Novel impulse grounding resistance tester

Abstract

The utility model provides a novel impulse grounding resistance tester, and relates to the technical field of high-voltage electrical test equipment. The tester comprises a portable box body, wherein a storage battery, a multi-stage boosting module, an optical fiber communication module and a measurement and control terminal are integrated in the portable box body. The storage battery supplies power to the multi-stage boosting module, and the multi-stage boosting module injects impact current into the tested grounding device through a wire. And the optical fiber communication module is connected with the multi-stage boosting module and the measurement and control terminal to realize signal isolation transmission. The measurement and control terminal is integrated on the outer side of the box body and used for controlling starting and stopping of the multi-stage boosting module and receiving test data. The casing of the box body and the internal components are isolated from the external environment through insulating materials to form a floating structure, so that the test is safe and accurate. The tester solves the technical problems of large size and poor safety of impact grounding resistance testing equipment in an outdoor scene, so that outdoor safe, portable and efficient impact grounding resistance measurement is realized.

Description

TECHNICAL FIELD

[0001] The utility model relates to high -voltage electrical test equipment technical field, specifically, relate to a novel impact grounding resistance tester. BACKGROUND

[0002] In the field of electric power, communication, the impact grounding resistance of grounding device is the key index of evaluating lightning protection performance. With the improvement of the intelligent degree of electrical equipment, the sensitivity of chips and other precision components to the impulse potential of ground net is intensified, and portable and safe outdoor impact resistance test equipment is urgently needed. However, the traditional impact grounding resistance tester depends on large high-voltage generator, needs fixed grounding point power supply, is bulky (usually more than 1m 3 ), and has the risk of electric leakage under high-voltage working condition, so it is difficult to meet the flexible deployment demand of complex field.

[0003] The prior art indirectly calculates the impact resistance through the power frequency tester, or uses the impact current generator to simulate the lightning waveform, but the former has significant error due to ignoring the soil discharge effect, and the latter can output real impact current, but the device has low integration degree and dispersed components (high-voltage power supply, control unit and oscilloscope are separated), so the overall volume is large and difficult to carry. In addition, the existing device relies on fixed grounding point to ensure safety, and in the environment without reliable grounding, it is easy to cause electric shock or equipment damage due to "floating ground" operation, which seriously restricts the feasibility and safety of outdoor test.

[0004] In summary, how to solve the technical problem of large volume and poor safety of the impact grounding resistance test equipment in the outdoor scene is an urgent problem. UTILITY MODEL CONTENT

[0005] The main purpose of the utility model is to provide a novel impact grounding resistance tester to at least solve the technical problem of large volume and poor safety of the impact grounding resistance test equipment in the outdoor scene, and realize safe, portable and efficient impact grounding resistance measurement in the outdoor through compact integration, floating ground safety protection and automatic data processing.

[0006] In order to achieve the above purpose, the utility model provides a novel impact grounding resistance tester, the tester comprises: a portable box, the inside of the portable box is integrated with a storage battery, a multi-stage voltage boosting module, an optical fiber communication module and a measurement and control terminal;

[0007] The storage battery is electrically connected with the multi-stage voltage boosting module, and the storage battery is used for power supply for the multi-stage voltage boosting module;

[0008] The output end of the multi-stage voltage boosting module is connected to the measured grounding device through a wire, and the multi-stage voltage boosting module is used for injecting impact current into the measured grounding device;

[0009] The optical fiber communication module is connected with the multi-stage voltage boosting module and the measurement and control terminal respectively, and is used for isolated transmission of signals between the multi-stage voltage boosting module and the measurement and control terminal.

[0010] The measurement and control terminal is integrated on the outside of the portable box, and is used for controlling starting and stopping of the multi-stage voltage boosting module and receiving test data transmitted by the optical fiber communication module.

[0011] The shell of the portable box and the storage battery, the multi-stage voltage boosting module and the optical fiber communication module are isolated from the external environment by insulation materials to form a floating ground structure.

