A5024301760- High voltage insulation and dielectric phenomena
- Power Transformer Diagnostics and Insulation
- Power Systems Fault Detection
- Non-Destructive Testing Techniques
- Lightning and Electromagnetic Phenomena
- Advanced Sensor and Control Systems
- Power System Reliability and Maintenance
- Electrical Fault Detection and Protection
- Image and Signal Denoising Methods
- Infrastructure Maintenance and Monitoring
- Elevator Systems and Control
- Ultrasonics and Acoustic Wave Propagation
- Currency Recognition and Detection
- Advanced Fiber Optic Sensors
- Smart Grid and Power Systems
- Geoscience and Mining Technology
- Maritime Navigation and Safety
Chinese People's Liberation Army
2025
Shandong University
2020-2023
A combined model based on improved information entropy and vague support vector machine (IVSVM) is introduced into transformer fault diagnosis using dissolved gas analysis in oil (DGA). The method used to obtain the weights of each weight raw data, processed training data corresponding types are inputted (VSVM) classifiers. Firstly, weighted by discretise original from mixed state for subsequent classifier training. Then, set divides events true, false unknown factors, which can optimise...
This study presents a combined model based on the exploratory factor analysis (EFA) and least square support vector machine (LSSVM) to predict contamination degree of insulator surface. Firstly, EFA method is utilised reduce numerous influence variables into few variables, which could decrease complexity model. Then, regarding above as new input LSSVM established degree. In order obtain optimal predictive value, non-dominated sorting genetic algorithm II applied optimization parameters. The...
For the development of converter transformer applications, research on discharge characteristics in oil is required. This article presents an analysis streamer caused by a needle-plate electrode oil-pressboard insulation under ac voltage and images time scale microseconds. Based image, Gaussian filter, image segmentation Otsu algorithm, Canny edge detection are used to detect image. By extracting profile effectively identified. The size quantity particles during analyzed. Research...
Abstract Basin‐type insulator often has small cracks due to stress concentration. The current method cannot accurately reflect the condition of find concentration areas. To solve these problems, a for detecting two‐dimensional plane ( δ 1 and 2 ) within different depth ranges in basin‐type is proposed based on critically refracted longitudinal (LCR) wave. First, acoustoelastic equation characterising relationship between variation LCR wave propagation time was derived. Next, characteristics...
Converter transformer is one of the most important equipment in DC transmission system. Its structural design more complex than general power transformer, and problems electrical insulation local overheating are prominent. The temperature rise will change material properties affect performance insulation. In this paper, a complete multi-physical field coupling simulation model established, electric distribution characteristics system affected by gradient analyzed. results show that converter...
For extremely large ultra-high-voltage (UHV) power transmission and distribution lines with typical project using hybrid reactive compensation (HRPC), single-phase earth fault (1LG), three-phase ground (3LG), phase-to-phase (2LS), two-phase grounding (2LG) often occurs. Circuit breaker is one of the most critical equipment UHV system. And interruption performance crucial to circuit breakers' breaking capability. In this study, formal expressions indicators for are deduced in case different...
Three-phase transformers are key components in power systems and plants. Security, stability increasing the life of important to system operation. When a three-phase transformer is energized, inrush current-due flux saturation core-results malfunction differential relay also causes stress impact transformer. These have an adverse effect on security system. In this paper, nonsynchronous suppressing method proposed suppress current transformers. The overvoltages caused by can be avoided....
The pulse current signal generated by partial discharge in the transformer winding will be affected structure during process from source through to external measurement device, which is manifested as attenuation, distortion or delay, propagation path and distance, it has a great relationship with characteristics of windings. simulation analysis method was used this paper establish multi-conductor transmission line model 180-turn single simplified distribution parameters, head interior were...
The effective measurement frequency band of the traditional pulse current method is up to 1MHz, which causes loss main energy information partial discharge signal. In view this, an ultra-wideband system with 30kHz-50MHz designed. used measure signals three types oil-paper insulation defect models built under laboratory conditions, in order obtain statistical characteristics that can characterize different parameters insulation. results show that: restore original waveform a greater extent,...
Insulation fault is the main form of power transformer fault, and partial discharge an important manifestation insulation fault. During detection transformers, different points are usually selected. When same signal transmitted through windings to points, it will be affected by winding structure propagation characteristics. Therefore, measurement results at also different. In this paper, a simulation model established study characteristics signals in transformer. Firstly, single discuss...
For extremely large ultra-high-voltage (UHV) power transmission and distribution lines using hybrid reactive compensation (HRPC), single-phase earth fault (1LG), three-phase ground (3LG), phase-to-phase (2LS), two-phase grounding (2LG) often occurs. This study uses numerical emulations to examine the indicators of interruption performance for circuit breaker in case different faults. Based on equivalent-valued parameter structure a UHV demonstration project, formal expressions are deduced,...