Anti-reverse power transmission insulation resistance test terminal equipment

Abstract

The utility model discloses reverse power transmission prevention insulation resistance test terminal equipment, which comprises a high-voltage switch, an insulation resistance measurement module, an alternating-current voltage measurement module, a reverse power transmission prevention module and a main control module, wherein the reverse power transmission prevention module is used for judging whether reverse power transmission occurs or not according to the voltage of an alternating current signal acquired by the alternating current voltage measurement module, and controlling the high-voltage switch to cut off a connection path between the high-voltage output end and a measured line when reverse power transmission occurs; the main control module is used for controlling the magnitude of the direct-current high voltage provided by the direct-current high-voltage module, the measuring gear of the insulation resistance measuring module and the opening / closing of the high-voltage switch, and determining the insulation resistance of the measured line according to the insulation resistance measuring data acquired by the insulation resistance measuring module; therefore, the insulation resistance of the tested line can be measured, the reverse power transmission condition can be prevented in the testing process, and the electric shock risk of high-voltage line maintenance workers is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of power distribution maintenance safety, in particular to an insulation resistance test terminal device for preventing reverse power transmission. Background Art

[0002] During line maintenance, an insulation resistance tester is required to test the insulation resistance value of the line to ground. Since the grounding hook on the line needs to be removed when using the insulation resistance tester, when abnormal reverse power transmission occurs, the high-voltage power supply will directly act on the insulation resistance tester through the test lead, which can easily cause electric shock accidents to operators. Therefore, it is necessary to provide an insulation resistance test device with anti-reverse power transmission function to reduce the risk of electric shock for high-voltage line maintenance operators. Utility Model Content

[0003] The purpose of the utility model is to provide an anti-reverse power transmission insulation resistance test terminal device, which monitors and prevents the reverse power transmission state during the test process on the premise of realizing the measurement of the insulation resistance value of the tested line to the ground, thereby reducing the risk of electric shock for high-voltage line maintenance workers.

[0004] In order to achieve the above-mentioned utility model purpose, the utility model provides the following technical solutions:

[0005] A terminal device for testing insulation resistance against reverse power transmission comprises: a box body, and a PCB circuit board, an operation panel and a high-voltage switch arranged in the box body; wherein:

[0006] The PCB circuit board is provided with a main control module, an anti-reverse power transmission module, a DC high voltage module, an insulation resistance measurement module and an AC voltage measurement module;

[0007] The operation panel is provided with a display interaction module, a first connection socket for connecting a test lead, and a second connection socket for connecting a ground lead;

[0008] Moreover, the high-voltage switch is used to conduct / disconnect the electrical connection between the high-voltage output end of the DC high-voltage module and the first connection socket;

[0009] The DC high voltage module is used to provide DC high voltage to the tested circuit via the first connection socket;

[0010] The insulation resistance measurement module is used to collect insulation resistance measurement data of the measured circuit;

[0011] The AC voltage measurement module is used to collect the voltage of the AC signal on the measured line;

[0012] The anti-reverse power transmission module is used to determine whether reverse power transmission occurs according to the voltage of the AC signal collected by the AC voltage measurement module, and when reverse power transmission occurs, control the high-voltage switch to cut off the electrical connection between the high-voltage output end of the DC high-voltage module and the first connection socket;

[0013] The main control module is used to control the magnitude of the DC high voltage provided by the DC high voltage module, the measurement gear of the insulation resistance measurement module and the opening / closing of the high voltage switch, and determine the insulation resistance of the measured circuit according to the insulation resistance measurement data collected by the insulation resistance measurement module;

[0014] The display interaction module is used to display the insulation resistance value of the measured line, the voltage value of the AC signal and the DC voltage value on the measured line, and input the configuration parameters of the main control module and the anti-reverse power transmission module according to user operations.

[0015] According to a specific implementation, in the anti-reverse power insulation resistance test terminal device provided by the utility model, a wireless communication module is also provided on the PCB circuit board; moreover, the wireless communication module is connected to the main control module, and is used to receive control instructions sent by the wireless terminal and transmit them to the main control module, and receive data transmitted by the main control module and send them to an external wireless terminal; the main control module is used to perform corresponding operations according to the control instructions.

