Verification assembly for residual current monitoring system, portable calibrator and portable monitoring equipment

Abstract

The utility model provides a verification assembly for a residual current monitoring system, and the assembly comprises a verification current generation module which is used for generating at least one path of verification current; a first end of each verification wire is electrically connected with a verification current output end of the verification current generation module, and a second end of the verification wire passes through a test hole of a current transformer of the residual current monitoring system and then is electrically connected with a common end of the verification current generation module during working; the at least one verification current transformer is in one-to-one correspondence with the at least one verification lead and is used for detecting the verification current on the corresponding verification lead; the main control unit is electrically connected with the verification current generation module and the verification current transformer; and the output unit is electrically connected with the main control unit. The utility model further provides a portable calibrator and portable monitoring equipment for the residual current monitoring system, and the portable calibrator and the portable monitoring equipment can simply and conveniently verify the residual current detection precision of an existing fixedly-installed residual current monitoring system.

Description

Technical Field

[0001] The utility model relates to the technical field of low-voltage distribution networks, in particular to a calibration component, a portable calibrator and a portable monitoring device for a residual current monitoring system. Background Art

[0002] In a low-voltage distribution network, accurate residual current monitoring of low-voltage distribution lines, distribution transformers, electrical equipment, etc. is a prerequisite for achieving electric shock protection. At present, a fixed residual current monitoring system has been installed in the low-voltage distribution network. For example, the Chinese patent application number CN217085087U previously applied by the applicant discloses a three-phase four-wire common neutral dual power supply residual current detection device. The device is fixedly installed in the low-voltage distribution network. As the years of use increase, the current transformer, main control unit and other components will age, which may affect the accuracy of residual current detection. It is very necessary to calibrate the measurement accuracy of the existing fixed residual current monitoring system or device in the low-voltage distribution network. Although the components of the residual current detection system can be disassembled and sent back to the R&D center for calibration, it is very inconvenient and cannot continuously monitor the residual current of the equipment to be tested. Therefore, it is very important to conveniently calibrate the existing fixed residual current monitoring system in the low-voltage distribution network.

[0003] In addition, there are also portable residual current detection devices that are not fixedly installed in the prior art, such as the Chinese patent publication number CN213715317U. However, these portable detection devices lack verification and calibration of their own detection results, and the measurement accuracy cannot be effectively measured. Utility Model Content

[0004] The utility model aims to at least solve the technical problem of inconvenient calibration of existing fixed residual current monitoring systems in low-voltage distribution networks, and provides a calibration component, a portable calibrator and a portable monitoring device for the residual current monitoring system.

[0005] In order to achieve the above-mentioned purpose of the present invention, according to the first aspect of the present invention, the present invention provides a verification component for a residual current monitoring system, including: a verification current generating module, used to generate at least one verification current; at least one verification wire, the first end of each verification wire is electrically connected to the verification current output end of the verification current generating module, and when working, the second end of the verification wire passes through the test hole of the current transformer of the residual current monitoring system and is electrically connected to the common end of the verification current generating module; at least one verification current transformer, corresponding one-to-one to at least one verification wire, used to detect the verification current on the corresponding verification wire; a main control unit, electrically connected to the verification current generating module and the verification current transformer, respectively; and an output unit, electrically connected to the main control unit.

[0006] The above technical solution: uses the verification current generated by the verification current generation module to simulate the load current, and directly passes the verification wire carrying the verification current through the test hole of the current transformer of the existing fixed residual current monitoring system to apply a simulated load current. The main control unit determines the amplitude, phase and other information of the actual verification current based on the output signal of the verification current transformer, and outputs the actual verification current information through the output unit. Relevant personnel combine the actual verification current information and the residual current output by the existing fixed residual current monitoring system before and after the verification current is applied to determine the residual current detection accuracy of the existing fixed residual current monitoring system. The residual current monitoring accuracy can be easily verified without dismantling the existing fixed residual current monitoring system and shutting down the equipment to be tested of the residual current monitoring system.

[0007] In a preferred embodiment of the present invention, the verification current generation module includes an amplitude modulation circuit, and an input end of the amplitude modulation circuit is connected to an AC voltage signal output end of the main control unit.

