitoring module is signal-connected to multiple local protection execution modules in the same power supply circuit, and is used to obtain the corrected leakage current value corresponding to each electrical device and calculate the current total leakage current value of the power supply circuit.

[0102] The circuit monitoring module compares the current total leakage current value with a preset first threshold and a second threshold. The first threshold is less than the second threshold, and the second threshold is less than or equal to the rated operating current value of the upstream leakage current protection device of the power supply circuit.

[0103] When the current total leakage current value exceeds the first threshold, the circuit monitoring module outputs a first-level early warning signal to each electrical device in the power supply circuit;

[0104] When the current total leakage current value exceeds the second threshold, the circuit monitoring module outputs a second-level warning signal to each electrical device in the power supply circuit, and collects the corrected leakage current value of each electrical device at the moment of outputting the second-level warning signal as a leakage snapshot before disconnection for storage.

[0105] The circuit monitoring module is also used to compare the corrected leakage current values ​​of each electrical device in the same power supply circuit with the corrected leakage current value in the leakage snapshot before the cut-off, based on the corrected leakage current value of the cut-off device in the leakage snapshot before the cut-off. The smaller the difference between the two values, the higher the suspicion of leakage fault of the electrical device.

[0106] The circuit monitoring module generates and outputs a fault investigation priority ranking of each electrical device in the power supply circuit according to the order of the suspicion of leakage fault from high to low.

[0107] In the above technical solution, the loop monitoring module can be installed in the distribution box or switch cabinet of the power supply circuit, maintaining signal connection with multiple local protection execution modules in the same power supply circuit via wired or wireless communication. This loop monitoring module can acquire the corrected leakage current value corresponding to each electrical device via RS485 bus, CAN bus, or wireless communication network, and accumulate the corrected leakage current values ​​of all devices in the same power supply circuit to obtain the current total leakage current value of the power supply circuit. The loop monitoring module can have a data storage area to temporarily store the corrected leakage current values ​​of each device and the calculated total leakage current value.

[0108] The circuit monitoring module compares the current total leakage current value with a preset first threshold and a second threshold. The first and second thresholds can be set based on the rated operating current value of the upstream leakage current device (RCD) of the power supply circuit. The first threshold is less than the second threshold, and the second threshold is less than or equal to the rated operating current value of the upstream RCD. For example, if the rated operating current value of the upstream RCD is 100mA, the first threshold can be set to 60mA, and the second threshold to 80mA. When the current total leakage current value exceeds the first threshold, the circuit monitoring module determines that the total leakage current of the current circuit is approaching a dangerous level and outputs a first-level warning signal to each electrical device in the power supply circuit. This first-level warning signal can be issued in the form of an audible and visual alarm, such as causing the indicator lights on each electrical device to flash slowly, or pushing a notification message to a handheld terminal via wireless communication to remind on-site operators to observe the equipment's operating status.

[0109] When the current total leakage current continues to rise and exceeds the second threshold, the loop monitoring module determines that the total leakage current of the current loop is approaching the operating boundary of the upstream protector and outputs a second-level warning signal to each electrical device in the power supply loop. The second-level warning signal can use an alarm method different from the first-level warning signal, such as flashing indicator lights or emitting a continuous buzzer. Simultaneously, the loop monitoring module collects the corrected leakage current value of each electrical device at the moment the second-level warning signal is output, storing it as a leakage current snapshot before disconnection in the internal data storage area of ​​the loop monitoring module. This snapshot records the leakage current value of each device at the same moment, used for subsequent fault source analysis and troubleshooting.

