阅读说明：本技术 一种暂态地电压局部放电检测仪校准系统 (Transient earth voltage partial discharge detector calibration system ) 是由 陈彬 刘小琛 刘伟东 于 2019-09-19 设计创作，主要内容包括：本发明涉及一种暂态地电压局部放电检测仪校准系统,其特征在于：由地电压校准仪、正弦信号发生器及上位机校验模块构成,所述的地电压校准仪由标准脉冲信号源及暂态地电压局部放电检测机构构成,所述的暂态地电压局部放电检测机构由暂态地电压局部放电检测仪、金属板及暂态地电波传感器构成,在所述的金属板上安装有暂态地电波传感器,该暂态地电波传感器通过信号电缆与暂态地电压局部放电检测仪连接,所述的正弦信号发生器通过同轴电缆连接至金属板,在该同轴电缆上串联有一个电阻。本发明具有校验准确、能够有效的诊断开关柜放电缺陷、易于实现的优点。(The invention relates to a transient earth voltage partial discharge detector calibration system, which is characterized in that: the device comprises a ground voltage calibrator, a sinusoidal signal generator and an upper computer verification module, wherein the ground voltage calibrator comprises a standard pulse signal source and a transient ground voltage partial discharge detection mechanism, the transient ground voltage partial discharge detection mechanism comprises a transient ground voltage partial discharge detector, a metal plate and a transient ground electric wave sensor, the metal plate is provided with the transient ground electric wave sensor, the transient ground electric wave sensor is connected with the transient ground voltage partial discharge detector through a signal cable, the sinusoidal signal generator is connected to the metal plate through a coaxial cable, and a resistor is connected to the coaxial cable in series. The invention has the advantages of accurate calibration, effective diagnosis of the discharge defect of the switch cabinet and easy realization.)

1. The utility model provides a transient state ground voltage partial discharge detector calibration system which characterized in that: the device comprises a ground voltage calibrator, a sinusoidal signal generator and an upper computer verification module, wherein the ground voltage calibrator comprises a standard pulse signal source and a transient ground voltage partial discharge detection mechanism, the transient ground voltage partial discharge detection mechanism comprises a transient ground voltage partial discharge detector, a metal plate and a transient ground electric wave sensor, the metal plate is provided with the transient ground electric wave sensor, the transient ground electric wave sensor is connected with the transient ground voltage partial discharge detector through a signal cable, the sinusoidal signal generator is connected to the metal plate through a coaxial cable, and a resistor is connected to the coaxial cable in series.

2. The system according to claim 1, wherein the calibration system comprises: the coaxial cable and the resistor are both 50 omega.

3. The system according to claim 1, wherein the calibration system comprises: the voltage amplitude of the pulse signal output by the standard pulse signal source is continuously adjustable from 10mV to 5V, and the adjustment fineness is not more than 10 mV; the pulse repetition frequency covers 25Hz to 10 kHz; the polarity is changeable; the rising time of the pulse wave property is not more than 0.1 mu s, and the falling time is not less than 100 mu s.

4. The system according to claim 1, wherein the calibration system comprises: the length and width of the metal plate are respectively 300mm, and the thickness of the metal plate is 3 mm.

5. The system according to claim 1, wherein the calibration system comprises: the amplitude of the output sinusoidal voltage of the sinusoidal signal generator is 10 mV-5V and is continuously adjustable, the adjustment fineness is not more than 10mV, the frequency is 1 MHz-100 MHz and is continuously adjustable, and the adjustment fineness is not more than 1 MHz.

6. The system according to claim 1, wherein the calibration system comprises: the upper computer checking module can realize the functions of remote control of a signal source, automatic measurement and data recording and automatic issuing of a test report.

7. The system according to claim 1, wherein the calibration system comprises: the frequency band of the transient ground voltage partial discharge detector is 3 MHz-100 MHz, the measuring range is not less than 60dBmV, the linearity error is not more than 20%, and the transient ground voltage partial discharge detector has a pulse counting function.

Technical Field

The invention belongs to the field of electrified detection instruments, relates to a detector calibration system, and particularly relates to a transient earth voltage partial discharge detector calibration system.

Background

Transient ground voltage partial discharge detection is an important method for monitoring partial discharge of a distribution network switch cabinet of a transformer substation. The transient ground voltage means that when partial discharge occurs in the switch cabinet, radiated electromagnetic waves are formed in the space around the discharge position, and the electromagnetic waves radiated outwards impact the metal cabinet body of the switch cabinet and are transmitted to the ground through the outer surface of the metal cabinet body in the form of electric pulses. The electric pulse passes through the impedance of the metal cabinet body, and a tiny transient voltage to ground is generated between the metal cabinet body and the ground. Through the change of monitoring the transient state of the metal cabinet body to the ground voltage, the internal partial discharge condition of cubical switchboard can be mastered in operation, the purpose of preventing cabinet body trouble is reached.

