A comprehensive fault arc protection electrical appliance test system

Abstract

The present invention proposes a comprehensive fault arc protection electrical appliance test system, comprising a host computer data analysis system, a computer control system, a multifunctional data acquisition card, a digital I / O card, a data acquisition module, a stepper motor control system, an electromagnetic switch control system, a switch state feedback system, an arc generator, a cable carbonization device, a cable cutting device, a load device, and a comprehensive test circuit; a carbonized cable used in the comprehensive test circuit is prepared by the arc generator, the cable cutting device, and the arc carbonization device; the computer control system sends pulses to the stepper motor controllers of the arc generator and the cable cutting device via a timing counter on the multifunctional data acquisition card, utilizes motor motion to change the displacement of a blade and an electrode, and provides a carbonized cable and an arc of a desired strength; the test process comprises a high-voltage carbonization stage and a low-voltage test stage. The present invention can accommodate the commonalities and differences between different standard tests, has a high degree of automation, and ensures a safe and reliable test process.

Description

Technical Field

[0001] The invention relates to the technical field of low-voltage protection electrical appliance testing, in particular to a comprehensive fault arc protection electrical appliance testing system. Background Art

[0002] Arc faults are a major cause of low-voltage electrical fires. To reduce the number of electrical fires caused by arc faults and improve power supply safety, installing arc fault protection devices in electrical lines is a crucial measure. Corresponding testing standards for arc fault protection devices have been promulgated both domestically and internationally: GB / T 31143, GB14287.4, IEC62606, and UL 1699-2017. These standards verify whether arc fault detection devices (AFDDs), arc fault detectors (AFDs), or arc fault circuit interrupters (AFCIs) can detect and identify potential arc faults in the line, and promptly disconnect the protected circuit or issue a signal to prevent electrical fires.

[0003] While the test items and test loads in the standards vary, many similarities exist. Arc fault protection devices require rigorous testing during the R&D and testing phases of various product categories. Domestic and international standards specify the technical requirements and test methods for various protective devices. UL1699, the US standard, targets products with a rated voltage of 120V and a frequency of 60Hz. GB / T 31143 and GB14287.4 are Chinese standards for products with a rated voltage of 220-230V and a frequency of 50Hz. Furthermore, GB / T 31143 complies with the requirements of IEC 62606. IEC 62606 or GB / T 31143 will be used to refer to these two standards. Comprehensive arc fault detection technology requires diverse test methods, numerous test items, and a lengthy testing process. For example, arc generators cannot maintain the arc for the required duration at low currents. The preparation of different types of carbonized cables is complex, making circuit switching difficult. The current rating of cable cutting devices is too high, making manual sample replacement dangerous. Therefore, based on the commonalities and differences between different standard tests, there is an urgent need to develop a comprehensive test system for arc fault protection electrical appliances with a high degree of automation and a safe and reliable testing process. This system also has important guiding significance for the development of arc fault protection electrical appliances and the formulation of relevant standards. Summary of the Invention

[0004] The present invention provides a comprehensive arc fault protection electrical appliance testing system, which can be compatible with the commonalities and differences between different standard tests, has a high degree of automation, and a safe and reliable testing process.

[0005] The present invention adopts the following technical solutions.

[0006] A comprehensive arc fault protection electrical appliance test system, comprising a host computer data analysis system, a computer control system, a multifunctional data acquisition card, a digital I / O card, a data acquisition module, a stepper motor control system, an electromagnetic switch control system, a switch state feedback system, an arc generator, a cable carbonization device, a cable cutting device, a load device, and a comprehensive test circuit;

[0007] The carbonized cable used in the comprehensive test circuit is prepared by the test system's arc generator, cable cutting device, and arc carbonization device. The computer control system sends pulses to the stepper motor controllers of the arc generator and cable cutting device through a multi-function data acquisition card timing counter. The motor motion changes the displacement of the blade and electrode to provide the carbonized cable and an arc of the desired strength.

[0008] When testing the comprehensive test circuit, the test links related to the arc carbonization device include the high-voltage carbonization stage and the low-voltage test link. The high and low voltages are output by the digital I / O card, and the asynchronous motor is controlled to rotate forward and reverse after being driven. The test is carried out under the condition of high and low voltage isolation. Among them, the load device is pressed into the comprehensive test circuit through the electromagnetic switch control system according to the selected test load; the computer control system sends the switch function code to the electromagnetic switch control system through the digital I / O card to switch the electromagnetic switch state of the comprehensive test circuit.

[0009] The load device includes pure resistive load and resistive inductive load. During the test, the load device is selected according to the test content, and the arc protection standards required by vacuum cleaners, switching power supplies, air compressors, induction cookers, microwave ovens, air purifiers, and hand drills are selected to simulate the load type required by the test.

[0010] The electromagnetic switch control system adopts the optocoupler relay drive mode. The high and low levels output by the PCI digital I / O card are isolated by the optocoupler and then drive the relay coil. The relay further drives the electromagnetic switch coil to realize the control of the electromagnetic switch.

[0011] In the computer control system, the switch function code is programmed according to the switch action sequence of the test item and sent to the electromagnetic switch control system via the PCI digital I / O card in preset steps and time intervals to achieve switching between different operating states of the integrated test circuit. To ensure the correct operation of the program and the output of the acquisition card, after each switching action, the auxiliary contact signal of the electromagnetic switch is fed back to the computer control system through the switch state feedback system.

[0012] The switch status feedback system uses a parallel-input and serial-output shift register to collect the auxiliary contact status of the comprehensive test circuit and feeds it back to the computer control system via the PCI digital I / O card;

[0013] The data acquisition module collects voltage, current, smoke, and temperature signals in real time during the operation of the comprehensive test circuit as required. When the electromagnetic switch moves to the preset step, the computer control system creates a corresponding multi-function data acquisition card acquisition task and configures the relevant acquisition channels to collect the output signals of the sensors installed in the comprehensive test circuit. The computer control system displays the waveform of the collected data in real time on the operation interface. After the test is completed, the waveform is magnified and observed to read the arc duration and effective value data.

[0014] The computer control system automatically creates a test waveform database based on the type of test items, providing data support for the subsequent verification of arc fault protection electrical device action characteristics and the development of fault arc detection algorithms.

[0015] When conducting tests in GB / T 31143-2014 and GB14287.4-2014 standards, the comprehensive test circuit of the test system includes a large-capacity programmable AC source, whose main circuit is connected to an AC380V / 50Hz power supply. The voltage and frequency of the large-capacity programmable AC source are adjusted to 220V and 50Hz, and then connected to the comprehensive test circuit through an electromagnetic switch control system.

[0016] When conducting the UL1699 test, the voltage and frequency of the high-capacity programmable AC source are adjusted to 110V and 60Hz. The three standards differ in their test load types, operating voltages, and operating parameters. The resistive and inhibitory loads of the load devices are set separately according to the standard requirements, and each load is controlled by an independent electromagnetic switch. The cable carbonization device uses high- and low-voltage isolation switches automatically switched by an asynchronous motor to ensure safety during the carbonization process. During testing, all electromagnetic switches are closed and opened in the required sequence and timing by the electromagnetic switch control system to meet the test requirements of the standard.

[0017] When conducting tests related to the arc carbonization device, the comprehensive test circuit of the test system includes an AC220V / 7kV transformer, an AC220V / 2kV transformer, an AC220V / 15 kV transformer, an asynchronous motor, a carbonization state test circuit, a knife switch, and a limit switch;

[0018] When conducting the carbonization test in GB / T 31143-2014 and IEC 60626 standards, the arc carbonization device uses 7kV and 2kV transformer circuits to prepare the carbonized cable;

[0019] When conducting the carbonization test in GB14287.4-2014, the arc carbonization device uses a 7kV transformer to prepare the carbonized cable;

[0020] When conducting the UL1699 standard test, except for the carbonization path arc clearing time test in the standard, the ABCD test of the suppressed load shielding test of the socket type, mobile type, cable type and combination AFCI, and the EMI filter test, which use the same 7kV and 2kV carbonization methods as GB / T31143-2014, in other carbonization tests, the arc carbonization device uses a 15kV transformer to conduct cyclic carbonization tests on the cable;

[0021] The asynchronous motor is used for automatic switching of the high and low voltage of the isolation knife switch during the carbonization process; the limit switch is used to detect whether the knife switch is in close contact; the carbonization state test circuit includes a 100W incandescent lamp and a photosensor.