[0012] Specifically, the multi-stage voltage boosting module comprises:

[0013] A voltage boosting unit, an input end of the voltage boosting unit being connected with the storage battery;

[0014] An energy storage unit, an input end of the energy storage unit being connected with an output end of the voltage boosting unit, and the energy storage unit being used for storing electric energy;

[0015] A waveform adjusting unit, an input end of the waveform adjusting unit being connected with the energy storage unit, and the waveform adjusting unit being used for adjusting a waveform parameter of the impulse current;

[0016] A discharge switch, an input end of the discharge switch being connected with an output end of the waveform adjusting unit, and an output end of the discharge switch being connected with the measured grounding device.

[0017] Specifically, the multi-stage voltage boosting module further comprises:

[0018] A current sensor, the current sensor being connected in series between the discharge switch and the measured grounding device, and the current sensor being used for detecting the impulse current;

[0019] A voltage sensor, the voltage sensor being connected in parallel across the measured grounding device, and the voltage sensor being used for detecting a voltage of the measured grounding device.

[0020] Specifically, the voltage boosting unit is a customized transformer, and a volume of the voltage boosting unit is less than 1 / 3 of a volume of a conventional power frequency transformer.

[0021] Specifically, the optical fiber communication module comprises:

[0022] A first optical fiber conversion unit, an input end of the first optical fiber conversion unit being connected with the current sensor and the voltage sensor, and the first optical fiber conversion unit being used for converting the current signal and the voltage signal into an optical signal;

[0023] A second optical fiber conversion unit, an input end of the second optical fiber conversion unit is connected with an output end of the first optical fiber conversion unit, an output end of the second optical fiber conversion unit is connected with the measurement and control terminal, and the second optical fiber conversion unit is used for converting optical signals into electrical signals and transmitting the electrical signals to the measurement and control terminal.

[0024] Specifically, the first optical fiber conversion unit is an RS232-to-optical fiber module, and the second optical fiber conversion unit is a USB-to-optical fiber module.

[0025] Specifically, the measurement and control terminal is provided with a data processing unit, an input end of the data processing unit is connected with the current sensor and the voltage sensor through the optical fiber communication module, and an output end of the data processing unit is connected with a display module of the measurement and control terminal.

[0026] Specifically, the portable box has a size of 420mm*400mm*400mm, an outer shell of the portable box is made of engineering plastic, and the battery, the multi-stage voltage boosting module and the optical fiber communication module in the portable box are isolated and fixed by a ceramic isolating piece.

[0027] Specifically, the insulating material is a polytetrafluoroethylene layer, and the polytetrafluoroethylene layer covers the inner wall of the portable box and the surfaces of the battery, the multi-stage voltage boosting module and the optical fiber communication module.

[0028] The utility model provides a novel impact grounding resistance tester, and the tester includes a portable box, which is internally integrated with a battery, a multi-stage voltage boosting module, an optical fiber communication module and a measurement and control terminal. The battery provides power support for the multi-stage voltage boosting module, and the multi-stage voltage boosting module injects an impact current into a measured grounding device through a wire to test the grounding resistance. The optical fiber communication module is responsible for isolating and transmitting signals between the multi-stage voltage boosting module and the measurement and control terminal, ensuring the stability and accuracy of the signals. The measurement and control terminal is integrated on the outside of the box, facilitating operation and control. It is responsible for controlling the start and stop of the multi-stage voltage boosting module and receiving test data transmitted by the optical fiber communication module. In addition, the shell of the portable box and each internal component are isolated from the external environment by an insulating material, forming a floating ground structure to ensure the safety and reliability of the test process. The tester solves the technical problem of large size and poor safety of the impact grounding resistance test equipment in an outdoor scene, thereby realizing safe, portable and efficient impact grounding resistance measurement outdoors. BRIEF DESCRIPTION OF DRAWINGS

[0029] The drawings accompanying the specification of this application form a part thereof, serve to provide further understanding of the present application, and together with the specification explain the present application. The use of the same reference numbers in different drawings and / or discussion indicates similar or identical items.

