High Voltage Shunt Reactors Research Articles

High voltage shunt reactor acoustic signal denoising based on the combination of VMD parameters optimized by coati optimization algorithm and wavelet threshold

The goal of this research is the application of variational mode decomposition (VMD) in the denoising process of acoustic signals from high-voltage shunt reactors. This paper propose a unique joint denoising method that combines improved VMD and wavelet threshold. The coati optimization algorithm (COA) was introduced to optimally find the optimal combination of VMD decomposition parameters. The optimized and improved VMD was then used to decompose the original noisy reactor acoustic signal. The correlation coefficient method was introduced to remove uncorrelated intrinsic mode functions (IMFs). The wavelet threshold denoising algorithm was applied for secondary noise reduction on the extracted IMFs. The denoised IMFs were subsequently superimposed and reconstructed to obtain the denoised acoustic signal. Comprehensive comparison and analysis of these methods were conducted through simulation experiments and practical tests. The results indicate that COA-VMD-Wavelet Threshold—significantly reduces the reconstructed signal errors with high practicality and effectiveness.

Analysis and treatment of oil chromatography of a 1000kV high voltage parallel reactor

In this paper, the author combined with gas chromatography to a 1000kV high voltage shunt reactor oil chromatography anomaly analysis, preliminary theoretical analysis conclusion, then in the maintenance process through the equipment breakdown and the fault cause, verify the correctness of the theoretical analysis, for the next step of equipment manufacturers equipment manufacturing and process control provides advice.

Intelligent Diagnosis Method for Mechanical Faults of High-Voltage Shunt Reactors Based on Vibration Measurements

Aiming at the difficulty of accurately identifying latent mechanical faults inside high-voltage shunt reactors (HVSRs), this paper proposes a new method for HVSR state feature extraction and intelligent diagnosis. The method integrates a modified complementary ensemble empirical mode decomposition (CEEMD)–permutation entropy–CEEMD (MCPCEEMD) method, mutual information theory (MI), multiscale fuzzy entropy (MFE), and an improved grasshopper optimization algorithm to optimize the probabilistic neural network (IGOA-PNN) model. First, we introduce MCPCEEMD for suppressing modal aliasing to decompose the HVSR raw vibration signals. Then, the correlation degree between the obtained intrinsic mode function (IMF) components and the HVSR original vibration signals is judged through MI, and the IMF with the highest correlation is selected for feature extraction. Furthermore, this study uses MFE to quantify the selected IMF. Finally, we employ piecewise inertial weights to improve GOA to select the best smoothing factor for PNN, and use the optimized IGOA-PNN model to identify feature subsets. The experimental results show that the proposed method can successfully diagnose different types and degrees of HVSR mechanical faults, and the identification accuracy rate reaches more than 98%. The high recognition accuracy of the proposed method is helpful for the state detection and field application of HVSRs.

АНАЛІТИЧНИЙ РОЗРАХУНОК ЗАСТУПНИМИ СХЕМАМИ МАГНІТНИХ ПОТОКІВ ТА ВТРАТ У МАГНІТНИХ СИСТЕМАХ ШУНТУВАЛЬНИХ РЕАКТОРІВ

For high-voltage shunt reactors with rods with non-magnetic gaps, an analytical method for calculating magnetic fluxes based on substitute circuits has been developed by substantiation by finite element modeling, and the calculation of main and additional losses in magnetic systems has been refined. The results of loss calculations are compared with their estimates during type tests of reactors. Bibl. 11, fig. 8, table.

Noise Characteristics and Control of High Voltage Shunt Reactor

Noise Characteristics and Control of High Voltage Shunt Reactor

Data Augmentation Using DCGAN for Improved Fault Detection of High Voltage Shunt Reactor

High voltage shunt reactor is an important equipment of power transmission systems. The accurate assessment of their operating status and the timely and correct diagnosis of faults and defects concern the operation safety of the entire grid. Health assessment of high voltage shunt reactors based on vibration signal, which can be used to characterize the hidden troubles of it, is a topic widely studied in deep learning and fault diagnosis. A large number of samples are needed to train the deep learning model, but it is not easy to acquire enough fault samples in the actual scene. In this paper, we utilize a Deep Convolutional Generative Adversarial Networks (DCGAN) to generate synthetic fault samples and enlarge the fault dataset to train the Convolution Neural Network (CNN) fault detection model. Results reveal that the performance through the CNN model can be improved by 3% with the synthetic samples generated by DCGAN, which is better than that of traditional Synthetic Minority Oversampling Technique (SMOTE) algorithm.