[0110] When the circuit monitoring module detects that the local protection execution module of any electrical device has cut off the power supply to that device because the corrected leakage current value exceeds the corrected leakage protection operating current threshold, the circuit monitoring module retrieves the previously stored leakage snapshot before the cutoff. Then, using the corrected leakage current value of the cut-off device in the snapshot as a benchmark, it compares the corrected leakage current values ​​of each electrical device in the same power supply circuit in the snapshot one by one. The smaller the difference between the two values, the higher the suspicion of leakage fault for that electrical device. For example, if four devices A, B, C, and D are connected to a power supply circuit, and the snapshot values ​​collected at the second-level warning trigger time are 18mA for device A, 15mA for device B, 12mA for device C, and 5mA for device D, when device A is cut off due to leakage current exceeding its corrected threshold, the circuit monitoring module uses device A's 18mA as a benchmark, calculates the difference between device B's 15mA and 18mA as 3mA, device C's 12mA and 18mA as 6mA, and device D's 5mA and 18mA as 13mA. Therefore, device B is determined to have the highest suspicion of leakage fault (smallest difference), followed by device C, and device D has the lowest suspicion. The circuit monitoring module generates a fault investigation priority ranking for each electrical device in the power supply circuit according to the order of leakage fault suspicion from high to low, that is, device B is investigated first, followed by device C, and then device D.

[0111] After obtaining the fault diagnosis priority ranking, the loop monitoring module can send the ranking results to the operator's handheld terminal or the field management platform via the communication network. This guides the operator to check each device sequentially according to priority, avoiding the time wasted by blindly checking each device one by one after it has been disconnected. This priority ranking can also be linked with the field management platform, displaying the suspicion level of each device in a list format on the platform's display screen. This helps managers quickly locate the device most likely to fail, narrowing the scope of the investigation and shortening the fault handling time.

[0112] The system assesses the likelihood of a fault by setting up a loop monitoring module to collect leakage current snapshots of each device at the same time and comparing them horizontally. It does not rely on historical data or machine learning models, has low computational requirements, and is suitable for real-time operation in embedded devices in resource-constrained temporary power supply sites.

[0113] In another technical solution, the circuit monitoring module is also used to attempt to restore the power supply to each of the uncut electrical devices in the power supply circuit in turn, according to the fault investigation priority order, after the local protection execution module cuts off the power supply to any electrical device.

[0114] The circuit monitoring module recalculates the current total leakage current value of the power supply circuit after each attempt to restore power to an electrical device.

[0115] If the current total leakage current value exceeds the second threshold, the loop monitoring module outputs a cut-off signal to the local protection execution module of the electrical equipment and continues to attempt to restore power supply to the next electrical equipment in the fault troubleshooting priority ranking.

[0116] If the current total leakage current value does not exceed the second threshold, the power supply status of the electrical equipment is maintained, and attempts are made to restore the power supply to the next electrical equipment in the fault troubleshooting priority ranking.

[0117] In the above technical solution, the circuit monitoring module initiates a power restoration process after the local protection execution module cuts off the power supply to any electrical device. This restoration process proceeds according to fault investigation priority, prioritizing the restoration of the least suspected electrical device and ending with the most suspected device. The circuit monitoring module obtains the fault investigation priority list generated in the aforementioned method, which is a list from highest to lowest priority. The restoration process starts from the end of the list, proceeding sequentially from the least suspected device towards the most suspected ones.

[0118] Before attempting to restore power to a piece of electrical equipment, the loop monitoring module first confirms that the equipment is currently in a disconnected state and has not been excluded from the restoration process. Upon confirmation, the loop monitoring module sends a power restoration command to the local protection execution module of that equipment. Upon receiving the command, the local protection execution module drives the switch actuator to close, restoring power to the equipment. After restoring power to the equipment, the loop monitoring module re-collects the calibrated leakage current values ​​of all operating equipment in the same power supply loop, including equipment that has had its power restored and equipment that was previously powered. The calibrated leakage current values ​​of these devices are then summed up to calculate the current total leakage current value.

[0119] The loop monitoring module compares the recalculated current total leakage current value with the second threshold. If the current total leakage current value exceeds the second threshold, it indicates that the device that has just had its power restored is the main cause of the excessive total leakage current. The loop monitoring module then outputs a cut-off signal to the local protection execution module of that device. Upon receiving this signal, the local protection execution module drives the switch actuator to disconnect, cutting off the power supply to the device and marking it as a fault source device. It will not attempt to restore the device again. If the current total leakage current value does not exceed the second threshold, it indicates that the device that has had its power restored is not the cause of the excessive total leakage current. The loop monitoring module maintains the power supply to that device and does not cut it off.