[0008] The above technical solution: the main control unit provides an initial AC current signal, and the amplitude of the initial AC current signal is adjusted by the amplitude modulation circuit.

[0009] In a preferred embodiment of the present invention, the verification current generation module further includes a phase modulation circuit, and the input end of the phase modulation circuit is connected to the output end of the amplitude modulation circuit.

[0010] The above technical solution: the phase of the AC current signal is adjusted by a phase modulation circuit.

[0011] In a preferred embodiment of the present invention, the output unit includes a display unit.

[0012] The above technical solution: uses the display unit to facilitate relevant personnel to intuitively obtain information such as the amplitude and phase of the actual verification current.

[0013] In a preferred embodiment of the present invention, it further includes a communication unit for connecting and communicating with a communication unit of a residual current monitoring system, and the communication unit is electrically connected to the main control unit.

[0014] The above technical solution facilitates obtaining the residual current measured by the residual current monitoring system before and after the verification current is applied.

[0015] In a preferred embodiment of the present invention, the verification current generation module generates two verification currents.

[0016] The above technical solution utilizes two verification currents to effectively verify whether the vector synthesis function of the existing installed residual current monitoring system is accurate.

[0017] In order to achieve the above-mentioned purpose of the present invention, according to the second aspect of the present invention, the present invention provides a portable calibrator for a residual current monitoring system, comprising a first shell and the calibration component for a residual current monitoring system described in the first aspect of the present invention; a verification current generating module and a main control unit are installed inside the first shell; at least one transformer connection port, at least one current interface and a common end interface are provided on the first shell, the output end of the verification current transformer is connected to the current detection end of the main control unit through the transformer connection port, the first end of the verification wire is connected to the verification current output end of the verification current generating module through the current interface, and the second end of the verification wire is connected to the common end of the verification current generating module through the common end interface.

[0018] The above technical solution: all components are carried on the first shell, which is convenient for transportation and carrying.

[0019] In order to achieve the above-mentioned purpose of the utility model, according to the third aspect of the utility model, the utility model provides a portable monitoring device, including: multiple residual current monitoring transformers, the residual current monitoring transformers are used to detect the current in the power supply line of the equipment to be tested; a verification current generating module, used to generate at least one verification current; at least one verification wire, the first end of each verification wire is electrically connected to the verification current output end of the verification current generating module, and when working, the second end of the verification wire passes through the test hole of the current transformer of the residual current monitoring system or the test hole of the residual current monitoring transformer and is electrically connected to the common end of the verification current generating module; at least one verification current transformer, corresponding one-to-one to at least one verification wire, for detecting the verification current on the corresponding verification wire; a main control unit, electrically connected to the verification current generating module, the verification current transformer and the residual current monitoring transformer respectively; an output unit, electrically connected to the main control unit.

[0020] The above technical solution: The above portable monitoring device can detect the residual current in the power supply line of the equipment under test through multiple residual current monitoring transformers, and can use verification wires, verification current generation modules, and verification current transformers to verify the detection accuracy of the residual current. The verification wires, verification current generation modules, and verification current transformers can also be used to simply verify the residual current detection accuracy of the existing fixed-installed residual current monitoring system.

[0021] In a preferred embodiment of the present invention, the verification current generation module includes an amplitude modulation circuit and a phase modulation circuit, the input end of the amplitude modulation circuit is connected to the AC voltage signal output end of the main control unit, and the input end of the phase modulation circuit is connected to the output end of the amplitude modulation circuit.

[0022] The above technical solution: uses an amplitude modulation circuit to adjust the amplitude of the verification current, and uses a phase modulation circuit to adjust the phase of the verification current.

[0023] In a preferred embodiment of the present invention, the output unit includes a display unit.