[0030] Figure 1 is a tangent plane schematic view of a novel impulse grounding resistance tester according to an embodiment of the present application;

[0031] 10, portable box; 20, battery; 30, multi-stage voltage boosting module; 40, optical fiber communication module; 50, measurement and control terminal; 60, measured grounding device; 31, voltage boosting unit; 32, energy storage unit; 33, waveform adjustment unit; 34, discharge switch; 35, current sensor; 36, voltage sensor; 41, first optical fiber conversion unit; 42, second optical fiber conversion unit; 51, data processing unit; 52, display module; 11, ceramic isolation; 12, polytetrafluoroethylene layer. DETAILED DESCRIPTION

[0032] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict. The present application will be described in detail below with reference to the accompanying drawings and in combination with embodiments.

[0033] The GIS gas chamber SF6 micro water density monitoring sensor provided by the embodiment of the present application, as shown in Figure 1 The present application provides a novel impulse grounding resistance tester, the tester comprises: a portable box 10, the inside of the portable box 10 is integrated with a battery 20, a multi-stage voltage boosting module 30, an optical fiber communication module 40 and a measurement and control terminal 50; the battery 20 is electrically connected with the multi-stage voltage boosting module 30, and the battery 20 is used for supplying power for the multi-stage voltage boosting module 30; the output end of the multi-stage voltage boosting module 30 is connected to a measured grounding device 60 through a wire, and the multi-stage voltage boosting module 30 is used for injecting impulse current to the measured grounding device 60; the optical fiber communication module 40 is connected with the multi-stage voltage boosting module 30 and the measurement and control terminal 50 respectively, and the optical fiber communication module 40 is used for isolating and transmitting signals between the multi-stage voltage boosting module 30 and the measurement and control terminal 50; the measurement and control terminal 50 is integrated on the outside of the portable box 10, and the measurement and control terminal 50 is used for controlling the start and stop of the multi-stage voltage boosting module 30 and receiving the test data transmitted by the optical fiber communication module 40; the shell of the portable box 10 and the battery 20, the multi-stage voltage boosting module 30, the optical fiber communication module 40 and the external environment are isolated by insulating materials to form a floating ground structure.

[0034] The portable box (10) of the new impact grounding resistance tester is made of engineering plastic material, and the box (10) is divided into battery compartment, booster module compartment and communication compartment. The lithium iron phosphate battery (20) is built-in in the battery compartment, the output end of the lithium iron phosphate battery (20) is directly welded and connected with the input end of the multi-stage booster module (30) through copper wire, the rated output voltage of the lithium iron phosphate battery (20) is 12V, and the capacity is 20Ah, which is used to provide continuous power to the multi-stage booster module (30).

[0035] The multi-stage booster module (30) includes a four-stage capacitor series voltage boosting circuit, the capacitance of each capacitor in the four-stage capacitor series voltage boosting circuit is 470μF, the withstand voltage is 1000V, the output end of the four-stage capacitor series voltage boosting circuit is connected to the metal grounding point of the measured grounding device (60) through copper core high-voltage wire, the maximum output voltage of the four-stage capacitor series voltage boosting circuit is 4000V, which is used to inject an impact current with a pulse width of 8ms and an amplitude of 100A to the measured grounding device (60). The photoelectric conversion unit of the optical fiber communication module (40) is connected with the RS485 communication port of the multi-stage booster module (30) through the SFP interface, the data transmission unit of the optical fiber communication module (40) is connected with the SFP optical port of the measurement and control terminal (50) through the optical fiber jumper, the transmission rate of the optical fiber communication module (40) is 1Gbps, which is used to convert the current sampling signal and voltage feedback signal of the multi-stage booster module (30) into optical signals and transmit them to the measurement and control terminal (50), and at the same time, the control command issued by the measurement and control terminal (50) is converted into an electrical signal and transmitted to the multi-stage booster module (30).