[0016] According to a specific implementation, in the anti-reverse power transmission insulation resistance test terminal device provided by the utility model, the high-voltage switch and the PCB circuit board are installed at the bottom of the box.

[0017] According to a specific implementation, in the anti-reverse power transmission insulation resistance test terminal device provided by the utility model, an alarm module is also provided on the operation panel, and the display interaction module and the alarm module are arranged on the front side of the operation panel.

[0018] According to a specific implementation, in the anti-reverse power supply insulation resistance test terminal device provided by the utility model, the display interaction module includes: a capacitive touch screen and multiple button switches; the alarm module includes: one or more status indicator lights, and / or, one or more buzzers.

[0019] According to a specific implementation, in the anti-reverse power transmission insulation resistance test terminal device provided by the utility model, the DC high voltage module includes: a battery unit, a PWM modulation unit, an inverter unit, a boost conversion unit, a low-pass filter unit and a voltage feedback unit; wherein,

[0020] The PWM modulation unit is used to output a PWM modulation signal according to the first control signal of the main control module or the feedback signal provided by the voltage feedback unit;

[0021] The inverter unit is used to convert the direct current provided by the battery unit into alternating current according to the PWM modulation signal output by the PWM modulation unit;

[0022] The boost conversion unit is used to perform voltage doubling operation and DC conversion operation on the AC power output by the inverter unit to output DC high voltage;

[0023] The low-pass filter unit is used to perform low-pass filtering on the DC high voltage output by the boost conversion unit;

[0024] The voltage feedback unit is used to generate a corresponding feedback signal according to the DC high voltage processed by the low-pass filter unit.

[0025] According to a specific implementation, in the anti-reverse power insulation resistance test terminal device provided by the utility model, the insulation resistance measurement module includes: an AD conversion chip, a multi-way analog switch and a plurality of different sampling bridges; wherein the multi-way analog switch is respectively connected to each of the sampling bridges, and according to the second control signal output by the main control module, the corresponding sampling bridge is selected to be connected to the measurement path; the AD conversion chip is used to convert the voltage signal collected by the sampling bridge into the insulation resistance measurement data.

[0026] According to a specific implementation, in the anti-reverse power transmission insulation resistance test terminal device provided by the utility model, the AC voltage measurement module includes: a voltage transformer, a rectifier bridge, an LC resonant filter sub-circuit, an operational amplifier sub-circuit and a voltage clamping sub-circuit; wherein, the high voltage side of the primary winding of the voltage transformer is connected to the connection path, and the low voltage side of the primary winding is grounded; the high voltage side and the low voltage side of the secondary winding of the voltage transformer are respectively connected to the two AC input ends of the rectifier bridge; the output end of the rectifier bridge is connected to the operational amplifier sub-circuit through the LC resonant filter sub-circuit; the LC resonant filter sub-circuit is configured to have a resonant frequency of 50 Hz so that the industrial frequency signal can pass through; the operational amplifier sub-circuit is used to amplify the voltage signal passing through the LC resonant filter sub-circuit; the voltage clamping sub-circuit is connected to the output end of the operational amplifier sub-circuit to clamp the voltage output by the operational amplifier sub-circuit.

[0027] According to a specific implementation, in the anti-reverse power insulation resistance test terminal device provided by the utility model, the anti-reverse power module includes: a microcontroller, which is used to perform AD conversion on the voltage signal output by the operational amplifier sub-circuit to obtain voltage data, and determine whether the voltage data exceeds a set threshold. If the set threshold is reached, a control signal is output to enable the high-voltage switch to cut off the connection path between the high-voltage output terminal and the circuit under test.

[0028] According to a specific implementation, in the anti-reverse power transmission insulation resistance test terminal device provided by the utility model, the main control module is a single-chip microcomputer; the single-chip microcomputer is connected to the microcontroller.

