Grounding resistance tester

Abstract

The utility model discloses a grounding resistance tester, comprising a power supply module used for supplying power to other modules, the power supply module comprises a battery pack and a power supply module, and the power supply module converts the output voltage of the battery pack into the corresponding required voltage of other modules; the constant current source is used for outputting voltage and current to the tested grounding resistor and the built-in resistor RS; a processor module; a display screen; the conditioning acquisition module comprises a built-in resistor RS, a first filtering and amplifying module for filtering and amplifying the voltage at the two ends of the built-in resistor RS, a second filtering and amplifying module for filtering and amplifying the voltage at the two ends of the tested grounding resistor, and an AD conversion module; the AD conversion module is in signal connection with the processor module; during testing, the constant current source, the built-in resistor RS and the tested grounding resistor are connected in series. The grounding resistance tester can realize continuous large current output so as to ensure that the test result is accurate. The test tool is additionally arranged and is adsorbed on a test plane such as a rim plane or a steel rail plane to assist the connection of the test clamp.

Description

Technical Field

[0001] The utility model relates to the technical field of grounding resistance testers, in particular to a grounding resistance tester used for grounding resistance testing of high-speed train sets. Background Art

[0002] The grounding technology of EMUs is not only related to the safety of EMUs, but also a key factor affecting the safe operation of high-speed railways. Safe and reasonable EMU grounding technology plays a very critical role in improving the safety performance of on-board equipment and the personal safety of on-board personnel. Therefore, it is necessary to accurately and effectively measure the grounding resistance of high-speed EMUs. At present, conventional double-arm DC bridges are widely used in power systems to measure small resistances, and the test current of this type of bridge is only at the mA level, which makes it difficult to detect the defect of reduced cross-sectional area of ​​the loop conductor. Utility Model Content

[0003] The technical problem to be solved by the utility model is to provide a grounding resistance tester capable of testing grounding resistance.

[0004] The technical solution adopted by the utility model to solve the above technical problems is: a ground resistance tester, comprising:

[0005] A power supply module, used to supply power to other modules, the power supply module includes a battery pack and a power supply module, the power supply module converts the output voltage of the battery pack into the voltage required by other modules;

[0006] Constant current source, used to supply the measured ground resistance and built-in resistance R S Output voltage and current;

[0007] Processor module,

[0008] Display screen, connected with processor module signal;

[0009] Conditioning acquisition module, including built-in resistor R S , Built-in resistor R for filtering and amplification S A first filtering and amplifying module for measuring the voltage at both ends of the grounding resistor, a second filtering and amplifying module for filtering and amplifying the voltage at both ends of the grounding resistor being measured, and an AD conversion module for converting analog signals output by the first filtering and amplifying module and the second filtering and amplifying module into digital signals; the AD conversion module is signal-connected to the processor module;

[0010] During the test, the constant current source and the built-in resistor R S , the ground resistance to be measured is connected in series.

[0011] Preferably, the constant current source provides a direct current of 1A to 50A.

[0012] Preferably, the ground resistance tester further comprises: a test fixture adsorbed on the wheel rim plane or the rail plane, and connected with an auxiliary test clamp;

[0013] The test fixture includes soft iron, and the soft iron is divided into left soft iron and right soft iron. The left soft iron and the right soft iron form an internal cavity, and a permanent magnet is placed in the cavity. The upper and lower contact points of the left soft iron and the right soft iron are respectively connected by upper and lower brass. The permanent magnet is connected to an external knob, and a fixed column extending out of the test fixture is connected to the soft iron. When the N and S poles of the permanent magnet are respectively connected to the left soft iron and the right soft iron and do not contact the upper and lower brass, the test fixture generates magnetic force, and the left soft iron and the right soft iron generate magnetic adsorption with external metal. When the N and S poles of the permanent magnet are in contact with the upper and lower brass, the left soft iron and the right soft iron do not generate magnetic adsorption with external metal.

