High-voltage line grounding point detection and positioning device without contact resistance influence

Abstract

The utility model provides a high-voltage line grounding point detection and positioning device without contact resistance influence. The high-voltage line grounding point detection and positioning device comprises a hanging clamp, a power supply module, a signal source module, a DSP unit, an embedded ARM, a current detection module, a voltage detection module and a display module. The device is respectively connected with a to-be-tested line and a grounding pile through a hanging clamp. The device injects an alternating current signal with a specific frequency into a to-be-detected line, then detects current and voltage signals of the to-be-detected line respectively and calculates line impedance, so that whether the to-be-detected line has a grounding phenomenon or not is accurately judged, and a grounding point is positioned.

Description

Technical Field

[0001] The utility model relates to the technical field of high - voltage line grounding detection devices, and is applicable to the detection of grounding points under the power - off state of 10kV transmission lines. Background Art

[0002] Most of the existing technologies are for online detection. A grounding wire state detection device and detection method need to be continuously connected to the line and the power grid line can be normally powered on to detect the grounding wire. When the power grid is in a power - off state, these existing online detection technologies fail and the device cannot work properly.

[0003] In addition, the existing grounding wire detection technologies under the power - off state can detect the type of grounding, but cannot accurately detect the location of the grounding point. A detection and positioning device for the grounding state of a line can be used under the power - off state. However, because an uncertain contact resistance will be generated when the device is connected to the power grid, the grounding point cannot be accurately positioned.

[0004] Therefore, a detection and positioning device for high - voltage line grounding points without the influence of contact resistance is proposed to realize the detection of whether the line to be measured has a grounding phenomenon and the accurate positioning of the grounding point under the condition of power grid power - off. Summary of the Invention

[0005] A detection and positioning device for high - voltage line grounding points without the influence of contact resistance can detect whether the line to be measured has a grounding phenomenon and accurately position the grounding point, and its operation process is simple and easy to master.

[0006] The above - mentioned device is connected to the line to be measured and the grounding stake respectively through hanging clips. The device injects an alternating current signal with a specific frequency into the line to be measured, and then detects the current and voltage signals of the line to be measured respectively and calculates the line impedance, so as to accurately judge whether the line to be measured has a grounding phenomenon and locate the grounding point.

[0007] In one embodiment, the device is composed of hanging clips, a power supply module, a signal source module, a DSP unit, an embedded ARM, a current detection module, a voltage detection module and a display module.

[0008] The power supply module filters the 12V DC battery, isolates the power supply by using a DC isolation power supply module, and supplies power to the DSP unit and the signal source module through Buck buck - down and Boost boost - up respectively. A rechargeable lithium - ion battery pack with a voltage of 12.6V can be selected, equipped with an intelligent IC protection board to stably output voltage and extend the battery life. At the same time, there is a power - on display lamp to prevent low - power use.

[0009] The signal source module can generate three-phase AC signals according to the PWM signals generated by the DSP unit. The power inversion is realized by the IPM chip. PSS10S92E6AG can be selected to convert DC signals into AC signals, which are then filtered and injected into the transmission line. At the same time, the output signals are fed back to the DSP unit in real time to adjust and control the PWM, thereby improving the accuracy of the signal source.

[0010] The DSP unit can generate PWM signals to control the signal source module to generate three-phase AC signals with specific frequencies, and can also measure voltage and current signals and implement protection control. TMS320F2812 can be selected, which has an ADC analog-to-digital converter built in.

[0011] The embedded ARM communicates with the DSP unit through a serial port. By calculating the measured current and voltage signals, it judges whether there is a grounding phenomenon and locates the grounding point. The ARM920T chip can be selected, which can be embedded with the Android operating system to make the detection device intelligent.

[0012] The hanging clip is made according to the Kelvin clip principle. Its two sides are respectively connected to the current detection module and the voltage detection module to detect the current signal and voltage signal on the line. Since the input impedance of the operational amplifier used to detect the voltage is very high, after the current detection branch and the voltage detection branch are connected in parallel, the voltage detection branch shunts very little current on the line to be measured. Since the contact resistance generated when the device is hung on the line is much smaller than the input impedance of the operational amplifier, it will not have a great impact on the voltage measurement either. Therefore, the device is not affected by the contact resistance, and thus can measure the voltage signal and current signal on the line to be measured more accurately.