In the field transient voltage method partial discharge detection process, the following problems are found in the calibration of a detection instrument: (1) UK EA company and HVPD company producing transient earth voltage partial discharge detector at the earliest have higher density of technical details of the detector, and do not provide objective calibration system for the market; (2) the transient ground voltage method partial discharge detection instrument has no related national and industrial calibration standards, and the calibration method has no uniform standard; (3) insulation defect types of the switch cabinet are various, signals detected by partial discharge of a transient earth voltage method also have different discharge characteristics, different partial discharge detection instruments may have different criteria, and calibrated instruments cannot objectively and truly reflect actual discharge conditions and effectively diagnose discharge defects of the switch cabinet.

At present, a mature calibration method for a transient ground voltage partial discharge detection instrument is not formed in China, and the standard development of transient ground voltage partial discharge detection work is not facilitated.

Disclosure of Invention

The invention aims to provide a transient ground voltage partial discharge detector calibration system which is accurate in calibration, can effectively diagnose the discharge defects of a switch cabinet and is easy to realize.

The technical problem to be solved by the invention is realized by the following technical scheme:

the utility model provides a transient state ground voltage partial discharge detector calibration system which characterized in that: the device comprises a ground voltage calibrator, a sinusoidal signal generator and an upper computer verification module, wherein the ground voltage calibrator comprises a standard pulse signal source and a transient ground voltage partial discharge detection mechanism, the transient ground voltage partial discharge detection mechanism comprises a transient ground voltage partial discharge detector, a metal plate and a transient ground electric wave sensor, the metal plate is provided with the transient ground electric wave sensor, the transient ground electric wave sensor is connected with the transient ground voltage partial discharge detector through a signal cable, the sinusoidal signal generator is connected to the metal plate through a coaxial cable, and a resistor is connected to the coaxial cable in series.

Moreover, the coaxial cable and the resistor are both 50 Ω.

Moreover, the voltage amplitude of the pulse signal output by the standard pulse signal source is continuously adjustable between 10mV and 5V, and the adjustment fineness is not more than 10 mV; the pulse repetition frequency covers 25Hz to 10 kHz; the polarity is changeable; the rising time of the pulse wave property is not more than 0.1 mu s, and the falling time is not less than 100 mu s.

The metal plates were 300mm long, 300mm wide, and 3mm thick.

And the amplitude of the output sinusoidal voltage of the sinusoidal signal generator is continuously adjustable from 10mV to 5V, the adjustment fineness is not more than 10mV, the frequency is continuously adjustable from 1MHz to 100MHz, and the adjustment fineness is not more than 1 MHz.

And the upper computer checking module can realize the functions of remote control of a signal source, automatic measurement and data recording and automatic issuing of a test report.

Moreover, the frequency band of the transient ground voltage partial discharge detector is 3 MHz-100 MHz, the measuring range is not less than 60dBmV, the linearity error is not more than 20%, and the transient ground voltage partial discharge detector has a pulse counting function.

The invention has the advantages and beneficial effects that:

the establishment of the transient ground voltage partial discharge detector calibration system constructs a complete transient ground voltage partial discharge detector magnitude system, can realize magnitude transfer and tracing of the transient ground voltage partial discharge detector, and can effectively ensure that the transient ground voltage partial discharge detector has complete function and accurate magnitude. Meanwhile, with the popularization of different types of transient earth voltage partial discharge detection instruments in China, the problem that the existing test standards and criteria are different among the various types of instruments is solved by establishing a calibration system, a unified detection and judgment standard is formed among the various types of transient earth voltage partial discharge detection instruments, and the calibration work of the transient earth voltage partial discharge detection instrument is standardized, so that the quality of the transient earth voltage partial discharge detection work is indirectly improved, and the accuracy and the reliability of transient earth voltage partial discharge detection data are improved.

Drawings

FIG. 1 is a schematic wiring diagram of the present invention;

FIG. 2 is a diagram of a magnitude system of a transient ground voltage partial discharge detector according to the present invention.

Description of the reference numerals

1-coaxial cable, 2-metal plate, 3-transient earth electric wave sensor, 4-signal cable and 5-resistor.

Detailed Description

The present invention is further illustrated by the following specific examples, which are intended to be illustrative, not limiting and are not intended to limit the scope of the invention.

