GIS Partial Discharge Research Articles

Competitive adsorption of SF6 decompositions on Ni-doped ZnO (100) surface: Computational and experimental study

In this paper, the adsorption models of three SF6 decomposition gas (SO2, SOF2, SO2F2) on the Ni-doped ZnO (100) surface were established based on density functional theory (DFT). The structural and electronic properties of intrinsic and Ni-doped ZnO (100) surface after gas adsorption were analyzed to clarify the adsorption capacity and sensing mechanism. In addition, the adsorption parameters of Ni-doped ZnO (100) surface and intrinsic ZnO (100) surface were compared. The results show that Ni-doped ZnO (100) surface has a strong chemical adsorption effect on SO2 and SO2F2, while exhibits weaker physical adsorption to SOF2. Compared with intrinsic ZnO (100) surface, the adsorption capacity of three gas molecules were obviously enhanced after Ni doping, implying Ni dopant can significantly improve the sensitivity and selectivity of ZnO materials to SO2, SOF2, SO2F2 gases. Meanwhile, gas sensing experiment of intrinsic and Ni-doped ZnO materials towards SO2, SOF2, and SO2F2 was carried out. All results lay a solid foundation for exploring high-performance ZnO based sensors to detect SF6 decomposition components for GIS partial discharge defect diagnose.

Experimental Study on Performance of SF6+N2Mixed Gas Insulation

This paper designed and constructed a 126kV GIS partial discharge test platform, performed frequency breakdown tests and lighting impulse tests at temperature of -30~20℃to SF 6 /N 2 gas mixture. The present experiment studied frequency breakdown tests in different temperatue and slightly inhomogeneous electric field, obtained change in frequency breakdown voltage as a function of temperature; Analysed positive and negative lightning impluse test in gas mixture, in which SF 6 had a propotion of 30%~60%, in different temperature. Results indicated 50% probability breakdown voltage variation in positive lightning impluse tests, and in a low temperature environment, the breakdown voltage increased at negative lightning impulse, the polarity effects varied with condition of pure SF 6 gas. The experimental results showed implement of SF 6 /N 2 mixed gas with 30% SF 6 supersedespure SF 6 gas, could effectively reduce the consume of SF 6 , and remit greenhouse efect.

Design of On-Line Monitoring System of Partial Discharge in GIS Based on the Combination of Acoustic and Electric

This paper describes the design and implementation of the on-line monitoring software system of partial discharge in GIS based on the combination of acoustic and electric in detail. The field operation experience show the system is stable and reliable which can meet the need of GIS on-line monitoring.

Development of GIS Partial Discharge Detection System Based on the New UHF Sensor Combination of Switchgear

In order to ensure power supply reliability and reduce a variety of power supply failure, we analyze the development status, advantages and disadvantages of partial discharge detection techniques about the various Gas -insulated Metal-enclosed Swith Gear (GIS). We put forward the application of ultra high frequency (UHF) technology for GIS partial discharge online monitoring technology methods to solve the problems of the difference of the pulse current method of anti-interference ability and ultrasonic sensitivity the problem of low. According to the deficiency of the traditional ultra high frequency sensor, we developed a new window type of ultra high frequency sensor, and compared with conventional in vitro type UHF sensor. Experimental results show that that the window-type UHF sensor sensitivity and anti-jamming capability are superior to conventional high-frequency sensor

A Dimension Reduction Method and its Application in GIS Partial Discharge Pattern Recognition Research

GIS partial discharge pattern recognition is an important part of its state evaluation, authors have set up 252kV GIS partial discharge detection simulation experiment platform based on UHF detection method, and designed four kinds of typical partial discharge models in laboratory, then established corresponding UHF signal mapping database through the experimental method, and also extracted the original feature parameters; because the original characteristic dimension is high, which is bad for pattern recognition, based on this, the article uses a species mean kernel principal component analysis method, it mapped the partial discharge original data samples to high-dimensional feature space, at first, it calculate all kinds of class mean vector data, and then do principal component analysis based on class mean vector space, build the class average kernel matrix, at last, the class kernel mean principal component analysis algorithm is established. Results show that characteristic of this method contained all the information of the original data, and dimension is less than GIS insulation defect category numbers, and it can realize data dimension reduction without information loss, which improve the pattern recognition rate.