[0022] When the test system performs the GB / T 3114-2014 carbonization test process, it is divided into the following steps:

[0023] Step A1: Preparation of carbonized cable, specifically: an asynchronous motor drives the knife switch to close to the high-voltage side, 220V / 7kV high-voltage side switch K5 is closed first, followed by switch K4, and the cable sample is subjected to insulation breakdown. After a delay, switch K4 is opened first, followed by switch K5. 220V / 2kV high-voltage side switch K7 is closed first, followed by switch K6, and the cable sample is carbonized. After a delay, switch K6 is opened first, followed by switch K7.

[0024] Step A2: Carbonization status detection of the carbonized cable. Specifically, the asynchronous motor drives the knife switch to close to the low-voltage side, K10 and K11 are closed, the photoresistor detects whether the 100W bulb is lit, and the computer control system collects the level output of the photosensitive module to determine whether the cable is successfully carbonized, and then all switches are disconnected;

[0025] Step A3: Connect the carbonized cable to the comprehensive test circuit to conduct a fault arc test;

[0026] When the test system performs the GB14287.4-2014 carbonization test process, it is divided into the following steps:

[0027] Step B1, preparation of carbonized cable, specifically: an asynchronous motor drives the knife switch to close to the high voltage side, the 220V / 7kV high voltage side switch K5 and the corresponding high voltage carbonized resistor switch after the cable carbonization device are closed first, and then the switch K4 is closed to carbonize the cable sample;

[0028] Step B2: The carbonized cable is connected to the comprehensive test circuit to conduct a fault arc test;

[0029] When the test system performs the UL1699 carbonization test process, the high-voltage carbonization circuit of the cable carbonization circuit is separated from the comprehensive test circuit.

[0030] The arc generator includes a fixed electrode, a moving electrode, a screw slide, a first stepping motor, a resistance detection module, and a switch limit. The moving electrode is a copper rod with a tip, and the fixed electrode is a graphite rod. The two electrodes are connected to the circuit through wires. The screw slide is a slide mechanism driven by a screw mechanism. The moving electrode is located on the screw slide driven by the first stepping motor. During the process of the moving electrode approaching the fixed electrode, the computer control system samples the average resistance between the two electrodes in real time through the resistance detection module, and judges whether the two electrodes are in close contact according to the average resistance. The switch limit is used to detect the reset situation of the moving electrode. After the test is completed, the first stepping motor controls the moving electrode to separate and reset to the initial position.

[0031] The arc generator controls the moving speed of the moving electrode with an adaptive variable-speed electrode control strategy based on the arc voltage. The specific process is as follows:

[0032] Step S1: Before the arc fault test of the arc generator starts, the moving electrode is in the reset state.

[0033] Step S2: In the test preparation stage, the moving electrode approaches the fixed electrode at a speed of - v 0. During the process, the average resistance between the two electrodes is detected. If the average resistance > Rh, continue to approach at a speed of - v 0. If the average resistance < Rh, it is determined that the fixed electrode and the moving electrode have completed contact, and the test preparation is completed.

[0034] Step S:3 When the experiment starts and the main circuit is powered on, the moving electrode initially moves away from the fixed electrode quickly at a speed of v 0. The voltage between the fixed electrode and the moving electrode is detected. If the effective value of the voltage U(t) is less than the lower limit Umin of the arc region, calculate v 1 according to △U1 = U(t) - Umin, and continue to control the moving electrode to move away from the fixed electrode at this speed. If the effective value of the voltage U(t) is greater than the lower limit Umin of the arc region, perform the next step. If the voltage U is greater than the upper limit Umax of the arc region, calculate v 1 according to △U1 = U(t) - Umax, and continue to control the moving electrode to approach the fixed electrode at this speed. If the effective value of the voltage U(t) is less than the upper limit Umax of the arc region, perform the next step.

[0035] Step S4: According to the real-time arc voltage and electrode gap during the arcing process, use the fitting model of the arc voltage and electrode gap s ( t ) = f U ( t ​)] Determine whether the current state is in the optimal stable arcing zone. If the arcing voltage is greater than the voltage range of the optimal stable arcing zone, adjust the moving electrode speed to v 2. Use the stepper motor to fine-tune the moving electrode to approach the fixed electrode; if the arc voltage is less than the voltage range of the optimal stable arcing zone, adjust the moving electrode speed to v 2. Use the stepper motor to fine-tune the moving electrode away from the fixed electrode; if the arc voltage is within the voltage range of the optimal stable arcing zone, the speed is 0, the electrode spacing does not change, and proceed to the next step.

[0036] Step S5: Determine whether the arc timing is over according to the test time required by different current levels. If the timing is not over, continue to determine the arc voltage. If the timing is over, continue to determine the arc voltage. v The speed control of 3 moves the electrode away from the fixed electrode; the test ends when the moving electrode moves away from the fixed electrode and reaches the reset point.

[0037] The cable cutting device is a guillotine-shaped structure, and includes an insulating arm, a cable test piece, a cutting blade, a cutting back plate, a screw rod, a second stepper motor, a second stepper motor drive and control module, and upper and lower limit modules;

[0038] The cutting blade is fixed to the inside of the insulating arm. The cable sample consists of two parallel wires connected to two wiring terminals and is placed on an insulated and high-temperature resistant cutting backplane. The wiring terminals are connected to the test main circuit of the comprehensive test circuit. The second stepper motor is connected to the lead screw through a coupling. The other end of the lead screw is connected to the sliding part of the insulating arm. The direction and speed of the second stepper motor are controlled by the host computer platform via the data acquisition card. When the second stepper motor rotates, it drives the insulating arm downward through the lead screw, driving the steel cutting blade to cut the cable sample. When the test main circuit is energized, cutting the cable sample can generate a parallel arc.

[0039] The second stepper motor is a reduction motor. After the test is completed, the second stepper motor rotates to reset the cutting blade to the highest position;

[0040] The moving stroke of the cutting blade is limited by the upper and lower limit modules. When the stroke exceeds the limit, the stepper motor will automatically stop running.

[0041] The cable cutting device is controlled by the cable test automatic control system, which includes terminal blocks, backup cables, wire crimpers, cutting backplanes, a third stepper motor, a waste wire recycler, and a fourth stepper motor. Both the third and fourth stepper motors are reduction motors.

[0042] The cutting backplane includes a cutting groove and a conductor groove. The cutting groove is aligned with the cutting blade and is used for cutting the conductor. The cutting blade can cut into the groove. The conductor groove is two U-shaped grooves with opposite ends, which are used to accommodate the cable. The conductor can move in the groove. The U-shaped grooves with opposite ends can ensure that the conductors are cut parallel and closely adjacent at the cutting position, while the grooves at other positions are separated to ensure that the conductors with cuts will not produce parallel breakdown after the experiment, thereby affecting the experiment.

[0043] The intersection of the wire groove and the cutting knife groove is the wire cutting point;

[0044] The wiring terminals are connected to the backup cables, which are used to supplement the cable samples during the test;

[0045] The wires in the backup cable are separated and placed in the wire groove of the cutting backplane after passing through the wire crimper. The wires pass through the wire crimper at the end of the cutting backplane and are collected on both sides of the baffle of the waste wire collector. The waste wire recycling period uses a stepping reduction motor to control the rotation to automatically collect and move the waste wires.

[0046] The third stepper motor controls the forward and backward movement of the cutting backboard, and the fourth stepper motor controls the waste wire collector and controls the movement of the wire from the point where it enters the cutting backboard to the point where it leaves the backboard;

[0047] The cutting groove in the cutting backplane is virtually positioned with the cutting blade. Based on the damaged width of the blade in each cutting experiment, the cutting blade is divided into 1, 2, 3...n parts according to the total length. After the cutting experiment is completed, the third stepper motor moves forward and backward to the uncut blade part corresponding to the cutting groove. Each part can only be cut once and moves sequentially according to the virtual positioning of the cutting blade after the cutting is completed, ensuring that the position of the blade cutting the wire is controllable. The entire cutting blade can be replaced after it has been fully used.

[0048] When the fourth stepper motor rotates, the wire is pulled to the right to recycle the waste wire. In the experiment, the wire cutting position moves to the right and separates. The wire at the cutting groove is the uncut wire part. When the wire in the backup cable is used up, the entire cable sample can be replaced.

