kV GIS Research Articles

Predicting of spatial electric field generated by substation switch operation based on AOS-GCN-LSTM Model

The radiation of adjacent field sources has a specific spatial correlation. In order to suppress electromagnetic disturbance and improve the electromagnetic compatibility of secondary equipment, the electric field’s spatial coupling characteristics and distribution law should be mastered. Therefore, a method for predicting the spatial electric field generated by substation switching operation based on the Atomic Orbital Search-Graph Convolution Network- Long and Short-Term Memory (AOS-GCN-LSTM) model is presented to deal with this problem. First, the GCN is used to construct graph data according to node characteristics and topology information. The feature selection uses the Maximum Information Coefficient (MIC) to extract the spatial correlation of the adjacent field source radiation. At the same time, the LSTM is used to capture the temporal correlation characteristics of different position field strengths in space. Then, the AOS is used to optimize the model with a hyperparameter. In addition, the simulation data of the full-wave simulation model of the spatial electric field generated by switch operation in a 220 kV GIS substation is an example of verification. The results show that the prediction error of the proposed method is below 3%, and it has strong adaptability to the application environment and good prediction performance.

Novel Diagnosis Method for GIS Mechanical Defects Based on an Improved Lightweight CNN Model With Load Adaptive Matching

Mechanical defects of GIS equipment seriously threaten power grid security, but on-site complex operating conditions create great challenges for defect diagnosis. Therefore, this paper proposes a novel diagnosis and state assessment method for GIS mechanical defects under varying currents. First, a time-frequency analysis method of GIS vibration signals based on neighboring mode noise suppression was proposed, and a defect type and severity diagnosis model with load adaptive matching was designed with the improved SqueezeNet (RF-SqzNet). Then, vibration datasets with different severities and currents of typical defects were established based on 110 kV GIS mechanical vibration platform. Finally, model validation and comparison analysis are carried out. Results show that the proposed method effectively mines feature and achieves accurate multiobjective diagnoses of the defect type and severity under varying currents, which is more accurate than traditional methods. The smaller model and faster computing speed are more suitable for edge deployment application.

A High-Reliable Wireless Sensor Network Coverage Scheme in Substations for the Power Internet of Things

With the construction of the Power Internet of Things (PIoT) in full swing as well as the development of wireless communication technology, the deployment of wireless sensor networks is the key to the intelligent transformation of power systems. This paper proposes an asymmetric double-layer wireless sensor network coverage scheme for the intelligent substation. We conducted field measurements in the substation to record the received power at different locations, which were compared with the prediction results of the simulation model established by Winprop to verify the effectiveness of the simulation method. Based on the simulation platform, two different simulation models of substation scenarios are built, including a 220 kV outdoor substation and a 110 kV GIS room. The coverage of received power and line-of-sight (LOS) transmission are analyzed for various nodes of different layers. Several node distribution planning methods are proposed and proven to be feasible according to the simulation results. The wireless coverage scheme can provide useful references for the implementation of PIoT in substations.

Radio Channel Measurements and Characterization in Substation Scenarios for Power Grid Internet of Things

Wireless communication technologies play a key role to support the implementation of power grid Internet of Things (PIoT). An in-depth knowledge of the radio channel is vital to the application of wireless communication technologies in PIoT. This paper investigates the radio channel measurements and characterization for PIoT substation scenarios. A novel channel sounder is designed for achieving omnidirectional measurements and phased array antennas based directional measurements, and a directional multipath components extraction algorithm is proposed. The channel sounding system is verified and is used to perform a series of 3.35 GHz omnidirectional and directional channel measurements in four substation scenarios, involving a 10 kV switch room, a 110 kV GIS room, a semi-indoor 110 kV substation and an outdoor 220 kV substation. Based on the measured channel impulse responses data, both large-scale and small-scale fading characteristics of substation channels are extracted and analyzed. Empirical models of path loss, shadow fading, Ricean K-factor and root-mean-square (RMS) delay spread are proposed. In addition, results of RMS angle spread of departure and RMS angle spread of arrival are presented. These results will provide useful reference for the deployment and optimization of wireless communication networks in PIoT substation scenarios.

Analysis and Research on Lightning Inrush Wave Overvoltage in EHV GIS Substation transformation project

When lightning intrudes into the over-voltage in the 500 kV substation, the lightning wave will be introduced into the substation along the line, which will seriously affect the insulation level of the equipment. In this paper, firstly, the working principle, characteristics, and lightning current simulation of the ZnO arrester are described. Then, the electromagnetic transient program (EMTP-ATP) used in a 500 kV GIS substation carried out the simulation research to the lightning over-voltage, specifically studied the lightning protection effect of metal oxide arrester, compared the lightning over-voltage under the different lightning locations and operation mode, and calculated the 500kV GIS Substation under the single in single out operation mode, 500kV. The influence of different positions of lightning arresters in GIS on the magnitude of lightning over-voltage and the lightning over-voltage on the substation equipment in GIS is also described.

