New Small Current Grounding Line Selection Device Signal Processing Algorithms

In our country, many distribution networks adopt ineffective grounding of power system network. These distribution systems can continue to operate for about one to two hours when single phase-to-ground fault. But as the enlargement of the power system, if the single phase-to-ground fault persists for a long time, other faults would occur and the safe operation of the power system would be break, so the faulted line should be found and cut away from the power system at once.At present, many selection methods have been advanced in allusion to the character of the ineffective grounding of power system network. Every method has its field, and this can't fulfill the safe demand of the power system. So in my paper, I advanced a new line selection method. This new line selection method is entitled controlled short-selection method. This line method can conquer the shortcomings of present selections and the weak signals of the single phase-to-ground faulty. So this line selection method is a perfect method.This line selection method makes the secondary wending of supply side transformer grounded though transformer and a GBT. The GBT would be controlled to engender a current signal, and this current signal would be checked to find the faulted line. This method has three advantages:1, The value of the current can be controlled, this makes the current can be checkedwhen the ground resistance is different. 2,The time of the current can be controlled, this makes the appearance of the currentcan be forecasted and checked easier. 3, The character of the current can be controlled, this makes the current be differentfrom other signals.This new line selection method has a character, this character is that the value, time and character of the current signal can be controlled and adjusted until the current signal has been checked. This new line selection method can dissolve the puzzle which has puzzled our power system many years and can boost the power quantity and the security of the supply of power. In my paper, to this new line selection method we would take some analysis:1, Analysis the working principle of the new line selection method.2,Build the formulation model of three phase with Simulink in MATLAB to checkthe going of the new line selection method in different ground resistance R_f andfire angle δ. 3, Study the signal disposing arithmetic of the new line selection method and searcha method which can distinguish the faulted line and the defaulted line. 4,Use dummy instrument to accomplish the signal checking of the newline selection method. In this section, Daq-pad accomplishes its hardwareand LabVIEW accomplishes its software.The machine has been made according to the new line selection method and this machine is studying means that we use this machine in laboratory and analysis the data in computer first and then use this machine in field and analysis the data on line.