[0036] The shell of the measurement and control terminal (50) is made of aluminum alloy, the measurement and control terminal (50) is fixed on the outer surface of the portable box (10) through bolts, the ARM Cortex-M7 processor is integrated in the measurement and control terminal (50), the ARM Cortex-M7 processor is connected with the data transceiver unit of the optical fiber communication module (40) through the GPIO pin, the ARM Cortex-M7 processor runs the FreeRTOS real-time operating system, which is used to perform the following operations: sending a start signal to the multi-stage booster module (30) through the SPI communication protocol to trigger the four-stage capacitor series voltage boosting circuit to work; receiving the impact current waveform data and grounding voltage data transmitted by the optical fiber communication module (40) in real time through the ADC acquisition module; using the FIR digital filtering algorithm to denoise the collected waveform data, and calculating the impact grounding resistance value of the measured grounding device (60) according to Ohm's law.

[0037] The outer wall of the portable box (10) is covered with a 3mm-thick epoxy resin insulation layer, the outer surface of the battery (20) and the multi-stage voltage boosting module (30) is covered with a silicone rubber insulation sleeve, and a polytetrafluoroethylene isolation pad is arranged between the circuit board of the optical fiber communication module (40) and the box (10). The above-mentioned insulation materials realize electrical isolation between the shell of the portable box (10), the battery (20), the multi-stage voltage boosting module (30), the optical fiber communication module (40) and the external environment, and form a floating ground structure with a ground impedance greater than 100MΩ. During the test, the operator inputs the test parameters through the touch screen of the measurement and control terminal (50), the measurement and control terminal (50) automatically generates a test report and displays the impulse current waveform and resistance calculation results, and the system is shut down by cutting off the power supply circuit of the battery (20) after the measurement is completed.

[0038] The embodiment converts the low-voltage direct current of the battery (20) into high-energy impulse current through a four-stage capacitor series voltage boosting circuit, solves the problem of bulky traditional power frequency large current test equipment, realizes optical-electric isolation transmission of high and low voltage side signals through the optical fiber communication module (40), avoids measurement errors caused by electromagnetic interference, and forms a floating ground structure through a composite insulation layer composed of epoxy resin, silicone rubber and polytetrafluoroethylene, so that the tester can still ensure operation safety in outdoor humid environment. The FIR filtering algorithm built-in the measurement and control terminal (50) can effectively eliminate high-frequency noise, and the real-time data processing function can improve the measurement result accuracy.

[0039] The following is a specific preferred embodiment:

[0040] Specifically, the multi-stage voltage boosting module 30 includes: a voltage boosting unit 31, an energy storage unit 32, a waveform adjusting unit 33, and a discharge switch 34, the input end of the voltage boosting unit 31 is connected with the battery 20; the input end of the energy storage unit 32 is connected with the output end of the voltage boosting unit 31, and the energy storage unit 32 is used for storing electric energy; the input end of the waveform adjusting unit 33 is connected with the energy storage unit 32, and the waveform adjusting unit 33 is used for adjusting the waveform parameters of the impulse current; the input end of the discharge switch 34 is connected with the output end of the waveform adjusting unit 33, and the output end of the discharge switch 34 is connected with the measured grounding device 60.

[0041] Specifically, the multi-stage voltage boosting module 30 further includes: a current sensor 35 and a voltage sensor 36, the current sensor 35 is connected in series between the discharge switch 34 and the measured grounding device 60, and the current sensor 35 is used for detecting the impulse current; the voltage sensor 36 is connected in parallel between the two ends of the measured grounding device 60, and the voltage sensor 36 is used for detecting the voltage of the measured grounding device 60.

[0042] Specifically, the step-up unit 31 is a custom transformer, and the volume of the step-up unit 31 is less than 1 / 3 of a conventional power frequency transformer.