[0013] The current detection module allows the current on the line to be measured to flow back to the ground after passing through a high-voltage resistor, without leaving any safety hazards on the instrument. The current sampling signal is obtained from the voltage on the high-voltage resistor, and after filtering and amplification, it is input into the DSP unit.

[0014] The voltage detection module measures the voltage signal on the line to be measured by voltage division and then amplification. The measured voltage signal is filtered and then input into the DSP unit. At the same time, it is compared with the signal at the transformer end to perform feedback control on the error.

[0015] The display module can display the geographical location information of the grounding point. The input voltage required for the liquid crystal display LCD is 3.3V, which can be directly connected to the embedded ARM. The input signal is the UART interface. The HDMI 7-inch high-definition capacitive touch screen can be selected. Except for the required power supply and ground wire, only two signal lines are needed, and the signal is more stable, and the design is more reliable and reasonable.

[0016] In one embodiment, the ADC (Analog-to-Digital Converter) in the DSP unit has high requirements for accuracy and speed. However, filtering processing is also required before signal input, and a second-order band-pass filter composed of amplifiers can be used.

[0017] The present utility model has the following advantages and effects compared with the prior art:

[0018] (1) Compared with the prior art of online detection such as the application No. CN202111659634.4, a grounding wire state detection device and detection method, this device can perform detection under a power-off state.

[0019] (2) Compared with, for example, the application No. CN201510469410.5, a device for detecting and locating the grounding state of a line, this device can accurately detect the grounding point without being affected by the contact resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic installation diagram of the device for detecting and locating the grounding point of a high-voltage line without the influence of contact resistance according to the present utility model;

[0021] Figure 2 It is a schematic structural diagram of the hanging clip of the device for detecting and locating the grounding point of a high-voltage line without the influence of contact resistance according to the present utility model;

[0022] Figure 3 It is a schematic structural diagram of an embodiment of the device for detecting and locating the grounding point of a high-voltage line without the influence of contact resistance according to the present utility model;

[0023] Figure 4 It is a schematic structural diagram of an application example of the device for detecting and locating the grounding point of a high-voltage line without the influence of contact resistance according to the present utility model. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0024] The following will describe in detail the specific embodiments of the device for detecting and locating the grounding point of a high-voltage line without the influence of contact resistance according to the present utility model with reference to the accompanying drawings.

[0025] Refer to Figure 1 as shown, Figure 1 It is a schematic installation diagram of the device for detecting and locating the grounding point of a high-voltage line without the influence of contact resistance according to the present utility model.

[0026] The device is respectively connected to the line to be measured and the grounding pile through hanging clips. The device injects an alternating current signal with a specific frequency into the line to be measured, and then detects the current and voltage signals of the line to be measured and calculates the line impedance, so as to accurately determine whether there is a grounding phenomenon in the line to be measured and locate the grounding point.

[0027] Refer to Figure 2 as shown,Figure 2 This is a schematic diagram of the hanging clip structure of the detection and positioning device for the grounding point of high-voltage lines without contact resistance influence of the present utility model.

[0028] During use, pinch the rubber splint 03 by hand to make it open at a certain angle, and the return spring 04 can ensure that the metal chuck 02 firmly clamps the line to be measured 01. The voltage signal and current signal on the line enter the device through two wires in the hanging wire 05 respectively.

[0029] See Figure 3 as shown Figure 3 This is a schematic diagram of the structure of an embodiment of the detection and positioning device for the grounding point of high-voltage lines without contact resistance influence of the present utility model.

[0030] In one embodiment, the device includes a hanging clip, a power supply module, a signal source module, a DSP unit, an embedded ARM, a current detection module, a voltage detection module, and a display module.

[0031] The power supply module filters the 12V DC battery, isolates the power supply using a DC isolation power supply module, and supplies power to the DSP unit and the signal source module through Buck buck-boost and Boost boost respectively. A rechargeable lithium-ion battery pack of 12.6V can be selected, equipped with an intelligent IC protection board to stably output voltage and extend the battery life. At the same time, there is a battery power display light to prevent low-power use.

[0032] The signal source module can generate three-phase AC signals according to the PWM signals generated by the DSP unit, and realizes power inversion by an IPM chip. PSS10S92E6AG can be selected to convert DC signals into AC signals, and then after filtering, inject them into the transmission line. At the same time, the output signal is fed back to the DSP unit in real time to adjust and control the PWM, thereby improving the signal source accuracy.