[0029] In this way, the anti-reverse power insulation resistance test terminal equipment provided by the utility model, by setting a high-voltage switch, an insulation resistance measurement module, an AC voltage measurement module, an anti-reverse power module and a main control module, can not only realize the measurement of the insulation resistance of the measured line, but also determine whether reverse power occurs during the test process, and then prevent reverse power transmission, thereby reducing the risk of electric shock for high-voltage line maintenance workers. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 A schematic diagram of the structure of the insulation resistance test terminal device for preventing reverse power transmission provided by the utility model;

[0031] Figure 2 This is a schematic diagram of the electrical connection between the operation panel and the PCB circuit board in the utility model;

[0032] Figure 3 This is a schematic diagram of the structural layout of the operating panel in the utility model;

[0033] Figure 4 This is a schematic diagram of the internal connections of the DC high voltage module in the utility model;

[0034] Figure 5 This is a schematic diagram of the internal connections of the insulation resistance measurement module of the utility model;

[0035] Figure 6 This is a circuit connection diagram of the AC voltage measurement module of the utility model. DETAILED DESCRIPTION

[0036] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. However, this should not be understood as the scope of the above subject matter of the present invention being limited to the following embodiments, and all technologies realized based on the content of the present invention belong to the scope of the present invention.

[0037] like Figure 1 and Figure 2As shown, the utility model provides an anti-reverse power transmission insulation resistance test terminal device, which includes: a box body 10, and a PCB circuit board 30, an operation panel 20 and a high-voltage switch 40 arranged in the box body 10; wherein,

[0038] The PCB circuit board 30 is provided with a main control module, an anti-reverse power transmission module, a DC high voltage module, an insulation resistance measurement module and an AC voltage measurement module;

[0039] The operation panel 20 is provided with a display interaction module 203, a first connection socket 201 for connecting a test lead, and a second connection socket 202 for connecting a ground lead;

[0040] Moreover, the high-voltage switch 40 is used to conduct / disconnect the electrical connection between the high-voltage output end of the DC high-voltage module and the first connection socket 201;

[0041] The DC high voltage module is used to provide DC high voltage to the tested circuit via the first connection socket 201;

[0042] The insulation resistance measurement module is used to collect insulation resistance measurement data of the measured circuit;

[0043] The AC voltage measurement module is used to collect the voltage of the AC signal on the measured line;

[0044] The anti-reverse power transmission module is used to determine whether reverse power transmission occurs according to the voltage of the AC signal collected by the AC voltage measurement module, and when reverse power transmission occurs, control the high-voltage switch to cut off the electrical connection between the high-voltage output end of the DC high-voltage module and the first connection socket;

[0045] The main control module is used to control the magnitude of the DC high voltage provided by the DC high voltage module, the measurement gear of the insulation resistance measurement module and the opening / closing of the high voltage switch, and determine the insulation resistance of the measured circuit according to the insulation resistance measurement data collected by the insulation resistance measurement module;

[0046] The display interaction module is used to display the insulation resistance value of the measured line, the voltage value of the AC signal and the DC voltage value on the measured line, and input the configuration parameters of the main control module and the anti-reverse power transmission module according to user operations.

[0047] Specifically, before measuring the insulation resistance of the measured circuit, the test lead is first connected to the first connection socket 201, and the ground lead is connected to the second connection socket 202; then, the measurement is started, the main control module controls the high-voltage switch 40 to connect the high-voltage output end of the DC high-voltage module with the measured circuit, and at the same time, the main control module controls the DC high-voltage module to generate DC high voltage and apply it to the measured circuit; then, during the measurement process, the main control module controls the measurement gear of the insulation resistance measurement module, and selects a suitable measurement gear to complete the test; at the same time, the anti-reverse power transmission module determines in real time whether reverse power transmission occurs, and then prevents the reverse power transmission situation, that is, disconnects the high-voltage switch, cuts off the connection path between the high-voltage output end and the measured circuit, and stops the test. Among them, the measurement input ends of the insulation resistance measurement module and the AC voltage measurement module are both connected to the high-voltage output end of the DC high-voltage module, and the grounding parts are all connected to the second connection socket 202, and grounding is achieved through the grounding lead.