[0024] The above technical solution facilitates intuitive display of the actual verification current and the detected residual current. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a structural diagram of a verification component for a residual current monitoring system in a preferred embodiment of the present invention;

[0026] Figure 2 This is a structural diagram of a verification current generation module in a preferred embodiment of the present invention;

[0027] Figure 3 This is a front view of a portable calibrator in a preferred embodiment of the present invention;

[0028] Figure 4 This is a structural block diagram of a portable monitoring device in a preferred embodiment of the present invention;

[0029] Figure 5 This is a front view of a portable monitoring device in a preferred embodiment of the present invention;

[0030] Figure 6 This is a schematic diagram of the internal structure of the main control unit in a preferred embodiment of the present invention;

[0031] Figure numerals: 1 verification current generating module; 2 verification wire; 3 test hole; 4 verification current transformer; 5 main control unit; 6 output unit; 7 first shell; 8 current interface; 9 common end interface; 10 transformer connection port; 11 residual current monitoring transformer; 12 communication unit; 13 second shell. DETAILED DESCRIPTION

[0032] The following describes embodiments of the present invention in detail. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended only to explain the present invention and are not to be construed as limiting the present invention.

[0033] In the description of the present invention, it should be understood that the terms "longitudinal", "transverse", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0034] In the description of the present utility model, unless otherwise specified and limited, it should be noted that the terms "installation", "connection" and "connection" should be understood in a broad sense. For example, it can be a mechanical connection or an electrical connection, or it can be the internal connection between two components. It can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to the specific circumstances.

[0035] The utility model discloses a verification component for a residual current monitoring system. In a preferred embodiment, referring to Figure 1 , the verification component includes:

[0036] The verification current generating module 1 is used to generate at least one verification current.

[0037] At least one verification wire 2, the first end of each verification wire 2 is electrically connected to the verification current output end of the verification current generating module 1, and when working, the second end of the verification wire 2 passes through the test hole 3 of the current transformer of the residual current monitoring system and is electrically connected to the common end of the verification current generating module 1.

[0038] At least one verification current transformer 4 corresponds to at least one verification wire 2 on a one-to-one basis, and is used to detect the verification current on the corresponding verification wire 2 .

[0039] The main control unit 5 is electrically connected to the verification current generating module 1 and the verification current transformer 4 respectively; the main control unit 5 can obtain the amplitude and phase of the verification current in each verification wire 2 according to the output signal of the verification current transformer 4, which is recorded as verification current information.

[0040] The output unit 6 is electrically connected to the main control unit 5. The output unit 6 can output verification current information.

[0041] In this embodiment, the main control unit 5 is preferably, but not limited to, a single-chip microcomputer and its peripheral circuits. The single-chip microcomputer model is preferably, but not limited to, MSP430. It can use its own D / A module to generate an initial AC current signal. The initial current signal is conditioned by the verification current generation module 1. This eliminates the need to separately set up components for generating the initial AC current signal, saving costs. The verification current generation module 1 is used to generate a simulated load current based on the initial current signal, and it adjusts the amplitude and / or phase of the AC current signal. Specifically, the generation circuit of each verification current signal in the verification current generation module 1 can utilize an existing AC current signal generation circuit, such as the circuit composed of an adjustable amplitude and phase adjustment circuit and a signal amplification circuit, as well as a voltage-to-current module, disclosed in Chinese Patent Publication No. CN108776245A, or a circuit composed of a constant gain operational amplifier phase adjustment circuit and a manual amplitude modulation operational amplifier circuit disclosed in Chinese Patent Publication No. CN218456524U. These are prior art and will not be described in detail here.

[0042] In this embodiment, preferably, the internal structure diagram of the main control unit 5 is as follows: Figure 6 As shown, it includes a main chip MSP430, which includes an AD (analog-to-digital conversion) unit and a D / A (digital-to-analog conversion) unit. The output ends of all current transformers are connected to different pins of the AD (analog-to-digital conversion) unit; it also includes a serial interface electrically erasable memory M24C16 for configuration parameter storage, and a serial flash memory W25Q128 for recording data storage. The touch screen interface realizes the connection between the microcontroller and the touch screen, and displays test data, waveforms, data queries, data export operations, etc. on the touch screen; the LED light bar is used to indicate the working status, and the USB module enables the microcontroller to export test data to a USB disk.