GIS partial discharge pattern recognition based on the chaos theory

Partial discharge (PD) is a key parameter which describes insulation condition of gas-insulated switchgear GIS, GIS internal defects can be discovered in time with the interferences such as corona discharge from the power system using Ultra-high frequency (UHF) method. Traditional method based on statistical characteristics is limited to the analysis of image features that describe the PD pattern plot, causing low recognition rate of some kinds of PD. In this paper, the acquisition of the PD characteristics caused by four typical insulation defects forms φ-v-n 3D PRPD pattern plots sample matrix. The largest Lyapunov exponent of each column of matrix is calculated. A 36-dimension vector is then obtained as the chaotic characteristics of the PD in different voltage phases. The experimental results show that the recognition method based on the chaotic characteristics performs well on all four kinds of insulation defects and can satisfy the recognition order. The method based on the chaotic characteristics has a strong recognition ability for the discharge physical models of gas gap, which is an advantage over the traditional method. The two recognition methods have a good complementary property. Combining the complementary chaotic and statistical characteristics in a decision-making level by using the Dempster-Shafer evidence theory results in an accuracy of above 98%.

UHF 센서 위치 최적화로 부분방전 신호 검출 방법

GIS partial discharge that occurred in the UHF band signal is effectively detected by the method to IEC60270 5pc the apparent minimum discharge can be detected over the GIS arrangement of the sensor interior and exterior of the UHF in accordance with the optimized position signal by considering the damping ratio is selected so that the signals can be obtained to be mounted. 362kV, 800kV GIS is installed on the internal and external sensors are UHF band signal attenuation is set by measuring the reference value, but the operation, 170kV case 362kV, 800kV on the basis of the measurement data and to be installed and operated. When 170kV per 1Bay by installing the built-in sensor 1 for detecting a partial discharge signal, But, GIS signal attenuation is large in the case of an internal partial discharge signal is not detected in some cases. Where the attenuation is great UHF signal of the sensor by increasing the quantity of partial discharge signals were acquired to allow relocation. The greater the spacing between the sensor and the sensor is applied simplifies the installation and reduces the cost in terms of maintenance of appropriate optimal position is calculated to detect the partial discharge signal is needed. Thus 170kV GIS signal power attenuation of a partial discharge by measuring the UHF sensor, and by relocating the proper position is calculated in accordance with the sensor signal decay rate and minimize the error of omission in detecting a partial discharge signal was optimized.

The Application of DPSO - BP Neural Network in GIS Partial Discharge Typical Defects Recognition

The BP neural network is a classifier commonly used in partial discharge type recognition, but the traditional BP algorithm with defects cannot satisfy the actual need. So the optimization algorithm of BP network was studied intensively. DPSO algorithm was used for optimizing the network, and DPSO-BP algorithm is applied to analyze typical defects of GIS, which can be identified by the types of partial discharge. Compared with traditional BP algorithm, DPSO-BP algorithm occupied obvious advantage in recognition effect. It has improved the learning speed of the algorithm, effectively avoid network training going into local minimum point, and maintain the generalization ability and fault tolerance of BP neural network at the same time.

Finite Element Simulation of Partical Discharge Acoustic Pressure Levels Distribution in Gas Insulated Switchgear

In this paper, we present an acoustic-structure couple interaction model of partial discharge (PD) in Gas Insulated Switchgear, the interaction between the internal acoustic source of partial discharge and structure of GIS is simulated with the finite element analysis, and the internal and external acoustic pressure levels distribution of GIS is obtained. The results based on the frequency sweep shown that the internal acoustic pressure levels is bigger than the external acoustic pressure levels of GIS in the ultrasonic frequency spectrum,it suggests that it should use the ultrasonic sensor with a broadband spectrum response to measure partial discharge in GIS, which can obtain high sensitivity. In addition, the external sound pressure of GIS is very small, and the signal of the Ultrasonic sensors must be amplified for measurement. Meanwhile, the outside acoustic pressure of the epoxy insulator is so small that it can properly judge the adjacent GIS unit partial discharge conditions.

The Research and Establishment of GIS Fault Simulation Test System

Abstract. In order to accurately analyze the field test results of the partial discharge in GIS and study on the partial discharge characteristics of typical insulation defects in GIS, this paper constructs a set of failure simulation test system which is based on the entity 363kV GIS which contains all the Main equipments. These system has artificial defect setting units and can applied voltage and current at the same time, it also can manually set a variety of GIS typical insulation defects at the defect setting units. The partial discharge detection and analysis in the case of the applied voltage and current can simulate actual field operating conditions of GIS.

The Software Design of Intelligent Diagnosis System for Partial Discharge Fault of GIS

The correct identification of GIS partial discharge type is essential for assessing the insulation status of GIS and developing a reasonable maintenance strategy. After the analysis of the intelligent diagnosis system design, the software architecture of host and remote computer is given by this article. Site host computer completes the data preprocessing and the remote host computer completes the function of real-time observation, data storage and inquiry, spectrum analysis and pattern recognition. The test shows that the software can complete the intelligent recognition of partial discharge.