Cable Coupling Characteristics of Wireless Network Convergence Nodes by Transient Electromagnetic Fields in Intelligent Substations

Switching operations in intelligent substations generate a wide range of extremely strong and asymmetric transient spatial electromagnetic fields, and this complex transient electromagnetic field can have a coupling effect with the wireless network sink node equipment cables. We conducted a study on the networking method of wireless network equipment in smart substations and analyzed the types of sink node cables used. In the GIS room of the 110 kV GIS smart substation, the transient spatial electromagnetic field generated by switching operation and the transient induced current of the sink node cable under different operating conditions were tested and obtained, and the time domain and frequency domain comparative analysis was performed. A near-field coupling model of the asymmetric and non-uniform cable transient spatial electric field at the sink node is established, and the validity of the model is verified by comparing and analyzing the measurement and simulation results. The results of the study can provide a reference for transient electromagnetic disturbances in 110 kV GIS intelligent substations and contribute to improving the reliability of wireless network equipment operation.

Experimental Study of High Frequency Impulse Overvoltages at Sayano-Shushenskaya HPP

High-frequency switching overvoltages with an oscillation frequency of up to several MHz are most dangerous for power transformers and cable bushings with XLPE insulation. A working group in charge for studying the influence of high-frequency impulse overvoltages on the operational reliability of power transformers has been established within the CIGRE framework. Experimental studies of high-frequency impulse overvoltages in the 500 and 15.75 kV networks at the Sayano-Shushenskaya HPP were carried out. A new digital recording system equipped with contactless capacitive sensors was used for measuring impulse overvoltages. By using such recording system, it became possible to obtain data on the overvoltages experienced simultaneously by cable bushings and power transformers on the 500 and 15.75 kV voltage sides. The study results have shown that the highest peak values of high-frequency overvoltages are induced by switching operations of disconnectors in the 500 kV GIS. The overvoltages emerging in the 500 kV network are transferred to the 15.75 kV voltage level via the capacitances between the 500/15.75 kV transformer windings. The resulting overvoltage level may be more than a factor of ten higher than the amplitude value of the nominal 15.75 kV voltage. An analysis model was developed in the ATP-EMTP software, which has been verified against the experimental data. The accomplished numerical analyses and experiments have shown that the use of RC circuits is the most efficient protection measure against high-frequency overvoltages.

Large-Scale Plate Load Tests to Determine the Collapse Potential at Santorini 150 kV GIS Substation Site

Two large-scale plate load tests were carried out at the foundation level of the Santorini 150 kV GIS Substation, where the subsoil was identified as collapsible. The purpose of these load tests was to establish in-situ, the magnitude of the expected settlements due to the collapse of the subsoil structure after inundation, while applying a bearing pressure equal to the maximum expected according to the structural design. After completion of the tests, which are described in detail, the resulting settlements were found to be acceptable, so no soil improvement measures were required and it was concluded that with the design and execution of these innovative load tests, it was possible to measure under actual field conditions the magnitude of settlement due to collapse of the soil structure. This led to a more economical foundation solution, compared to the one that would have been adopted were only laboratory tests taken into account in the calculation of settlements.

Study on the characteristics of the potential rise of shell under VFTO in the GIS pumped storage power station

Compared with the traditional GIS station, complex wiring and operation mode of pumped-storage plant diversity, working condition of frequent transformation, makes the plant to produce very fast transient overvoltage (VFTO) probability increase greatly. VFTO will form a transient coupled to the GIS shell casing transient earth voltage (TEV), and then to station personnel safety and the reliability of the secondary equipment poses a great threat. But at the moment because of the limitation of testing technology such as understanding of the academic study of TEV is lack of system. Based on a typical 500 kV gis pumped-storage power station, this paper established a system equivalent model of GIS, network frame and calculates the amplitude, frequency spectrum characteristic of the TEV and influence on VFTO characteristics, and analyzes the fault location, power supply mode, branch bus, the influence of vertical grounding electrodes on the TEV characteristics, For the characteristics of the TEV rules and parameters. Research on TEV characteristics of GIS of pumped storage power station has important reference value for further perfecting relevant theories.