[0014] Preferably, the ground resistance tester further comprises: a tester panel, and the display screen is mounted on the tester panel;

[0015] The tester panel also includes:

[0016] Constant current source positive electrode interface, connected to the positive electrode of the constant current source;

[0017] A voltage collection positive electrode interface, connected to the voltage positive electrode of the first filtering and amplifying module;

[0018] A voltage collection negative electrode interface, connected to the voltage negative electrode of the first filtering and amplifying module;

[0019] Constant current source negative electrode interface, connected to the negative electrode of the constant current source.

[0020] Preferably, the tester panel further comprises:

[0021] A power indicator light, including multiple LED lights, for indicating the remaining power of the battery pack;

[0022] Charging indicator light, used to indicate the charging status of the battery pack;

[0023] Charging socket, used to connect external power source to the battery pack;

[0024] USB port, connected to the processor module signal for data transmission;

[0025] The power switch is used to start or stop the battery pack from providing power.

[0026] Preferably, the ground resistance tester further includes an input anti-interference module, which is signal-connected to the processor module and is used to shield high-frequency interference.

[0027] Preferably, the ground resistance tester further includes a wireless communication module, which is signal-connected to the processor module and is used for wireless communication with an external network.

[0028] The beneficial effect of the utility model is that during the test, the constant current source and the built-in resistor R S , the ground resistance to be measured is connected in series. By obtaining the built-in resistance R S The voltage at both ends is used to calculate the current passing through, and the resistance value of the ground resistance to be measured is calculated based on the voltage at both ends of the ground resistance to be measured. This ground resistance tester can achieve continuous large current output, and the maximum measurement current of the ground resistance tester can reach DC 50A to ensure accurate test results. By adding a test fixture, adsorbing the test fixture to the test plane such as the wheel flange plane or the rail plane, and connecting the test clamp to the test fixture, the test can be carried out. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a principle block diagram of the ground resistance tester of the utility model;

[0030] Figure 2 It is a panel schematic diagram of a tester panel of the ground resistance tester of the utility model;

[0031] Figure 3 This is the working principle circuit diagram of the ground resistance tester of the utility model;

[0032] Figure 4 It is a schematic diagram of the test fixture of the utility model and the external metal plate in an adsorption state;

[0033] Figure 5 It is a schematic diagram showing that the test fixture of the utility model is in a detached state from the external metal plate.

[0034] Among them: 1. Constant current source positive interface; 2. Voltage acquisition positive interface; 3. Voltage acquisition negative interface; 4. Constant current source negative interface; 5. Power indicator light; 6. Display screen; 7. USB port; 8. Charging indicator light; 9. Charging port; 10. Power switch. DETAILED DESCRIPTION

[0035] Now the utility model is further described in detail in conjunction with the accompanying drawings and preferred embodiments. These drawings are simplified schematic diagrams, which only illustrate the basic structure of the utility model in a schematic manner, and therefore only show the components related to the utility model.

[0036] like Figure 1 As shown, a ground resistance tester comprises:

[0037] The power supply module is used to supply power to other modules. The power supply module includes a battery pack and a power module. The power module converts the output voltage of the battery pack into the voltage required by other modules. The power module mainly provides ±5V, 12V, 24V and other power sources for other modules.

[0038] Constant current source, used to supply the measured ground resistance and built-in resistance R S Output voltage and current; the constant current source uses ADC9987 as the constant current source main control module, the constant current source provides a DC current of 1A to 50A, and the maximum output power of the constant current source is 800VA.

[0039] Processor module: The processor module is used to analyze, process and calculate the data obtained during the test, display the results on the display screen 6, and store the data obtained during the test. The processor module adopts the STM32F4 series 32-bit processor.

[0040] The display screen 6 is connected to the processor module signal. The measured voltage, current and resistance are displayed visually through the display screen 6.