[0043] In this embodiment, the verification wire 2 is preferably, but not limited to, a copper wire or an aluminum wire, the outer layer of which is an insulating layer and the inner layer is a copper wire or an aluminum wire. Figure 2 As shown, one end of the verification wire 2 is electrically connected to the verification current output end of the verification current generating module 1. During operation, the other end passes through the test hole 3 of the current transformer of the existing fixedly installed residual current monitoring system and is electrically connected to the common end of the verification current generating module 1. In this way, a verification current is applied to the current transformer measurement circuit of the existing fixedly installed residual current monitoring system.

[0044] Generally speaking, existing fixed-installation residual current monitoring systems include one current transformer or two current transformers. When the four power lines (three live wires and one neutral wire) of the three-phase four-wire system of the device under test of the residual current monitoring system are relatively concentrated, one current transformer is used to simultaneously clamp the four power lines. The main control unit of the residual current monitoring system obtains the residual current of the power supply circuit of the device under test according to a preset conversion relationship based on the output signal of the current transformer. At this time, the second end of the verification wire 2 can be passed through the test hole 3 of the current transformer. When the three live wires and one neutral wire of the four power lines of the three-phase four-wire system of the device under test of the residual current monitoring system are relatively dispersed, the test hole of one current transformer is used to simultaneously clamp the three live wires, and the test hole of another current transformer is used to clamp the one neutral wire. The main control unit of the residual current monitoring system calculates the residual current of the power supply circuit of the device under test according to the existing vector sum formula based on the output signals of the two current transformers. At this time, the second end of the verification wire 2 can be passed through the test hole 3 of any current transformer. In order to verify whether the vector synthesis function of the residual current monitoring system continues to be accurate and effective, two verification wires 2 can be used to pass through the test holes 3 of the two current transformers respectively.

[0045] In this embodiment, when the verification component is working, there is no need to disassemble the existing installed residual current monitoring system or shut down the device to be tested. In specific applications, after the second end of one verification wire 2 is passed through the test hole 3 of a current transformer of the residual current monitoring system, or after the second ends of two verification wires 2 are passed through the test holes 3 of two current transformers of the residual current monitoring system, they are connected to the common end (i.e., ground) of the verification current generating module 1, and the relevant personnel read the residual current amplitude and phase currently output by the residual current monitoring system, which is recorded as the first residual current information; the verification component is started, that is, the verification current is output in the verification wire 2, and the relevant personnel obtain the amplitude and phase of the verification current in each verification wire 2 from the output unit 6, which is recorded as the verification current information, and read the residual current amplitude and phase currently output by the residual current monitoring system, which is recorded as the second residual current information; the relevant personnel perform vector synthesis on the verification current information and the first residual current information according to the vector synthesis formula to obtain the target residual current information (including the amplitude and phase of the target residual current), calculate the vector difference between the target residual current information and the second residual current information, and verify the residual current test accuracy of the residual current monitoring system according to the size of the vector difference. It should be noted that the above calculation processes all adopt existing methods, which are no longer within the scope of protection of the present utility model.

[0046] Further preferably, in order to facilitate relevant personnel to visually observe the verification current information, the output unit 6 can be a display unit, such as an LED display. The display unit is electrically connected to the main control unit. Further preferably, the display unit can be a touch screen, such as Figure 6As shown, this makes it easier for relevant personnel to input control information.

[0047] In a preferred embodiment, the verification current generation module 1 includes an amplitude modulation circuit, the input of which is connected to the AC voltage signal output terminal (e.g., a D / A unit pin) of the main control unit 5. In this embodiment, the amplitude modulation circuit is preferably, but not limited to, an existing current op amp gain circuit, such as the manual amplitude modulation op amp circuit disclosed in Chinese Patent Publication No. CN218456524U. This is prior art and will not be further described here. The first end of the verification wire 2 is connected to the output terminal of the amplitude modulation circuit.

[0048] In a preferred embodiment, referring to Figure 2 The verification current generation module 1 further includes a phase modulation circuit, the input of which is connected to the output of the amplitude modulation circuit. This phase modulation circuit is a conventional circuit, and reference may be made to the phase modulation circuit disclosed in Chinese Patent Publication No. CN106443097A or Chinese Patent Publication No. CN103248116A, which will not be described in detail here. The first end of the verification wire 2 is connected to the output of the phase modulation circuit.

