Unlock instant, AI-driven research and patent intelligence for your innovation.

Method of earth capacitance discharge for small current earthing system

A technology of small current grounding and ground capacitance, which is applied in the protection of response to fault current, etc., can solve problems such as damage to the system accident, the inability to discharge the electric charge, and the safe operation of the system, and achieve the effect of preventing ferromagnetic resonance.

Inactive Publication Date: 2006-07-26
ANHUI HUAKAI ELECTRIC NET TECH
View PDF0 Cites 1 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] In the above fault phase arc suppression method, at the moment when the fault phase is grounded in order to judge whether it is an instantaneous fault or to remove the fault, the electric charge will be stored on the capacitance of the system to ground. After the faulty phase and healthy phase-to-ground voltage recover, overvoltage occurs. The overvoltage of the faulty phase-to-ground can be up to 2 times, and the over-voltage of the healthy phase-to-ground can reach more than 3.5 times. The damage to the system insulation may cause accidents; the other On the one hand, since the neutral point is not grounded, the stored charge cannot be discharged, but only through the voltage transformer, which may cause the saturation of the voltage transformer and ferromagnetic resonance, which endangers the safe operation of the system

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Method of earth capacitance discharge for small current earthing system
  • Method of earth capacitance discharge for small current earthing system
  • Method of earth capacitance discharge for small current earthing system

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0016] see figure 1 , this embodiment is aimed at the fault phase arc suppression method using metallic grounding in the fault phase. In the specific implementation, the charge discharge impedance Z is input at the same time when the fault phase is released from the metallic ground arc suppression.

[0017] The working process is as follows:

[0018] After the C-phase single-phase grounding occurs, Jc is closed, and the transfer switch Jo is closed on its contact 1, and the grounding arc suppression is implemented. Considering the instantaneous fault, after the insulation recovery of the fault point (recovery time is about 1-10 seconds), the conversion The switch Jo turns and closes on its contact 2, and releases the discharge impedance Z at the same time as the arc suppression is released. At this time, the charge stored in the relative ground capacitance of the sound phase A and B is discharged through the relative ground capacitor, transformer, and input Impedance Z and th...

Embodiment 2

[0021] see figure 2 , this embodiment is aimed at the arc suppression method of putting arc suppression impedance grounding in the fault phase. In the specific implementation, when the fault phase arc suppression impedance grounding is released, the discharge impedance Z is simultaneously input.

[0022] In this embodiment, the setting of the arc suppression impedance of the fault phase is to make the fault phase-to-ground voltage generated by the capacitive current flowing through the arc suppression impedance smaller than the insulation value of the fault point to realize arc suppression; and the setting of the discharge impedance Z is to discharge The charge stored in the capacitance of the system to the ground enables the system to return to the normal voltage state to the ground after the fault is eliminated and the arc is eliminated; If the voltage is lower than the insulation value of the fault point, the value of the arc-extinguishing impedance is selected; if the val...

Embodiment 3

[0026] see image 3 , this embodiment is also aimed at the arc suppression method of switching on the arc suppression impedance grounding in the fault phase. In specific implementation, when the fault phase arc suppression impedance grounding is released, the discharge impedance Z is simultaneously switched on.

[0027] After the C-phase single-phase grounding occurs, Jc is closed and put into the arc suppression impedance Zx to implement arc suppression. Considering the instantaneous fault, after the insulation recovery of the fault point (recovery time is about 1-10 seconds), the switch Jc is opened, and the switch Jo is closed at the same time. This action is to put in the discharge impedance Z while releasing the arc suppression, and improve the charge stored in the relative ground capacitance of phase A, and discharge it through the circuit composed of the relative ground capacitor, transformer, input discharge impedance Z and the earth; perfect The charge stored in the p...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

This invention relates to small current earth system discharging method to capacitor discharge, which is characterized by the following: in the fault arc delaminating system, for judging instant fault or eliminating fault to delaminate arc, forming fault phase relative to the earth capacitor charge through phase and earth or middle linear or non-linear resistance to form the said relative memory charge releasing channel. This invention method can effectively prevent fault phase to generate voltage to introduce iron resonance to be helpful for fault point ignition.

Description

Technical field: [0001] The invention relates to a protection method for a small current grounding system. Background technique: [0002] In the small current grounding system, or called the neutral point ungrounded system, there are two types of arc suppression methods, one is the neutral point arc suppression method, such as the arc suppression method in which the neutral point is grounded through the arc suppression coil; the other is It is the fault phase arc suppression method. The fault phase arc suppression method refers to that when a single-phase grounding occurs in a small current grounding system, the fault phase is directly grounded through contactors, thyristors and other switching elements, or the impedance is placed between the fault phase and the ground. In between, implement arc suppression. [0003] There are two types of single-phase grounding in small current grounding systems, permanent grounding and non-permanent grounding. Non-permanent grounding is ...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
IPC IPC(8): H02H3/16
Inventor 张云一
Owner ANHUI HUAKAI ELECTRIC NET TECH