[0049] The method of using the test system is as follows:

[0050] Step 1: Select the required test standard, test item, test device, and test load on the human-computer interaction interface of the computer control system. Before starting the test, set the test current, test voltage, and data acquisition range options, and select the corresponding resistive load and sensor according to the test option and test current.

[0051] Step 2: Based on the above settings, the computer control system automatically generates switch control instructions. The PCI digital I / O card sends the control instructions to the switch control system, which drives the corresponding relay after optical coupling isolation, and then the corresponding electromagnetic switch is actuated.

[0052] Step 3: The switch control system connects the arc generator, cable cutting device, cable carbonizing device, and various types of load devices to the comprehensive test circuit at different times according to the sequence of computer instructions. The switch status feedback system is activated after each switching action and feeds back the switch status to the computer control system. The system determines whether to proceed to the next action based on whether the control instruction sent and the feedback status are consistent.

[0053] Step 4: During the test, the data acquisition module is turned on in specific switching steps or links, namely: the average value of the pressure sensor is collected during the movement of the electrode; voltage and current data are collected during the electrode arcing, cable cutting, and cable carbonization tests. During this process, the system power-on time after the arc is generated is determined according to the arcing time required by the standard;

[0054] In step 4, when using an arc generator for testing, during the test preparation phase, the resistance between the two electrodes during the arcing process of the arc generator is detected to determine whether the two electrodes are tightly connected. After the test begins, the initial velocity is used to control the separation of the electrodes until the voltage between the two electrodes is within the arc voltage arcing control zone. During the arcing control phase, the arc voltage is used to determine whether the electrode position is within the arcing control zone or the stable arcing zone. The arcing coarse control strategy or the arcing fine control strategy is used to control the electrode speed, thereby ensuring the arcing continuity of the arc generator. After the test is completed, the electrodes continue to separate until they are reset. This solves the problem that arc generators are difficult to generate arcs that meet test standards under low current conditions.

[0055] In step 4, when using the cable carbonization device, different samples are prepared according to different standards, and the circuit switching is controlled by the electromagnetic switch control system to achieve high-voltage carbonization of cable samples of different standards. The successful carbonization of the cable sample is automatically detected and the arc fault protection electrical appliance detection test is started. After the test starts, the computer control system automatically switches the knife switch to complete the high-voltage carbonization. When the carbonized cable is connected to the comprehensive experimental circuit, the computer control system collects the voltage and current during the experiment and monitors whether the cotton is on fire.

[0056] In step 4, when a cable cutting device is used for testing, the cutting back plate of the cable cutting device is used to ensure that the cable sample is closely parallel to and separated from other positions at the cutting position; the computer control system reads the cutting test bench position record file, and the stepper motor drives the cutting test bench to move a unit distance horizontally, and stores the new position in the file; the reduction motor is used to control the forward and backward movement of the cutting back plate to change the position of the cutting blade, and the reduction motor is used to control the cable waste wire recycler so that the cable sample is automatically replaced; at the beginning of the experiment, the blade and cable reach the new position, and the stepper motor drives the blade to move down to cut the cable. When the voltage is less than the initial voltage, it means that the cable has been cut, and after a delay, the blade is reset to the initial position; the collected data during the test is displayed on the human-computer interaction interface and saved in the fault arc database.

[0057] The present invention provides a comprehensive arc fault protection electrical appliance test system, which includes a computer control system, a data acquisition module, a stepper motor control system, a data acquisition card, an electromagnetic switch control system, a switch state feedback system, an arc generator, a cable carbonization device, a cable cutting device, various load devices, and a comprehensive test circuit. The test circuit of the test system of the present invention can comprehensively perform various test items in the IEC 62606-2017, GB / T 31143-2014, GB14287.4-2014, and UL1699A-2017 standards, and meets circuit switching requirements for testing different types of carbonized cables in multiple standards.

[0058] The present invention proposes an adaptive variable speed electrode control strategy based on arc voltage during the arcing process of an arc generator, which can improve the qualified rate of arc generation by the arc generator.

[0059] The present invention provides an automatic control system for a cable test piece of a cable cutting device, which can improve the test efficiency during the testing process of the cable cutting device.

[0060] The present invention has a high overall degree of automation, a safe and reliable testing process, a high success rate of fault arc simulation, and test data that meets standard requirements. It can test various types of fault arc protection electrical appliances, shortens the test cycle, and improves test efficiency.

[0061] The advantages of the present invention are:

[0062] 1. The present invention proposes a comprehensive test system that complies with domestic and international standards for testing arc fault protection appliances. The system can meet the differentiated test items of different standards and realize the integrated switching and testing of different types of cable carbonization test circuits. The present invention designs a comprehensive arc fault test circuit that includes three different arc generating devices, namely an arc generator, a cable carbonization device, and a cable cutting device, and various types of loads. The circuit is switched by an electromagnetic switch control system to realize the occurrence of arc faults under different devices, at different times, at different positions, and under different load types, thereby realizing comprehensive testing of different arc fault protection appliance detection standards at home and abroad. The electromagnetic switch control system controls the circuit switching to realize high-voltage carbonization of cable samples of different standards, automatically detect the successful carbonization of the cable sample, and start the arc fault protection appliance detection test, thereby meeting the comprehensive test under differentiated conditions of cable carbonization devices between different detection standards.

[0063] 2. The present invention proposes an adaptive variable speed electrode control strategy based on arc voltage during the arcing process of the arc generator, which can improve the qualified rate of the arc generator in generating arc duration that meets the test standards. In the test preparation stage, the resistance between the two electrodes during the arcing process of the arc generator is detected to determine whether the two electrodes are tightly connected. After the test starts, the initial velocity is used to control the separation of the electrodes until the voltage between the two electrodes is within the arc voltage arcing control area. In the arcing control stage, the arc voltage is used to determine whether the electrode position is in the arcing control area or the stable arcing area, and the arcing coarse control strategy or the arcing fine control strategy is used to control the electrode speed, thereby ensuring the arcing continuity of the arc generator. After the test is completed, the electrodes continue to separate until they are reset. This method solves the problem that it is difficult for an arc generator to generate an arc that meets the test standard market under low current conditions.

[0064] 3. The present invention proposes an automatic control system for cable specimens of a cable cutting device, which can improve the test efficiency during the testing process of the cable cutting device and avoid safety issues caused by manual operation. The present invention ensures that the cable specimen is closely parallel to and separated from other positions at the cutting position by modifying the cutting back plate of the cable cutting device. The reduction motor is used to control the forward and backward movement of the cutting back plate to change the position of the cutting blade, and the reduction motor is used to control the cable waste wire recycler so that the cable specimen is automatically replaced, thereby realizing the automatic replacement of the cable specimen and the blade of the cable cutting device. The cable cutting device is mainly aimed at 75-500A parallel fault arcs. This method can ensure the maximum utilization of the cutting blade and the cable specimen, while reducing the safety hazards caused by manual replacement of the cable specimen and the blade. BRIEF DESCRIPTION OF THE DRAWINGS

[0065] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments:

[0066] Attachment Figure 1 It is a schematic diagram of the architectural principle of the present invention;

[0067] Attachment Figure 2 It is a structural schematic diagram of the comprehensive test circuit of the present invention;

[0068] Attachment Figure 3 is a flow chart of a test process control strategy related to an arc generator of the present invention;

[0069] Attachment Figure 4 This is a schematic diagram of the test circuit for cutting a cable test piece to generate a parallel arc;

[0070] Attachment Figure 5 It is a schematic diagram of a cable cutting device with a guillotine structure;

[0071] Attachment Figure 6 is a schematic diagram of a cutting back plate of a cable cutting device;

[0072] Attachment Figure 7 It is a top view schematic diagram of the cable sample and the back plate when the cable cutting device is working;

[0073] Attachment Figure 8 It is a forward schematic diagram of the cable sample and the back plate when the cable cutting device is working;

[0074] Attachment Figure 9 is a forward schematic diagram of the blade of the cable cutting device cutting the cable;

[0075] Attachment Figure 10 is a side view of a blade of a cable cutting device cutting a cable;

[0076] Attachment Figure 11 Schematic diagram of the relationship between arc voltage and electrode spacing during the arc control process in an embodiment of the present invention. DETAILED DESCRIPTION

[0077] As shown in the figure, a comprehensive arc fault protection electrical appliance test system includes a host computer data analysis system, a computer control system, a multi-function data acquisition card, a digital I / O card, a data acquisition module, a stepper motor control system, an electromagnetic switch control system, a switch state feedback system, an arc generator, a cable carbonization device, a cable cutting device, a load device and a comprehensive test circuit;

[0078] The carbonized cable used in the comprehensive test circuit is prepared by the test system's arc generator, cable cutting device, and arc carbonization device. The computer control system sends pulses to the stepper motor controllers of the arc generator and cable cutting device through a multi-function data acquisition card timing counter. The motor motion changes the displacement of the blade and electrode to provide the carbonized cable and an arc of the desired strength.