[0043] Specifically, the fiber-optic communication module 40 includes a first fiber-optic conversion unit 41 and a second fiber-optic conversion unit 42. The input end of the first fiber-optic conversion unit 41 is connected to the current sensor 35 and the voltage sensor 36, and the first fiber-optic conversion unit 41 is used to convert the current signal and the voltage signal into an optical signal. The input end of the second fiber-optic conversion unit 42 is connected to the output end of the first fiber-optic conversion unit 41, and the output end of the second fiber-optic conversion unit 42 is connected to the measurement and control terminal 50. The second fiber-optic conversion unit 42 is used to convert the optical signal into an electrical signal and transmit it to the measurement and control terminal 50.

[0044] Specifically, the first fiber-optic conversion unit 41 is an RS232-to-fiber module, and the second fiber-optic conversion unit 42 is a USB-to-fiber module.

[0045] Specifically, the measurement and control terminal 50 is built-in with a data processing unit 51. The input end of the data processing unit 51 is connected to the current sensor 35 and the voltage sensor 36 through the fiber-optic communication module 40, and the output end of the data processing unit 51 is connected to a display module 52 of the measurement and control terminal 50.

[0046] Specifically, the size of the portable box 10 is 420mm x 400mm x 400mm, and the outer shell of the portable box 10 is made of engineering plastic. The battery 20, the multi-stage step-up module 30, and the fiber-optic communication module 40 inside the portable box 10 are isolated and fixed by a ceramic isolator 11.

[0047] Specifically, the insulating material is a polytetrafluoroethylene layer 12, which covers the inner walls of the portable box 10 and the surfaces of the battery 20, the multi-stage step-up module 30, and the fiber-optic communication module 40.

[0048] The preferred embodiment includes the following when implemented:

[0049] The portable box 10 of the new impact grounding resistance tester is made of engineering plastic, and the size is 420mm x 400mm x 400mm. The inside of the portable box 10 is divided into a battery compartment, a step-up module compartment, and a communication compartment by a ceramic isolator 11. The thickness of the ceramic isolator 11 is 5mm, and the voltage resistance level is 10kV. The ceramic isolator 11 is used to fix the battery 20, the multi-stage step-up module 30, and the fiber-optic communication module 40 and achieve physical isolation.

[0050] The battery 20 is a lithium iron phosphate battery pack. The positive electrode of the battery 20 is directly connected to the input end of the step-up unit 31 of the multi-stage step-up module 30 through a copper wire, and the negative electrode of the battery 20 is grounded through a copper wire. The step-up unit 31 is a customized transformer. The cross-sectional area of the core of the customized transformer is 1 / 5 of that of a traditional power frequency transformer, the thickness adjustment is 5 / 3 times that of a traditional transformer, the winding is wound with three layers of insulated flat copper wire, and the interlayer is filled with epoxy resin. The overall volume of the step-up unit 31 is reduced to 1 / 3 of that of a traditional power frequency transformer, while maintaining equivalent power output. The input voltage of the step-up unit 31 is 12V, and the output voltage is 1000V, which is used to step up the low-voltage direct current of the battery 20 to high-voltage direct current. The output end of the step-up unit 31 is connected to the input end of the energy storage unit 32 through a copper core wire. The energy storage unit 32 includes four groups of parallel electrolytic capacitor groups. Each group of electrolytic capacitor groups has a capacity of 2200μF and a withstand voltage of 1200V, and is used to store stepped-up electrical energy.

[0051] The output end of the energy storage unit 32 is connected to the input end of the waveform adjustment unit 33. The waveform adjustment unit 33 includes an adjustable inductance coil and an IGBT switch array. The inductance range of the adjustable inductance coil is 1mH to 10mH, and the on-time of the IGBT switch array is adjustable from 1μs to 10ms. The waveform adjustment unit 33 is used to convert the direct current output by the energy storage unit 32 into a standard impulse current waveform with a pulse width of 8ms and a rising edge time of 0.5ms. The output end of the waveform adjustment unit 33 is connected to the input end of the discharge switch 34 through a copper core high-voltage wire. The discharge switch 34 is a vacuum relay. The output end of the discharge switch 34 is connected to the metal grounding point of the measured grounding device 60 through a copper core wire.