[0048] In implementation, the high voltage switch 40 and the PCB circuit board 30 are installed at the bottom of the box 10, and the display interaction module 203 on the operation panel 20 is electrically connected to the PCB circuit board 30 through a flexible flat cable 204. Figure 3 As shown, the operation panel 20 is also provided with an alarm module, and the display interaction module and the alarm module are provided on the front of the operation panel; wherein the display interaction module includes: a capacitive touch screen 203a and three key switches 203b; the alarm module 205 includes: three status indicator lights and a buzzer. For example, the three key switches can correspond to the common operation of starting the device, shutting down the device and running self-test respectively; the three status indicator lights can correspond to the test state, fault state and reverse power supply state respectively.

[0049] like Figure 2 As shown, in the anti-reverse power insulation resistance test terminal device provided by the utility model, a wireless communication module is also provided on the PCB circuit board; moreover, the wireless communication module is connected to the main control module, and is used to receive the control instructions sent by the wireless terminal and transmit them to the main control module, and receive the data transmitted by the main control module and send them to the external wireless terminal; the main control module is used to perform corresponding operations according to the control instructions; such as starting the device, updating the configuration parameters, and turning on / off the high-voltage switch lamp.

[0050] like Figure 4 As shown, in the anti-reverse power transmission insulation resistance test terminal device provided by the utility model, the DC high voltage module includes: a battery unit, a PWM modulation unit, an inverter unit, a boost conversion unit, a low-pass filter unit and a voltage feedback unit; wherein,

[0051] The PWM modulation unit is used to output a PWM modulation signal according to the first control signal of the main control module or the feedback signal provided by the voltage feedback unit;

[0052] The inverter unit is used to convert the direct current provided by the battery unit into alternating current according to the PWM modulation signal output by the PWM modulation unit;

[0053] The boost conversion unit is used to perform voltage doubling operation and DC conversion operation on the AC power output by the inverter unit to output DC high voltage;

[0054] The low-pass filter unit is used to perform low-pass filtering on the DC high voltage output by the boost conversion unit;

[0055] The voltage feedback unit is used to generate a corresponding feedback signal according to the DC high voltage processed by the low-pass filter unit.

[0056] Therefore, in the anti-reverse power transmission insulation resistance test terminal device provided by the utility model, the DC high-voltage module can be controlled by the main control module to generate multiple levels of DC voltages such as 250V, 500V, 1000V, and 2500V; at the same time, by setting a suitable cut-off frequency of the low-pass filter unit, the high-frequency interference of the previous stage can be filtered out, thereby obtaining a more stable DC high voltage and improving the measurement accuracy; moreover, the PWM modulation unit can dynamically adjust the PWM pulse width according to the current output DC high voltage, and then dynamically adjust the output DC voltage, thereby ensuring the stability of the DC high voltage output during the measurement process and effectively improving the accuracy of the insulation resistance test results.

[0057] like Figure 5 In the anti-reverse power transmission insulation resistance test terminal device provided by the utility model, the insulation resistance measurement module includes: an AD conversion chip, a multi-way analog switch and a plurality of different sampling bridges; wherein the multi-way analog switch is respectively connected to each of the sampling bridges, and according to the second control signal output by the main control module, the corresponding sampling bridge is selected to be connected to the measurement path; the AD conversion chip is used to convert the voltage signal collected by the sampling bridge into the insulation resistance measurement data.

[0058] like Figure 6As shown, in the anti-reverse power transmission insulation resistance test terminal device provided by the utility model, the AC voltage measurement module includes: a voltage transformer PT, a rectifier bridge B1, an LC resonant filter sub-circuit, an operational amplifier sub-circuit and a voltage clamping sub-circuit; wherein, the high voltage side of the primary winding of the voltage transformer PT is connected to the measurement path, and the low voltage side of the primary winding is grounded; the high voltage side and the low voltage side of the secondary winding of the voltage transformer PT are respectively connected to the two AC input ends of the rectifier bridge B1; the output end of the rectifier bridge is connected to the operational amplifier sub-circuit through the LC resonant filter sub-circuit; the LC resonant filter sub-circuit is configured to have a resonant frequency of 50 Hz so that the power frequency signal passes through; the operational amplifier sub-circuit is used to amplify the voltage signal passing through the LC resonant filter sub-circuit; the voltage clamping sub-circuit is connected to the output end of the operational amplifier sub-circuit to clamp the voltage output by the operational amplifier sub-circuit.