[0079] When testing the comprehensive test circuit, the test links related to the arc carbonization device include the high-voltage carbonization stage and the low-voltage test link. The high and low voltages are output by the digital I / O card, and the asynchronous motor is controlled to rotate forward and reverse after being driven. The test is carried out under the condition of high and low voltage isolation. Among them, the load device is pressed into the comprehensive test circuit through the electromagnetic switch control system according to the selected test load; the computer control system sends the switch function code to the electromagnetic switch control system through the digital I / O card to switch the electromagnetic switch state of the comprehensive test circuit.

[0080] The load device includes pure resistive load and resistive inductive load. During the test, the load device is selected according to the test content, and the arc protection standards required by vacuum cleaners, switching power supplies, air compressors, induction cookers, microwave ovens, air purifiers, and hand drills are selected to simulate the load type required by the test.

[0081] The electromagnetic switch control system adopts the optocoupler relay drive mode. The high and low levels output by the PCI digital I / O card are isolated by the optocoupler and then drive the relay coil. The relay further drives the electromagnetic switch coil to realize the control of the electromagnetic switch.

[0082] In the computer control system, the switch function code is programmed according to the switch action sequence of the test item and sent to the electromagnetic switch control system via the PCI digital I / O card in preset steps and time intervals to achieve switching between different operating states of the integrated test circuit. To ensure the correct operation of the program and the output of the acquisition card, after each switching action, the auxiliary contact signal of the electromagnetic switch is fed back to the computer control system through the switch state feedback system.

[0083] The switch status feedback system uses a parallel-input and serial-output shift register to collect the auxiliary contact status of the comprehensive test circuit and feeds it back to the computer control system via the PCI digital I / O card;

[0084] The data acquisition module collects voltage, current, smoke, and temperature signals in real time during the operation of the comprehensive test circuit as required. When the electromagnetic switch moves to the preset step, the computer control system creates a corresponding multi-function data acquisition card acquisition task and configures the relevant acquisition channels to collect the output signals of the sensors installed in the comprehensive test circuit. The computer control system displays the waveform of the collected data in real time on the operation interface. After the test is completed, the waveform is magnified and observed to read the arc duration and effective value data.

[0085] The computer control system automatically creates a test waveform database based on the type of test items, providing data support for the subsequent verification of arc fault protection electrical device action characteristics and the development of fault arc detection algorithms.

[0086] When conducting tests in GB / T 31143-2014 and GB14287.4-2014 standards, the comprehensive test circuit of the test system includes a large-capacity programmable AC source, whose main circuit is connected to an AC380V / 50Hz power supply. The voltage and frequency of the large-capacity programmable AC source are adjusted to 220V and 50Hz, and then connected to the comprehensive test circuit through an electromagnetic switch control system.

[0087] When conducting the UL1699 test, the voltage and frequency of the high-capacity programmable AC source are adjusted to 110V and 60Hz. The three standards differ in their test load types, operating voltages, and operating parameters. The resistive and inhibitory loads of the load devices are set separately according to the standard requirements, and each load is controlled by an independent electromagnetic switch. The cable carbonization device uses high- and low-voltage isolation switches automatically switched by an asynchronous motor to ensure safety during the carbonization process. During testing, all electromagnetic switches are closed and opened in the required sequence and timing by the electromagnetic switch control system to meet the test requirements of the standard.

[0088] When conducting tests related to the arc carbonization device, the comprehensive test circuit of the test system includes an AC220V / 7kV transformer, an AC220V / 2kV transformer, an AC220V / 15 kV transformer, an asynchronous motor, a carbonization state test circuit, a knife switch, and a limit switch;

[0089] When conducting the carbonization test in GB / T 31143-2014 and IEC 60626 standards, the arc carbonization device uses 7kV and 2kV transformer circuits to prepare the carbonized cable;

[0090] When conducting the carbonization test in GB14287.4-2014, the arc carbonization device uses a 7kV transformer to prepare the carbonized cable;

[0091] When conducting the UL1699 standard test, except for the carbonization path arc clearing time test in the standard, the ABCD test of the suppressed load shielding test of the socket type, mobile type, cable type and combination AFCI, and the EMI filter test, which use the same 7kV and 2kV carbonization methods as GB / T31143-2014, in other carbonization tests, the arc carbonization device uses a 15kV transformer to conduct cyclic carbonization tests on the cable;

[0092] The asynchronous motor is used for automatic switching of the high and low voltage of the isolation knife switch during the carbonization process; the limit switch is used to detect whether the knife switch is in close contact; the carbonization state test circuit includes a 100W incandescent lamp and a photosensor.

[0093] like Figure 2 As shown, when the test system performs the GB / T 3114-2014 carbonization test process, it is divided into the following steps:

[0094] Step A1: Preparation of carbonized cable, specifically: an asynchronous motor drives the knife switch to close to the high-voltage side, 220V / 7kV high-voltage side switch K5 is closed first, followed by switch K4, and the cable sample is subjected to insulation breakdown. After a delay, switch K4 is opened first, followed by switch K5. 220V / 2kV high-voltage side switch K7 is closed first, followed by switch K6, and the cable sample is carbonized. After a delay, switch K6 is opened first, followed by switch K7.

[0095] Step A2: Carbonization status detection of the carbonized cable. Specifically, the asynchronous motor drives the knife switch to close to the low-voltage side, K10 and K11 are closed, the photoresistor detects whether the 100W bulb is lit, and the computer control system collects the level output of the photosensitive module to determine whether the cable is successfully carbonized, and then all switches are disconnected;

[0096] In this step, the asynchronous motor drives the knife switch to close to the low-voltage side, K10 and K11 are closed, the photoresistor detects whether the 100W bulb is lit, the computer control system collects the level output of the photosensitive module, determines whether the carbonization is successful, and then all switches are disconnected.

[0097] Step A3: Connect the carbonized cable to the comprehensive test circuit to conduct a fault arc test;

[0098] In this step, if carbonization is successful, the knife switch remains on the low-voltage side throughout the test. For example, the test steps for verifying a sudden series arc fault in the circuit in 9.9.2.2 are as follows: Close switches K1, K2, K14, K15, K17, K18, K11, and the AFDD series branch with a resistive load corresponding to the current level; after a short delay, disconnect K17 and insert the cable test sample in series with the load. Throughout the test, collect voltage, current, smoke, and temperature data and transmit them to the computer control system. Finally, disconnect all switches. For verifying a current-limited parallel arc, close switches K1, K2, K11, K12, K13, K17, K18, and the AFDD series branch with a resistive load to detect the expected current. Then disconnect K12, K13, and K17, close K14 and K15. A current-limited parallel arc now occurs in the circuit, and data is collected throughout the test. Finally, disconnect all switches.

[0099] like Figure 2 As shown, when the test system performs the GB14287.4-2014 carbonization test process, it is divided into the following steps:

[0100] Step B1, preparation of carbonized cable, specifically: an asynchronous motor drives the knife switch to close to the high voltage side, the 220V / 7kV high voltage side switch K5 and the corresponding high voltage carbonized resistor switch after the cable carbonization device are closed first, and then the switch K4 is closed to carbonize the cable sample;

[0101] This step is a series carbonization path arc test: the asynchronous motor drives the knife switch to close to the high-voltage side, the 220V / 7kV high-voltage side K5 and the corresponding high-voltage carbonization resistor switch after the cable carbonization device are closed first, and K4 is closed later, and the cable sample is carbonized. After a delay, K4 is disconnected first, and K5 and the carbonization resistor are disconnected later, and the high-voltage carbonization process is completed; the asynchronous motor drives the knife switch to close to the low-voltage side, K1, K2, K14, K15, K18, K11 and the resistance test load switch after the cable carbonization device are closed to generate a series arc, collect data, delay for a period of time, and finally disconnect all switches.

