CN103605053B - Local discharge of gas-insulator switchgear test unit and method under surge voltage - Google Patents

Abstract

The invention discloses a partial discharge test device and method for a gas-insulated combined electrical appliance under an impulse voltage. One end of the tube and bushing is connected to the impulse voltage generator, and the other end is connected to a high-voltage conductor, the high-voltage conductor is arranged in the cavity, at least one pot insulator is arranged in the cavity and the cavity is divided into multiple defect test cavity units; The current sensor is connected to the chamber, the UHF sensor is installed inside each defect test chamber unit, the ultrasonic sensor is arranged on the outer surface of the chamber, and the current sensor, UHF sensor, and ultrasonic sensor are respectively connected to the partial discharge signal processing device. The invention can complete the detection and result analysis of the GIS partial discharge under the impulse voltage carried out on site.

Description

Device and method for partial discharge test of gas-insulated combined electrical appliances under impulse voltage

technical field

The invention relates to a gas-insulated combined electrical appliance, in particular to a partial discharge test device and method for a gas-insulated combined electrical appliance under impulse voltage.

Background technique

Gas insulated switchgear (Gas lnsulated Switchgear, GIS) is one of the important components of the UHV power grid. After optimized design, cable terminals, inlet and outlet bushings, etc. are installed in their respective sealed rooms, and finally assembled in a whole shell filled with SF6 as the insulating medium.

Defects inside GIS that affect the performance of insulating media mainly include: serious installation errors, poor contact between conductors, high-voltage conductor protrusions, fixed particles, insulator defects, steam, etc.

With the increase of my country's power grid voltage, more and more attention has been paid to the on-site impact test of GIS (gas insulated combined electrical equipment). The on-site impact withstand voltage test and partial discharge detection can effectively improve the accuracy of fault diagnosis of GIS equipment. Since there is no standard and recognized test method for partial discharge detection under impulse voltage, the construction of GIS partial discharge test device under impulse voltage and the study of corresponding test methods are of great significance for the on-site detection and result analysis of GIS partial discharge under impulse voltage. Important reference and reference significance.

Contents of the invention

The technical problem to be solved by the present invention is to provide a partial discharge test device and method for gas insulated combined electrical appliances under impulse voltage, which can realize the detection of partial discharge of GIS under impulse voltage, and effectively improve the accuracy of fault diagnosis of GIS equipment.

In order to solve the above technical problems, the present invention provides a partial discharge test device for gas-insulated combined electrical appliances under impulse voltage, which is characterized in that it includes an impulse voltage generator, a voltage divider, a gas-insulated combined electrical appliance, a current sensor, a UHF sensor, Ultrasonic sensor, and partial discharge signal processing device. The impulse voltage generator is respectively connected to the voltage divider and the bushing of the gas-insulated combined electrical appliance, and the impulse voltage is applied to the high-voltage conductor of the cavity of the gas-insulated combined electrical appliance; the high-voltage conductor is arranged in the cavity, and at least one pot insulator is arranged in the cavity And the cavity is divided into multiple defect test cavity units; the grounding bar of the cavity passes through the middle of the current sensor and serves as the primary winding of the sensor to provide a signal source; each defect test cavity unit is equipped with a UHF sensor, an ultrasonic sensor The current sensor, the UHF sensor and the ultrasonic sensor are respectively connected to the partial discharge signal processing device, and the output end of the voltage divider is connected to the partial discharge signal processing device at the same time. The bushing and the impulse voltage generator are connected through wires, and the function of the bushing is to transmit the impulse voltage to the conductor in the gas-insulated combined electrical appliance.

The aforementioned partial discharge test device for gas-insulated combined electrical appliances under impulse voltage is characterized in that the ultrasonic sensor is externally mounted, and the current sensor is a high-frequency current sensor with a maximum bandwidth of 102 MHz.

The aforementioned partial discharge test device for gas-insulated combined electrical appliances under impulse voltage is characterized in that the voltage divider is a capacitive voltage divider.

The aforementioned partial discharge test device for gas-insulated composite electrical appliances under impulse voltage is characterized in that: the partial discharge signal processing device compares and analyzes the partial discharge signals measured by the high-frequency sensor, ultrasonic sensor and pulse current sensor, divides the voltage The impulse voltage signal obtained by the device is used as the reference phase signal of partial discharge.

The partial discharge signal processing device includes an oscilloscope, and the comparative analysis includes comparing the amplitude of the pulse current signal, the ultra-high frequency signal and the ultrasonic signal, the consistency of occurrence and the position of the relative external voltage signal, and suppressing the interference and effective signal extraction.