[0059] Specifically, the voltage transformer PT is used to sense the line AC voltage, and at the same time can filter out the DC high voltage used to measure the insulation resistance, ensuring that the measured voltage signal comes from the AC voltage generated by the reverse power transmission; the rectifier bridge B1 converts the AC signal output by the voltage transformer PT into a pulsating DC signal, which is convenient for the subsequent anti-reverse power transmission module to sample; the inductor L1 and the capacitor C1 form an LC resonant filter sub-circuit, and the parameters of the inductor L1 and the capacitor C1 are adjusted to adjust their resonant frequency to 50Hz, so that the industrial frequency signal passes, improves the measurement accuracy, and reduces interference; the operational amplifier sub-circuit composed of the operational amplifier U1, resistors R1, and R2 amplifies the voltage signal at a low multiple and plays an isolation role at the same time; the resistor R4 and the diode D1 form a voltage clamping sub-circuit, which clamps the output voltage of the AC voltage measurement module to VCC to prevent abnormally high voltage from damaging subsequent modules.

[0060] During implementation, in the anti-reverse power transmission insulation resistance test terminal device provided by the utility model, the anti-reverse power transmission module includes: a microcontroller, which is used to perform AD conversion on the voltage signal output by the operational amplifier subcircuit to obtain voltage data, and determine whether the voltage data exceeds a set threshold value. If the set threshold value is reached, a control signal is output to enable the high-voltage switch to cut off the connection path between the high-voltage output terminal and the circuit under test.

[0061] In this way, the analog voltage signal output by the AC voltage measurement module is continuously converted into AD through high-frequency conversion by the microcontroller, thereby measuring the dynamic amplitude of the AC voltage. At the same time, after each measurement, it is immediately determined whether it is a valid reverse power supply voltage, thereby disconnecting the high-voltage switch in the shortest time after the reverse power supply fault occurs.

[0062] Furthermore, the main control module is a single-chip microcomputer; the single-chip microcomputer is connected to the microcontroller to realize information interaction; and the display interaction module is connected to the main control module to display the insulation resistance value, the DC high voltage value, the set threshold and the voltage value of the AC signal, or set the operating parameters of the main control module according to the interactive operation; the alarm module is connected to the main control module to issue an alarm based on the device operating status and reverse power supply status monitored by the main control module.

[0063] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A terminal device for testing insulation resistance against reverse power transmission, characterized in that: include: A box body, and a PCB circuit board, an operation panel and a high-voltage switch arranged in the box body; wherein, The PCB circuit board is provided with a main control module, an anti-reverse power transmission module, a DC high voltage module, an insulation resistance measurement module and an AC voltage measurement module; The operation panel is provided with a display interaction module, a first connection socket for connecting a test lead, and a second connection socket for connecting a ground lead; Moreover, the high-voltage switch is used to conduct / disconnect the electrical connection between the high-voltage output end of the DC high-voltage module and the first connection socket; The DC high voltage module is used to provide DC high voltage to the tested circuit via the first connection socket; The insulation resistance measurement module is used to collect insulation resistance measurement data of the measured circuit; The AC voltage measurement module is used to collect the voltage of the AC signal on the measured line; The anti-reverse power transmission module is used to determine whether reverse power transmission occurs according to the voltage of the AC signal collected by the AC voltage measurement module, and when reverse power transmission occurs, control the high-voltage switch to cut off the electrical connection between the high-voltage output end of the DC high-voltage module and the first connection socket; The main control module is used to control the magnitude of the DC high voltage provided by the DC high voltage module, the measurement gear of the insulation resistance measurement module and the opening / closing of the high voltage switch, and determine the insulation resistance of the measured circuit according to the insulation resistance measurement data collected by the insulation resistance measurement module; The display interaction module is used to display the insulation resistance value of the measured line, the voltage value of the AC signal and the DC voltage value on the measured line, and input the configuration parameters of the main control module and the anti-reverse power transmission module according to user operations.