[0102] Step B2: The carbonized cable is connected to the comprehensive test circuit to conduct a fault arc test;

[0103] This step is a parallel carbonization path arc test: the asynchronous motor drives the knife switch to close to the high-voltage side, K5 on the 220V / 7kV high-voltage side is closed first, and K4 is closed later, and the cable sample is carbonized. After a delay, K4 is disconnected first, and K5 is disconnected later, and the high-voltage carbonization process ends; the asynchronous motor drives the knife switch to close to the low-voltage side, and the resistance test load switch behind the carbonization device of K1, K2, K14, K15, K18, and K11 is closed to generate a parallel arc, collect data, and finally disconnect all switches after a delay.

[0104] like Figure 2 As shown, when the test system performs the UL1699 carbonization test process, the high-voltage carbonization circuit for the cable carbonization circuit is separated from the comprehensive test circuit.

[0105] During the UL1699 carbonization test, the standard explicitly states that the test circuit can be modified to prevent current from flowing through the device under test during the high-voltage carbonization period. This modification separates the high-voltage carbonization circuit from the integrated test circuit. The carbonization path arc clearing time test, the carbonization path arc clearing time test for the Suppressive Load Shielding Tests A, B, C, and D, and the EMI filter shielding test follow the same carbonization cable preparation and testing methods as those used in the national standard. The carbonization path arc occurrence test (load energized, load de-energized), the carbonization path arc interruption test, the Suppressive Load Shielding Tests A, B, C, and D, and the carbonization path arc occurrence test for the EMI filter test are all separate carbonization test options for 15kV transformers.

[0106] For the carbonization path arc generation test: the asynchronous motor drives the knife switch to the high-voltage side, K9 and the resistance switch corresponding to the current level after the cable carbonization device are closed, K8 is closed, and the 15KV carbonization stage is entered. The power is delayed for 10 seconds, K8 is disconnected, and then all switches are disconnected. The asynchronous motor drives the knife switch to the low-voltage side, K1, K2, K14, K15, K18, K11 and the resistance switch of the AFCI series branch are closed, and the power is delayed for 10 seconds. During this process, the data acquisition card collects voltage, current, smoke, and temperature, and detects whether the cotton outside the sample is on fire through the flame sensor installed at the cable carbonization device. If the AFCI trips or the cotton is on fire but the AFCI does not trip, the current test is terminated. If the above two phenomena do not occur, the above process is repeated in a cycle, and the maximum number of cycles is 15 times.

[0107] For the Suppressed Load Shielding Test B: The asynchronous motor drives the knife switch to the high-voltage side, K9, K21, K1, K2, K14, K15, the AFDD series branch resistive load, the AFDD parallel branch shielding load, and K18 are closed. 2. K8 and K17 are closed, and the 15kV carbonization stage begins. The power is delayed for 10 seconds. K8 and K17 are disconnected, and then K9, K21, and the AFDD series branch resistive load are disconnected. The asynchronous motor drives the knife switch to the low-voltage side, K11 and the resistive load behind the carbonization device are closed, and the power is delayed for 10 seconds. 4. Subsequent testing and test cycles are similar to the carbonization path arc generation test. The remaining test items involving the carbonization path cables of 40.2 and 42.2 are carried out according to the above procedures.

[0108] The arc generator includes a fixed electrode, a movable electrode, a lead screw slide, a first stepper motor, a resistance detection module, and a switch limit. The movable electrode is a copper rod with a tip, the fixed electrode is a graphite rod, and the electrodes on both sides are connected to the circuit through wires. The lead screw slide is a slide mechanism driven by a lead screw mechanism. The movable electrode is located on the lead screw slide driven by the first stepper motor. In the process of the movable electrode approaching the fixed electrode, the computer control system samples the average resistance between the two electrodes in real time through the resistance detection module, and determines whether the two electrodes are in close contact based on the average resistance value; the switch limit is used to detect the reset status of the movable electrode; after the test is completed, the first stepper motor controls the movable electrode to separate and reset to the initial position.

[0109] In this example, the arc generator obtains the arc voltage through the voltage sensor and calculates the arc voltage effective value U(t). The arc voltage range of the arc control zone is set to [Umin, Umax] = [20V, 45V]. The voltage U(t) lower than the arc control zone voltage is compared with the arc control zone voltage lower limit U min =20V, and make the difference between U(t) which is higher than the arc control zone voltage and the upper limit voltage U maxTake the difference with 45V. According to the difference result ΔU1, use the stepper motor to control the moving speed of the moving electrode as v v1 = ΔU1 * v′, v where v′ is the adjustment speed per unit voltage, v the positive of v1 is the electrode separation direction, and the negative is the electrode approaching direction, to avoid the arc voltage crossing the arc ignition control area upward or downward due to a relatively fast adjustment speed and the inability to start the arc due to a relatively slow adjustment speed exceeding the test time; v The reference speed of v′ is 0.5mm / s, so as to roughly adjust the arc voltage and control the electrode voltage U(t) within the range of [Umin, Umax] = [20V, 45V];

[0110] Obtain the associated data of different arc voltages and electrode spacings through experimental data, and use a neural network to fit the arc voltage and electrode spacing data to obtain the optimal fitting relationship between the arc voltage and electrode spacing as s ( t ) = f U ( t ) ]; Classify and analyze the arc ignition data and stable arc ignition conditions of the arc voltage and electrode spacing, and determine s ( t ) = f U ( t ) ] in the stable arc ignition area, and adjust the control within this area to eliminate the influence caused by the randomness during the fault arc ignition process and the loss of the moving electrode and fixed electrode of the arc generator during the arc ignition process;

[0111] After the rough adjustment, the electrode voltage U(t) is within the range of [Umin, Umax]. If U(t) is above or below the stable arc ignition area, then according to the difference result ΔU2, use the stepper motor to control the moving speed of the moving electrode as: v v2 = Δ s / t ; t v2 = ΔU2 / U′′; If U(t) < U0, then ΔU2 = U(t) - U0, if U(t) > U0, then ΔU2 = U(t) - U1. The positive of v2 is the electrode separation direction, and the negative is the electrode approaching direction, t where t is the time required to adjust ΔU2, and U′′ is the voltage that can be adjusted per unit time;

[0112] ​​Since the arc state during the arcing process is greatly affected by the arc voltage and the electrode spacing, there are limitations to the adjustable voltage per unit time, to avoid the electrode spacing falling out of or exceeding the arcing control area at a relatively fast adjustment speed; the reference value of U′′ is 10V / s; thus, the arc voltage is finely adjusted. If U(t) is within the stable arcing area range, the moving speed of the electrode is 0 and the electrode position remains unchanged.

[0113] According to the arcing time requirements for different current levels, after the timing ends, arcing control is completed, and the moving electrode is reset at a speed of v3.

[0114] As Figure 11 shown, in this example, the effective value range of the arc voltage in the arcing control area is set as: [20V, 45V], that is, the lower limit of the voltage in the arcing control area Umin = 20V, and the upper limit of the voltage in the arcing control area Umax = 45V. The optimal stable arcing area is within the arcing control area, and this area is selected according to different current levels by the fitting relationship model s(t)=f [ U(t) ] between the arc voltage and the electrode spacing.

[0115] The arc generator controls the moving speed of the moving electrode with an adaptive variable-speed electrode control strategy based on the arc voltage. The specific process is as follows:

[0116] Step S1: Before the start of the arc fault test using the arc generator, the moving electrode is in the reset state.

[0117] Step S2: In the test preparation stage, the moving electrode approaches the fixed electrode at a speed of -v0. During the process, the average resistance of the two electrodes is detected. If the average resistance > Rh, it continues to approach at a speed of -v0. If the average resistance < Rh, it is determined that the fixed electrode and the moving electrode have completed contact, and the test preparation is completed.

