基本介紹
- 中文名：SL-01行波電流選線裝置
- 別名：SL-01小電流接地選線裝置
- 出線方式：電纜或者架空線路
- 出線數：最多24回
產品別稱,產品簡介,性能參數,產品特點,技術優勢,
產品別稱
SL-01行波電流選線裝置又稱SL-01小電流接地選線裝置
產品簡介
在電力系統中，把中性點不接地或經消弧線圈、電阻接地的系統叫小電流接地系統,在小電流接地系統中最常見的故障是單相接地。由於故障電流微弱、干擾信號很大、鐵磁諧振影響等原因，現有選線技術選線準確率不足50%。
SL-01行波電流選線裝置是由清華大學電機系研製，衡天北斗科技組織生產製造。裝置通過中國電力工業電力設備及儀表質量檢驗測試中心檢測。它成功解決了中性點非有效接地系統單相接地選線的難題，實現了接地選線理論和技術的重大突破，獲國家發明專利，被專家鑑定為“是一項處於國際領先水平的技術”。
性能參數
中性點接地方式：適用於中性點不接地、消弧線圈接地和經高電阻接地系統。
出線數：最多24回（可擴展）
母線段數：最多3段（可擴展）
參數整定方式：線上修改：選線裝置運行時可直接修改運行參數。
離線修改：由離線計算機修改後，由串列通訊口傳送給選線裝置。
通訊接口：CAN、RS232/485、乙太網等通訊接口 支持IEC61850
通訊規約：103、CDT或根據用戶需求自定義
通訊波特率：19200 B/S
輸出觸電：最多8路
額定工作頻率：50HZ
額定工作電壓：AC/DC 220V, 允許偏差-15% ～+15%
環境溫度： -25℃～55℃
濕度：5% ～95%
大氣壓力： 66kPa ～110kPa
外形尺寸：441mm * 322mm* 177mm 標準4U機箱
重量：8.5kg
可存儲32次最近發生的故障信息，失電後不丟失。配置通訊接口後可把故障信息傳至綜自系統
產品特點
1 新原理
該裝置基於暫態行波原理，單相接地故障行波與中性點接地方式無關，故障特徵明顯，解決了以往產品原理上故障特徵不明顯的不足，選線準確率達100%
2 新算法
裝置採用小波變換技術，解決了暫態行波特徵提取問題，而以往產品採用傅立葉變換手段，無法正確分析暫態行波特徵。
3 新技術
裝置採用超高速採樣技術，解決了暫態行波的獲取問題，而以往產品無法正確獲取暫態行波。
4新成果
裝置不僅能準確可靠選出永久接地故障線路，還能準確記錄瞬時接地故障或者電弧故障線路。
5安裝維護方便
裝置採用標準工業機箱結構，不同功能的外掛程式並行獨立工作，互不影響，相互之間採用CAN通訊模式進行數據傳輸。由於採用分立式模組，安裝及維修非常方便，並使維護成本降至最低。
6 抗干擾能力強
7自動報警功能
當接地發生時，裝置蜂鳴器開啟，面板報警燈亮，液晶屏上顯示故障線路名稱，同時裝置自動把接地數據及報警信號遠傳到綜自主站系統。
8與變電站綜自系統進行無縫集成
現場運行情況
該裝置既適用於架空線路，也適用於電纜線路、架空電纜混合線路；既適用於中性點不接地系統，也適用於經高阻接地和經消弧線圈接地系統。廣泛適用於電力、石油、化工、冶金、煤炭、紡織、鐵路、軍工等電力部門及大中型工礦企業的66kV及以下電壓等級配電系統。
技術優勢
1、
裝置採用暫態電流行波原理。
2、
裝置利用現代數學工具小波變換技術進行信號處理。
3、
採用上述原理和算法保證了選線的正確性能夠達到100%。
4、
不需要外加信號進行接地選線，避免了在正常電力系統中加入其他頻率的信號，也避免了外加信號源對保護及自動裝置的影響。不需要另外加裝信號接收裝置，避免信號接收裝置故障造成不必要的一次設備停電。
5、
能夠適用於有零序CT和沒有零序CT的各種出線。
6、
能適用於中性點不接地、經消弧線圈接地和經高阻接地的系統。
7、
可以通過升級實現一定的測距功能。
8、
數據採集速率為1M，採用並行處理的CPU系統，能夠抓取單相瞬時接地信號。系統中的故障一般由絕緣老化引起，通常是間歇性瞬時接地故障，逐步發展成永久性接地故障。通過對瞬時性故障信號的抓取，裝置可以預報迴路絕緣的老化。以便提前停電做相應的處理，減少由於絕緣老化造成故障的損失。
9、
能夠支持103規約和CDT規約，同時可以支持IEC-61850規約進行通信。
10、
能夠用於數位化變電站的接地選線。
-北京衡天北斗科技有限公司
英文說明：
Introduction to Traveling Wave based FaultFeeder Selector
1.Overview
Neutral grounding of power distribution system is divided intotwo ways: effective grounding and non-effective grounding ways. Effective groundingincludes neutral point grounded directly, grounded through low resistance orlow reactance, While non-effective grounding includes neutral point ungrounded,grounded through Peterson coil or grounded through high resistances. Atpresent, the neutral point in power distribution systems mostly ungrounded. Andthe power distribution system is called NUGS. In NUGS, when single-phase-to-groundfault occurs, phase-to-phase voltage is invariant, and the current has tinychanges. And protection relay will not trip the fault. On the other hand, single-phase-to-groundfault should be detected and cleared. SL-01 Travelling wave based fault feederselector samples the current travelling wave signal, which is independentof neutral point grounding ways, and can achieve fault feeder selection correctlyand reliably. SL-01 Travelling wave based fault feeder selector canbe applied to 6-35kv power distribution system.
2.Basic principles
