配電柜中性點(diǎn)直接接地系統(tǒng)接地時(shí)零序元件的特性是怎樣的呢？這是很多人都不理解的，下面就來講講吧。

　　What are the characteristics of the zero sequence elements when the neutral point of the distribution cabinet is directly grounded? This is something that a lot of people don't understand, so let's talk about it.

　　故障點(diǎn)的零序電壓高，離故障點(diǎn)越遠(yuǎn)，零序電壓越低，中性點(diǎn)接地變壓器的零序電壓為零。零序電流的分布主要取決于輸電線路的零序阻抗和中性點(diǎn)接地變壓器的零序阻抗，與電源的數(shù)量和位置無關(guān)。當(dāng)電力系統(tǒng)運(yùn)行方式發(fā)生變化時(shí)。

　　The zero sequence voltage of the fault point is high, the farther away from the fault point, the lower the zero sequence voltage, and the zero sequence voltage of the neutral earthed transformer is zero. The distribution of zero-sequence current mainly depends on the zero-sequence impedance of the transmission line and the zero-sequence impedance of the neutral ground transformer, and has nothing to do with the number and position of the power supply. When there is a change in the way the power system operates.

　　如果輸電線路和中性點(diǎn)接地的變壓器數(shù)量不變，則零序阻抗和零序等效網(wǎng)絡(luò)不變。然而，電力系統(tǒng)的正序阻抗和負(fù)序阻抗會(huì)隨著系統(tǒng)的運(yùn)行方式而變化，這將間接影響零序分量的大小。對(duì)于故障線路，配電柜安裝兩端零序功率方向與正序功率方向相反，零序功率方向?qū)嶋H上是從線路流向母線。

　　If the number of transformers on the transmission line and the neutral ground is constant, the zero-sequence impedance and zero-sequence equivalent network are constant. However, the positive sequence impedance and negative sequence impedance of power system will change with the operation mode of the system, which will indirectly affect the size of zero sequence component. For faulty lines, the zero-sequence power direction at both ends of the PDC is opposite to the positive sequence power direction. The zero-sequence power direction actually flows from the line to the bus.

　　電氣成套人員認(rèn)為保護(hù)的配置小電流接地系統(tǒng)的輸電線路一般采用三級(jí)電流保護(hù)，以應(yīng)對(duì)相間短路故障；由于小電流接地系統(tǒng)沒有接地點(diǎn)，單相接地短路只被視為異常運(yùn)行狀態(tài)。一般是利用母線上的絕緣監(jiān)測(cè)裝置發(fā)出信號(hào)，操作人員切斷電源尋找接地設(shè)備。

　　Three-phase current protection is generally used in transmission lines with small current grounding system to cope with phase to phase short circuit fault. Since the system with low current grounding has no ground point, a single phase grounding short circuit is only considered an abnormal operating condition. Generally, the insulation monitoring device on the bus is used to send out signals, and the operator cuts off the power supply to find grounding equipment.

　　配電柜中性點(diǎn)直接接地系統(tǒng)的特性這樣了，如果您還有什么問題的話，就來網(wǎng)站www.ywf-lanzhou.com進(jìn)行咨詢吧。

　　Distribution cabinet neutral point direct grounding system characteristics of such, if you have any questions, please come to the website www.ywf-lanzhou.com for consultation.