CN-121978485-A - Partial discharge signal enhancement system and method

CN121978485ACN 121978485 ACN121978485 ACN 121978485ACN-121978485-A

Abstract

The invention discloses a partial discharge signal enhancement system and a method, which belong to the technical field of the enhancement of the partial discharge signal of a high-voltage cable, wherein the method comprises a signal acquisition enhancement module and a signal bridging module, wherein the signal bridging module is used for forming a partial discharge signal bridging channel for electrically connecting a first cable aluminum sheath and a second cable aluminum sheath so as to transmit a cable bridging signal through the partial discharge signal bridging channel; the signal acquisition enhancement module is used for acquiring a cable bridging signal, amplifying power of the cable bridging signal when the cable bridging signal is judged to be a partial discharge signal based on a preset voltage amplitude, acquiring an enhanced partial discharge signal, and injecting the enhanced partial discharge signal into the partial discharge signal bridging channel to realize compensation of attenuation of the partial discharge signal. The system and the method for enhancing the partial discharge signal, disclosed by the invention, realize enhancement of the partial discharge signal and provide a basis for realizing accurate detection and positioning of the partial discharge signal.

Inventors

LI YINGE
ZHOU YUAN
YU XIN
WU JI
YU SHIHU
GAO JIAN
FAN YAZHOU
PENG XIANGYANG
WANG RUI
LI LI

Assignees

广东电网有限责任公司电力科学研究院

Dates

Publication Date: 20260505
Application Date: 20260326

Claims (10)