2. The anti-reverse power transmission insulation resistance test terminal device according to claim 1, characterized in that: A wireless communication module is also provided on the PCB circuit board; moreover, the wireless communication module is connected to the main control module, and is used to receive control instructions sent by the wireless terminal and transmit them to the main control module, as well as receive data transmitted by the main control module and send them to an external wireless terminal; the main control module is used to perform corresponding operations according to the control instructions.

3. The anti-reverse power transmission insulation resistance test terminal device according to claim 2, characterized in that: The high voltage switch and the PCB circuit board are installed at the bottom of the box.

4. The anti-reverse power transmission insulation resistance test terminal device according to claim 3, characterized in that: The operation panel is also provided with an alarm module, and the display interaction module and the alarm module are arranged on the front side of the operation panel.

5. The anti-reverse power transmission insulation resistance test terminal device according to claim 4, characterized in that: The display interaction module includes: a capacitive touch screen and a plurality of key switches; the alarm module includes: one or more status indicator lights, and / or, one or more buzzers.

6. The anti-reverse power transmission insulation resistance test terminal device according to any one of claims 1 to 5, characterized in that: The DC high voltage module includes: a battery unit, a PWM modulation unit, an inverter unit, a boost conversion unit, a low-pass filter unit and a voltage feedback unit; wherein, The PWM modulation unit is used to output a PWM modulation signal according to the first control signal of the main control module or the feedback signal provided by the voltage feedback unit; The inverter unit is used to convert the direct current provided by the battery unit into alternating current according to the PWM modulation signal output by the PWM modulation unit; The boost conversion unit is used to perform voltage doubling operation and DC conversion operation on the AC power output by the inverter unit to output DC high voltage; The low-pass filter unit is used to perform low-pass filtering on the DC high voltage output by the boost conversion unit; The voltage feedback unit is used to generate a corresponding feedback signal according to the DC high voltage processed by the low-pass filter unit.

7. The anti-reverse power transmission insulation resistance test terminal device according to claim 6, characterized in that: The insulation resistance measurement module includes: an AD conversion chip, a multi-way analog switch and a plurality of different sampling bridges; wherein the multi-way analog switch is respectively connected to each of the sampling bridges, and selects the corresponding sampling bridge to be connected to the measurement path according to the second control signal output by the main control module; the AD conversion chip is used to convert the voltage signal collected by the sampling bridge into the insulation resistance measurement data.

8. The anti-reverse power transmission insulation resistance test terminal device according to claim 7, characterized in that: The AC voltage measurement module includes: a voltage transformer, a rectifier bridge, an LC resonant filter subcircuit, an operational amplifier subcircuit and a voltage clamping subcircuit; wherein, the high voltage side of the primary winding of the voltage transformer is connected to the measurement path, and the low voltage side of the primary winding is grounded; the high voltage side and the low voltage side of the secondary winding of the voltage transformer are respectively connected to the two AC input ends of the rectifier bridge; the output end of the rectifier bridge is connected to the operational amplifier subcircuit through the LC resonant filter subcircuit; the LC resonant filter subcircuit is configured to have a resonant frequency of 50 Hz so that the industrial frequency signal can pass through; the operational amplifier subcircuit is used to amplify the voltage signal passing through the LC resonant filter subcircuit; the voltage clamping subcircuit is connected to the output end of the operational amplifier subcircuit to clamp the voltage output by the operational amplifier subcircuit.

9. The anti-reverse power transmission insulation resistance test terminal device according to claim 8, characterized in that: The anti-reverse power transmission module includes: a microcontroller, which is used to perform AD conversion on the voltage signal output by the operational amplifier subcircuit to obtain voltage data, and determine whether the voltage data exceeds a set threshold. If the set threshold is reached, a control signal is output to enable the high-voltage switch to cut off the connection path between the high-voltage output terminal and the circuit under test.

10. The anti-reverse power transmission insulation resistance test terminal device according to claim 9, characterized in that: The main control module is a single chip microcomputer; the single chip microcomputer is connected to the microcontroller.

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