[0033] The DSP unit can generate PWM signals to control the signal source module to generate three-phase AC signals with specific frequencies, and realize the measurement and protection control of voltage and current signals. TMS320F2812 can be selected, which has an ADC analog-to-digital converter built in.

[0034] The embedded ARM communicates with the DSP unit through a serial port, calculates the measured current and voltage signals, judges whether there is a grounding phenomenon, and locates the grounding point. The ARM920T chip can be selected, and the Android operating system can be embedded to make the detection device intelligent.

[0035] The hooking clamp is made according to the Kelvin clamp principle, and its two sides are respectively connected to the current detection module and the voltage detection module to detect the current signal and the voltage signal on the circuit. Because the input impedance of the operational amplifier used to detect the voltage is very high, after the current detection branch and the voltage detection branch are connected in parallel, the voltage detection branch has very little shunting of the current on the circuit to be measured. Because the contact resistance generated by the device being hooked to the circuit is much smaller than the input impedance of the operational amplifier, it will not have a significant impact on the voltage measurement. Therefore, the device is not affected by the contact resistance, and can measure the voltage signal and current signal on the circuit to be measured more accurately.

[0036] The current detection module returns the current on the circuit to be tested to the ground after passing through the high-voltage resistor, without leaving any safety hazards on the instrument. The current sampling signal is obtained from the voltage on the high-voltage resistor, and is input into the DSP unit after filtering and amplification.

[0037] The voltage detection module measures the voltage signal on the circuit to be tested by voltage division and amplification. The measured voltage signal is input into the DSP unit after filtering and compared with the signal at the transformer end to provide feedback control for the error.

[0038] The display module can display the geographical location information of the grounding point. The input voltage required for the liquid crystal display LCD is 3.3V, which can be directly connected to the embedded ARM. The input signal is a UART interface, and an HDMI 7-inch high-definition capacitive touch screen can be selected. In addition to the required power supply and ground wire, only two signal wires are required, the signal is more stable, and the design is more reliable and reasonable.

[0039] In one embodiment, the accuracy and speed of the ADC digital-to-analog converter of the DSP unit are very high, but filtering is also required before the signal is input, and a second-order bandpass filter composed of an amplifier can be used.

[0040] In order to more clearly describe the detection and positioning device for the grounding point of a high-voltage line without the influence of contact resistance of the present invention, a preferred application example is described below.

[0041] common Figure 4 As shown, Figure 4 The utility model is a structural schematic diagram of an application example of the detection and positioning device of the grounding point of a high-voltage line without the influence of contact resistance.

[0042] Battery 01 is a 12V battery. You can choose a 12.6V rechargeable lithium-ion battery pack, equipped with an intelligent IC protection board to stabilize the output voltage and extend the battery life. At the same time, there is a power indicator light to prevent low power use.

[0043] Buck circuit 02 and Boost circuit 03 provide 5V and 15V power supplies to DSP unit 05 and IPM chip 06 respectively.

[0044] The embedded ARM 04 plays the role of overall control. ARM integrates embedded control, efficient data acquisition and network communication. The core calculation speed is very fast and can provide a friendly human-computer operation interface. The ARM920T chip can be selected and embedded in the Android operating system to make the detection device intelligent.

[0045] DSP unit 05 is the core unit of control, algorithm and signal processing. It usually adopts Harvard pipeline architecture and is equipped with special hardware multipliers. It is required to be able to process the sampled signals and perform software filtering and fast Fourier decomposition on the signals. TMS320F2812 can be selected, which has built-in ADC analog-to-digital converter and PWM wave control module, and can generate PWM wave to control IPM chip 06 to generate three-phase AC signal.

[0046] IPM chip 06 is a chip composed of high-speed and low-power switch tubes, optimized gate-level drive circuits and fast protection circuits. It has integrated fault detection circuits such as overvoltage, overcurrent and overheating. Compared with conventional inverter bridge AC signal sources, this signal source does not need to design PWM drive circuits, AC inverter bridges and protection circuits. The combination of IPM chip 06 and DSP unit 05 simplifies the logic circuit, reduces power consumption, and improves the accuracy and reliability of the circuit. PSS10S92E6AG can be used. The three-phase AC signal generated by it is filtered by filter 07 and transmitted to the primary circuit of isolation transformer 08.

