Direct-current test transmission instrument with self-checking function

Abstract

The utility model belongs to the field of electric power test equipment, and particularly discloses a direct current test transmission instrument with a self-checking function, which comprises a box body, a power supply module, a high voltage generating module, a measuring module and a single chip microcomputer are arranged in the box body, a fixed seat and a checking module are arranged on the box body, and the checking module comprises a standard resistor module. The standard resistance module is detachably connected to the fixed seat, the power supply module, the high-voltage generation module and the fixed seat are sequentially connected, the standard resistance module is connected with the output end of the high-voltage generation module, and the high-voltage generation module and the measurement module are respectively connected with the single chip microcomputer. According to the utility model, the standard resistance module is used as an output load of the high-voltage generation module, the current of the standard resistance module is collected through the measurement module, and the actual output voltage of the high-voltage generation module is calculated according to the resistance, so that the voltage output function verification of the direct-current test transmission instrument before the test is realized.

Description

Technical Field

[0001] This utility model belongs to the field of power testing equipment, and specifically relates to a DC test transmitter with self-calibration function. Background Technology

[0002] The DC power supply tester is a high-voltage testing instrument commonly used in 10kV and below distribution network lines and equipment. It has a significant effect in finding ground faults and overcomes the accident hazards caused by traditional power supply based on line insulation.

[0003] The working principle of a DC power transmitter is as follows: it inputs a high-voltage DC signal to the line under test and then detects the leakage current of the line to determine whether there is a grounding or phase-to-phase short circuit fault. When a grounding or phase-to-phase short circuit is found in the line, the DC power transmitter will trip and stop outputting high-voltage DC. Therefore, the accuracy of the voltage output of the DC power transmitter directly affects the accuracy of the test results. Typically, testers need to periodically inspect the DC power transmitter to verify its output voltage, output current, and control accuracy. However, due to various influencing factors such as the frequency of use, operating environment, and transportation process of the DC power transmitter at different times, the internal components of the DC power transmitter may age prematurely or fail, causing the DC power transmitter to malfunction. Existing DC power transmitters lack self-calibration functions, and relying solely on periodic inspections makes it difficult for testers to detect faults in a timely manner. When the DC voltage output by the DC power transmitter does not reach the set value or is unstable during use, the accuracy of the test results will be affected, and testers will be unable to identify potential insulation faults in the line based on the power transmitter's output.

[0004] In view of this, the present invention proposes a DC test transmitter with self-calibration function to solve the above-mentioned technical problems. Utility Model Content

[0005] The purpose of this utility model is to provide a DC tester with self-calibration function to solve the technical problems in the background art, where the DC tester cannot detect its own faults in a timely manner by adopting a periodic inspection method, and when the DC voltage output by the DC tester is inaccurate or unstable, the test personnel cannot correctly judge the insulation fault potential of the circuit under test based on the DC tester.

[0006] To achieve the above objectives, this utility model provides a DC test instrument with self-calibration function, comprising:

[0007] The enclosure is equipped with a high-voltage output terminal, a grounding terminal, and a mounting base.

[0008] Power supply module, high voltage generator module, measurement module and microcontroller;

[0009] The power supply module, high voltage generating module, and measurement module are all housed inside the enclosure. The power supply module is connected to the input terminal of the high voltage generating module, and the output terminal of the high voltage generating module is connected to the measurement module, the mounting base, and the high voltage output terminal, respectively. The microcontroller is connected to both the high voltage generating module and the measurement module.

[0010] A verification module is mounted on the housing. The verification module includes a standard resistor module and a temperature sensor. The standard resistor module is detachably connected to the mounting base, and the temperature sensor is connected to the microcontroller.

[0011] Preferably, the above technical solution further includes a fault simulation module, which includes a transparent housing and a sliding push rod. The sliding push rod is slidably disposed inside the transparent housing. The sliding push rod includes a handle and a conductive part. One end of the conductive part is connected to the grounding terminal through a wire. One end of the transparent housing is provided with an electrode, which is connected to the high-voltage output terminal through a wire.

