The principle of PD detector and what is the working principle of PD detector?

The principle of partial discharge detector is a research method for measuring the current of high-frequency pulses. When the experiment produces a partial discharge under the test voltage, the pulse control signal of the partial discharge detector will be discharged through the system coupling capacitor and sent to the input data unit, and then we can learn to obtain the pulse signal pickup through the information input unit at the same time, and the amplification pulse signal can be improved after the low noise amplifier is amplified.

Selecting the desired frequency band in the filter amplifier and amplifying it through the main amplifier effect to achieve the desired pair of values and zero marker pulses, a visible discharge pulse will be generated above the elliptical scan baseline of the oscilloscope screen. It is also sent to the pulse peak, which can also show its peak.

The operating time of the unit internal control system of the time window is measured and the data is displayed on a weekly basis with a pulse peak meter. During this time, it is also possible to prominently study the corresponding display areas on the oscilloscope screen to eliminate the interference of the fixed phase of the enterprise. After the test voltmeter analyzes the capacitance voltage divider, it will generate a signal that affects the zero crossing of the test voltage, which we can display on the oscilloscope screen zero standard pulse, where the main test voltage is indicated by the digital voltmeter.

The principle of partial discharge detector is very complex, we only know that in the usual use of partial discharge detector, the operation must be carried out in accordance with the requirements of regulations, and do a good job of daily maintenance and repair work, if any abnormal situation is found, it should be solved in time, so as not to affect the normal work.

In view of the arc, trace, and corona will form some form of ionization and interfere with the surrounding air molecules, the ultrasonic detector detects the high-frequency noise generated by this phenomenon and uses the "heterodyne method" to compile it into a sound signal that can be heard by the human ear. Under normal circumstances, electrical equipment should be silent, and although there is sometimes a constant hum or steady mechanical noise, this is completely different from the sound signal produced by a partial amplification. The ultrasonic signal generated by the electrical equipment is received by the instrument and its sound quality and intensity are analyzed.

Partial discharge instrument (also known as partial discharge tester) is one of the most common pulse current detection methods, mainly collecting low-frequency signals in partial discharge to prevent radio interference, and the principle of partial discharge instrument is often used to measure the partial discharge of high-voltage capacitors such as transformers, cables, high-voltage switches, transformers, zinc oxide arresters, etc.

The principle of partial discharge is that when the sample is partially discharged, the instantaneous change voltage at both ends of the sample is transmitted to the impedance through the coupling capacitor, and the pulse voltage signal generated by the pulse current i flowing through the impedance is collected, and the parameters such as the apparent discharge amount of the partial discharge are obtained after amplification and processing.

SPR-JF- Partial Discharge Monitoring System is a set of monitoring devices for detecting, analyzing and continuously monitoring the partial discharge signal of high-voltage switchgear, which is suitable for various types of 10KV and 35KV switchgear. The system is composed of a system host and a PD detection sensor, and the system host is used to process the PD signal obtained by the PD detection sensor, and screen the PD signal to complete the numerical recording, analysis and judgment, alarm and other functions of the PD signal.

Second, technical parameters.

Operating supply voltage.

110 264VAC, 155 370VDC rated power 3W

Operating ambient temperature.

Measure the frequency range.

Measure sensitivity.

60dBm measurement response time.

10s measuring range.

60dbm～0dbm

Alarm threshold setting.

40dBm 0dBm (Adjustment Interval 1dBm).

Alarm threshold default.

20 dbm

Dimensions: 115*72*60mm

Installation location: Switch cabinet cable room.

Installation: Bracket mounting.

Communication interface RS485

Third, the product structure.

Schematic diagram of the structure.

Schematic diagram of the system.

3. Product features.

1. Continuous sampling and extraction of effective partial discharge signals, the process is uninterrupted.

3. The partial discharge sensor has wide and low noise, high sensitivity, large dynamic range and digitalization.

4. Small size and light weight, it does not affect the existing equipment during installation, and it is easy to install.

5. The sensor is installed inside the switch cabinet, and its internal electromagnetic signal is easy to receive, and the external interference is almost shielded, and the sensitivity is high.

Fifth, product advantages.