Research on Diagnosis Method of GIS Insulation Defects Based on Polynomial Fitting

GIS is currently widely used in the power system and is the Developing Trends of Electrical appliances manufacturing. At present, a lot of research on GIS PD, but the study of the recognition of the PD severity is less. By analyzing a large number of partial discharge sample data, a new GIS PD severity diagnostic method is proposed in this paper. Partial discharge is divided into three stages (initial stage, development stage and dangerous stage) in the method according to the severity of the partial discharge. These three stages are fitted with non-linear mapping and get the fitting parameters. GIS partial discharge fault reference database can be dynamically generated with these fitting parameters. The similarity between the detected data and the reference data is discriminated with the least square method and Supplier division method, and then the GIS PD severity can be diagnosed. A large number of simulation results initially confirmed the effectiveness and feasibility of the proposed method.

Study of the Ultrasonic Characteristics of Typical Partial Discharge on GIS

This Paper studied the typical PD in GIS by ultrasonic method. A GIS PD simulating and testing system is established, including a PD simulating system, an ultrasonic detecting system and a conventional pulse current method measurement system. The thesis focuses on four typical kinds of PD signals in GIS, including metal particles, bad contacts on high and grounding potential conductor, the protrusion on the high potential conductor. The statistics characteristics are obtained which include N-Φ spectrogram (relationship between discharge frequency and discharge phase Spectrogram) and Umax-Φ spectrogram (relationship between discharge amplitude and discharge phase Spectrogram). Experimental results show that low-frequency ultrasonic sensors can detect this four PD signals， signal spectra analysis shows that ultrasonic signals of different statistical model are with different characteristics. The results provide test data for the pattern recognition of Partial Discharge in GIS.

A Study on Partial Discharge in GIS based on the Sensor Array Technology

A Study on Partial Discharge in GIS based on the Sensor Array Technology

Portable Acoustic-Electric Combined System for Partial Discharge Detection in GIS

A portable acoustic-electric detection system for GIS partial discharge is developed. This system integrates both high and low-speed data acquisition devices, and is capable of multichannel joint detection of ultra-high-frequency and high-frequency current as well as ultrasonic signal generated during the GIS partial discharge process. The software of this system is developed based on LabVIEW. It can successively capture, acquire and store the pulse waveform of partial discharge, calculate the phase of discharge pulse and realize time-frequency analysis and amplitude-phase distribution analysis of PD signals at the same time. By calculating the time difference of multi-channel ultra-high-frequency (UHF) signals and of PD ultrasonic signals or the time difference between the two, the system is able to locate the PD source. This system has been applied to on-site partial discharge detection of 220kV and 500kV GIS substations, and the test results have verified the performance of the system.

The Application of Partial Discharge Measurement and Location on CGIS

While the demand of electric power increases and the installation space of power equipment is fixed in a factory, the cubical gas insulated switchgear (CGIS) is gradually applied to medium voltage system due to its small size and easy maintenance. However, it also takes longer time for the repair of CGIS accident. Therefore, the preventive maintenance (PDM) is very important and the most effective method is partial discharge measurement. Unfortunately, the metal-cladded GIS usually make PDM inconvenient, especially for the partial discharge location. This paper provides a fast and easy method for the location of partial discharge in GIS, it can locate the defect quickly and effectively, and the related strategy can be made in advance.

New Calibration Technique Combined with Actual Charge of Partial Discharge in GIS using Three-dimensional Electromagnetic Analysis

New Calibration Technique Combined with Actual Charge of Partial Discharge in GIS using Three-dimensional Electromagnetic Analysis

Identification of Insulation Defect by Sequential Measurement of Partial Discharge in GIS

Identification of Insulation Defect by Sequential Measurement of Partial Discharge in GIS

ガス絶縁開閉装置の沿面針部分放電等価回路モデル

It is well known that the phase distribution of partial discharge in GIS depends on the source of discharge. However, the equivalent circuit model has not been considered sufficiently. On the other hand, the authors have proposed an extended Whitehead circuit model, and have explained the difference of the phase distribution of discharge. In this paper the case of needle on spacer is treated in a model GIS (300kV), and the difference of phase distribution is measured. Next the dust figures are obtained, and charged regions on the spacer are discussed. Finally, it is stated that the EMTP simulation by the extended Whitehead circuit model agrees with the result of experiments fairly well.

A novel technique for detecting electromagnetic wave caused by partial discharge in GIS

For the insulation diagnosis of GIS, it is necessary to detect partial discharge (PD) under noisy condition and to specify the direction of electromagnetic wave radiation due to PD. We proposed "phase gate control method" for discriminating the electromagnetic wave caused by PD in SF/sub 6/ gas from external noises. The proposed method enabled us to discriminate PD of about 100 pC in SF/sub 6/ gas from external noises of more than 10000 pC in air. We also compared polarization characteristics of electromagnetic wave radiated from PD with those from a half-wave dipole antenna, and could estimate the radiation length of electromagnetic wave caused by PD. The results derived in this paper contribute to the insulation diagnosis of GIS on-site.