[0120] Regardless of whether the above judgment result is to cut off or maintain power supply, after the loop monitoring module completes the processing of the current device and stabilizes the total leakage current reading, it continues to try to restore power supply to the next electrical device in the fault troubleshooting priority ranking. It repeats the above cycle of confirming status, sending restoration command, recalculating total leakage current, comparing and judging and deciding whether to maintain power supply or cut off again, until all devices in the sorting list that are in the cut-off state have been tried or the current total leakage current value continues to exceed the second threshold and there are no more devices to try, then the restoration process ends.

[0121] Using the above method, the system can automatically restore power to non-faulty equipment without manual inspection after a fault is disconnected. Because the restoration order is from lowest to highest suspicion, the equipment least likely to fail is restored first, minimizing power restoration time and impacting normal construction. Simultaneously, after each device is restored, the total leakage current is immediately verified. If the total leakage current exceeds the limit again after restoration, the device is immediately disconnected again, isolating the fault source within a minimal area. This restoration process is entirely automated by the loop monitoring module, requiring no operator intervention, thus improving the efficiency of power restoration after fault handling in temporary power supply projects while ensuring safety.

[0122] Example 1

[0123] In a temporary power supply project at a construction site, a handheld electric drill is connected to the power supply management system. The drill's baseline leakage current threshold is 30mA, the baseline action time threshold is 0.1s, and the preset maximum safety threshold is also 30mA. A capacitive humidity sensor is installed inside the drill's power plug housing, and this sensor is connected to the drill's corresponding local protection execution module and dynamic correction module.

[0124] On a sunny morning, the humidity sensor detected an ambient humidity of 55% at the drill's location. The dynamic correction module generated an amplitude correction factor of 0.95 and a rate correction factor of 1.0 based on this humidity value. Multiplying the base current threshold of 30mA by 0.95 yielded a corrected leakage current threshold of 28.5mA, while the corrected action time threshold remained unchanged at 0.1s. The local protection execution module used 28.5mA and 0.1s as the current protection settings. At this time, the drill was operating normally, and the leakage current detected by the zero-sequence current transformer was 4.5mA, lower than 28.5mA. Therefore, the local protection execution module did not activate, and the drill continued to operate normally.

[0125] Around 9:00 AM, water spraying began to reduce dust in the construction area. The water mist spread to the drilling area, and the ambient humidity, as detected by the humidity sensor, gradually rose to 75%. The dynamic correction module regenerated an amplitude correction factor of 0.7 based on this humidity value, while the rate correction factor remained at 1.0. Multiplying the base current threshold of 30mA by 0.7 yielded a corrected leakage current threshold of 21mA, while the action time threshold remained unchanged at 0.1s. The local protection execution module updated the protection settings to 21mA and 0.1s. At this time, water mist adhered to the surface of the drill, causing a decrease in insulation resistance. The leakage current detection value rose to 13mA, but remained below 21mA, and the drill continued to operate normally. The dust suppression spraying did not cause any accidental shutdown.

[0126] Around 10:00 AM, the operator accidentally dropped the electric drill into a shallow puddle. The operator quickly retrieved the drill, but water had already seeped into the drill's casing through the seams, causing a sharp drop in the insulation resistance of the internal wiring. The zero-sequence current transformer detected a rapid increase in leakage current to 23mA, exceeding the corrected leakage protection operating current threshold of 21mA. The timer in the local protection execution module immediately started counting. After 0.1 seconds, if the leakage current remained above 23mA, the local protection execution module activated the electromagnetic relay, cutting off the power supply to the drill. The operator did not experience any electric shock during the entire process, and other electrical equipment in the same power supply circuit, including the cutting machine and lighting fixtures, continued to operate normally without any impact.