A transient earth voltage partial discharge detector calibration system is innovative in that: the device comprises a ground voltage calibrator, a sinusoidal signal generator and an upper computer verification module, wherein the ground voltage calibrator comprises a standard pulse signal source and a transient ground voltage partial discharge detection mechanism, the transient ground voltage partial discharge detection mechanism comprises a transient ground voltage partial discharge detector, a metal plate 2 and a transient ground electric wave sensor 3, the metal plate is provided with the transient ground electric wave sensor, the transient ground electric wave sensor is connected with the transient ground voltage partial discharge detector through a signal cable 4, the sinusoidal signal generator is connected to the metal plate through a coaxial cable 1, and a resistor 5 is connected to the coaxial cable in series.

The coaxial cable and the resistor are both 50 omega.

The voltage amplitude of the pulse signal output by the standard pulse signal source is continuously adjustable from 10mV to 5V, and the adjustment fineness is not more than 10 mV; the pulse repetition frequency covers 25Hz to 10 kHz; the polarity is changeable; the rising time of the pulse wave property is not more than 0.1 mu s, and the falling time is not less than 100 mu s.

The length and width of the metal plate are respectively 300mm, and the thickness of the metal plate is 3 mm.

The amplitude of the output sinusoidal voltage of the sinusoidal signal generator is 10 mV-5V and is continuously adjustable, the adjustment fineness is not more than 10mV, the frequency is 1 MHz-100 MHz and is continuously adjustable, and the adjustment fineness is not more than 1 MHz.

The upper computer checking module can realize the functions of remote control of a signal source, automatic measurement and data recording and automatic issuing of a test report.

The frequency band of the transient ground voltage partial discharge detector is 3 MHz-100 MHz, the measuring range is not less than 60dBmV, the linearity error is not more than 20%, and the transient ground voltage partial discharge detector has a pulse counting function.

And (3) detection frequency band calibration: the wiring is as shown in fig. 1, the amplitude of the output signal of the sinusoidal signal generator is adjusted to a proper value and maintained, the frequency of the sinusoidal wave is changed between the specified cut-off frequencies of the measured instrument, and the center frequency fc in the substantially constant area of the output signal of the measured instrument is measured. And reducing the frequency of the sine wave signal by the step length of 1MHz, ensuring the amplitude of the output voltage to be unchanged, and finding out a frequency point (-6dB point) when the normalized output of the measured instrument is reduced to 0.501, wherein the frequency point is the actually measured lower limit cut-off frequency. And increasing the frequency of the sine wave signal by 1MHz step length, and measuring the actually measured upper limit cut-off frequency by the same method.

And (3) calibrating the linearity of the detector: the wiring is as shown in fig. 1, and the signal generator is set to output a sine wave signal with a frequency f (f takes a certain value in the range of 3MHz to 50 MHz). Adjusting the output amplitude of the signal generator to enable the display amplitude of the detector to be larger than or equal to 30dB, and recording the output voltage U of the signal generator and the response value A of the detector; adjusting the output amplitude of the signal generator to be lambda U (lambda is 0.8, 0.6, 0.4, 0.2), and recording the response value A of the detector_λ。

And (3) calculating the linearity error of each measuring point according to the formula (1).

And (3) stability test: the detector stability test wiring is the same as the linearity test wiring, as shown in fig. 1. Setting the output waveform of the signal generator to be sine wave, setting the peak-to-peak amplitude to be 1V and the frequency to be a certain proper value within the range of 3-50MHz, starting the detector for continuous working for 1 hour, and recording the response value of the detector after starting and continuous working for 1 hour.

The magnitude system of the transient ground voltage partial discharge detector is shown in fig. 2. The voltage and current signals output by the sine signal generator and the pulse signal generator can be traced to national measurement standards of voltage, current, frequency and time respectively. The sinusoidal signal generator and the pulse signal generator output signals to the metal plate, a sensor of the transient ground voltage partial discharge detector, namely the tested object, receives the signals through the metal plate, the signals are voltage signals, the amplitude, the frequency and the like of the voltage signals are read through the oscilloscope, and the voltage and frequency measurement of the oscilloscope reading the signals can also trace to the national measurement reference of the voltage and the frequency through various measurement standards. Meanwhile, the signal is read to a transient ground voltage partial discharge detector through a sensor of a tested object, the conversion of voltage and frequency signals to partial discharge signals is realized in the detector, and the magnitude transmission of partial discharge is completed.

Although the embodiments of the present invention and the accompanying drawings are disclosed for illustrative purposes, those skilled in the art will appreciate that: various substitutions, changes and modifications are possible without departing from the spirit and scope of the invention and the appended claims, and therefore the scope of the invention is not limited to the disclosure of the embodiments and the accompanying drawings.