Arc fault generator

Abstract

The present invention discloses a fault arc generating device, which includes a fault arc generating mechanism, a voltage transmitter, a PLC program controller, a driving device and a driving device controller. The fault arc generating device of the present invention includes a fixed electrode, a movable electrode and a fault arc signal collecting terminal respectively connected to the fixed electrode and the movable electrode, the fault arc signal collecting terminal is connected to the PLC program controller, the PLC program controller is connected to the driving device controller, the driving device controller is connected to the driving device, the driving device is connected to the movable electrode and can drive the movable electrode to move in a direction close to or away from the fixed electrode. The fault arc generating device of the present invention can accurately control the relative position of the movable electrode and the fixed electrode and the moving frequency of the movable electrode, and the fault arc generating device of the present invention can form a stable and reliable fault arc, ensuring a high test accuracy.

Description

Technical Field

[0001] The invention belongs to the technical field of fault arc detection, and in particular relates to a fault arc generating device. Background Art

[0002] With the rapid development of the national economy, industrial and civilian electricity consumption has increased significantly, and the resulting electrical components and conductive lines have caused leakage, loose contacts, breakdown short circuits caused by aging electrical equipment, and other faults, leading to a large number of electrical fire accidents. In order to better prevent accidents caused by arc faults, the General Administration of Quality Supervision, Inspection and Quarantine and the National Standardization Administration jointly issued the "GB14287.4-2014" standard, requiring mandatory testing of products such as fault arc protectors and implementing it on April 1, 2015. At present, there is no complete standard fault arc generator product internationally or domestically, which has become a major problem for the majority of fault arc protection product research and development companies. Due to the lack of standard fault arc signals, only a few companies in China currently master this technology.

[0003] Currently, only the National CCC Testing Center is equipped with fault arc generating equipment. Since the testing equipment of the National CCC Certification Center is mainly used to test products that are declared for inspection, it is not suitable for actual production and product development. In addition, due to the differences in the way the National CCC Center collects the arc signal, it causes large distortion during testing. Summary of the invention

[0004] In order to overcome the above disadvantages, an object of the present invention is to provide a fault arc generating device, which can accurately generate a fault arc and provide a standard fault arc signal source for testing.

[0005] The fault arc generating device of the present invention includes a fault arc generating mechanism, which includes a fixed electrode and a movable electrode, the movable electrode is arranged opposite to the fixed electrode, the fixed electrode is connected to a power supply, and the movable electrode is connected to a load, and also includes a PLC program controller, a drive device and a drive device controller. The fault arc generating device also includes a fault arc signal collection terminal connected to the fixed electrode and the movable electrode respectively, the fault arc signal collection terminal is connected to the PLC program controller, the PLC program controller is connected to the drive device controller, the drive device controller is connected to the drive device, and the drive device is connected to the movable electrode and can drive the movable electrode to move toward or away from the fixed electrode. When the movable electrode of the fault arc generating device of the present invention contacts the fixed electrode, the voltage signal collected by the fault arc signal collecting terminal is 0V. When the movable electrode moves away from the fixed electrode and a gap is generated between the movable electrode and the fixed electrode, an arc is generated at the gap. The driving device controller of the present invention receives instructions from the PLC program controller to accurately control the position and movement frequency of the movable electrode. Therefore, the fault arc generating device of the present invention can generate a stable and reliable fault arc with high test accuracy.

[0006] Furthermore, it also includes a voltage transmitter, the input end of the voltage transmitter is connected to the fault arc signal collection terminal, and the output end of the voltage transmitter is connected to the PLC program controller. Therefore, the high-voltage circuit of the fault arc generating mechanism can be isolated through the voltage transmitter, and converted into a standard 4-20mA signal, and transmitted to the PLC program controller.

[0007] Furthermore, the driving device is a stepping motor, and the driving device controller is a stepping driver.

[0008] Furthermore, the fault arc generating mechanism also includes a fixed block for fixing the fixed electrode, a mobile base for fixing the mobile electrode, and a screw coaxially connected to the output shaft of the stepper motor, at least two slides are arranged on the mobile base, a threaded hole matching the screw is arranged in the middle of the slide, the screw passes through the slide, and also includes a sliding part connected to the mobile base. Therefore, the stepper driver drives the stepper motor according to the program control information obtained by the feedback of the PLC program controller, and the screw rotates under the drive of the stepper motor, and drives the mobile base to move steadily in the direction of approaching or moving away from the fixed electrode. The relative position of the mobile electrode and the fixed electrode and the moving frequency of the mobile electrode can be accurately controlled by the stepper driver, and the fault arc generated by the fault arc generating device of the present invention is accurate and meets the test requirements.