[0118] Step S3: At the start of the experiment, after the main circuit is powered on, the moving electrode initially moves away from the fixed electrode at a speed of v0; the voltage between the fixed electrode and the moving electrode is detected. If the effective value of the voltage U(t) is less than the lower limit Umin of the arc region, then v1 is calculated according to △U1 = U(t) - Umin, and the moving electrode is continued to be controlled to move away from the fixed electrode at this speed; if the effective value of the voltage U(t) is greater than the lower limit Umin of the arc region, the next step is executed; if the voltage U is greater than the upper limit Umax of the arc region, then v1 is calculated according to △U1 = U(t) - Umax, and the moving electrode is continued to be controlled to approach the fixed electrode at this speed; if the effective value of the voltage U(t) is less than the upper limit Umax of the arc region, the next step is executed.

[0119] Step S4: Based on the real-time arc voltage and electrode gap during the arcing process, use the fitting model s(t)=f[U(t)] of the arc voltage and electrode gap to determine whether the current state is in the optimal stable arcing zone. If the arcing voltage is greater than the voltage range of the optimal stable arcing zone, adjust the speed of the moving electrode to v2, and use the stepper motor to fine-tune the moving electrode to approach the fixed electrode; if the arcing voltage is less than the voltage range of the optimal stable arcing zone, adjust the speed of the moving electrode to v2, and use the stepper motor to fine-tune the moving electrode away from the fixed electrode; if the arcing voltage is within the voltage range of the optimal stable arcing zone, the speed is 0, the electrode gap does not change, and proceed to the next step.

[0120] Step S5: Determine whether the arc timing has ended based on the test time required for different current levels. If the timing has not ended, continue to determine the arc voltage. If the timing has ended, control the moving electrode to move away from the fixed electrode at a speed of v3. The test ends when the moving electrode moves away from the fixed electrode and reaches the reset point.

[0121] The cable cutting device is a guillotine-shaped structure, and includes an insulating arm, a cable test piece, a cutting blade, a cutting back plate, a screw rod, a second stepper motor, a second stepper motor drive and control module, and upper and lower limit modules;

[0122] The cutting blade is fixed to the inside of the insulating arm. The cable sample consists of two parallel wires connected to two wiring terminals and is placed on an insulated and high-temperature resistant cutting backplane. The wiring terminals are connected to the test main circuit of the comprehensive test circuit. The second stepper motor is connected to the lead screw through a coupling. The other end of the lead screw is connected to the sliding part of the insulating arm. The direction and speed of the second stepper motor are controlled by the host computer platform via the data acquisition card. When the second stepper motor rotates, it drives the insulating arm downward through the lead screw, driving the steel cutting blade to cut the cable sample. When the test main circuit is energized, cutting the cable sample can generate a parallel arc.

[0123] The second stepper motor is a reduction motor. After the test is completed, the second stepper motor rotates to reset the cutting blade to the highest position;

[0124] The moving stroke of the cutting blade is limited by the upper and lower limit modules. When the stroke exceeds the limit, the stepper motor will automatically stop running.

[0125] The cable cutting device is controlled by the cable test automatic control system, which includes terminal blocks, backup cables, wire crimpers, cutting backplanes, a third stepper motor, a waste wire recycler, and a fourth stepper motor. Both the third and fourth stepper motors are reduction motors.

[0126] The cutting backplane includes a cutting groove and a conductor groove. The cutting groove is aligned with the cutting blade and is used for cutting the conductor. The cutting blade can cut into the groove. The conductor groove is two U-shaped grooves with opposite ends, which are used to accommodate the cable. The conductor can move in the groove. The U-shaped grooves with opposite ends can ensure that the conductors are cut parallel and closely adjacent at the cutting position, while the grooves at other positions are separated to ensure that the conductors with cuts will not produce parallel breakdown after the experiment, thereby affecting the experiment.

[0127] The intersection of the wire groove and the cutting knife groove is the wire cutting point;

[0128] The wiring terminals are connected to the backup cables, which are used to supplement the cable samples during the test;

[0129] The wires in the backup cable are separated and placed in the wire groove of the cutting backplane after passing through the wire crimper. The wires pass through the wire crimper at the end of the cutting backplane and are collected on both sides of the baffle of the waste wire collector. The waste wire recycling period uses a stepping reduction motor to control the rotation to automatically collect and move the waste wires.

[0130] The third stepper motor controls the forward and backward movement of the cutting backboard, and the fourth stepper motor controls the waste wire collector and controls the movement of the wire from the point where it enters the cutting backboard to the point where it leaves the backboard;

[0131] The cutting groove in the cutting backplane is virtually positioned with the cutting blade. Based on the damaged width of the blade in each cutting experiment, the cutting blade is divided into 1, 2, 3...n parts according to the total length. After the cutting experiment is completed, the third stepper motor moves forward and backward to the uncut blade part corresponding to the cutting groove. Each part can only be cut once and moves sequentially according to the virtual positioning of the cutting blade after the cutting is completed, ensuring that the position of the blade cutting the wire is controllable. The entire cutting blade can be replaced after it has been fully used.

[0132] When the fourth stepper motor rotates, the wire is pulled to the right to recycle the waste wire. In the experiment, the wire cutting position moves to the right and separates. The wire at the cutting groove is the uncut wire part. When the wire in the backup cable is used up, the entire cable sample can be replaced.

[0133] The method of using the test system is as follows:

[0134] Step 1: Select the required test standard, test item, test device, and test load on the human-computer interaction interface of the computer control system. Before starting the test, set the test current, test voltage, and data acquisition range options, and select the corresponding resistive load and sensor according to the test option and test current.

[0135] Step 2: Based on the above settings, the computer control system automatically generates switch control instructions. The PCI digital I / O card sends the control instructions to the switch control system, which drives the corresponding relay after optical coupling isolation, and then the corresponding electromagnetic switch is actuated.

[0136] Step 3: The switch control system connects the arc generator, cable cutting device, cable carbonizing device, and various types of load devices to the comprehensive test circuit at different times according to the sequence of computer instructions. The switch status feedback system is activated after each switching action and feeds back the switch status to the computer control system. The system determines whether to proceed to the next action based on whether the control instruction sent and the feedback status are consistent.

[0137] Step 4: During the test, the data acquisition module is turned on in specific switching steps or links, namely: the average value of the pressure sensor is collected during the movement of the electrode; voltage and current data are collected during the electrode arcing, cable cutting, and cable carbonization tests. During this process, the system power-on time after the arc is generated is determined according to the arcing time required by the standard;

[0138] In step 4, when using an arc generator for testing, during the test preparation phase, the resistance between the two electrodes during the arcing process of the arc generator is detected to determine whether the two electrodes are tightly connected. After the test begins, the initial velocity is used to control the separation of the electrodes until the voltage between the two electrodes is within the arc voltage arcing control zone. During the arcing control phase, the arc voltage is used to determine whether the electrode position is within the arcing control zone or the stable arcing zone. The arcing coarse control strategy or the arcing fine control strategy is used to control the electrode speed, thereby ensuring the arcing continuity of the arc generator. After the test is completed, the electrodes continue to separate until they are reset. This solves the problem that arc generators are difficult to generate arcs that meet test standards under low current conditions.

[0139] In step 4, when using the cable carbonization device, different samples are prepared according to different standards, and the circuit switching is controlled by the electromagnetic switch control system to achieve high-voltage carbonization of cable samples of different standards. The successful carbonization of the cable sample is automatically detected and the arc fault protection electrical appliance detection test is started. After the test starts, the computer control system automatically switches the knife switch to complete the high-voltage carbonization. When the carbonized cable is connected to the comprehensive experimental circuit, the computer control system collects the voltage and current during the experiment and monitors whether the cotton is on fire.

[0140] In step 4, when a cable cutting device is used for testing, the cutting back plate of the cable cutting device is used to ensure that the cable sample is closely parallel to and separated from other positions at the cutting position; the computer control system reads the cutting test bench position record file, and the stepper motor drives the cutting test bench to move a unit distance horizontally, and stores the new position in the file; the reduction motor is used to control the forward and backward movement of the cutting back plate to change the position of the cutting blade, and the reduction motor is used to control the cable waste wire recycler so that the cable sample is automatically replaced; at the beginning of the experiment, the blade and cable reach the new position, and the stepper motor drives the blade to move down to cut the cable. When the voltage is less than the initial voltage, it means that the cable has been cut, and after a delay, the blade is reset to the initial position; the collected data during the test is displayed on the human-computer interaction interface and saved in the fault arc database.