[0127] During this process, because the corrected current threshold was 21mA, lower than the baseline value of 30mA, the drill triggered the protection action more sensitively after its insulation performance deteriorated, cutting off the power supply in time before the operator touched the equipment. If the baseline threshold of 30mA had been used, the leakage current of 23mA would have been lower than 30mA and would not have triggered the protection action, posing a risk of electric shock to the operator if they continued to use the drill. Furthermore, the threshold was 28.5mA in the morning when humidity was low and 21mA after watering. The threshold adjusted according to humidity changes, avoiding the problem of oversensitivity in dry environments and insufficient protection in humid environments that can occur with a fixed threshold scheme.

[0128] This embodiment demonstrates that the present invention can adjust the protection threshold in real time according to the humidity changes of the location of the electrical equipment, providing stricter protection when the ambient humidity is high, while avoiding accidental disconnection when the humidity is low, thus balancing electrical safety and construction continuity.

[0129] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and embodiments shown and described herein.

Claims

1. A safe power supply management system for portable electrical equipment in temporary power supply projects, characterized in that, include: Multiple environmental detection modules are installed on each electrical device side, and each environmental detection module is used to collect the current ambient humidity data of the location of the electrical device. The reference parameter storage module has preset reference leakage current threshold and reference action time threshold. The dynamic correction module is connected to the plurality of environmental detection modules and the reference parameter storage module respectively, and is used to generate the corrected leakage current threshold and the corrected action time threshold for each electrical device according to the current environmental humidity data of the location of each electrical device. When the current ambient humidity data at the location of any electrical device increases, the dynamic correction module correspondingly reduces the reference leakage current threshold of the electrical device, and the corrected leakage current threshold of each electrical device is not higher than the preset maximum safety threshold, and the corrected action time threshold of each electrical device does not exceed the reference action time threshold. Multiple local protection execution modules are respectively set on the side of each electrical device. Each local protection execution module is signal connected to the dynamic correction module and is used to cut off the power supply to the electrical device when the leakage current detection value of the electrical device exceeds the corrected leakage current action current threshold of the electrical device and the duration exceeds the corrected action time threshold of the electrical device.

2. The safe power supply management system for portable electrical equipment in temporary power supply projects according to claim 1, characterized in that, The preset maximum safety threshold is 30mA.

3. The safe power supply management system for portable electrical equipment in temporary power supply projects according to claim 1, characterized in that, It also includes a device identification module, which is used to identify the device type of each connected electrical device and send a parameter call instruction to the reference parameter storage module according to the identified device type; The reference parameter storage module is pre-set with reference leakage current threshold and reference action time threshold corresponding to different equipment types. In response to the parameter call command, the reference parameter storage module outputs the reference leakage current threshold and reference action time threshold corresponding to the device type to the dynamic correction module, which serve as the reference leakage current threshold and reference action time threshold for the electrical equipment, so that electrical equipment of different types can obtain differentiated leakage protection parameters that match their electrical characteristics.

4. The safe power supply management system for portable electrical equipment in temporary power supply projects according to claim 1, characterized in that, It also includes an error correction module, which is used to compensate online for the zero-point drift deviation of the detection circuit itself in the leakage current detection loop caused by the ambient humidity, based on the current ambient humidity data, and output the corrected leakage current value. The corrected leakage current value is the detection loop current value after compensating for the zero-point drift deviation, and the corrected leakage current value includes the inherent leakage current component generated by the electrical equipment and power supply cable to ground; the leakage current detection value is the corrected leakage current value, and the local protection execution module performs a disconnection action based on the corrected leakage current value.