[0009] Furthermore, the sliding part includes a slider and a movable slide rail, the slider is arranged on the movable base, the movable slide rail is arranged along the length direction of the screw rod, and the slider and the movable slide rail are mutually engaged and can move along the movable slide rail. Therefore, under the mutual cooperation of the movable slide rail and the slider, the moving process of the movable base can be ensured to be stable, and a stable fault arc can be formed.

[0010] Furthermore, the sliding part includes a slide plate and a moving slot, the moving slot is arranged along the length direction of the screw rod, the slide plate is located in the moving slot, a plurality of universal beads are arranged on the surface of the slide plate in contact with the moving slot, and the width of the opening of the moving slot is smaller than the width of the slide plate. Therefore, the slide plate can slide in the moving slot and will not fall off from the moving slot.

[0011] Furthermore, it also includes a connecting block fixed on the slide, a part of the connecting block extends out of the moving slot and is fixedly connected to the moving base, and a cylindrical hole for the screw rod to pass through is provided in the middle of the connecting block along the setting direction of the moving slot, and the inner diameter of the cylindrical hole is larger than the outer diameter of the screw rod. Therefore, when the moving base moves driven by the screw rod, the movement process of the moving base is smooth through the cooperation between the slide and the moving slot.

[0012] Furthermore, the fixed block and the movable base are respectively provided with electrode accommodating cavities for accommodating the fixed electrode and the movable electrode, and rubber tubes extending away from the fixed block and the movable base are respectively provided on the side wall of the fixed block at both ends of the electrode accommodating cavity, the rubber tubes are connected with the electrode accommodating cavity, and the rubber tubes are interference fit with the fixed electrode and the movable electrode. Therefore, the rubber tubes can fix the positions of the fixed electrode and the movable electrode to prevent shaking when an arc is generated or when the movable electrode moves, thereby interfering with the generation of a fault arc. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a structural block diagram of Embodiment 1 of the present invention;

[0014] Figure 2 It is a structural schematic diagram of a fault arc generating mechanism according to the first embodiment of the present invention;

[0015] Figure 3 This is a flowchart of the program design of the first embodiment of the present invention;

[0016] Figure 4 This is a flowchart of the first embodiment of the present invention;

[0017] Figure 5It is a structural schematic diagram of a fault arc generating mechanism according to a second embodiment of the present invention;

[0018] Figure 6 The figure is a schematic diagram of the connection relationship among the slide plate, the movable slot and the connection block according to the second embodiment of the present invention.

[0019] In the figure:

[0020] 10-fault arc generating mechanism, 20-voltage transmitter, 30-PLC program controller, 40-drive device controller, 1-fixed electrode, 11-fixed electrode discharge end, 121-first fault arc signal acquisition terminal, 122-second fault arc signal acquisition terminal, 2-movable electrode, 21-movable electrode discharge end, 3-fixed block, 31-electrode accommodating cavity, 4-movable base, 41-slide seat, 5-screw, 6-stepping motor, 71-slider, 72-movable slide rail, 73-slide plate, 74-movable card slot, 741-cylindrical hole, 75-universal ball, 76-connecting block, 8-rubber tube, 9-base plate. DETAILED DESCRIPTION

[0021] The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more definite definition of the protection scope of the present invention.

[0022] Embodiment 1:

[0023] See attached Figure 1 As shown, the fault arc generating device of the present invention includes a fault arc generating mechanism 10, a voltage transmitter 20, a PLC program controller 30, a driving device and a driving device controller 40.

[0024] See attached Figure 2 As shown, the fault arc generating mechanism 10 includes a fixed electrode 1 and a movable electrode 2, wherein the movable electrode 2 is arranged opposite to the fixed electrode 1, and the end of the fixed electrode 1 close to the movable electrode 2 is the fixed electrode discharge end 11, and the end surface of the fixed electrode discharge end 11 is a plane, and the end of the movable electrode 2 close to the fixed electrode 1 is the movable electrode discharge end 21, and the end surface of the movable electrode discharge end 21 is a cone. The longitudinal section of the movable electrode discharge end 21 is a sector, and its radius is 3.5 mm and the angle is 35 degrees. The main body of the fixed electrode 1 of the present invention is a round rod with a diameter of 6 mm, and the material is T2 copper, and the main body of the movable electrode 2 is a round rod with a diameter of 6 mm, and the material is carbon-graphite.