Claims

1. A comprehensive arc fault protection device test system, characterized by: It includes host computer data analysis system, computer control system, multi-function data acquisition card, digital I / O card, data acquisition module, stepper motor control system, electromagnetic switch control system, switch state feedback system, arc generator, cable carbonization device, cable cutting device, load device and comprehensive test circuit; The carbonized cable used in the comprehensive test circuit is prepared by the test system's arc generator, cable cutting device, and arc carbonization device. The computer control system sends pulses to the stepper motor controllers of the arc generator and cable cutting device through a multi-function data acquisition card timing counter. The motor motion changes the displacement of the blade and electrode to provide the carbonized cable and an arc of the desired strength. When testing the comprehensive test circuit, the test links related to the arc carbonization device include the high-voltage carbonization stage and the low-voltage test link. The digital I / O card outputs high and low levels between the high and low voltages, which are then driven to control the forward and reverse rotation of the asynchronous motor. The test is carried out under the condition of high and low voltage isolation. Among them, the load device is pressed into the comprehensive test circuit through the electromagnetic switch control system according to the selected test load. The computer control system sends the switch function code to the electromagnetic switch control system through the digital I / O card to switch the electromagnetic switch state of the comprehensive test circuit. The load device includes pure resistive load and resistive inductive load. During the test, the load device is selected according to the test content, and the arc protection standards required by vacuum cleaners, switching power supplies, air compressors, induction cookers, microwave ovens, air purifiers, and hand drills are selected to simulate the load type required by the test. The electromagnetic switch control system adopts the optocoupler relay drive mode. The high and low levels output by the PCI digital I / O card are isolated by the optocoupler and then drive the relay coil. The relay further drives the electromagnetic switch coil to realize the control of the electromagnetic switch. In the computer control system, the switch function code is programmed according to the switch action sequence of the test item and sent to the electromagnetic switch control system via the PCI digital I / O card in preset steps and time intervals to achieve switching between different operating states of the integrated test circuit. To ensure the correct operation of the program and the output of the acquisition card, after each switching action, the auxiliary contact signal of the electromagnetic switch is fed back to the computer control system through the switch state feedback system. The switch status feedback system uses a parallel-input and serial-output shift register to collect the auxiliary contact status of the comprehensive test circuit and feeds it back to the computer control system via the PCI digital I / O card; The data acquisition module collects voltage, current, smoke, and temperature signals in real time during the operation of the comprehensive test circuit as required. When the electromagnetic switch moves to the preset step, the computer control system creates a corresponding multi-function data acquisition card acquisition task and configures the relevant acquisition channels to collect the output signals of the sensors installed in the comprehensive test circuit. The computer control system displays the waveform of the collected data in real time on the operation interface. After the test is completed, the waveform is magnified and observed to read the arc duration and effective value data. The computer control system automatically creates a test waveform database based on the type of test items, providing data support for the subsequent verification of arc fault protection electrical device action characteristics and the development of fault arc detection algorithms.

2. A comprehensive arc fault protection device test system according to claim 1, characterized in that: When conducting tests in GB / T 31143-2014 and GB14287.4-2014 standards, the comprehensive test circuit of the test system includes a large-capacity programmable AC source, whose main circuit is connected to an AC380V / 50Hz power supply. The voltage and frequency of the large-capacity programmable AC source are adjusted to 220V and 50Hz, and then connected to the comprehensive test circuit through an electromagnetic switch control system. When conducting the UL1699 test, the voltage and frequency of the large-capacity programmable AC source are adjusted to 110V and 60Hz. The test load type, operating voltage, and operating parameters of the three standards are different. The resistance load and inhibitory load of the load device are set separately according to the standard requirements, and each load is controlled by an independent electromagnetic switch. The cable carbonization device uses high and low voltage isolation switches automatically switched by asynchronous motors to ensure the safety of the carbonization process; during the test, all electromagnetic switches are closed and opened in the required action sequence and action time through the electromagnetic switch control system to meet the test requirements of the above standards.

3. The comprehensive arc fault protection device test system according to claim 1, characterized in that: When conducting tests related to the arc carbonization device, the comprehensive test circuit of the test system includes an AC220V / 7kV transformer, an AC220V / 2kV transformer, an AC220V / 15 kV transformer, an asynchronous motor, a carbonization state test circuit, a knife switch, and a limit switch; When conducting the carbonization test in GB / T 31143-2014 and IEC 60626 standards, the arc carbonization device uses 7kV and 2kV transformer circuits to prepare the carbonized cable; When conducting the carbonization test in GB14287.4-2014, the arc carbonization device uses a 7kV transformer to prepare the carbonized cable; When conducting the UL1699 standard test, except for the carbonization path arc clearing time test in the standard, the ABCD test of suppressed load shielding of socket-type, mobile, cable-type and combination AFCI, and the EMI filter test, which adopt the same 7kV and 2kV carbonization methods as GB / T 31143-2014, in other carbonization tests, the arc carbonization device uses a 15kV transformer to conduct cyclic carbonization tests on the cable; The asynchronous motor is used for automatic switching of the high and low voltage of the isolation knife switch during the carbonization process; the limit switch is used to detect whether the knife switch is in close contact; the carbonization state test circuit includes a 100W incandescent lamp and a photosensor.

4. A comprehensive arc fault protection device testing system according to claim 3, characterized in that: When the test system performs the GB / T 3114-2014 carbonization test process, it is divided into the following steps: Step A1: Preparation of carbonized cable, specifically: an asynchronous motor drives the knife switch to close to the high-voltage side, 220V / 7kV high-voltage side switch K5 is closed first, followed by switch K4, and the cable sample is subjected to insulation breakdown. After a delay, switch K4 is opened first, followed by switch K5. 220V / 2kV high-voltage side switch K7 is closed first, followed by switch K6, and the cable sample is carbonized. After a delay, switch K6 is opened first, followed by switch K7. Step A2: Carbonization status detection of the carbonized cable. Specifically, the asynchronous motor drives the knife switch to close to the low-voltage side, K10 and K11 are closed, the photoresistor detects whether the 100W bulb is lit, and the computer control system collects the level output of the photosensitive module to determine whether the cable is successfully carbonized, and then all switches are disconnected; Step A3: Connect the carbonized cable to the comprehensive test circuit to conduct a fault arc test; When the test system performs the GB14287.4-2014 carbonization test process, it is divided into the following steps: Step B1, preparation of carbonized cable, specifically: an asynchronous motor drives the knife switch to close to the high voltage side, the 220V / 7kV high voltage side switch K5 and the corresponding high voltage carbonized resistor switch after the cable carbonization device are closed first, and then the switch K4 is closed to carbonize the cable sample; Step B2: The carbonized cable is connected to the comprehensive test circuit to conduct a fault arc test; When the test system performs the UL1699 carbonization test process, the high-voltage carbonization circuit of the cable carbonization circuit is separated from the comprehensive test circuit.

5. The comprehensive arc fault protection device test system according to claim 1, characterized in that: The arc generator includes a fixed electrode, a movable electrode, a lead screw slide, a first stepper motor, a resistance detection module, and a switch limit. The movable electrode is a copper rod with a tip, the fixed electrode is a graphite rod, and the electrodes on both sides are connected to the circuit through wires. The lead screw slide is a slide mechanism driven by a lead screw mechanism. The movable electrode is located on the lead screw slide driven by the first stepper motor. In the process of the movable electrode approaching the fixed electrode, the computer control system samples the average resistance between the two electrodes in real time through the resistance detection module, and determines whether the two electrodes are in close contact based on the average resistance value; the switch limit is used to detect the reset status of the movable electrode; after the test is completed, the first stepper motor controls the movable electrode to separate and reset to the initial position.