The test method for the partial discharge test device of the gas-insulated combined electric appliance under the impulse voltage is characterized in that it includes the following steps:

Step 1, setting defects in the defect test chamber unit, the defects include metal tips, pollution along the surface of insulators or free metal particles;

Step 2, voltage application: apply impulse voltages of different amplitudes to the impulse voltage generator in a step-by-step manner;

Step 3, collection of partial discharge signals: when the impulse voltage is applied, the current sensor, UHF sensor and ultrasonic sensor are used to simultaneously collect partial discharge signals;

Step 4, comparative analysis of signals: Comparative analysis of the characteristics of the partial discharge current signal, UHF signal and ultrasonic signal.

The aforementioned test method is characterized in that: the comparative analysis includes comparing the amplitude of the pulse current signal, the ultra-high frequency signal and the ultrasonic signal, the consistency of occurrence and the position where the relative external voltage signal occurs, and suppresses and effectively interferes. signal extraction.

Beneficial effects achieved by the present invention: The partial discharge test device for gas-insulated combined electrical appliances under impulse voltage of the present invention overcomes the defects of the prior art, and can complete the detection and result analysis of partial discharge of GIS under impulse voltage on site.

Description of drawings

Fig. 1 is a schematic diagram of the structure of the partial discharge test device of the gas-insulated combined electric appliance under the impulse voltage of the present invention;

Fig. 2 is the test method flow chart of partial discharge test device of the present invention.

The reference signs in the figure are: 1: impulse voltage generator; 2: voltage divider; 3: bushing; 4: cavity; 5: pot insulator; 6: end cover; 7: defect test cavity unit; 8: High voltage conductor; 9: Current sensor; 10: UHF sensor; 11: Ultrasonic sensor; 12: Partial discharge signal processing device.

Detailed ways

Below in conjunction with accompanying drawing, further elaborate the present invention. It should be understood that these examples are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of the present application.

As shown in Figure 1. The partial discharge test device for gas-insulated composite electrical appliances under impulse voltage mainly includes a 200kV impulse voltage generator, a 110kV GIS test section, a pulse current method measurement system, a UHF method measurement system and an ultrasonic method measurement system. The impulse voltage generator 1 is respectively connected to the voltage divider 2 and the gas-insulated combined electrical appliance. The gas-insulated combined electrical appliance includes a bushing 3. One end of the bushing is connected to the impulse voltage generator, and the other end is connected to a high-voltage conductor 8. The high-voltage conductor 8 Set in the cavity 4, the cavity 4 is provided with an end cover 6, at least one pot insulator 5 is set in the cavity 4 and the cavity is divided into a plurality of defect test cavity units 7; the grounding bar of the cavity 4 is from The current sensor 9 passes through the middle and serves as the primary winding of the sensor to provide a signal source; each defect test chamber unit 7 is provided with a UHF sensor 10, an ultrasonic sensor 11 is arranged on the outer surface of the chamber 4, and the current sensor 9, UHF sensor 10. The ultrasonic sensors 11 are respectively connected to the partial discharge signal processing device 12, and the output end of the voltage divider 2 is simultaneously connected to the partial discharge signal processing device.

The impulse voltage generator applies the impulse voltage to the high-voltage conductor of the GIS cavity through the bushing. The partial discharge signals of the UHF sensor 10, the ultrasonic sensor 11 and the pulse current sensor 9 are connected to the partial discharge signal processing device, and the voltage signal is applied. The partial discharge signal processing device is simultaneously connected through the voltage divider 2 . The partial discharge signal processing device includes an oscilloscope, which uses a Tektronix 7254 high-speed oscilloscope with a bandwidth of 2.5GHz and a maximum sampling rate of 10GS/s. Multiple UHF sensors built in different positions of GIS are used to collect UHF signals, and UHF sensors in different positions can be selected according to needs in the test. The ultrasonic sensor adopts an external type and can move freely on the GIS cavity. The current sensor adopts a high-frequency current sensor with a maximum bandwidth of 102MHz. The voltage divider is a 10000:1 capacitive voltage divider.

The peak value of the test voltage is 400kV, and the waveform adopts four voltage waveforms: standard lightning impulse, standard operating impulse, oscillating lightning impulse and oscillating operating impulse in accordance with the IEC60060-3 standard. The test starts from 20kV and adopts a step-by-step step by step every 20kV The voltage is applied by a boost method.