1. Provide uninterrupted real-time condition monitoring for the switchgear;

2. Predict the alarm to prevent the occurrence of failure disasters and reduce or avoid losses;

3. The service life of equipment and systems is increased, and the availability rate is improved;

4. Reduce maintenance costs, reduce failure rates, and reduce equipment downtime.

Ultrasonic partial discharge detector, which can sense high-frequency signals generated by faults, vibrations, leaks and electrical partial discharge of operating equipment. It uses a unique heterodyne method to convert these signals into audio signals, which can be heard through the headphones and the intensity indicator is seen on the hands. The heterodyne method is like a radio, which accurately converts signals into sound that people can easily recognize and understand.

The advantage of using ultrasonic technology is that it is easy to understand and convenient, ultrasonic is a high-frequency short-wave signal, this sound wave is not directly heard by the human ear, when we can fully detect these sounds through the ultrasonic full-function detector.

With the development of modernization, the application of high-voltage switchgear is becoming more and more extensive, and it is one of the indispensable and important equipment in the power system. The safety and reliability of high-voltage switchgear are directly related to the stable operation of the power system, so it is particularly important to test its withstand voltage.

The power frequency withstand voltage test of high-voltage switchgear refers to the power on of the high-voltage switchgear and the operation of it for a certain period of time under the rated voltage to test its stability and reliability in terms of electrical performance, mechanical performance and environmental adaptability. The test can effectively detect the quality of high-voltage switchgear and ensure the safe operation of the power system.

The specific steps of the power frequency withstand voltage test of high-voltage switchgear are as follows:

First of all, the high-voltage switchgear is inspected to ensure that its performance meets the requirements. Then, connect the high-voltage switchgear to the power supply and energize it at the rated voltage. In the process of high-voltage switchgear operation, it needs to be comprehensively monitored and recorded, including changes in current, voltage, temperature and other parameters.

The test time is generally 4 hours, and the high-voltage switchgear needs to be tested under different load conditions during the test process to ensure its reliability under different load conditions.

At the end of the test, the high-voltage switchgear needs to be thoroughly inspected and evaluated. The test content includes the appearance, electrical performance, mechanical properties, environmental adaptability and other aspects of the high-voltage switchgear. The results of the assessment should meet the requirements of national standards and industry standards.

The significance of the power frequency withstand voltage test of high-voltage switchgear is:

On the one hand, the quality of high-voltage switchgear can be effectively detected and evaluated to ensure the safe operation of the power system. On the other hand, it can provide an important reference for the production and design of high-voltage switchgear, and improve its quality and reliability.

It should be noted that the power frequency withstand voltage test of high-voltage switchgear is a very dangerous test, which requires professional testers to operate, and at the same time, it is necessary to strictly abide by the relevant safety regulations and operating procedures to ensure the safety during the test.

To sum up, the power frequency withstand voltage test of high-voltage switchgear is a very important test, which is of great significance for ensuring the safe operation of the power system. In progress.

The principle of partial discharge testing is the high-frequency pulse current measurement method (i.e., the ERA method).

When the partial discharge of the test CA under the test voltage, the discharge pulse signal is sent to the input unit through the coupling capacitor CA, and the pulse signal is picked up by the input unit, which is amplified by the low-noise preamplifier, and the filter amplifier selects the required frequency band and the main amplifier amplification caution (reaching the required amplitude and generating the zero mark pulse), and then generates a visible discharge pulse on the elliptical scanning baseline of the oscilloscope screen, and also sends it to the pulse peak meter to display its peak.

The time window unit controls the working time of the pulse peak meter during each week of the test voltage, such as Xiaozheng, and highlights the corresponding display area of the oscilloscope during this working time, so that it can eliminate the interference of the fixed phase.

The test slag repentance voltmeter generates a test voltage zero-crossing mark signal through the capacitor voltage divider, which can display the zero standard pulse on the oscilloscope screen, and the test voltage is indicated by the digital voltmeter.

When the field strength of the applied voltage in the car equipment is enough to cause the discharge of the insulated part of the equipment, but the discharge phenomenon of the discharge area does not form a fixed discharge channel, it is called partial discharge.

The partial discharge tester is a digital partial discharge detector that uses the principle of pulse current method

The pulsed current method refers to the instantaneous voltage change δu at both ends of the sample CX when partial discharge occurs. In this case, if the electrical CK is coupled to a sense impedance Zd, a pulse current i is generated in the circuit, and the pulse current is generated through the sense impedance. By detecting, amplifying and displaying the impulse voltage information, some basic parameters of partial discharge (mainly discharge amount q) can be determined.