[0041] Conditioning acquisition module, including built-in resistor R S , Built-in resistor R for filtering and amplification S A first filtering and amplifying module for measuring the voltage at both ends of the grounding resistor, a second filtering and amplifying module for filtering and amplifying the voltage at both ends of the grounding resistor being measured, and an AD conversion module for converting analog signals output by the first filtering and amplifying module and the second filtering and amplifying module into digital signals; the AD conversion module is signal-connected to the processor module;

[0042] like Figure 3 As shown, during the test, the constant current source and the built-in resistor R S , the ground resistance to be measured is connected in series. By obtaining the built-in resistance R S The voltage at both ends is used to calculate the current flowing through the ground resistor, and the resistance value of the ground resistor under test is calculated based on the voltage at both ends of the ground resistor under test.

[0043] Measure the built-in resistance R S The voltage across the two ends is U S Calculate the current value I in the series circuit. The current value I calculation formula is as follows:

[0044]

[0045] Measure the voltage U across the grounding resistance being measured C , the resistance value Rc of the measured grounding resistance is calculated by the processor module, and the calculation formula of the resistance value Rc is as follows:

[0046] Specifically, in an optional implementation, the ground resistance tester further comprises: a test fixture, adsorbed on the wheel rim plane or the rail plane, and connected with an auxiliary test clamp;

[0047] The test fixture includes soft iron, which is divided into left soft iron and right soft iron. The left soft iron and the right soft iron form an internal cavity, and a permanent magnet is placed in the cavity. The upper and lower contact points of the left soft iron and the right soft iron are connected by upper and lower brass respectively. The permanent magnet is connected to the external knob, and the fixed column extending from the outside of the test fixture is connected to the soft iron. Figure 4 As shown, when the N and S poles of the permanent magnet are connected to the left soft iron and the right soft iron respectively and are not in contact with the upper and lower brass, the test fixture generates magnetic force, the left soft iron and the right soft iron generate magnetic adsorption with the external metal, and the test fixture and the external metal plate are in an adsorption state. Figure 5 As shown, when the N and S poles of the permanent magnet are in contact with the upper and lower brass, the left soft iron and the right soft iron do not generate magnetic adsorption with the external metal plate, and the test fixture is in a detached state from the external metal.

[0048] During the test, the test connection cable uses a four-wire high-current Kelvin test clip and the cable uses a 10mm 2 Cables meet the requirements of excessive current. One end of the test clamp is clamped on the metal part of the vehicle body, and the other end is clamped on the fixed column of the test fixture. Clean the installation surface. The test fixture can be magnetically adsorbed on the rim plane or rail plane to avoid increasing contact resistance. For test planes such as rim plane or rail plane, ordinary test clamps cannot be clamped on these planes. By adding a test fixture, the test fixture is adsorbed on the test plane such as rim plane or rail plane, and the test clamp is connected to the test fixture, the test can be carried out.

[0049] Specifically, in an optional implementation manner, Figure 2 As shown, the ground resistance tester further includes: a tester panel, and the display screen 6 is installed on the tester panel;

[0050] The tester panel also includes:

[0051] Constant current source positive electrode interface 1, connected to the positive electrode of the constant current source;

[0052] The voltage collection positive electrode interface 2 is connected to the voltage positive electrode of the first filtering and amplifying module;

[0053] The voltage collection negative electrode interface 3 is connected to the voltage negative electrode of the first filtering and amplifying module;

[0054] Constant current source negative electrode interface 4, connected to the negative electrode of the constant current source;

[0055] A power indicator light 5, comprising a plurality of LED lights, for indicating the remaining power of the battery pack;

[0056] A charging indicator light 8, used to indicate the charging status of the battery pack;

[0057] Charging socket 9, used for connecting an external power source to the battery pack;

[0058] USB port 7, connected to the processor module signal for data transmission;

[0059] The power switch 10 is used to start or stop the battery pack from providing power.

[0060] Specifically, in an optional implementation manner, Figure 1 As shown, the ground resistance tester also includes an input anti-interference module, which is connected to the processor module signal and is used to shield high-frequency interference.

[0061] Specifically, in an optional implementation manner, Figure 1 As shown, the ground resistance tester also includes a wireless communication module, which is connected to the processor module signal and is used for wireless communication with an external network. The wireless communication module has a wireless network card that meets IEEE802.11n and below standards, and can be connected to the factory WIFI or 5G.

