The single phase grounding fault location is the focus which researchers pay attention to and study in the small current grounding power systems. With the improvement of automatic level in distribution systems, the study about it is urgent daily.In this paper, the important point is the study about the application of wavelet analysis in single phase grounding fault location of small current gr...

Low sensitivity and low reliability in the relays of single-phase-to-earth fault line selection are always the problems in ungrounded neutral system. Through reviewing of the existing theories on fault line selection systematically, this paper points out the defects and drawbacks of those. It introduces the idea that a low resistor can be turned on and off for a while when the single-phase gro...

That the neutral point is not grounded or grounded with arc suppression coil is defined as neutral point indirectly grounded. In the small current grounding power systems, when the single phase-to-ground fault occurs, because the amplitude of steady state current is small and intermittent arc ground, fault line selecting is very difficult. Several methods have been developed to solve the probl...

The shortages of method are analyzed on detecting earth fault of DC system by the principle of electrical bridge balance and frequency conversion in the thesis. It advances a method of synthesis criterion, which detects earth fault with Huoer sensor of the principle of magnetic potential balance and through detecting the positive and negative pole bus voltage, insulation resistance and leakage...

Aim at 110kV Kang-Ping transmission line and 220kV Da-An transmission line, systematic researching include lightning proof performance, lightning proof calculating methods and measures how to enhance proof lightning performance. On the basis of research for power transmission line\\\’s lightning-proof property, this paper calculate the lightning-withstand level when lightning strike to t...

Wastewater Treatment by high-voltage discharge is the novelty method of wastewater treatment technology which has been widely developed in home and abroad. Pulse power supply is important part of the technology, and it\\\’s also a bottleneck of development of the technology. Unipolar pulse discharge will lead to charge accumulate to reactor. With the charge not releasing, the tail voltag...

As a new type grounding device, hollow grounding device has played an important role in high resistivity soil and less-area grounding engineering. But it is still blank in the theoretic aspect of grounding resistance calculation, design method for substation which is important to the design and application for that device. Based on the ground current field theory, this paper built an operati...

Because of a series of advantage, there are a lot national power distribution network with neutral-point grounding. But the fault current in single-phase grounding is so small that it is very hard to detect, single-phase grounding protect problem have no very effectual solution as yet. In fact with conventional relay protection we can not found out the fault line at all, the special fault line...

With the development of power industry and the rise of voltage grade, more and more gas insulated substations (GIS) are used in modern power systems. The operation experiences of GIS show that there were repeated arc regnitions between moving and static contacts and it brought the very fast transient overvoltage (VFTO) as the high frequency surge when disconnector switchings operated the no-l...

The substation grounding system is an important method to ensure power system running safely, protect the safe of staff and instructions, the design of grounding system is one of the most important electric design. With the development of electric power system capacity, the value of failure current flowing into ground increased greatly. Particularly, after start operating converter station, t...