[0012] Preferably, in the above technical solution, the high-voltage generating module includes an electronic boost module, a high-frequency boost transformer, and a voltage multiplier rectifier module. The power supply module, electronic boost module, high-frequency boost transformer, voltage multiplier rectifier module, and high-voltage output terminal are connected in sequence. One output terminal of the voltage multiplier rectifier module and the input terminal of the high-frequency boost transformer are respectively connected to the fixed base. The measurement module is connected to the high-voltage output terminal, and the electronic boost module is connected to the microcontroller.

[0013] Preferably, in the above technical solution, the standard resistor module includes a first standard resistor, a second standard resistor, and a third standard resistor. The first and second standard resistors are respectively connected to the input terminal of the high-frequency step-up transformer through the mounting bracket. The third standard resistor is connected to the output terminal of the voltage doubler rectifier module through the mounting bracket. The measurement module is connected to the first, second, and third standard resistors through the mounting bracket.

[0014] Preferably, the above technical solution further includes an automatic discharge module, and the output terminal of the voltage doubler rectifier module is connected to the automatic discharge module.

[0015] Preferably, the above technical solution further includes a data storage module, which includes a memory and a timer, and the memory and the timer are respectively connected to the microcontroller.

[0016] Preferably, the above technical solution further includes a display and voice module and a button module, which are respectively connected to the microcontroller.

[0017] Compared with existing technologies, this utility model has the following beneficial effects:

[0018] 1. This utility model uses a standard resistor module to simulate the output load of a high-voltage generator module before conducting experiments on the circuit under test. The microcontroller collects the current value of the standard resistor module through a measurement module and the ambient temperature through a temperature sensor. It performs compensation calculations on the standard resistor module to obtain a high-precision resistance value. The microcontroller calculates the voltage value of the standard resistor module based on the resistance value and the current value collected by the measurement module, which is the actual output voltage of the high-voltage generator module. By comparing it with the set value, the voltage output error of the high-voltage generator module is obtained. At the same time, by observing the current change of the standard resistor module, the voltage output fluctuation of the high-voltage generator module can be obtained, thus realizing the voltage output verification function of the DC test instrument.

[0019] 2. This utility model simulates the grounding short-circuit fault state of an actual line by adjusting the distance between the conductive part of the sliding push rod and the electrode of the fault simulation module. The conductive part of the sliding push rod is connected to the grounding terminal of the DC test instrument, and the electrode is connected to the high-voltage output terminal, so as to realize the verification of the insulation fault detection performance of the DC test instrument. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the overall structure of this utility model.

[0021] Figure 2 This is a schematic diagram of the overall circuit principle of this utility model.

[0022] Figure 3 This is a schematic diagram showing the connection between the standard resistor module and the high voltage generator module of this utility model.

[0023] Figure 4 This is a cross-sectional structural diagram of the fault simulation module of this utility model.

[0024] In the diagram: 1—Box, 2—Display and voice module, 3—Button module, 4—Standard resistor module, 5—Fault simulation module, 6—High voltage output terminal, 7—Grounding terminal, 8—Fixed base, 100—Power supply module, 101—High voltage generation module, 102—Measurement module, 103—Microcontroller, 104—Temperature sensor, 105—Automatic discharge module, 106—Data storage module, 501—Transparent shell, 5011—Electrode, 502—Sliding push rod, 5021—Conductive part, R1—First standard resistor, R2—Second standard resistor, R3—Third standard resistor, T1—High frequency step-up transformer, 1011—Electronic step-up module, 1012—Voltage doubler rectifier module. Detailed Implementation

[0025] The specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings. However, it should be understood that the scope of protection of this utility model is not limited to the specific embodiments.

