Novel lightning arrester resistive current on-line monitoring device

Abstract

The utility model discloses a novel lightning arrester resistive current on-line monitoring device which comprises a valve plate type current sensor, a voltage waveform shaping module, a microprocessor module, a communication module, a power supply module, a display module and an electric energy quality chip. The output end of the valve plate type current sensor is connected with a current interface at the input end of the power quality chip; the input end of the voltage waveform shaping module is connected with the voltage output signal end of the PT cabinet; the output end of the voltage waveform shaping module is connected with an input end voltage interface of the power quality chip; the output end of the electric energy quality chip is connected with the input end I / O port of the microprocessor module; the input end of the communication module is connected with a communication interface at the corresponding end of the microprocessor module; the input end of the display module is connected with an I / O port of the output end of the microprocessor module; and the output end of the power supply module is connected with a corresponding power supply port of the microprocessor module. The novel lightning arrester resistive current on-line monitoring device has the advantages of being high in measurement precision, good in real-time performance, easy and convenient to operate and the like, can accurately reflect the performance state of a lightning arrester, and provides powerful guarantee for safe operation of an electric power system.

Description

TECHNICAL FIELD

[0001] The utility model relates to a novel lightning arrester resistive current on -line monitoring device belongs to current monitoring device. BACKGROUND

[0002] Lightning arrester is the important overvoltage protection device in power system, for protecting electrical equipment from the high transient overvoltage harm of lightning, and limit the follow-up time and amplitude. However, long-term suffering lightning can lead to lightning arrester performance degradation, and its main performance is the increase of resistive leakage current. At present, the lightning arrester performance on -line monitoring device in market mostly can only monitor total leakage current, cannot accurately measure resistive current, this limits the accuracy of lightning arrester performance evaluation and maintenance. Although there are various resistive current monitoring methods, such as third harmonic method, active power method, but due to the limitation of monitoring principle, its measurement accuracy is often lower. SUMMARY

[0003] In view of the deficiency of prior art, the utility model provides a novel lightning arrester resistive current on -line monitoring device, the device utilizes the zinc oxide valve piece in series in lightning arrester loop as current collection sensor, combines the high voltage voltage phase signal provided by PT cabinet, obtains lightning arrester resistive current through accurate calculation.

[0004] The technical scheme of the utility model is as follows:

[0005] A novel high-voltage switch cabinet in-cabinet temperature and humidity control and dehumidification and cooling device, comprising: a valve piece current sensor, a voltage waveform shaping module, a microprocessor module, a communication module, a power module, a display module, and a power quality chip.

[0006] The valve piece current sensor output end is connected with the power quality chip input end current interface.

[0007] The voltage waveform shaping module input end is connected with the PT cabinet voltage output signal end.

[0008] The voltage waveform shaping module output end is connected with the power quality chip input end voltage interface.

[0009] The output end of the power quality chip is connected with the microprocessor module input end I / O port.

[0010] The input end of the communication module is connected with the microprocessor module corresponding end communication interface.

[0011] The input end of the display module is connected with the microprocessor module output end I / O port.

[0012] The power module output end is connected with the microprocessor module corresponding power port.

[0013] Among them:

[0014] Valve plate type current sensor: two pieces of zinc oxide valve plate are stacked and fixed by screws in series in the lightning arrester circuit, which is used for collecting the total leakage current size I and phase of the lightning arrester.

[0015] Voltage waveform shaping module: through the resistance of 100k ohms and 5V stabilizing tube, the 220V AC voltage signal output by the PT cabinet is converted into a square wave signal containing voltage phase with a frequency of 50Hz, which is used as the input of the voltage phase signal.

[0016] Power quality chip: RN8302B chip is used to measure the current effective value I and the phase difference alpha between voltage and current, and the resistive current IR of the lightning arrester is calculated according to the formula IR=Icos alpha.

[0017] Microprocessor module: STM32F103ZET6 chip is used to realize data processing, communication control and display functions.

[0018] Communication module: RS485 communication module is used to realize data communication between the device and the host computer or other monitoring systems.

[0019] Display module: color liquid crystal screen is used to display the resistive current and other parameters monitored in real time.

[0020] Power module: 220VAC is converted into 12VDC, and then 12VDC is converted into 3.3VDC module to provide stable power supply for the whole device.

[0021] Main innovations:

[0022] Zinc oxide valve plate is used as a current acquisition sensor, combined with the high voltage phase signal provided by the PT cabinet, to realize accurate measurement of resistive current.

[0023] Through the voltage waveform shaping module, the alternating voltage signal is converted into a square wave signal containing voltage phase, which improves the accuracy of phase measurement.

[0024] The power quality chip RN8302B is used to realize accurate measurement of current effective value and phase difference, thereby improving the calculation accuracy of resistive current.

[0025] The device integrates communication module and display module, which is convenient for users to monitor and remotely manage in real time.

[0026] The beneficial effects of the utility model are as follows:

[0027] The novel lightning arrester resistive current online monitoring device has the advantages of high measurement accuracy, good real-time performance and simple operation, and can accurately reflect the performance state of the lightning arrester, providing strong guarantee for the safe operation of the power system. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 is a system block diagram of the utility model;

[0029] Figure 2 Structure diagram of valve plate type current sensor. DETAILED DESCRIPTION

[0030] The utility model will be further described below with reference to the drawings. The following examples are only used to more clearly illustrate the technical scheme of the utility model, and cannot limit the protection scope of the utility model.