When a fault occurs in power system, fault generatedtraveling waves will propagate from the fault point to the system troughfeeders. Based on the superposition principle, post-fault power network can be equalto superposition of the fault generated network and normal load power network. Whenthe fault generated travelling wave propagates along the feeder, it will bereflected at the point where wave impedance changes. The bus bar in the substationis a typical wave impedance discontinuity point. Assume N feeders are connectedto the bus bar, the fault occurs in feeder N, as shown in figure 1.
Figure 1: Fault generated traveling waves atthe bus bar
When the initial fault generated travellingwave arrives the bus bar, the initial current traveling wave measured in each feederis:
In which, is current traveling wave from the fault point; is the initialcurrent traveling wave measured at the fault feeder； is the initialcurrent traveling wave measured at the sound feeder. Assume that N feeders havethe same wave impedance, and the initial current traveling wave at the faultfeeder is the source to the one at the sound feeder, therefore:
We can see: because N is much higher than 2, the initialcurrent traveling wave at the fault feeder is far greater than the one at thesound feeder; The polarity of initial current traveling waveat the fault feeder is reversed to the one at the sound feeder; if the initialcurrent traveling waves at all feeders are equal, then the fault is in the busbar, which is the basic principle of current traveling waves based fault feederselection.
3.Working process
Under normal operation, high-speed travellingwave data sampling unit continuously collects data, the sampled data are storedin a cache. If there is no start signal, the data will be covered by the laterdata automatically；When the travelling wave starting component starts, the data sampledby high-speed sampling unit are transferred from the cache to buffer. Thenwavelet transform is used to analyze the traveling wave. The result is sent tothe central control unit.
Centralcontrol unit will receive all results from the high-speed traveling wave datasampling unit, and determine the fault feeder. Through LCD display, light,buzzer and communication of the warn to the remote control center, the feederselector will report the fault instantly after the fault occurs, and upload therecord fault information to the control center according to the need.
4.Characteristics
● New Principle
It’s based onthe transient traveling waves.
● New Algorithm
It’s based onmodern mathematical tool--wavelet transform—to analyze signals.
● New Hardware
It’s based onadvanced data sampling systems and multi-CPU parallel processing technology.
● Extensive Application,
It can be appliedto power distribution system with overhead lines or cables, and with all kindsof neutral point grounding system.
5.Specifications
● Size: 441mm x 322mmx 177mm，weight：8.5kg.
● Rated voltage: AC/DC 220V, allowablevariation-15%~+15%.
●Rated frequency: 50Hz/60Hz.
● Ambient temperature: -25℃~55℃
● Humidity: 5%~95%
● Atmospheric pressure: 66KPA~110KPA
● Communication protocol: IEC-60870- 103, CDTand IEC61850
● Communication interface: RS232, RS485 andRJ45
●Capacity: one device can monitor 24 feedersand 3 bus bars