[0026] refer to Figures 1 to 4 A DC tester with self-calibration function includes a housing 1, a fault simulation module 5, a power supply module 100, a high voltage generation module 101, a high voltage output terminal 6, a grounding terminal 7, a mounting base 8, a measurement module 102, a microcontroller 103, a calibration module, an automatic discharge module 105, and a data storage module 106. The power supply module 100, the high voltage generation module 101, the measurement module 102, and the microcontroller 103 are all located inside the housing 1. The display and voice module 2, the button module 3, the high voltage output terminal 6, the grounding terminal 7, and the mounting base 8 are respectively located on the housing 1. The two ends of the fault simulation module 5 are connected to the high voltage output terminal 6 and the grounding terminal 7 respectively through wires.

[0027] The power supply module 100 is connected to the input terminal of the high voltage generating module 101. The output terminal of the high voltage generating module 101 is connected to the measurement module 102, the mounting base 8, and the high voltage output terminal 6, respectively. Both the high voltage generating module 101 and the measurement module 102 are connected to the microcontroller 103. The high voltage generating module 101 is used to convert the DC voltage of the power supply module 100 into a 0-8kV DC high voltage. The measurement module 102 is used to measure the output voltage and current values ​​of the high voltage generating module 101. The automatic discharge module 105 is connected to the high voltage generating module 101 and is also connected to the microcontroller 103. The automatic discharge module 105 is used to discharge the high voltage generating module 101. In this embodiment, the power supply module 100 can be an AC220V to DC power supply or a high-capacity battery.

[0028] The display and voice module 2, the button module 3, and the data storage module 106 are respectively connected to the microcontroller 103. The data storage module 106 includes a timer 1061 and a memory 1062, which are respectively connected to the microcontroller 103.

[0029] The high-voltage generation module 101 includes an electronic boost module 1011, a high-frequency boost transformer T1, and a voltage doubler rectifier module 1012. The electronic boost module 1011 is connected to the microcontroller 103. The power supply module 100, the electronic boost module 1011, the high-frequency boost transformer T1, the voltage doubler rectifier module 1012, and the high-voltage output terminal 6 are connected in sequence. The output terminal of the voltage doubler rectifier module 1012 and the input terminal of the high-frequency boost transformer T1 are respectively connected to the mounting base 8. The measurement module 102 is connected to the high-voltage output terminal 6. In this embodiment, the electronic boost module 1011 is composed of an IGBT drive module and an IGBT module. The voltage doubler rectifier module 1012 is composed of multiple voltage doubler rectifier circuits of different stages connected in series. The microcontroller 103 controls the electronic boost module 1011 to output two PWM voltage signals with opposite phases, which are input to the high-frequency boost transformer T1. After being boosted by the high-frequency boost transformer T1, the voltage doubler rectifier module 1012 outputs a 0-8kV DC high voltage.

[0030] The calibration module includes a standard resistor module 4 and a temperature sensor 104. The standard resistor module 4 is detachably connected to the mounting base 8. The standard resistor module 4 includes a first standard resistor R1, a second standard resistor R2, and a third standard resistor R3. The third standard resistor R3 is connected to the output terminal of the voltage doubler rectifier module 1012 via the mounting base 8. The first standard resistor R1 and the second standard resistor R2 are respectively connected to the input terminal of the high-frequency step-up transformer T1 via the mounting base 8. The measurement module 102 is connected to the first standard resistor R1, the second standard resistor R2, and the third standard resistor R3 via the mounting base 8. The second standard resistor R2 and the third standard resistor R3 are connected to measure the current values ​​of the first standard resistor R1, the second standard resistor R2 and the third standard resistor R3. The temperature sensor 104 is connected to the microcontroller 103. In this embodiment, the first standard resistor R1, the second standard resistor R2 and the third standard resistor R3 are all red glaze film resistors with an accuracy of 1%. The temperature sensor 104 is a CJMCU-175 temperature sensor, and the microcontroller 103 is an STM32F103C8T6 microcontroller.