Research on the influence and suppression technology of micron foreign matter for gas insulated switchgear

Breaking–closing of the circuit breaker inevitably produces micron metal dust, significantly affecting the internal insulation state of the GIS. This paper first analyzes the force characteristics of micron metal dust and its separation characteristics inside the circuit breaker, then builds a test platform supporting 520 kV power frequency withstand voltage and 1175 kV lightning impulse withstand voltage based on true type 363 kV GIS to investigate the influence of micron foreign matter on the insulation performance of GIS. Subsequently, ANSOFT is used to simulate the electric field distortion when there is micron metal dust inside the circuit breaker, and the influence of foreign matter on the degree of electric field distortion under the action of the flow field. The characteristics of the influence of micron foreign matter on the insulation performance of foreign matter inside the GIS are summarized. Secondly, using artificial micron foreign matter, the pulse current and the UHF methods are adopted to detect the discharge amount. The sensitivity of different detection methods to the discharge detection of the micron foreign matter is analysed, plus the partial discharge characteristics of the micron foreign matter under different voltages. Afterwards, based on the test results of micron foreign matter, two improvement measures are proposed, including the treatment of foreign matter inside the GIS and the dual-light source angiography inspection, so as to reduce the influence of micron foreign matter on the insulation status of the GIS. Finally, through the AC withstand voltage test of artificial embedded foreign matter and the insulation margin check under 1.1 times lightning impact, the effectiveness of the measures proposed in this paper is verified, thus providing technical support for certifying the impact of micron foreign matter on the insulation state during equipment operation and maintenance.

ANALISIS TINGKAT LABOUR UTILITATION RATE (LUR) PRODUKTIVITAS TENAGA KERJA PADA PEKERJAAAN PASANGAN BATA PEMBANGUNAN GIS 150 kV KOTA PADANG

One of the elements that affect the achievement of construction project objectives is labor productivity. The level of labor productivity can be measured in various ways, where one method that is already known is the Labor Utilization Rate (LUR) method. Here it is assessed how much the LUR level of each worker is, namely the level of effectiveness of workers at work. Several factors that can affect the level of productivity, in this case are age, work experience, education level, wage suitability, health, relations between workers, and managerial. The purpose of this research is to 1). determine the level of Labor Utilization Rate (LUR) of labor productivity; 2). determine the factors that influence age, work experience, education level, wage suitability, health, relations between workers, and managerial on labor productivity and, 3) determine which factors are the most dominant influencing productivity levels in bricklaying work. The research was conducted at the 150 kV GIS construction project in Padang City by observing the productivity level of each 10 workers for 3 days and accompanied by filling out a questionnaire. Based on observations in the field, then taking and collecting data, namely productivity data and questionnaires, then data processing was carried out with the help of the SPSS version 21 program. the 150 kV GIS development project in Padang City is 89.29% > 50%. This shows productive because it is more than 50%. Variables that have been determined, with a significance value of 0.053 > 0.05, so that it simultaneously has no effect. Then, partially age with a sig value of 0.011 <0.05 and work experience with a sig of 0.041 <0.05, so that it affects the level of productivity. From this study also found that managerial variables have an effect, which is the most dominant, which has a beta value of 1.953.

Analysis on switching overvoltage of 500 kV GIS disconnector

The 500 kV GIS disconnector of a pumped storage power station is detected to have the risk of operating overvoltage breakdown of the gas chamber. In this paper, the causes of the operating overvoltage of the disconnector of GI equipment are analyzed, and the insulation impact of the overvoltage generated during the operation of the disconnector at different positions on the adjacent equipment is studied, Finally, the possibility of reducing switching overvoltage by changing the contact of disconnector and adding closing resistance is introduced.

Real-Time Monitoring of High Voltage Switch Based on CAD

In the process of online real-time monitoring of intelligent digital filter high-voltage switchgear, the mechanical state diagnosis of high-voltage circuit breaker is based on fully understanding the mechanical characteristics of each component of circuit breaker. In this paper, K-means clustering algorithm is applied to the mechanical state detection of digital filter high-voltage switchgear. The mechanical state of the digital filter high-voltage switchgear is monitored in real time by using 126 kV GIS. Through fault simulation experiment and mechanical stability experiment, the corresponding changes of characteristics of each mechanical component of circuit breaker in signal waveform and corresponding data changes are found. The experimental results show that this method has good running speed and stability and is more suitable for the real-time monitoring of intelligent digital filter high-voltage switchgear.