[0052] The current sensor 35 is a Hall effect sensor. The current sensor 35 is connected in series between the discharge switch 34 and the measured grounding device 60. The current sensor 35 has a range of 0-200A and an accuracy of ±0.5%, and is used to collect the instantaneous value of the impulse current in real time. The voltage sensor 36 is a resistance voltage divider sensor. The high-voltage end of the voltage sensor 36 is connected in parallel across the measured grounding device 60. The voltage sensor 36 has a voltage division ratio of 1000:1 and is used to measure the impulse voltage of the measured grounding device 60.

[0053] The first fiber-optic conversion unit 41 of the fiber-optic communication module 40 is an RS232-to-fiber module, the RS232 interface of the first fiber-optic conversion unit 41 is connected to the analog output terminal of the current sensor 35 and the analog output terminal of the voltage sensor 36 through a shielded cable, the conversion rate of the first fiber-optic conversion unit 41 is 115200bps, and the first fiber-optic conversion unit 41 is used to convert the current and voltage analog signals into optical signals with a wavelength of 1310nm. The second fiber-optic conversion unit 42 is a USB-to-fiber module, the second fiber-optic conversion unit 42 is connected to the first fiber-optic conversion unit 41 through a single-mode optical fiber, the USB interface of the second fiber-optic conversion unit 42 is connected to the data processing unit 51 of the measurement and control terminal 50 through a USB2.0 data line, and the second fiber-optic conversion unit 42 is used to restore the optical signals into electrical signals and transmit the electrical signals to the data processing unit 51.

[0054] The data processing unit 51 of the measurement and control terminal 50 adopts an STM32H743 microcontroller, the ADC sampling rate of the data processing unit 51 is 1MSPS, the data processing unit 51 receives the current and voltage data transmitted by the fiber-optic communication module 40 through an SPI interface, the data processing unit 51 is built-in with an FIR digital filtering algorithm, the cutoff frequency of the filter is set to 10kHz, and the filter is used to eliminate high-frequency interference signals. The data processing unit 51 calculates the impulse grounding resistance value according to Ohm's law, the calculation formula is the ratio of the real-time impulse voltage to the impulse current peak value, and the calculation result is transmitted to the display module 52 through an LVDS interface. The display module 52 is a 7-inch TFT liquid crystal screen with a resolution of 800×480, and the display module 52 displays the impulse current waveform, the impulse voltage waveform and the calculated resistance value in real time.

[0055] The inner wall of the portable box 10 and the outer surface of the battery 20, the multi-stage voltage boosting module 30 and the fiber-optic communication module 40 are covered with a polytetrafluoroethylene layer 12, the thickness of the polytetrafluoroethylene layer 12 is 2mm, the volume resistivity of the polytetrafluoroethylene layer 12 is 1×10^18Ω·cm, and the polytetrafluoroethylene layer 12 is used to form a floating ground structure with an insulation impedance to ground greater than 100MΩ. During testing, an operator sets the impulse current parameters through the touch screen of the measurement and control terminal 50, the measurement and control terminal 50 sends a control instruction to the IGBT switch array of the waveform adjustment unit 33 through the fiber-optic communication module 40, triggers the impulse current output, simultaneously collects and processes the sensor data, and finally generates a test report containing a waveform diagram and a resistance value.

[0056] The embodiment realizes compact high-voltage energy storage through customizing the transformer voltage boosting unit 31 and the energy storage unit 32 of four sets of parallel electrolytic capacitors, solves the problem of large size of traditional power frequency voltage boosting equipment; the IGBT switch array of the waveform adjusting unit 33 accurately controls the rising edge time of the impact current, and ensures to meet the requirements of the DL / T475 standard; the combination of the RS232 to fiber module and the USB to fiber module realizes full optical isolation transmission of high and low voltage side signals, and eliminates the measurement error caused by the ground potential difference; the composite insulation structure of the polytetrafluoroethylene layer 12 and the ceramic isolation piece 11 enables the tester to still maintain safe insulation performance in an outdoor humid environment.