[0031] The fault simulation module 5 includes a transparent housing 501 and a sliding push rod 502. The sliding push rod 502 is slidably disposed inside the transparent housing 501. The sliding push rod 502 includes a handle and a conductive part 5021. The surface of the transparent housing 501 is provided with a scale. One end of the transparent housing 501 is provided with an electrode 5011. The high-voltage output terminal 6 is connected to the electrode 5011 through a wire. The conductive part 5022 of the sliding push rod 502 is connected to the grounding terminal 7 through a wire. The maximum distance between the end of the sliding push rod 502 and the electrode 5011 opposite to each other is 15cm. By pushing the handle 5021 to adjust the distance between the sliding push rod 502 and the electrode 5011, the electrode 5011 with high voltage input discharges to the conductive part 5022 of the sliding push rod 502 to simulate a small current grounding fault in a real circuit.

[0032] The working principle of this utility model is as follows:

[0033] Before testing the circuit under test, the testers inserted the standard resistor module 4 into the housing 1, and connected the third standard resistor R3 to the voltage doubler rectifier module 1012 of the high-voltage generator module 101 as the load of the voltage doubler rectifier module 1012. The self-calibration program was started via the button module 3, causing the high-voltage generator module 101 to output voltage signals at five levels: 400V, 1KV, 4kV, 6kV, and 8kV, each lasting 10 seconds. The microcontroller 103 collected the current value of the third standard resistor R3 through the measurement module 102, and then calculated the actual output voltage of the high-voltage generator module 101 based on the resistance value of the third standard resistor R3. When the microcontroller 103 detected that the user-set voltage matched the voltage of the high-voltage generator module 101, the test was completed. When the actual output voltage difference of 01 is greater than the set threshold (5% of the set voltage), the microcontroller 103 controls the display and voice module 2 to output the text and voice alarm "output voltage low". When the microcontroller 103 detects through the measurement module 102 that the voltage fluctuation across the third standard resistor R3 exceeds 5% of the set voltage, the microcontroller 103 controls the display and voice module 2 to output the text and voice alarm "output voltage abnormal". When the microcontroller 103 detects through the measurement module 102 that the current value flowing through the third standard resistor R3 exceeds the user-set threshold, it indicates that there is a short circuit fault in the instrument. The microcontroller 103 controls the electronic boost module 1011 to stop outputting and controls the automatic discharge module 105 to discharge.

[0034] The microcontroller 103 acquires the current values ​​across the first standard resistor R1 and the second standard resistor R2 through the measurement module 102, and then calculates the voltage values ​​across the first standard resistor R1 and the second standard resistor R2 based on their resistance values, thereby monitoring the input pulse voltage of the high-frequency step-up transformer T1. On the one hand, this reduces the troubleshooting scope when the DC tester malfunctions and improves the troubleshooting efficiency of the DC tester. On the other hand, when the microcontroller 103 detects through the measurement module 102 that the currents across the first standard resistor R1 and the second standard resistor R2 are in phase, the microcontroller 103 controls the electronic step-up module 1011 to stop outputting and controls the display and voice module 2 to output a text and voice alarm for "electronic step-up module fault," preventing the IGBT transistors in the electronic step-up module 1011 from being directly connected, which could cause a short circuit at the input of the high-frequency step-up transformer T1.

[0035] Temperature sensor 104 is used to collect temperature data in the environment. Microcontroller 103 collects temperature data from temperature sensor 104 and calculates the actual resistance values ​​of the first standard resistor R1, the second standard resistor R2 and the third standard resistor R3 of standard resistor module 4, thereby improving the accuracy of voltage calculation for the first standard resistor R1, the second standard resistor R2 and the third standard resistor R3.

[0036] Timer 1061 is used to record the time when the microcontroller 103 detects a fault in the high voltage generating module 101, and memory 1062 is used to store the fault information of the high voltage generating module 101.

