Dissertation > Excellent graduate degree dissertation topics show

Research on Integration Control System in Arc-Suppressing and Fault-Line Selection of Single-Phase-to-Ground Fault in Resonant Grounded Systems

Author: LianHongBo
Tutor: YangYiHan
School: North China Electric Power University (Hebei)
Course: Proceedings of the
Keywords: resonant grounded system principal-auxiliary arc-suppression coil single-phase-to-ground fault line selection integration validity of methods reclosing on phase-to-ground fault
CLC: TM862
Type: PhD thesis
Year: 2006
Downloads: 495
Quote: 10
Read: Download Dissertation


In China, most 6~66kV power systems are non-effectively grounded systems;and withthe increasing of system capacitive current to ground, more and more power systems becomeresonant grounded systems. It enhances the security and reliability of the power networks,with the system capacitive current compensated by arc-suppression coil. For a long time,researchers pay great attention to the optimization of the compensating ability of thearc-suppression coil. Because of the compensation of the arc-suppression coil, thezero-sequence current signal become weaker and is prone to be disturbed. Then thesingle-phase-to-ground fault line selection problem is never well settled in the resonantsystem. This paper studies the optimization of the compensating ability of the arc-suppressioncoil and the validity of single-phase-to-ground line selection methods.Analyzing the merits and demerits of the arc-suppression coils in existence, this paperproposes and designs a principal-auxiliary arc-suppression coil, which will be in more favorof the extinguishing of all kinds of grounded arcs. This principal-auxiliary arc-suppressioncoil is made up of principal coil and auxiliary coil. The principal coil adopts some automatictap-adjusting arc-suppression coil, and realizes the presetting function. The auxiliaryarc-suppression coil is designed on the TCR technique, composing of N fine-tuning coils,switched by N thyristors, the inductance of witch adopts binary-weave system, which form 2Ncompensation values, and realizes the following-setting function. It makes quick and effectivecompensation through the cooperation of the principal coil and auxiliary coil.Because of the compensation of the arc-suppression coil, the zero-sequence currentsignal become weaker and is prone to be disturbed. The unbalance current existing when thepower system is healthy is one disturbance source, which affects the characteristic of theamplitude and phase-angle. It is proved in the field operating that it is some important factorthat affecting the success-ratio of the single-phase-to-ground-fault line selection in resonantgrounded systems. In this paper, it is proposed that the unbalance current can be brought bythe unbalance of system capacitance to ground of the three phases, but also can be brought bythe parameter unbalance of the three CTs. By the phasor analysis, this paper gives anqualitative relational expression between the lien selection method reliability and unbalanceof system capacitance to ground, fault zero-sequence voltage, damping ratio of the powersystem. This paper considers it a valid method to adopt the method of abrupt change ofzero-sequence current, which could well settle that problem. When the unbalance current isinduced by the parameter unbalance of the three CTs, this paper also proposed some way todiminish its unfavorable affection, in which, the line-to-line voltage is induced as somereference to accordingly subtract the unbalance current signal from the fault zero-sequencecurrent.It is the developing direction in the resonant grounded system to make an integrated andcoordinated control system between the arc-suppression of the arc-suppression coil and thesingle-phase-to-ground fault line selection. This paper puts forward and expatiates theapplication principle of the method of abrupt change of zero-sequence current. But, whensome intermittent grounding arc occurs, it could make mistake with that method used withoutany consideration. This paper induced the wavelet analysis into this method, in which thecontrol system could self-adapt to different line selection method with the different faultstyles.To improve the success ratio of line selection in resonant grounded systems, it issome importance measure to confirm the applicability of all kinds of methods, whichcalls validity of methods. The paper determines the validity of methods through datamining on large numbers of local data based on rough set theory. Using decision tablesas a main tool, this approach can extract the decision rules between the line selection andfault signal features, by discretizing the feature of the fault samples, and then makingreduction of the redundant information.Through the analysis of the field faults, It is found that there are many short-timegrounding fault. This paper proposes the auto-reclosing technique for thesingle-phase-to-ground fault in non-valid grounded systems (for short, named as reclosing onphase-to-ground fault). Also, this paper proposed the integration of the measure, control,record and protection on the single-phase-to-ground fault.This paper introduced the field operation instance of the principal-auxiliaryarc-suppression coil. A 10kV high voltage physical simulation system is also introduced inthis paper.

Related Dissertations

  1. The Ah Chengarchitectural Regeneration Design Research Concerned about the Jin Dynasty Culture,TU984.114
  2. Research of the Space Compounding of the Exhibition and Convention Building,TU242
  3. Power System Dynamic Voltage Stability Simulation Study Based on Precise Integration Method,TM712
  4. Research and Implement of SDO Model in University Enroll System Based on SOA,G647
  5. The Technologies for Interoperability of Heterogeneous Enterprise Applications and Their Application in Material SCM,TP311.52
  6. Research on Integration Technologies of LXI Automatic Test System,TP274
  7. On Explanatory Power of Conceptual Integration Theory for the Ttanslation of Chinese Ancient Classic Through the Analysis of the English Versions of Tao Te Ching,H315.9
  8. The True Estimations of China’s Unemployment and the Re-examination of Okun’s Law,F224
  9. The Split Crisis of Psychology and A Way of Its Integration,B84-0
  10. Lijiang City, urban and rural basic public service equalization,D67
  11. The Study of A Company Information Management Optimization,TP315
  12. Highly skilled personnel training mode of resource integration,G718.5
  13. Contemporary China Exploration targeting rural compulsory education,G522.3
  14. Research and Implementation of Distributed Data Integration Visual Modeling,TP311.52
  15. Analysis on the Practice of Development of Urban and Rural Integration,F127
  16. Path of local government cooperation in regional integration dimension,F127
  17. Analysis of China’s Household Electrical Appliance Industry Supply Chain Integration,F426.6
  18. Study on the Resource Integration and Restructuring of Coal Enterprises in Shanxi,F426.21
  19. CAD/CAPP/CAM Integrated System Development for Key Components in Marine Diesel,U664.121
  20. The Conceptual Perspective comic humor language,H13
  21. Japanese administrative culture change and integration and its Implications for China,D630

CLC: > Industrial Technology > Electrotechnical > High Voltage Engineering > Overvoltage and Its Protection > Over-voltage protection devices
© 2012 www.DissertationTopic.Net  Mobile