[0025] The fault arc generating device of the present invention also includes a first fault arc signal acquisition terminal 121 and a second fault arc signal acquisition terminal 122 respectively connected to the fixed electrode 1 and the movable electrode 2. The first fault arc signal acquisition terminal 121 and the second fault arc signal acquisition terminal 122 are respectively connected to the PLC program controller 30. The PLC program controller 30 is connected to the drive device controller 40. The drive device controller 40 is connected to the drive device. The drive device is connected to the movable electrode 2 and can drive the movable electrode 2 to move toward or away from the fixed electrode. The model of the voltage transmitter 20 of the fault arc generating device listed in this embodiment is JXDA4U-W32. The PLC program controller 30 uses the Siemens S7-222 programmable controller, and the PLC program controller 30 is programmed through STEP7-Micro / EIN (see the attached Figure 3 As shown), a control signal is output to the drive device controller 40 through proportional integral calculus (PID) calculation. The fixed electrode 1 of the present invention is connected to the power supply, and the movable electrode 2 is connected to the load. Therefore, under the action of the voltage transmitter 20, the high-voltage circuit generating the fault arc can be isolated and converted into a standard 4-20mA signal and transmitted to the PLC program controller 30.

[0026] The driving device of the present invention is a stepping motor 6, and the driving device controller 40 is a stepping driver. The stepping driver model selected in this embodiment is 3M458.

[0027] See again Figure 2 As shown, the fault arc generating mechanism 10 of the present invention further includes a fixed block 3, a movable base 4 and a screw 5 coaxially connected to a stepping motor 6. The fixed electrode 1 of the present invention is fixed on the fixed block 3, and the movable electrode 2 is fixed on the movable base 4. Electrode accommodating cavities 31 for accommodating the fixed electrode 1 and the movable electrode 2 are respectively provided through the fixed block 3 and the movable base 4, and rubber tubes 8 extending away from the fixed block 3 are provided at positions at both ends of the electrode accommodating cavity 31 on the side wall of the fixed block 3, and rubber tubes 8 extending away from the movable base 4 are provided at both ends of the electrode accommodating cavity 31 on the side wall of the movable base 4, the rubber tubes 8 are connected to the electrode accommodating cavity 31, and the rubber tubes 8 are interference fit with the fixed electrode 1 and the movable electrode 2, thereby preventing the fixed electrode 1 and the movable electrode 2 from jumping when a fault arc is generated.

[0028] Two slides 41 are fixedly arranged on the lower surface of the movable base 4, and a threaded hole is arranged through the middle of the slide 41. The fault arc generating device of the present invention also includes a screw rod 5 which cooperates with the internal thread of the slide 41. The screw rod 5 passes through the slide 41. The screw rod 5 is arranged along the moving direction of the movable base 4. The screw rod 5 is coaxially connected to the stepper motor 6 and rotates under the action of the stepper motor 6, thereby driving the movable base 4 to move along the setting direction of the screw rod 5.

[0029] The fault arc generating device of the present invention further comprises a sliding part connected to the mobile base 4. The sliding part of this embodiment comprises a slider 71 arranged at the bottom of the mobile base 4 and a movable slide rail 72 located below the mobile base 4, the movable slide rail 72 is arranged along the length direction of the screw rod 5, and the slider 71 is arranged on the movable slide rail 72 and can move along the movable slide rail 72. Therefore, under the mutual cooperation of the movable slide rail 72 and the slider 71, the moving process of the mobile base 4 is ensured to be stable.

[0030] The fault arc generating device of this embodiment further comprises a substrate 9. The substrate 9 of the present invention is a 3240 epoxy board with a thickness of 50 mm. The fixed electrode 1 and the movable electrode 2 are both arranged on the upper surface of the substrate 9, thereby avoiding the generation of interference arcs.

[0031] The working process of the fault arc generating device of the present invention is as follows: Figure 4 As shown. In the fault arc generating device of the present invention, when the movable electrode 2 contacts the fixed electrode 1, the voltage signal between the first fault arc signal acquisition terminal 121 and the second fault arc signal acquisition terminal 122 is 0V. When the movable electrode 2 moves away from the fixed electrode 1 and a gap is generated between the movable electrode 2 and the fixed electrode 1, an arc is generated at the gap, and after being converted by the voltage transmitter 20, the signal is sent to the PLC program controller 30, which sends instructions to the drive device controller 40 according to the built-in program and drives the stepper motor 6. Driven by the stepper motor 6, the lead screw 5 rotates and drives the movable base 4 to move steadily toward or away from the fixed electrode. The relative position of the movable electrode and the fixed electrode and the moving frequency of the movable electrode can be accurately controlled by the stepper driver. The fault arc generating device of the present invention can generate a standard fault arc with high test accuracy.