1. The partial discharge signal enhancement system is applied to a cable joint area, and the cable joint area comprises a first cable aluminum sheath, a second cable aluminum sheath and a cable joint, wherein the first cable aluminum sheath and the second cable aluminum sheath are electrically connected through the cable joint cross-connection, and the partial discharge signal enhancement system is characterized by comprising a signal acquisition enhancement module and a signal bridging module, wherein: The first end of the signal bridging module is electrically connected with the first cable aluminum sheath, and the second end of the signal bridging module is electrically connected with the second cable aluminum sheath; the first end of the signal acquisition enhancement module is electrically connected with the first end of the signal bridging module, and the second end of the signal acquisition enhancement module is electrically connected with the second end of the signal bridging module; The signal bridging module is used for forming a partial discharge signal bridging channel for electrically connecting the first cable aluminum sheath and the second cable aluminum sheath so as to transmit cable bridging signals through the partial discharge signal bridging channel; The signal acquisition enhancement module is used for acquiring the cable cross-over signal, amplifying the power of the cable cross-over signal when the cable cross-over signal is judged to be a partial discharge signal based on a preset voltage amplitude, acquiring an enhanced partial discharge signal, and injecting the enhanced partial discharge signal into the partial discharge signal cross-over channel.
2. The partial discharge signal enhancement system of claim 1, wherein the signal acquisition enhancement module is configured to obtain the cable bridge signal, power amplify the cable bridge signal when the cable bridge signal is determined to be a partial discharge signal based on a preset voltage magnitude, obtain an enhanced partial discharge signal, and inject the enhanced partial discharge signal into the partial discharge signal bridge channel, comprising: Acquiring the cable cross-over signal; When the cable bridging signal is judged to be a partial discharge signal based on the preset voltage amplitude, a signal delay enhancing action is performed based on a preset delay signal, and the signal delay enhancing action comprises the following steps: Performing delay control on the cable cross-over signal to obtain a delay partial discharge signal; And carrying out power amplification on the delayed partial discharge signal to obtain an enhanced partial discharge signal, and injecting the enhanced partial discharge signal into the partial discharge signal cross-over channel.
3. The partial discharge signal enhancement system of claim 2, wherein the signal acquisition enhancement module is further configured to: acquiring historical partial discharge signal data, and determining first fixed time delay meeting preset periodic conditions based on the historical partial discharge signal data; Executing the signal delay enhancing action based on the first fixed delay to acquire an actual execution delay; and taking the actual execution time delay as the preset time delay signal.
4. The partial discharge signal enhancement system of claim 1, wherein the signal acquisition enhancement module comprises a signal acquisition sub-module, a signal enhancer module, and a signal injection sub-module, wherein: The first end of the signal acquisition sub-module is electrically connected with the first cable aluminum sheath, the second end of the signal acquisition sub-module is electrically connected with the first end of the signal bridging module, and the third end of the signal acquisition sub-module is electrically connected with the first end of the signal enhancer module; the second end of the signal enhancer module is electrically connected with the first end of the signal injection sub-module; The second end of the signal injection sub-module is electrically connected with the second end of the signal bridging module; the signal acquisition sub-module is used for forming a partial discharge signal bridging channel electrically connecting the first cable aluminum sheath and the second cable aluminum sheath with the signal bridging module so as to transmit cable bridging signals through the partial discharge signal bridging channel; The signal enhancer module is used for carrying out power amplification on the cable cross-over signal to obtain an enhanced partial discharge signal when the cable cross-over signal is judged to be a partial discharge signal based on a preset voltage amplitude, and transmitting the enhanced partial discharge signal to the signal injection sub-module; the signal injection submodule is used for injecting the enhanced partial discharge signal into the partial discharge signal bridging channel to realize compensation of partial discharge signal attenuation.
5. The partial discharge signal enhancement system of claim 4, wherein the signal enhancer module comprises a signal acquisition unit, a signal buffer unit, and a signal generation unit, wherein: the first end of the signal acquisition unit is used as the first end of the signal enhancer module, the second end of the signal acquisition unit is electrically connected with the first end of the signal buffer unit, the second end of the signal buffer unit is electrically connected with the first end of the signal generation unit, and the second end of the signal generation unit is used as the second end of the signal enhancer module; The signal acquisition unit is used for sampling and converting the cable cross-over connection signal to obtain a partial discharge digital signal; The signal buffer unit is used for judging the cable cross-over signal based on a preset voltage amplitude and a partial discharge digital signal, and transmitting the partial discharge digital signal to the signal generating unit when judging that the cable cross-over signal is a partial discharge signal; The signal generating unit is used for converting the partial discharge digital signal into an analog voltage signal and outputting the analog voltage signal to the signal injection submodule.
6. A partial discharge signal enhancement system as defined in claim 4, wherein: The signal enhancer module is electrically connected with the first end of the signal bridging module through a reference ground wire, and the reference ground wire is used for receiving a reverse signal from the partial discharge signal bridging channel and transmitting the reverse signal to the signal enhancer module so as to realize reverse transmission inhibition.
7. A partial discharge signal enhancement system as claimed in claim 1, wherein: The signal acquisition and enhancement module comprises an A-phase signal acquisition and enhancement module, a B-phase signal acquisition and enhancement module and a C-phase signal acquisition and enhancement module; The signal bridging module comprises an A-phase signal bridging module, a B-phase signal bridging module and a C-phase signal bridging module; For any one of the in-phase signal acquisition enhancement module, the B-phase signal acquisition enhancement module, the C-phase signal acquisition enhancement module, the a-phase signal bridging module, the B-phase signal bridging module, and the C-phase signal bridging module: The first end of the signal bridging module is electrically connected with the corresponding phase aluminum sheath of the first cable, and the second end of the signal bridging module is electrically connected with the corresponding phase aluminum sheath of the second cable; the first end of the signal acquisition enhancement module is electrically connected with the first end of the signal bridging module, and the second end of the signal acquisition enhancement module is electrically connected with the second end of the signal bridging module; The signal bridging module is used for forming a current phase partial discharge signal bridging channel which is used for electrically connecting the first cable corresponding phase aluminum sheath and the second cable corresponding phase aluminum sheath so as to transmit a current phase cable bridging signal through the current phase partial discharge signal bridging channel; The signal acquisition enhancement module is used for acquiring the current phase cable bridging signal, amplifying the power of the current phase cable bridging signal when the current phase cable bridging signal is judged to be a partial discharge signal based on a preset voltage amplitude, acquiring a current phase enhancement partial discharge signal, and injecting the current phase enhancement partial discharge signal into the partial discharge signal bridging channel to realize compensation of attenuation of the partial discharge signal.
8. The partial discharge signal enhancement method is characterized by being applied to a partial discharge signal enhancement system, wherein the partial discharge signal enhancement system comprises a signal acquisition enhancement module and a signal bridging module, the signal bridging module is used for forming a partial discharge signal bridging channel for electrically connecting a first cable aluminum sheath and a second cable aluminum sheath, and the method takes the signal acquisition enhancement module as an execution main body and comprises the following steps: acquiring a cable bridging signal based on the local discharge signal bridging channel, and performing power amplification on the cable bridging signal to acquire an enhanced local discharge signal when the cable bridging signal is judged to be a partial discharge signal based on a preset voltage amplitude; And injecting the enhanced partial discharge signal into the partial discharge signal cross-over channel.
9. The method for enhancing a partial discharge signal according to claim 8, wherein said obtaining a cable cross-over signal based on said partial discharge signal cross-over channel, when said cable cross-over signal is determined to be a partial discharge signal based on a preset voltage amplitude, power amplifying said cable cross-over signal to obtain an enhanced partial discharge signal, comprises: Acquiring the cable bridging signal based on the partial discharge signal bridging channel; When the cable bridging signal is judged to be a partial discharge signal based on the preset voltage amplitude, a signal delay enhancing action is performed based on a preset delay signal, and the signal delay enhancing action comprises the following steps: Performing delay control on the cable cross-over signal to obtain a delay partial discharge signal; And carrying out power amplification on the delayed partial discharge signal to obtain an enhanced partial discharge signal, and injecting the enhanced partial discharge signal into the partial discharge signal cross-over channel.
10. The partial discharge signal enhancement method of claim 9, further comprising: acquiring historical partial discharge signal data, and determining first fixed time delay meeting preset periodic conditions based on the historical partial discharge signal data; Executing the signal delay enhancing action based on the first fixed delay to acquire an actual execution delay; and taking the actual execution time delay as a preset time delay signal.

