Study on Capacitive Leakage Error of Current Transformer in Distribution Network: Theory and Testing

2019 ◽  
Author(s):  
Kui Xiong ◽  
Changxi Yue ◽  
Jicheng Yu ◽  
He Li ◽  
Kai Zhu
Keyword(s):  
Network Theory ◽  
Distribution Network ◽  
Current Transformer ◽  
Leakage Error

Improved Newton's Method for Calculation of Power Distribution Network Theory Energy Loss

2013 ◽  
Vol 756-759 ◽  
pp. 2936-2939
Author(s):  
Xiao Ming Wang ◽  
Li Zhang
Keyword(s):  
Energy Loss ◽  
Network Theory ◽  
Power Distribution ◽  
Distribution Network ◽  
Current Transformer ◽  
Load Curve ◽  
Power Distribution Network ◽  
Loss Calculation ◽  
Transformer Substation ◽  
Network Power

At present commonly used distribution network loss calculation theory method, the not fully consider load curve changes. Thus, the theory energy loss too small, and the management energy loss too large. On this issue, the article puts forward an improved Newtons method for distribution network theory energy loss calculation. According to the current transformer substation of 24h a distribution network power records, the trend of the model results show that the total distribution network energy loss. The experimental results show that, compared with traditional methods, improved Newtons method to calculate the result more close to the energy loss calculation theory statistical energy loss.

scholarly journals Three-Dimensional Electro-Thermal Analysis of a New Type Current Transformer Design for Power Distribution Networks

Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1792
Author(s):  
Bingbing Dong ◽  
Yu Gu ◽  
Changsheng Gao ◽  
Zhu Zhang ◽  
Tao Wen ◽  
...  
Keyword(s):  
Boundary Condition ◽  
Temperature Field ◽  
Temperature Gradient ◽  
Field Distribution ◽  
Distribution Network ◽  
Current Transformer ◽  
Internal Temperature ◽  
Temperature Field Distribution ◽  
Type Design ◽  
New Type

In recent years, the new type design of current transformer with bushing structure has been widely used in the distribution network system due to its advantages of miniaturization, high mechanical strength, maintenance-free, safety and environmental protection. The internal temperature field distribution is an important characteristic parameter to characterize the thermal insulation and aging performance of the transformer, and the internal temperature field distribution is mainly derived from the joule heat generated by the primary side guide rod after flowing through the current. Since the electric environment is a transient field and the thermal environment changes slowly with time as a steady field under the actual conditions, it is more complex and necessary to study the electrothermal coupling field of current transformer (CT). In this paper, a 3D simulation model of a new type design of current transformer for distribution network based on electric-thermal coupling is established by using finite element method (FEM) software. Considering that the actual thermal conduction process of CT is mainly by conduction, convection and radiation, three different kinds of boundary conditions such as solid heat transfer boundary condition, heat convection boundary condition and surface radiation boundary condition are applied to the CT. Through the model created above, the temperature rise process and the distribution characteristics of temperature gradient of the inner conductor under different current, different ambient temperatures and different core diameters conditions are studied. Meanwhile, the hottest temperature and the maximum temperature gradient difference are calculated. According to this, the position of weak insulation of the transformer is determined. The research results can provide a reference for the factory production of new type design of current transformer.

Error Calculating and Compensating Method of All-Optical Fiber Current Transformer in ± 10 kV DC Distribution Network

2019 ◽  
Vol 14 (11) ◽  
pp. 1606-1615
Author(s):  
Jicheng Yu ◽  
Changxi Yue ◽  
Jun Li ◽  
Dengyun Li ◽  
He Li
Keyword(s):  
Optical Fiber ◽  
Distribution Network ◽  
Current Transformer ◽  
Electromagnetic Current ◽  
Current Transformers ◽  
Wave Plate ◽  
Remote Transmission ◽  
Dc Distribution ◽  
All Optical ◽  
Database Technology

Current transformer is one of the main equipment in ±10 kV DC distribution network. Traditional electromagnetic current transformer has poor anti-jamming capacity and poor insulation, so it cannot realize transient protection. The emergence of all-optical fiber current transformer brings solutions to these problems, which has attracted more and more attention. In this study, aiming at the problem of error and compensation of λ/4 waveform of all-fiber current transformer, the fabrication method of λ/4 waveform is studied, the mathematical model of the waveform is established, the influence of the waveform error on the scale factor is analyzed, and a calculating device of angle difference and ratio difference to compare the error is designed. The device adopts the principle of traceability of quantities to collect the state data of the wave plate. At the same time, in order to collect data for errors, database technology and network technology are used to realize remote transmission of monitoring data. The error of the λ/4 wave plate is compensated, the bidirectional principle generated by the birefringence in the fiber ring is analyzed, and the data logic description of the transformer sensitive ring is performed. The phase delay and the angle of the shaft are selected as the main factors causing the error. Compensation is performed by means of peak segmentation and variable cancellation. In the experimental process, compared with the error sampling of the traditional transformer, the error calculated by the current amplitude and phase angle parameters obtained by the all-fiber current transformer is more accurate, and the compensation scheme can suppress the size of the birefringence and improve sensing accuracy of fiber optic current transformers. This study provides a powerful reference for the error analysis of all-fiber current transformer λ/4 wave plates, which is beneficial to promote the better application of such current transformers.

Vulnerability Assessment and Analysis of Active Distribution Network Structure

2014 ◽  
Vol 568-570 ◽  
pp. 1843-1849
Author(s):  
Da Chuan Liu ◽  
Jian Hua Zhang ◽  
Dan Wang ◽  
Hai Nan Li ◽  
Bo Zeng
Keyword(s):  
Power System ◽  
Complex Network ◽  
Network Structure ◽  
Network Theory ◽  
Large Scale ◽  
Fossil Fuels ◽  
Distribution Network ◽  
Complex Network Theory ◽  
Active Distribution Network ◽  
The Impact

Owing to more and more people concern about environment issues and reduction of fossil fuels, a growing number of distributed generations (DGs) are being interconnected to the power system. The active distribution network (ADN) provides an effective way to achieve the large scale connection and efficient utilization of them. This paper analyzes the vulnerability performance of active distribution network quantitatively and discusses the impact of DGs on the distribution network transmission efficiency under different grid structure through the application of complex network theory in power system. The example results show that meshed network structure can effectively promoting the consumption of DG and verify the feasibility of applying complex network theory to the distribution network for vulnerability analysis.

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