[0049] In a preferred embodiment, the system further includes a communication unit 12 for communicating with the communication unit 12 of the residual current monitoring system, and the communication unit 12 is electrically connected to the main control unit 5. The communication unit 12 is preferably, but not limited to, a wireless communication unit such as 4G, 5G, WIFI, Bluetooth, etc. that matches the communication unit 12 of the residual current monitoring system, or a wired RS485 or RS232 serial port unit.

[0050] In a preferred embodiment, the verification current generating module 1 generates two verification currents, either a single one or both of which can be used simultaneously.

[0051] The utility model also discloses a portable calibrator for residual current monitoring system, referring to Figure 3 As shown, it includes a first housing 7 and the above-mentioned verification component for the residual current monitoring system;

[0052] The first housing 7 is internally mounted with a verification current generating module 1 and a main control unit 5;

[0053] Reference Figure 3 The first housing 7 is provided with at least one transformer connection port 10, at least one current interface 8 and a common terminal interface 9. The output end of the current transformer 4 is connected to the current detection end of the main control unit 5 through the transformer connection port 10. Figure 6As shown, the current detection end of the main control unit 5 can be an AD input pin, the first end of the verification wire 2 is connected to the verification current output end of the verification current generation module 1 through the current interface 8, and the second end of the verification wire 2 is connected to the common end of the verification current generation module 1 through the common end interface 9.

[0054] In this embodiment, referring to Figure 3 As shown, the transformer connection port 10 is a cable interface that matches the cable at the output end of the current transformer, and the current interface 8 and the common end interface 9 are interfaces that match the connection mode of the two ends of the verification wire 2.

[0055] In this embodiment, the first housing 7 is provided with heat dissipation holes to release the heat generated by the operation of the internal circuit components to ensure the reliable operation of the portable calibrator. The first housing 7 is preferably made of plastic to reduce weight and facilitate transportation.

[0056] In this embodiment, preferably, the communication unit may be provided inside or on the case of the first housing 7 , and the output unit 6 is provided on the surface of the first housing 7 .

[0057] The utility model also discloses a portable monitoring device, referring to Figure 4 Shown, including:

[0058] Multiple residual current monitoring transformers 11, the residual current monitoring transformers 11 are used to detect the current in the power supply line of the device to be tested, and the main control unit 5 performs vector synthesis based on the current information monitored by all the residual current monitoring transformers 11 installed in the power supply line of the device to be tested to obtain the residual current of the power supply line of the device to be tested (such as a three-phase four-wire power supply line);

[0059] Verification current generating module 1, used to generate at least one verification current;

[0060] At least one verification wire 2, the first end of each verification wire 2 is electrically connected to the verification current output end of the verification current generation module 1, and when working, the second end of the verification wire 2 passes through the test hole 3 of the current transformer of the residual current monitoring system (in this case, it is a scenario for verifying the test accuracy of the existing installed residual current monitoring system) or the test hole 3 of the residual current monitoring transformer 11 (in this case, it is a self-calibration scenario) and is then electrically connected to the common end of the verification current generation module 1;

[0061] At least one verification current transformer 4, corresponding one-to-one to at least one verification wire 2, for detecting the verification current on the corresponding verification wire 2;

[0062] The main control unit 5 is electrically connected to the verification current generating module 1, the verification current transformer 4 and the residual current monitoring transformer 11 respectively;

[0063] The output unit 6 is electrically connected to the main control unit 5 .

[0064] In this embodiment, the verification module includes at least one verification wire 2, a verification current generating module 1, a verification current transformer 4, and a main control unit 5. The main control unit 5 can display the verification current information on the verification wire 2 in the manner described above for the verification module. In the self-verification scenario, the main control unit 5 can also perform vector synthesis on the current vector detected by the residual current monitoring transformer 11 to obtain the residual current of the power supply circuit of the device under test, which is recorded as the test residual current. The verification module can verify the monitoring accuracy of the test residual current. The specific method is as disclosed in the verification module described above and will not be repeated here.