Description

Partial discharge signal enhancement system and method Technical Field The invention relates to the technical field of high-voltage cable partial discharge signal enhancement, in particular to a partial discharge signal enhancement system and method. Background Along with the advent of the intelligent information age, electric energy has become an indispensable energy source in people's daily life, and the reliability of power supply is related to people's daily life and production life. In urban distribution network systems, power cables of various voltage levels gradually form an intricate distribution network. The power cable belongs to typical capacitive power equipment, local insulation damage causes the failure of the whole insulation system, and the monitoring of the state of cable insulation is related to the safe and stable operation of the urban power system. In the current cable partial discharge detection work, the positioning of partial discharge is particularly important. In the prior art, the partial discharge positioning mainly depends on a time difference positioning method, namely, the partial discharge sensors are respectively arranged at a plurality of middle joint positions of the cable to perform on-line monitoring. When partial discharge occurs at a certain position in the cable, partial discharge signals of the partial discharge signals are transmitted along the cable body, so that time difference is generated, and the position information of the discharge source can be obtained by means of back calculation according to the time difference, and positioning is completed. However, in daily maintenance, most cables are installed by direct burial, calandria and other modes, and when partial discharge positioning is performed, detection devices are often installed at cable terminals on two sides only for positioning, and the method has extremely high requirements on signal transmission attenuation. Meanwhile, although partial discharge positioning can effectively realize calculation of discharge source position information, the power cable mainly aims at 50Hz power frequency signals to determine parameters in design, and transmission of high-frequency signals in the power cable is not considered. The center frequency of the partial discharge signal is often higher than 1MHz, and when the high-frequency signal is transmitted in the power cable, attenuation can be generated due to leakage current of the cable body, non-uniformity of a multi-layer shielding structure of the cable and the like, and particularly when the partial discharge signal is transmitted to a cable intermediate joint, great impedance mismatch can be generated. In addition, the intrinsic impedance value of the cable body is about 30-50 ohms, the wave impedance of the middle joint is possibly larger than 1k ohms, and the huge transmission impedance difference can generate obvious signal reflection, so that the forward transmitted signal energy is reduced, and great attenuation is generated. It has been shown by current research that the effective transmission distance in the power cable is less than 1km when the frequency of the partial discharge signal is 10MHz, which can be reduced to hundreds of meters when an intermediate connector is included. The length between two middle joints of an actual power cable is about 500-700 m, which indicates that the transmission of partial discharge signals can only pass through 2-3 middle joints, and when the length of the cable is large, the problem that effective measurement of the partial discharge signals cannot be realized at two terminal positions of the cable, so that the partial discharge positioning is invalid can occur. Disclosure of Invention The invention provides a partial discharge signal enhancement system and a partial discharge signal enhancement method, which can solve the technical problem that the partial discharge signal cannot be effectively measured at two terminal positions of a cable to cause the failure of partial discharge positioning when the length of the cable is large in the prior art, realize the enhancement of the partial discharge signal and provide a basis for realizing the accurate detection and positioning of the partial discharge signal. The invention provides a partial discharge signal enhancement system which is applied to a cable joint area, wherein the cable joint area comprises a first cable aluminum sheath, a second cable aluminum sheath and a cable joint, the first cable aluminum sheath and the second cable aluminum sheath are electrically connected through the cable joint cross-connection, and the partial discharge signal enhancement system comprises a signal acquisition enhancement module and a signal bridging module, wherein: The first end of the signal bridging module is electrically connected with the first cable aluminum sheath, and the second end of the signal bridging module is electrically connected with the second cable aluminum s