[0062] This ground resistance tester can achieve continuous large current output, and the maximum measurement current of the ground resistance tester can reach DC 50A to ensure accurate test results. The conditioning acquisition module includes a first filter amplifier module for filtering and amplifying the voltage across the built-in resistor RS, and a second filter amplifier module for filtering and amplifying the voltage across the measured ground resistance, which can accurately measure the ground resistance; at the same time, the device is equipped with a wireless communication module, which can be connected to the external factory digital test platform to realize the digitization of debugging operation records and improve the efficiency of maintenance operations.

[0063] The above description only describes the specific implementation methods of the utility model. Various examples do not limit the essential content of the utility model. Ordinary technicians in the relevant technical field can modify or deform the specific implementation methods described above after reading the description without departing from the essence and scope of the utility model.

Claims

1. A ground resistance tester, characterized in that: include: A power supply module, used to supply power to other modules, the power supply module includes a battery pack and a power supply module, the power supply module converts the output voltage of the battery pack into the voltage required by other modules; Constant current source, used to supply the measured ground resistance and built-in resistance R S Output voltage and current; Processor module; A display screen (6) is connected to the processor module signal; Conditioning acquisition module, including built-in resistor R S , Built-in resistor R for filtering and amplification S A first filtering and amplifying module for measuring the voltage at both ends of the grounding resistor, a second filtering and amplifying module for filtering and amplifying the voltage at both ends of the grounding resistor being measured, and an AD conversion module for converting analog signals output by the first filtering and amplifying module and the second filtering and amplifying module into digital signals; the AD conversion module is signal-connected to the processor module; During the test, the constant current source and the built-in resistor R S , the ground resistance to be measured is connected in series.

2. The ground resistance tester according to claim 1, characterized in that: The constant current source provides a direct current of 1A to 50A.

3. The ground resistance tester according to claim 1, characterized in that: Also includes: The test fixture is adsorbed on the wheel rim plane or rail plane to assist the test clamp connection; The test fixture includes soft iron, and the soft iron is divided into left soft iron and right soft iron. The left soft iron and the right soft iron form an internal cavity, and a permanent magnet is placed in the cavity. The upper and lower contact points of the left soft iron and the right soft iron are respectively connected by upper and lower brass. The permanent magnet is connected to an external knob, and a fixed column extending out of the test fixture is connected to the soft iron. When the N and S poles of the permanent magnet are respectively connected to the left soft iron and the right soft iron and do not contact the upper and lower brass, the test fixture generates magnetic force, and the left soft iron and the right soft iron generate magnetic adsorption with external metal. When the N and S poles of the permanent magnet are in contact with the upper and lower brass, the left soft iron and the right soft iron do not generate magnetic adsorption with external metal.

4. The ground resistance tester according to claim 1, characterized in that: Also includes: A tester panel, the display screen (6) being mounted on the tester panel; The tester panel also includes: Constant current source positive electrode interface (1), connected to the positive electrode of the constant current source; A voltage collection positive electrode interface (2) connected to the voltage positive electrode of the first filtering and amplifying module; A voltage collection negative electrode interface (3) connected to the voltage negative electrode of the first filtering and amplifying module; The constant current source negative electrode interface (4) is connected to the negative electrode of the constant current source.

5. The ground resistance tester according to claim 4, characterized in that: The tester panel also includes: A power indicator light (5), comprising a plurality of LED lights, for indicating the remaining power of the battery pack; A charging indicator light (8), used to indicate the charging status of the battery pack; A charging socket (9) for connecting an external power source to the battery pack; A USB socket (7), connected to the processor module signal for data transmission; The power switch (10) is used to start or stop the battery pack from providing power.

6. The ground resistance tester according to claim 1, characterized in that: Also includes The input anti-interference module is connected to the processor module signal to shield high-frequency interference.

7. The ground resistance tester according to claim 1, characterized in that: Also includes The wireless communication module is signal-connected to the processor module and is used for wireless communication with an external network.

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