配电网消弧线圈自动跟踪补偿装置的初步设计与仿真研究

我国3～66kV配电网一般为中性点不接地系统,近几年随着城市电网改造,越来越多的电缆线路代替架空线路,线路对地电容增大。当电网的单相接地电流大于一定值时,接地电弧不容易自行熄灭,使故障扩大,此时采用中性点经消弧线圈接地方式。消弧线圈可以补偿电网的单相接地电容电流以及减缓弧隙恢复电压上升速度,保证电弧可靠熄灭。本文针对10kV配电网设计消弧线圈自动跟踪补偿装置,采用晶闸管投切电容式(TSC)的调谐原理,并在传统设计的基础上改进设计。最后,利用PSCAD/EMTDC软件对中性点经消弧线圈接地系统的各种状态(包括正常运行和单相接地故障)进行仿真,对本文的设计进行了验证,证明了其可行性与可靠性。

The primary design and simulation research on automation tracking and compensating arc suppression coil of distribution network

The neutral points of 3~66kV distribution network are usually non-grounding in our country.In recent year,with the reconstruction of city power system more and more cables instead the trolley wires.In addition,the grounded capacitor increases.When capacitive current at single-phase earth fault exceeds limited values,the arc to ground unable to eliminate naturally,enlarge the fault.To solve these problems,the compensating method of neutral point grounding through arc suppression coil is used.When occurring single-phase earth fault,the capacitive current is compensated by the inductance current,provided by arc suppression coil,which can restrain the residual current under permitted limits.Thus the arc is extinguished and the arc over-voltage is restrained.This paper designs the arc suppression coil device for 10kV distribution network.This paper use the thyristor switches the capacitor,and ameliorate the tradition structure.Then simulating all kinds of the conditions of the electric power system with neutral grounding through the arc suppression coil was done by PSCAD/EMTDC to validate the design of this paper.All of the results of these simulations demonstrate the feasibility and reliability of this set.