[0057] The above merely describes preferred embodiments of the present application and is not intended to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A new type of impulse grounding resistance tester characterized in that, The portable box (10) is integrated with a battery (20), a multi-stage voltage boosting module (30), an optical fiber communication module (40) and a measurement and control terminal (50) inside. The battery (20) is electrically connected with the multi-stage voltage boosting module (30), and is used to supply power for the multi-stage voltage boosting module (30). An output end of the multi-stage voltage boosting module (30) is connected to a measured grounding device (60) through a wire, and the multi-stage voltage boosting module (30) is used to inject an impulse current into the measured grounding device (60). The optical fiber communication module (40) is connected with the multi-stage voltage boosting module (30) and the measurement and control terminal (50) respectively, and is used to transmit signals between the multi-stage voltage boosting module (30) and the measurement and control terminal (50) in isolation. The measurement and control terminal (50) is integrated outside the portable box (10), and is used to control the start and stop of the multi-stage voltage boosting module (30) and receive test data transmitted by the optical fiber communication module (40). The shell of the portable box (10) and the battery (20), the multi-stage voltage boosting module (30), the optical fiber communication module (40) and the external environment are isolated by an insulating material to form a floating ground structure. The multi-stage voltage boosting module (30) comprises:

2. The impulse ground resistance tester of claim 1, wherein, a voltage boosting unit (31) connected with the battery (20) at an input end; an energy storage unit (32) connected with an output end of the voltage boosting unit (31) at an input end, and used to store electric energy; a waveform adjusting unit (33) connected with the energy storage unit (32) at an input end, and used to adjust waveform parameters of the impulse current; a discharge switch (34) connected with an output end of the waveform adjusting unit (33) at an input end, and connected with the measured grounding device (60) at an output end. The multi-stage voltage boosting module (30) further comprises:

3. The impulse ground resistance tester of claim 2, wherein, a current sensor (35) connected in series between the discharge switch (34) and the measured grounding device (60), and used to detect the impulse current; a voltage sensor (36) connected in parallel to both ends of the measured grounding device (60), and used to detect a voltage of the measured grounding device (60). The voltage boosting unit (31) is a customized transformer, and the volume of the voltage boosting unit (31) is less than 1 / 3 of that of a conventional power frequency transformer.

4. The impulse ground resistance tester of claim 2, wherein, The optical fiber communication module (40) comprises:

5. The impulse ground resistance tester of claim 3, wherein, a first optical fiber conversion unit (41) connected with the current sensor (35) and the voltage sensor (36) at an input end, and used to convert current signals and voltage signals into optical signals; ​ A second optical fiber conversion unit (42) is connected with the output end of the first optical fiber conversion unit (41), and the output end of the second optical fiber conversion unit (42) is connected with the measurement and control terminal (50), and the second optical fiber conversion unit (42) is used for converting optical signals into electrical signals and transmitting to the measurement and control terminal (50).

6. The impulse ground resistance tester of claim 5, wherein, The first optical fiber conversion unit (41) is an RS232-to-fiber module, and the second optical fiber conversion unit (42) is a USB-to-fiber module.

7. The test instrument of claim 3, wherein, The measurement and control terminal (50) is provided with a data processing unit (51), the input end of the data processing unit (51) is connected with the current sensor (35) and the voltage sensor (36) through the optical fiber communication module (40), and the output end of the data processing unit (51) is connected with a display module (52) of the measurement and control terminal (50).

8. The test instrument of claim 1, wherein, The size of the portable box (10) is 420mm*400mm*400mm, the shell of the portable box (10) is made of engineering plastics, and the battery (20), the multi-stage voltage boosting module (30) and the optical fiber communication module (40) in the portable box (10) are isolated and fixed by a ceramic isolation piece (11).

9. The test instrument of claim 1, wherein, The insulating material is a polytetrafluoroethylene layer (12) covering the inner wall of the portable box (10) and the surface of the battery (20), the multi-stage voltage boosting module (30) and the optical fiber communication module (40).

Images