The partial discharge signal processing device 12 records the partial discharge signal and the applied voltage signal collected by the current sensor 9, the UHF sensor 10 and the ultrasonic sensor 11 at the same time, and performs comparative analysis of the partial discharge signal under different detection methods. The signal comparative analysis is mainly Comparing the amplitude and consistency of the pulse current signal, the UHF signal and the ultrasonic signal, and the position of the relative external voltage signal, through comparative analysis, on the one hand, suppress interference and extract effective signals, such as suppressing interference When extracting effective signals, when there is inconsistency between pulse current signal detection and UHF detection signal, especially when only pulse current signal is detected but UHF signal and ultrasonic signal are not detected, it should be considered whether there is an external interference. On the other hand, it provides test data for the selection of detection methods in on-site detection, such as comparing the sensitivity of the three detection methods, which method detects the largest amplitude, and the difficulty of on-site implementation, etc. The detection provides the best detection method.

As shown in Figure 2, the specific experimental steps are as follows:

Step 1. Setting up defects: First, set up defects in the defect test chamber unit, including defects such as metal tips, dirt along the surface of insulators, and free metal particles.

Step 2. Voltage application: apply test voltages of different amplitudes by applying pressure step by step.

Step 3, partial discharge signal collection: while applying the impulse voltage, use the current sensor, UHF sensor and ultrasonic sensor to collect the partial discharge signal at the same time;

Step 4. Comparative analysis of signals: comparative analysis of the consistency and amplitude of the partial discharge current signal, UHF signal and ultrasonic signal.

The above has disclosed the present invention with preferred embodiments, but it is not intended to limit the present invention, and all technical solutions obtained by adopting equivalent replacement or equivalent transformation methods fall within the protection scope of the present invention.

Claims (4)

1. local discharge of gas-insulator switchgear test unit under a surge voltage, it is characterized in that: comprise impulse voltage generator (1), impulse voltage generator connects voltage divider (2) and gas insulated combined electrical equipment respectively, described gas insulated combined electrical equipment comprises sleeve pipe (3), sleeve pipe one end is connected with impulse voltage generator, the other end connects high-pressure conductor (8), described high-pressure conductor (8) is arranged in cavity (4), at least one disc insulator (5) to be arranged in cavity (4) and cavity to be divided into multiple defect test Cavity unit (7), the earthing bar of cavity (4) is as a winding of current sensor (9), each defect test Cavity unit (7) inside arranges superfrequency sensor (10), ultrasonic sensor (11) is arranged at cavity (4) outside surface, current sensor (9), superfrequency sensor (10), ultrasonic sensor (11) are connected with signal processing of partial discharge device (12) respectively, and voltage divider (2) output terminal accesses signal processing of partial discharge device simultaneously, described signal processing of partial discharge device (12) is to superfrequency sensor (10), being analyzed of ultrasonic sensor (11) and the local discharge signal measured by pulses of current sensor (9), the surge voltage signal that voltage divider (2) obtains is as the reference phase signal of shelf depreciation, signal processing of partial discharge device comprises oscillograph, comparative analysis content comprises contrast pulsed current signal, the amplitude of ultrahigh-frequency signal and ultrasonic signal, the position that the consistance occurred and relatively impressed voltage signal occur, and carry out the extraction of suppression and the useful signal disturbed.

2. local discharge of gas-insulator switchgear test unit under surge voltage according to claim 1, is characterized in that: described current sensor (9) is High Frequency Current Sensor, and maximum bandwidth is 102MHz.

3. local discharge of gas-insulator switchgear test unit under surge voltage according to claim 1, is characterized in that: described voltage divider (2) is condenser divider.

4. under surge voltage, local discharge of gas-insulator switchgear tests the test method of test unit, it is characterized in that, comprises the following steps:

Step one, arranges defect in defect test Cavity unit, and described defect comprises metal tip, insulator along face filth or free metal particulate;

Step 2, the applying of voltage: surge voltage impulse voltage generator being applied to different amplitude in the mode of exerting pressure step by step;

Step 3, the collection of local discharge signal: utilize current sensor (9), superfrequency sensor (10) and ultrasonic sensor (11) simultaneously to gather local discharge signal while applying surge voltage;

Step 4, the comparative analysis of signal: comparative analysis shelf depreciation current signal, ultrahigh-frequency signal and ultrasound signal characteristics, the position that described comparative analysis comprises contrast pulsed current signal, ultrahigh-frequency signal occurs with the amplitude of ultrasonic signal, the consistance of appearance and relative impressed voltage signal, and carry out the extraction of suppression and the useful signal disturbed.