A New Vibration Analysis Approach for Monitoring the Working Condition of a High-Voltage Shunt Reactor

With the rapid development of power grids, the voltage level and capacity of high-voltage shunt reactors (HVSRs) are increasing year by year, and HVSR faults are increasing, especially HVSRs core winding faults. The HVRSs core winding faults seriously threaten the safe and stable operation of power grids. To solve this problem, we propose a feature extraction method for HVSR core winding faults identification to improve the accuracy of faults identification. This method relies on the combined application of qualitative analysis of phase space reconstruction (PSR) and quantitative calculation of an improved K-means clustering method. First, we employ PSR to qualitatively analyze the HVSR vibration signal and extract the phase trajectory feature quantity of the vibration signal. Then, this paper uses an improved K-means clustering optimized by an improved grasshopper optimization algorithm (GOA) to cluster the phase trajectory features, so as to obtain the cluster center coordinates. Furthermore, we employ the distance from the cluster center displacement vector to the origin and the angle change to perform quantitative calculations to realize fault identification. Finally, the fault simulation experimental data sets of 10kV and 20kV HVSRs verify the effectiveness of the proposed method. The experiment results show that the proposed method has better accuracy and can truly reflect the state characteristics of the HVSR core winding. The proposed high-accuracy method helps to improve the efficiency of on-site HVSRs condition assessment and maintenance.

Simulation Analysis of Vibration and Noise Characteristics of High Voltage Shunt Reactor Based on Multi-physical Field Coupling

In order to study the vibration characteristics of the high-voltage shunt reactor, a finite element model of the single-phase reactor was established based on the analysis of the vibration mechanism of the reactor body, by using COMSOL multi-physical field coupling simulation software. The magnetic flux density distribution of reactor core, windings, stress distribution and vibration displacement of iron core were analysed by simulation. The sound pressure distribution of the iron core was analysed based on the pressure sound field model. The results indicate that the magnetostrictive effect of the iron core reactor, the electromagnetic attraction between the iron core cakes and the ampere force on the winding are the main factors for its vibration. In addition, the reactor vibration to be mainly concentrated at the core air gap. The results obtained by multi-physics simulation are basically consistent with the measured data, which verifies the effectiveness of the simulation method. The conclusions can provide theoretical basis for the analysis and monitoring of reactor vibration and noise.

Electromagnetic Transient Analysis of 750kV Four-circuit Transmission Line on the Same Tower

The ATP-EMTP program is used to calculate the power frequency overvoltage, open-phase power frequency resonant overvoltage, induced voltage and current, secondary arc current and recovery voltage, and switching overvoltage of 750kV four-circuit transmission line on the same tower. The study reveals that the configuration of four circuits on the same tower has little influence on the power frequency and switching overvoltage, but greatly influences the secondary arc current and recovery voltage, and induced voltage and current. Therefore, measures like installing high-voltage shunt reactor and neutral grounding reactor and line transposition are required. Also, the induced voltage and current ratings of earthing switch are proposed.

Optimisation of electric arc model parameters based on simplex annealing and genetic algorithms

This paper presents the method for obtaining the coefficients of the dynamic Cassie-Mayr electric arc model by means of annealing and genetic optimisation algorithms. The extraction of the coefficients can be obtained by means of the iterative fitting process based on e.g. multiple measurements results. However, this requires a significant effort and can generate significant costs. The approach presented in this paper relies solely on simulations. The methodology used herein consists in finding the match to the maximum produced TRV generated during high-voltage shunt reactor current breaking, for ideal switch and conductance based Cassie-Mayr circuit breaker models. This is done for a given chopping current value assigned to the ideal switch which is used as a target. The arc model coefficients are obtained by means of the optimisation process for various values of the desired chopping current level to be reflected by the Cassie-Mayr conductance-based electric arc model. As a result, an advanced conductance based model can be used for assessment of switching overvoltage. Genetic and simplex annealing algorithms have been selected for optimisation. The models as well as the optimisation process were conducted in EMTP-ATP software using its built-in functionalities. The article presents the error assessment and sample traces.