[0047] The isolation transformer 08 boosts the three-phase AC signal to increase the power supplied to the circuit to be tested, and the high voltage is connected to the circuit to be tested. A leakage transformer with a 2x relationship can be selected.

[0048] The three-phase AC signal is filtered through the filter 09, and the amplifier 10 reduces the voltage signal so that it is within the range of the digital-to-analog converter of the DSP unit 05. After being processed by the filter 11, it is sent to the DSP unit 05 for sampling and calculation, thereby forming a feedback loop, making the AC signal output to the circuit to be tested more reliable.

[0049] The display module 12 needs to meet the conditions of stable control, few signal lines, HDMI interface, and touch control. An HDMI 7-inch high-definition capacitive touch screen can be selected. The touch screen only needs to be connected to the embedded ARM 03 through a USB cable and an HDMI cable. There is no screen burn-in phenomenon, and the service life is longer. It can clearly display the operation interface of the device, display the grounding point status and geographical location information in real time, and has sensitive touch, which is convenient for human-computer friendly interaction.

[0050] After filtering the voltage signal and current signal on the circuit under test, the detection methods of resistance current detection, voltage division and then amplification are respectively adopted, and then the amplifier 13 and amplifier 14 are used for conditioning and amplification, and finally the signal is input into the DSP unit 05. The amplifier can be an integrated differential operational amplifier INA129. Compared with ordinary amplifiers, differential amplifiers can effectively suppress the influence of common-mode noise in the input signal and the floating of ground wire level voltage on the circuit.

[0051] As a preferred application example, the device injects an AC signal with a specific frequency into the circuit under test, and then detects the current and voltage signals of the circuit under test respectively and calculates the line impedance, so as to accurately judge whether there is a grounding phenomenon in the circuit under test and locate the grounding point.

[0052] The above are only the preferred embodiments of the present invention, and do not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the content of the specification and drawings of the present invention, or directly or indirectly applied in other related technical fields, shall be included in the patent protection scope of the present invention by the same token.

Claims

1. A device for detecting and locating the grounding point of a high-voltage line without the influence of contact resistance, characterized in that: Connect to the line to be tested and the grounding stake respectively through the hanging clip; The device includes a hooking clip, a power module, a signal source module, a DSP unit, an embedded ARM, a current detection module, a voltage detection module and a display module; The power module filters the 12V DC battery, uses a DC isolation power module to isolate the power supply, and uses Buck step-down and Boost step-up to power the DSP unit and signal source module respectively; The signal source module can generate a three-phase AC signal based on the PWM signal generated by the DSP unit, and inject it into the circuit to be tested after LC filtering. At the same time, the output signal is fed back to the DSP in real time for adjusting and controlling PWM, thereby improving the accuracy of the signal source; The hook-up clip is made according to the Kelvin clip principle. Its two sides are connected to the current detection module and the voltage detection module respectively to detect the current signal and the voltage signal on the line respectively. Because the input impedance of the operational amplifier used for voltage detection is very high, after the current detection branch and the voltage detection branch are connected in parallel, the voltage detection branch has very little diversion of the current on the line to be tested. Because the contact resistance generated by the device being connected to the line is much smaller than the input impedance of the operational amplifier, it will not have a significant impact on the voltage measurement; Therefore, the device is not affected by contact resistance, and can measure the voltage and current signals on the circuit to be tested more accurately. The current detection module returns the current on the circuit to be tested to the ground after passing through the high-voltage resistor, leaving no safety hazard on the instrument; the current sampling signal is obtained from the voltage on the high-voltage resistor, and is input into the DSP unit after filtering and amplification; The voltage detection module measures the voltage signal on the circuit to be tested by voltage division and amplification. The measured voltage signal is input into the DSP unit after filtering and compared with the signal at the transformer end to provide feedback control for the error. The display module is directly connected to the embedded ARM and can display the geographical location information of the grounding point; The device injects an AC signal of a specific frequency into the line to be tested through a hanging clamp, and then detects the current and voltage signals of the line to be tested respectively and calculates the line impedance, so as to accurately determine whether the line to be tested has a grounding phenomenon and locate the connection point.

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