It should be pointed out here that the actual partial discharge inside the test product cannot be measured. Due to the extremely complex transmission path and direction of the partial discharge pulse inside the tested product, we only need to use the comparison method to visually inspect the tested product. In discharge charging, a certain amount of electricity is injected into both ends of the test sample before the test, the magnification is adjusted to establish a scale, and then the part of the discharge pulse received inside the test sample is compared with the actual situation.

voltage and scale to obtain the apparent discharge charge of the test object.

The digital partial discharge detector ensures the reliability of the detection data through digital signal processing, adaptive filtering and other interference signal processing methods.

The new generation of GDPD-3000C ultrasonic and geoelectric wave portable intelligent partial discharge detector adopts advanced cloud computing and intelligent modeling technology to realize the measurement, recording, transmission, storage, analysis and exchange of partial discharge signals, and provides strong technical support for the on-site measurement of partial discharge. Surveyors use GDPR-3000C to collect partial discharge information, and can intelligently diagnose the insulation status of the detected equipment in real time through cloud computing.

The partial discharge detection system has a wide range of applications, the detection sensitivity and accuracy are very high, under the proper calibration, the discharge amount of the discharge pulse can be directly read, it is a very practical equipment, today I will give you a specific introduction to what the working principle of the partial discharge detector is.

The principle of the PD detector is a current measurement method for high-frequency pulses. When the experiment produces partial discharge at the test voltage, the pulse signal of the partial discharge detector will be discharged through the coupling capacitor and sent to the input unit, and then the pulse signal can be obtained through the input unit, and the pickup can amplify the pulse signal after being amplified by the low noise amplifier.

Selecting the desired frequency band in the filter amplifier, after the main amplifier amplification effect, that is, the desired pair of values and zero marker pulses are reached, above the elliptical scan baseline of the oscilloscope screen, a visible discharge pulse is generated, which is also sent to the pulse peak, and its peak can also be displayed.

The units of the time window control the test voltage and display the operating hours of the pulse peak meter on a weekly basis. During this time, the corresponding display area can also be highlighted on the oscilloscope screen to eliminate interference from fixed phases. After the test voltmeter passes through the capacitor divider, it generates a signal that the test voltage crosses zero, which can display a zero standard pulse on the oscilloscope screen, where the test voltage is indicated by a digital voltmeter.

The principle of the partial discharge detector is very complex, we only know that when using the partial discharge detector in ordinary times, it must be operated in accordance with the requirements of the specification, and do a good job of daily maintenance and maintenance, if any abnormalities are found, it should be dealt with in time so as not to affect the normal work.

Respondent: Huatian Power.

1.Early faults can be detected before other detection methods such as infrared detection.

2.It is highly sensitive and can detect weak signals like blinking.

3.It has strong anti-interference ability and can be used in complex environments.

4.Portable equipment, easy to carry and easy to operate.

5.The detection distance of the instrument can be greatly increased by a long-distance probe or ultrasonic long-range receiver, which can detect a distance of more than 30 meters and a distance of more than 45 meters). Bearing lubrication monitoring, engine, electric pump cavitation, motor, compressor, operating equipment and lubrication failure detection, ultrasonic seal non-destructive test, cargo box, weld, hatch, gasket, electrical equipment detection, electrical partial discharge (corona), high-voltage arc, ignition, electric spark, leakage traces, insulation aging, power switch, transformer, relay, circuit breaker, busbar board, insulation device detection, heat exchanger section liquid, boiler and cooler, condenser, Nianwu exhaust system, heating system, withstand voltage test, Pressure Vacuum, Vessel, Air, Oxygen, Nitrogen, Refrigerant Leakage, Valve Valve, Hydraulic Seat Leakage or Blockage Detection, Steam Valve, Steam Removal Gate, Air Duct Detection, Mechanical Fault Diagnosis, Ultrasonic Acoustic Emission Test, Automobile Aircraft Ship Cockpit Seal Test, Transmission Line Detection, Remote Inspection, Pipeline Leakage Detection, General Mechanical Combustion Companion Detection and Elimination.