6. A comprehensive arc fault protection device testing system according to claim 5, characterized in that: The arc generator uses an adaptive variable speed electrode control strategy based on arc voltage to control the moving speed of the moving electrode. The specific process is as follows: Step S1: Before starting an arc fault test using an arc generator, the movable electrode is in a reset state; Step S2, test preparation stage, move the electrode towards the fixed electrode at a speed of - v 0, and during this process, detect the average resistance of the two electrodes. If the average resistance > Rh, continue to move towards it at a speed of - v 0. If the average resistance < Rh, it is determined that the fixed electrode and the moving electrode have completed contact, and the test preparation is completed; Step S3: The experiment starts. After the main circuit is powered on, the moving electrode is initially v 0 and quickly move away from the fixed electrode; detect the voltage between the fixed electrode and the mobile electrode. If the effective value of the voltage U(t) is less than the lower limit of the arc area Umin, calculate according to △U1=U(t)-Umin v 1. Continue to control the moving electrode away from the fixed electrode at this speed; If the voltage effective value U(t) is greater than the lower limit Umin of the arc area, proceed to the next step; If the voltage RMS U is greater than the upper limit Umax of the arc area, then calculate according to △U1=U(t)-Umax v 1. Continue to control the moving electrode to approach the fixed electrode at this speed; If the voltage effective value U(t) is less than the upper limit Umax of the arc area, proceed to the next step; Step S4: Based on the real-time arc voltage and electrode gap during arcing, a fitting model of arc voltage and electrode gap is used. s ( t )= f [ U ( t )] Determine whether the current state is in the optimal stable arcing zone. If the arcing voltage is greater than the voltage range of the optimal stable arcing zone, adjust the moving electrode speed to v 2. Use the stepper motor to fine-tune the moving electrode to approach the fixed electrode; if the arc voltage is less than the voltage range of the optimal stable arcing zone, adjust the moving electrode speed to v 2. Use the stepper motor to fine-tune the moving electrode away from the fixed electrode. If the arc voltage is within the voltage range of the optimal stable arcing zone, the speed is 0, the electrode spacing remains unchanged, and the next step is carried out. Step S5: Determine whether the arc timing is over according to the test time required by different current levels. If the timing is not over, continue to determine the arc voltage. If the timing is over, continue to determine the arc voltage. v The speed control of 3 moves the electrode away from the fixed electrode; the test ends when the moving electrode moves away from the fixed electrode and reaches the reset point.

7. The comprehensive arc fault protection device test system according to claim 1, characterized in that: The cable cutting device is a guillotine-shaped structure, and includes an insulating arm, a cable test piece, a cutting blade, a cutting back plate, a screw rod, a second stepper motor, a second stepper motor drive and control module, and upper and lower limit modules; The cutting blade is fixed to the inside of the insulating arm. The cable sample consists of two parallel wires connected to two wiring terminals and is placed on an insulated and high-temperature resistant cutting backplane. The wiring terminals are connected to the test main circuit of the comprehensive test circuit. The second stepper motor is connected to the lead screw through a coupling. The other end of the lead screw is connected to the sliding part of the insulating arm. The direction and speed of the second stepper motor are controlled by the host computer platform via the data acquisition card. When the second stepper motor rotates, it drives the insulating arm downward through the lead screw, driving the steel cutting blade to cut the cable sample. When the test main circuit is energized, cutting the cable sample can generate a parallel arc. The second stepper motor is a reduction motor. After the test is completed, the second stepper motor rotates to reset the cutting blade to the highest position; The moving stroke of the cutting blade is limited by the upper and lower limit modules. When the stroke exceeds the limit, the stepper motor will automatically stop running.

8. The comprehensive arc fault protection device test system according to claim 7, characterized in that: The cable cutting device is controlled by the cable test automatic control system, which includes terminal blocks, backup cables, wire crimpers, cutting backplanes, a third stepper motor, a waste wire recycler, and a fourth stepper motor. Both the third and fourth stepper motors are reduction motors. The cutting backplane includes a cutting groove and a conductor groove. The cutting groove is aligned with the cutting blade and is used for cutting the conductor. The cutting blade can cut into the groove. The conductor groove is two U-shaped grooves with opposite ends, which are used to accommodate the cable. The conductor can move in the groove. The U-shaped grooves with opposite ends can ensure that the conductors are cut parallel and closely adjacent at the cutting position, while the grooves at other positions are separated to ensure that the conductors with cuts will not produce parallel breakdown after the experiment, thereby affecting the experiment. The intersection of the wire groove and the cutting knife groove is the wire cutting point; The wiring terminals are connected to the backup cables, which are used to supplement the cable samples during the test; The wires in the backup cable are separated and placed in the wire groove of the cutting backplane after passing through the wire crimper. The wires pass through the wire crimper at the end of the cutting backplane and are collected on both sides of the baffle of the waste wire collector. The waste wire recycling period uses a stepping reduction motor to control the rotation to automatically collect and move the waste wires. The third stepper motor controls the forward and backward movement of the cutting backboard, and the fourth stepper motor controls the waste wire collector and controls the movement of the wire from the point where it enters the cutting backboard to the point where it leaves the backboard; The cutting groove in the cutting backplane is virtually positioned with the cutting blade. Based on the damaged width of the blade in each cutting experiment, the cutting blade is divided into 1, 2, 3...n parts according to the total length. After the cutting experiment is completed, the third stepper motor moves forward and backward to the uncut blade part corresponding to the cutting groove. Each part can only be cut once and moves sequentially according to the virtual positioning of the cutting blade after the cutting is completed, ensuring that the position of the blade cutting the wire is controllable. The entire cutting blade can be replaced after it has been fully used. When the fourth stepper motor rotates, the wire is pulled to the right to recycle the waste wire. In the experiment, the wire cutting position moves to the right and separates. The wire at the cutting groove is the uncut wire part. When the wire in the backup cable is used up, the entire cable sample can be replaced.

9. The comprehensive arc fault protection device testing system according to claim 1, characterized in that: The method of using the test system is as follows: Step 1: Select the required test standard, test item, test device, and test load on the human-computer interaction interface of the computer control system. Before starting the test, set the test current, test voltage, and data acquisition range options, and select the corresponding resistive load and sensor according to the test option and test current. Step 2: Based on the above settings, the computer control system automatically generates switch control instructions. The PCI digital I / O card sends the control instructions to the switch control system, which drives the corresponding relay after optical coupling isolation, and then the corresponding electromagnetic switch is actuated. Step 3: The switch control system connects the arc generator, cable cutting device, cable carbonizing device, and various types of load devices to the comprehensive test circuit at different times according to the sequence of instructions sent by the computer; The switch status feedback system is turned on after each switch action and feeds back the switch status to the computer control system. The system decides whether to proceed to the next action based on whether the control instruction sent is consistent with the feedback status. Step 4: During the test, the data acquisition module is turned on in specific switching steps or links, namely: the average value of the pressure sensor is collected during the movement of the electrode; voltage and current data are collected during the electrode arcing, cable cutting, and cable carbonization tests. During this process, the system power-on time after the arc is generated is determined according to the arcing time required by the standard; In step 4, when an arc generator is used for testing, during the test preparation phase, the resistance between the two electrodes during the arcing process of the arc generator is detected to determine whether the two electrodes are tightly connected. After the test begins, the electrodes are separated by controlling the initial velocity until the voltage between the two electrodes is within the arc voltage arcing control region. During the arcing control phase, the arc voltage is used to determine whether the electrode position is within the arcing control region or the stable arcing region. The coarse arcing control strategy or the fine arcing control strategy is used to control the electrode speed, thereby ensuring the arcing continuity of the arc generator. After the test is completed, the electrodes continue to separate until they are reset. This solves the problem that arc generators are difficult to generate arcs that meet test standards under low current conditions; In step 4, when using the cable carbonization device, different samples are prepared according to different standards, and the circuit switching is controlled by the electromagnetic switch control system to achieve high-voltage carbonization of cable samples of different standards. The successful carbonization of the cable sample is automatically detected and the arc fault protection electrical appliance detection test is started. After the test starts, the computer control system automatically switches the knife switch to complete the high-voltage carbonization. When the carbonized cable is connected to the comprehensive experimental circuit, the computer control system collects the voltage and current during the experiment and monitors whether the cotton is on fire. In step 4, when the cable cutting device is used for testing, the cutting back plate of the cable cutting device is used to ensure that the cable sample is closely parallel to the cutting position and separated from other positions; the computer control system reads the cutting test bench position record file, and the stepper motor drives the cutting test bench to move a unit distance and stores the new position in the file; the reduction motor is used to control the cutting back plate to move back and forth to change the position of the cutting blade, and the reduction motor is used to control the cable waste wire collector to automatically change the cable sample; at the beginning of the experiment, the blade and cable reach the new position, and the stepper motor drives the blade to move down to cut the cable. When the voltage is less than the initial voltage, it means that the cable has been cut. After a delay, the blade returns to its initial position. The collected data during the test is displayed on the human-computer interaction interface and saved in the fault arc database.

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