[0031] As Figure 1 Indicated, a novel high voltage switchgear in-cabinet temperature and humidity control and dehumidification cooling device, include: valve plate type current sensor, voltage waveform shaping module, microprocessor module, communication module, power module, display module, electric energy quality chip;

[0032] Valve plate type current sensor output end and electric energy quality chip input end current interface connection;

[0033] Voltage waveform shaping module input end and PT cabinet voltage output signal end are connected;

[0034] Voltage waveform shaping module output end and electric energy quality chip input end voltage interface connection;

[0035] The output end of electric energy quality chip is connected with the input end I / O of microprocessor module;

[0036] The input end of communication module is connected with the corresponding end communication interface of microprocessor module;

[0037] The input end of display module is connected with the output end I / O of microprocessor module;

[0038] The output end of power module is connected with the corresponding power port of microprocessor module.

[0039] Among them:

[0040] Valve plate type current sensor: adopt two pieces of zinc oxide valve plate superposition and use screw fixed series connection installation in arrester loop, for collecting the total leakage current size I and phase of arrester. As Figure 2 Indicated, including valve sheet one 1 and valve sheet two 2, superimposed together, the lower of valve sheet one 1 is thin copper sheet one 3, the upper of valve sheet two 2 is thin copper sheet two 4, and is fixed in series through the connecting bolt one 5 of upper and the connecting bolt two 6 of lower. Utilize zinc oxide valve plate as current acquisition sensor, combines the high voltage voltage phase signal provided by PT cabinet, realizes the accurate measurement of resistive current.

[0041] Voltage waveform shaping module: through the resistance of 100k ohm and 5V voltage stabilizing tube, the 220V AC voltage signal output by the PT cabinet is converted into a square wave signal containing voltage phase with 50Hz frequency, as the input of voltage phase signal. Through the voltage waveform shaping module, the AC voltage signal is converted into a square wave signal containing voltage phase, which improves the accuracy of phase measurement.

[0042] Power quality chip: RN8302B chip is used to measure the current effective value I and the phase difference α of voltage and current, and the resistive current IR of the arrester is calculated according to the formula IR=Icosα. The power quality chip RN8302B is used to realize the accurate measurement of current effective value and phase difference, thereby improving the calculation accuracy of resistive current.

[0043] Microprocessor module: STM32F103ZET6 chip is used to be responsible for data processing, control communication and display functions.

[0044] Communication module: RS485 communication module is used to realize data communication between the device and the host computer or other monitoring systems.

[0045] Display module: color liquid crystal screen is used to display the monitored resistive current and other parameters in real time.

[0046] Power module: 220VAC is converted into 12VDC, and then 12VDC is converted into 3.3VDC module, which provides stable power supply for the whole device.

[0047] The above is only the preferred embodiment of the present application, it should be pointed out that for ordinary skilled in the art, without departing from the technical principles of the present application, can make a number of improvements and deformation, these improvements and deformation should also be considered as the protection scope of the present application.

Claims

1. A novel arrester resistive current online monitoring device, characterized in that: Including valve-type current sensor, voltage waveform shaping module, microprocessor module, communication module, power module, display module, power quality chip; The output end of the valve plate type current sensor is connected to the current interface of the input end of the power quality chip; The voltage waveform shaping module input terminal is connected to the PT cabinet voltage output signal terminal; The output terminal of the voltage waveform shaping module is connected to the voltage interface of the input terminal of the power quality chip; The output terminal of the power quality chip is connected to the input I / O port of the microprocessor module; The input end of the communication module is connected to the communication interface of the corresponding end of the microprocessor module; The input terminal of the display module is connected to the output I / O port of the microprocessor module; The output end of the power module is connected to the power port corresponding to the microprocessor module.

2. A novel arrester resistive current online monitoring device according to claim 1, characterized in that: The valve plate type current sensor uses two zinc oxide valve plates stacked together and fixed with screws to be installed in series in the arrester circuit to collect the total leakage current of the arrester.

3. A novel arrester resistive current online monitoring device according to claim 1, characterized in that: The voltage waveform shaping module uses a 100k ohm resistor and a 5V voltage regulator tube to convert the 220VAC AC voltage signal output by the PT cabinet into a 50Hz frequency square wave signal containing voltage phase.

4. A novel arrester resistive current online monitoring device according to claim 1, characterized in that: The power quality chip uses RN8302B to measure the effective value of current I and the phase difference α between voltage and current, and then the arrester resistive current IR can be obtained according to IR=Icosα.

5. The novel arrester resistive current online monitoring device according to claim 1 is characterized in that: The microprocessor module adopts STM32F103ZET6 chip.

6. A novel arrester resistive current online monitoring device according to claim 1, characterized in that: The communication module adopts RS485 communication module.

7. The novel arrester resistive current online monitoring device according to claim 1 is characterized in that: The power supply module uses a 220VAC to 12VDC, and then a 12VDC to 3.3VDC module.

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