[0065] In a preferred embodiment, referring to Figure 2 As shown, the verification current generation module 1 includes an amplitude modulation circuit and a phase modulation circuit. The input end of the amplitude modulation circuit is connected to the AC voltage signal output end of the main control unit, and the input end of the phase modulation circuit is connected to the output end of the amplitude modulation circuit. The specific circuit structures of the amplitude modulation circuit and the phase modulation circuit have been described in the verification module and will not be repeated here.

[0066] In a preferred embodiment, Figure 5 As shown, the device further includes a second housing 13, within which the verification current generation module 1 and the main control unit 5 are mounted. The second housing 13 is provided with an output unit 6, as well as an output connector for the residual current monitoring transformer 11, a connector for the verification wire 2, and an output connector for the verification current transformer 4. The second housing 13 can be made of plastic, making it lightweight and easy to carry, and is provided with heat dissipation holes for heat dissipation.

[0067] Throughout this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," "one implementation," "a preferred implementation," or "some examples" indicate that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0068] Although the embodiments of the present invention have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and purpose of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A calibration component for a residual current monitoring system, characterized in that: include: A verification current generating module, configured to generate at least one verification current; At least one verification wire, a first end of each verification wire is electrically connected to the verification current output terminal of the verification current generation module, and when in operation, the second end of the verification wire passes through the test hole of the current transformer of the residual current monitoring system and is electrically connected to the common terminal of the verification current generation module; At least one verification current transformer, corresponding one-to-one to at least one verification wire, and configured to detect a verification current on the corresponding verification wire; A main control unit is electrically connected to the verification current generating module and the verification current transformer respectively; The output unit is electrically connected to the main control unit.

2. The verification component for a residual current monitoring system according to claim 1, characterized in that: The verification current generation module includes an amplitude modulation circuit, and an input end of the amplitude modulation circuit is connected to an AC voltage signal output end of the main control unit.

3. The verification component for a residual current monitoring system according to claim 2, characterized in that: The verification current generation module further includes a phase modulation circuit, wherein an input end of the phase modulation circuit is connected to an output end of the amplitude modulation circuit.

4. The verification component for a residual current monitoring system according to claim 1, wherein: The output unit includes a display unit.

5. The verification component for a residual current monitoring system according to claim 1, wherein: It also includes a communication unit for connecting and communicating with a communication unit of a residual current monitoring system, and the communication unit is electrically connected to the main control unit.

6. The verification component for a residual current monitoring system according to any one of claims 1 to 5, characterized in that: The verification current generating module generates two verification currents.

7. A portable calibrator for a residual current monitoring system, characterized in that: The device comprises a first housing and a verification assembly for a residual current monitoring system according to any one of claims 1 to 6; A verification current generation module and a main control unit are installed inside the first housing; The first shell is provided with at least one transformer connection port, at least one current interface and a common end interface. The output end of the verification current transformer is connected to the current detection end of the main control unit through the transformer connection port, the first end of the verification wire is connected to the verification current output end of the verification current generation module through the current interface, and the second end of the verification wire is connected to the common end of the verification current generation module through the common end interface.

8. A portable monitoring device, characterized in that: include: Multiple residual current monitoring transformers, which are used to detect the current in the power supply circuit of the device under test; A verification current generating module, configured to generate at least one verification current; At least one verification wire, a first end of each verification wire is electrically connected to the verification current output end of the verification current generation module, and when in operation, the second end of the verification wire passes through the test hole of the current transformer of the residual current monitoring system or the test hole of the residual current monitoring transformer and is electrically connected to the common end of the verification current generation module; At least one verification current transformer, corresponding one-to-one to at least one verification wire, and configured to detect a verification current on the corresponding verification wire; The main control unit is electrically connected to the verification current generating module, the verification current transformer and the residual current monitoring transformer respectively; The output unit is electrically connected to the main control unit.

9. A portable monitoring device according to claim 8, characterized in that: The verification current generation module includes an amplitude modulation circuit and a phase modulation circuit. The input end of the amplitude modulation circuit is connected to the AC voltage signal output end of the main control unit, and the input end of the phase modulation circuit is connected to the output end of the amplitude modulation circuit.

10. A portable monitoring device according to claim 8 or 9, characterized in that: The output unit includes a display unit.

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