Comparative research into transients by switching of high voltage shunt reactor

This article deals with results of performed studies of transient phenomena in application of controlled switching technique by switching high voltage 123kV, 100MVAr shunt reactor. First, for switching a single-pole hydraulically operated SF6 circuit breaker has been selected and after that, one with electric motor-drive. In preparing of experimental part of studies the EMTP-ATP software has been used in computer simulations, further for analyses the cases of optimal controlled switching and switching within time deviation limits. For simulation of uncontrolled switching with current chopping and arc-reignition dynamic model of arc behavior has been implemented. The field tests with both circuit breakers have been repeated in similar network conditions for further statistical analyses. During some tests, the transient phenomena of uncontrolled switching have been observed. The achieved experimental results were compared with the computer simulations.

An investigation of transient overvoltage generation when switching high voltage shunt reactors by SF/sub 6/ circuit breaker

The work reported in this paper can be grouped into three categories: empirical investigations; analytical studies; and computer simulations. The studies have identified the causes of high transient overvoltages which are produced when switching high voltage shunt reactors. Laboratory and site testing have shown that multiple reignition is the most likely cause of the high overvoltages. Circuit analysis has been carried out to identify the conditions which lead to multiple reignitions. A computer model has been developed to allow the likelihood of multiple reignitions occurring to be assessed.

Poynting vector probe for measuring power at extremely low power factor

The paper describes a new probe for the measurement of power flow from a source of supply to a load which is characterised by having an extremely low power factor. Power is measured by sensing the electric and magnetic fields in a defined region between the source and the load. A co-axial configuration is chosen to simplify the integration of the Poynting vector that represents the rate of flow of electromagnetic energy. This leads to a simple design that enables the measurement of voltage and current by sensing the corresponding electric and magnetic fields in an integrated structure incorporating both sensors. The new probe is particularly suitable for the measurement of load losses in large, high-voltage power transformers and shunt reactors in which the power factor is extremely low. A small experimental unit is described, together with the associated electronic circuit.

Reactors and Power Transformers

A method is presented which will enable the test engineer to rapidly determine the optimum parameters of a test circuit for the generation of switching surges on high voltage shunt reactors and power transformers. For any given impulse generator and load inductance the selected parameters will result in the maximum efficiency of the test circuit, minimum duration of test voltage and at the same time will satisfy the waveshape requirements of ANSI standards.

Switching Surge Test Circuits for High Voltage Shunt Reactors and Power Transformers

Switching Surge Test Circuits for High Voltage Shunt Reactors and Power Transformers

Measurement of Shunt Reactor Loss at High Voltage with an Alternating Current Comparator Bridge

The application of a high voltage capacitance bridge based on the current comparator to the measurement of the loss angle of high voltage shunt reactors is described. Measurements on three core-less 55 MVA, 735 kV single phase shunt reactors are discussed and a comparison is made with the results of a calorimetric determination of loss which indicates agreement to better than 2 percent. Other bridge techniques for this type of measurement are reviewed.

The Design and Testing of EHV Shunt Reactors

The design and testing of high-voltage shunt reactors is discussed. The advantages of a gapped-core construction employing radial laminated limb sections with a relatively small number of air gaps, resulting in a simple mechanical construction, are described. A comparison is made between testing methods for transformers and reactors, special attention being paid to test power, loss measurement, measuring accuracy, and special tests. A bridge method for loss measurements is described. Among the various dielectric tests discussed, particular mention is made of the induced voltage test and its unrealistic representation of actual service conditions. It is suggested that this test be replaced by one utilizing a lightly damped oscillation produced by an impulse generator. The need for vibration measurements as a check on mechanical behavior is stressed.