5. The safe power supply management system for portable electrical equipment in temporary power supply projects according to claim 1, characterized in that, The environmental detection module is also used to calculate the rate of change of humidity within a preset time window; The dynamic correction module includes an amplitude correction factor and a rate correction factor. The amplitude correction factor is generated based on the current ambient humidity value and is used to perform nonlinear compensation on the reference leakage current threshold. The rate correction factor is generated based on the humidity change rate and is used to perform nonlinear compensation on the reference operating time threshold. The dynamic correction module outputs the corrected leakage current threshold as the product of the reference leakage current protection operating current threshold and the amplitude correction factor, and outputs the corrected operating time threshold as the product of the reference operating time threshold and the rate correction factor.

6. The safe power supply management system for portable electrical equipment in temporary power supply projects according to claim 5, characterized in that, The dynamic correction module further includes a limiting unit, which is used to limit the amplitude correction factor to the range of 0.5 to 1.0 and the rate correction factor to the range of 0.5 to 1.

0.

7. The safe power supply management system for portable electrical equipment in temporary power supply projects according to claim 1, characterized in that, It also includes a fault detection module, which is signal-connected to the environmental detection module and is used to output a fault shielding signal to the dynamic correction module when the current environmental humidity data exceeds the preset effective range. After receiving the fault shielding signal, the dynamic correction module stops outputting the corrected leakage current threshold and the corrected action time threshold. The local protection execution module directly uses the reference leakage current threshold and the reference action time threshold to determine leakage protection.

8. The safe power supply management system for portable electrical equipment in temporary power supply projects according to claim 3, characterized in that, When the device identification module cannot identify the device type of the currently connected electrical equipment, the reference parameter storage module outputs a default reference parameter. The default reference parameter is the lowest leakage current threshold and the shortest action time threshold corresponding to all device types pre-stored in the reference parameter storage module. The local protection execution module is also used to lock the power supply output of the power device when the device identification module cannot identify the device type of the currently connected power device, until an external manual confirmation release signal is received.

9. The safe power supply management system for portable electrical equipment in temporary power supply projects according to claim 4, characterized in that, Also includes: The circuit monitoring module is signal-connected to multiple local protection execution modules in the same power supply circuit, and is used to obtain the corrected leakage current value corresponding to each electrical device and calculate the current total leakage current value of the power supply circuit. The circuit monitoring module compares the current total leakage current value with a preset first threshold and a second threshold. The first threshold is less than the second threshold, and the second threshold is less than or equal to the rated operating current value of the upstream leakage current protection device of the power supply circuit. When the current total leakage current value exceeds the first threshold, the circuit monitoring module outputs a first-level early warning signal to each electrical device in the power supply circuit; When the current total leakage current value exceeds the second threshold, the circuit monitoring module outputs a second-level warning signal to each electrical device in the power supply circuit, and collects the corrected leakage current value of each electrical device at the moment of outputting the second-level warning signal as a leakage snapshot before disconnection for storage. The circuit monitoring module is also used to compare the corrected leakage current values ​​of each electrical device in the same power supply circuit with the corrected leakage current value in the leakage snapshot before the cut-off, based on the corrected leakage current value of the cut-off device in the leakage snapshot before the cut-off. The smaller the difference between the two values, the higher the suspicion of leakage fault of the electrical device. The circuit monitoring module generates and outputs a fault investigation priority ranking of each electrical device in the power supply circuit according to the order of the suspicion of leakage fault from high to low.

10. The safe power supply management system for portable electrical equipment in temporary power supply projects according to claim 9, characterized in that, The circuit monitoring module is also used to attempt to restore the power supply to each electrical device that was not disconnected in the power supply circuit in turn, according to the fault investigation priority order, after the local protection execution module cuts off the power supply to any electrical device. The circuit monitoring module recalculates the current total leakage current value of the power supply circuit after each attempt to restore power to an electrical device. If the current total leakage current value exceeds the second threshold, the loop monitoring module outputs a cut-off signal to the local protection execution module of the electrical equipment and continues to attempt to restore power supply to the next electrical equipment in the fault troubleshooting priority ranking. If the current total leakage current value does not exceed the second threshold, the power supply status of the electrical equipment is maintained, and attempts are made to restore the power supply to the next electrical equipment in the fault troubleshooting priority ranking.