[0037] The testers connected the fault simulation module 5 to the high-voltage output terminal 6 and the grounding terminal 7 respectively, and then adjusted the distance between the conductive part 5021 and the electrode 5011. By operating the button module 3, the high-voltage generating module 101 outputs DC high voltage. Under the action of high voltage, a discharge phenomenon occurs between the conductive part 5021 and the electrode 5011. The output terminal of the voltage doubler rectifier module 1012 detects a leakage current higher than the rated current output by the DC test instrument. After the microcontroller 103 detects the leakage current at the voltage doubler rectifier module 1012 through the measurement module 102, the microcontroller 103 outputs a control signal to the high-voltage generating module 101 to stop its output, and controls the automatic discharge module 105 to discharge the high-voltage generating module 101, thus realizing the detection of the fault detection function of the DC test instrument.

[0038] The foregoing description of specific exemplary embodiments of the present invention is for illustrative and explanatory purposes. These descriptions are not intended to limit the invention to the precise forms disclosed, and it will be apparent that many changes and variations can be made in accordance with the foregoing teachings. The exemplary embodiments were chosen and described in order to explain the specific principles of the invention and its practical application, thereby enabling those skilled in the art to implement and utilize various different exemplary embodiments of the invention, as well as various different choices and variations. The scope of the present invention is intended to be defined by the claims and their equivalents.

Claims

1. A DC test transmitter with self-calibration function, characterized in that, include: The enclosure is equipped with a high-voltage output terminal, a grounding terminal, and a mounting base; Power supply module, high voltage generator module, measurement module and microcontroller; The power supply module, high voltage generating module, and measurement module are all housed inside the enclosure. The power supply module is connected to the input terminal of the high voltage generating module, and the output terminal of the high voltage generating module is connected to the measurement module, the mounting base, and the high voltage output terminal, respectively. The microcontroller is connected to both the high voltage generating module and the measurement module. A verification module is mounted on the housing. The verification module includes a standard resistor module and a temperature sensor. The standard resistor module is detachably connected to the mounting base, and the temperature sensor is connected to the microcontroller.

2. The DC test instrument with self-calibration function according to claim 1, characterized in that, It also includes a fault simulation module, which includes a transparent housing and a sliding push rod. The sliding push rod is slidably disposed inside the transparent housing. The sliding push rod includes a handle and a conductive part. One end of the conductive part is connected to the grounding terminal through a wire. One end of the transparent housing is provided with an electrode, which is connected to the high-voltage output terminal through a wire.

3. The DC test instrument with self-calibration function according to claim 1, characterized in that, The high-voltage generating module includes an electronic boost module, a high-frequency boost transformer, and a voltage multiplier rectifier module. The power supply module, electronic boost module, high-frequency boost transformer, voltage multiplier rectifier module, and high-voltage output terminal are connected in sequence. The output terminal of the voltage multiplier rectifier module and the input terminal of the high-frequency boost transformer are respectively connected to the fixed base. The measurement module is connected to the high-voltage output terminal, and the electronic boost module is connected to the microcontroller.

4. The DC test instrument with self-calibration function according to claim 3, characterized in that, The standard resistor module includes a first standard resistor, a second standard resistor, and a third standard resistor. The first and second standard resistors are respectively connected to the input terminal of the high-frequency step-up transformer through the mounting bracket. The third standard resistor is connected to the output terminal of the voltage doubler rectifier module through the mounting bracket. The measurement module is connected to the first, second, and third standard resistors through the mounting bracket.

5. The DC test instrument with self-calibration function according to claim 3, characterized in that, It also includes an automatic discharge module, and the output terminal of the voltage doubler rectifier module is connected to the automatic discharge module.

6. The DC test instrument with self-calibration function according to claim 1, characterized in that, It also includes a data storage module, which includes a memory and a timer, and the memory and the timer are respectively connected to the microcontroller.

7. The DC test instrument with self-calibration function according to claim 1, characterized in that, It also includes a display and voice module and a button module, which are respectively connected to the microcontroller.

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