[0032] Embodiment 2:

[0033] The difference between this embodiment and the first embodiment is only that the sliding part is different. Figure 5 and Figure 6As shown, the sliding part of the fault arc generating device of this embodiment includes a slide plate 73 and a moving card slot 74, the slide plate 73 is located in the moving card slot 74, a plurality of universal beads 75 are arranged on the lower surface of the slide plate 73, the moving card slot 74 is arranged along the length direction of the screw rod 5, the opening of the moving card slot 74 faces upward, and the width of the opening is smaller than the width of the slide plate 73. Therefore, the slide plate 73 can move smoothly in the moving card slot 74, and will not fall off from the moving card slot 74 when moving. The mobile base 4 in this embodiment is connected to the slide plate 73 through a connecting block 76 arranged on the upper surface of the slide plate 73, the upper end of the connecting block 76 extends out of the moving card slot 74, and is fixedly connected to the mobile base 4, and a cylindrical hole 741 for the screw rod 5 to pass through is arranged in the middle of the connecting block 76 along the setting direction of the moving card slot 74, and the inner diameter of the cylindrical hole 741 is larger than the outer diameter of the screw rod 5. Therefore, under the action of the stepping motor 6 , the screw rod 5 rotates and drives the movable base 4 to move along the movable slide groove 74 , and the slide plate 73 can ensure that the movable base 4 moves smoothly.

[0034] The above implementation modes are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with this technology to understand the content of the present invention and implement it, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A fault arc generating device, comprising a fault arc generating mechanism, wherein the fault arc generating mechanism comprises a fixed electrode and a movable electrode, wherein the movable electrode is arranged opposite to the fixed electrode, the fixed electrode is connected to a power source, and the movable electrode is connected to a load, wherein: It also includes a PLC program controller, a drive device and a drive device controller, the fault arc generating device also includes a fault arc signal acquisition terminal connected to the fixed electrode and the movable electrode respectively, the fault arc signal acquisition terminal is connected to the PLC program controller, the PLC program controller is connected to the drive device controller, the drive device controller is connected to the drive device, the drive device is connected to the movable electrode and can drive the movable electrode to move toward or away from the fixed electrode. It also includes a voltage transmitter, the input end of the voltage transmitter is connected to the fault arc signal collection terminal, and the output end of the voltage transmitter is connected to the PLC program controller. The model of the voltage transmitter of the fault arc generating device is JXDA4U-W32, the model of the PLC program controller is S7-222 programmable controller, the driving device controller is a stepper driver, and the model of the stepper driver is 3M458. The PLC program controller is programmed through STEP 7-Micro / EIN. Through proportional calculus calculation, the control signal is output to the drive device controller. Under the action of the voltage transmitter, the high-voltage circuit that generates the fault arc is isolated and converted into a standard 4-20mA signal and transmitted to the PLC program controller. Under the action of the voltage transmitter, the high-voltage circuit that generates the fault arc is isolated and converted into a standard 4-20mA signal and transmitted to the PLC program controller. The fault arc generating mechanism further comprises a fixed block for fixing the fixed electrode and a movable base for fixing the movable electrode. The fixed block and the movable base are respectively provided with electrode accommodating cavities for accommodating the fixed electrode and the movable electrode. Rubber tubes extending away from the fixed block and the movable base are respectively provided on the side wall of the fixed block at both ends of the electrode accommodating cavity. The rubber tubes are connected to the electrode accommodating cavity, and the rubber tubes are interference fit with the fixed electrode and the movable electrode.

2. The arc fault generating device according to claim 1, characterized in that: The driving device is a stepping motor, and the driving device controller is a stepping driver.

3. The arc fault generating device according to claim 2, characterized in that: The fault arc generating mechanism also includes a screw rod coaxially connected to the output shaft of the stepper motor, at least two slide seats are arranged on the movable base, a threaded hole matching the screw rod is arranged in the middle of the slide seat, the screw rod passes through the slide seat, and also includes a sliding part connected to the movable base.

4. The arc fault generating device according to claim 3, characterized in that: The sliding part includes a slider and a movable slide rail, the slider is arranged on the movable base, the movable slide rail is arranged along the length direction of the screw rod, and the slider and the movable slide rail are mutually engaged and can move along the movable slide rail.

5. The arc fault generating device according to claim 3, characterized in that: The sliding part includes a slide plate and a movable slot, the movable slot is arranged along the length direction of the screw rod, the slide plate is located in the movable slot, a plurality of universal beads are arranged on the surface of the slide plate in contact with the movable slot, and the width of the opening of the movable slot is smaller than the width of the slide plate.

6. The arc fault generating device according to claim 5, characterized in that: It also includes a connecting block fixed on the slide, a partial area of ​​the connecting block extends out of the movable slot and is fixedly connected to the movable base, and a cylindrical hole for the screw rod to pass through is provided in the middle of the connecting block along the setting direction of the movable slot, and the inner diameter of the cylindrical hole is larger than the outer diameter of the screw rod.

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