Research on Mechanical Defect Detection and Diagnosis Method for GIS Equipment Based on Vibration Signal

Gas insulated switchgear equipment (GIS) is widely used in power system, and more attention has been paid to discharge defects than mechanical defects. However, since mechanical defects are a major cause of the failure in GIS, it is of great significance to carry out relevant research on mechanical defects. Detection and diagnosis methods of mechanical defects based on vibration signal are studied in this paper. Firstly, vibration mechanisms of GIS are analyzed. Due to structural differences between single phase insulated type GIS and three phase insulated type GIS, there are big differences in vibration mechanisms between the two types of GISs. Secondly, experimental research on mechanical defects is carried out based on a 110 kV GIS equipment and a self-developed vibration detection system; results show that mechanical defects can be diagnosed by analyzing signal amplitude, frequency spectrum and waveform distortion rate, and a large current is more beneficial for diagnosing mechanical defects. Lastly, field application has been carried out on 220 kV GIS equipment, and a poor contact defect is found, demonstrating that abnormal diagnosis can be realized by method proposed in this paper. Experimental research and field application demonstrate the feasibility and effectiveness of detection and diagnosis method for mechanical defects based on vibration signal and provide experience for subsequent engineering application.

다물체동역학을 이용한 72.5 ㎸ GIS 차단기 스프링조작기의 롤러 동응력해석

72.5 ㎸ GIS 스프링 방식 조작기의 동적성능을 해석하기 위해 조작기의 동역학적 모델링을 수행하였다. 스프링 조작기의 링크와 롤러가 접촉할 때, 롤러의 구조안전성을 조사하기 위해 동적응력해석이 수행되었다. 롤러는 링크를 지지해주고 동작 시 충격하중을 받게 되므로 구조안전성 검토가 반드시 필요하다. 다물체 동역학 해석 결과와 동적특성 시험 결과를 비교하여 해석 모델의 유용성을 확인하였다. 기구 접촉부분의 주요요소인 롤러를 탄성체로 모델링하였고, 탄성체동역학 해석을 수행하여 동응력 결과를 도출해내었다. 각 롤러는 항복강도에 비해 약 19%, 4%의 안전율을 가져 롤러의 건정성이 확인되었다.

Design and trial production of a 500 kV GIS and Gil bus internal fault simulation platform

Design and trial production of a 500 kV GIS and Gil bus internal fault simulation platform

Simulation Analysis of Earthquake Resistance and Isolation of 220kV GIS Equipment in Tianjin

The anti-seismic and isolation simulation analysis of a 220 kV GIS equipment is carried out using finite element software. The response spectroscopy method is used to simulate the displacement and acceleration dynamic response of the whole structure under the two working conditions before and after the isolation device is installed, and to analyze the change of the natural frequency of the structure. The results show that the relative deformation of 220 kV GIS equipment is smaller than before isolation, and the vibration characteristics of the overall structure are close to the single-particle model, and the structure’s seismic performance is significantly enhanced for the maximum acceleration of the overall structure is reduced by 90%.

Adopting Spectral Analysis in Partial Discharge Fault Diagnosis of GIS With a Micro Built-in Optical Sensor

As partial discharge (PD) monitoring has become a significant means of insulation fault diagnosis, built-in UHF sensors is increasingly adopted in GIS. In this letter, we report a hypersensitive triple-band optical PD sensor which is combined to a UHF sensor with an existing flange assembled on GIS. By experiments performed on an 110 kV GIS chamber, it demonstrates that with the spectral information obtained by this novel optical sensor, the discharge severity evaluation and the multi-source discharge clustering can be realized without any signal strength and phase-resolves statistics, which has a practical significance for the fault diagnosis of HVDC equipment such as DC GIL and DC bushing.

Seismic performance evaluation of 72.5 kV GIS for design verification (II) – Seismic analysis

Seismic performance evaluation of 72.5 kV GIS for design verification (II) – Seismic analysis

Electrical performance analysis of 110 kv GIS terminal extension conducting rod

As GIS terminal is in cooperation with GIS switch, the GIS terminal with 470 mm structure is usually equipped with a 757 mm structure GIS switch. In order to study the influence of the extended conductive pole on the electrical performance of GIS cable terminal, the contact resistance of the extended conductive pole is measured. The measurement results show that the contact resistance meets the requirements of conductive flow. Through finite element simulation calculation of the influence of the extended conducting rod on the GIS terminal electric field distribution, it was found that the maximum field strength of the cable terminal of the extended conducting rod increased by 2 kv/mm, which was smaller than the breakdown field strength of sulfur hexafluoride gas, and the extended conducting rod did not affect the safe and stable operation of the GIS terminal. Extend the conductive rod by finite element simulation calculation interface without air gap and 0.1 mm gap, the distribution of electric field in both cases, contact resistance conforms to the requirements under the premise, extend the conductive rod interface is 0.1 mm gap the maximum field strength of 1.4 kv/mm, less than the sulfur hexafluoride gas breakdown voltage, contact air gap does not affect the safe and stable operation of the GIS terminal.