MNS低壓抽屜柜如何避免短路故障？從高壓側(cè)各相幅頻特性的細(xì)微差別可以看出，如果主頻的幅值相對較大，另一臺300MVA電源的空載振動特性諧波試驗表明，電網(wǎng)經(jīng)常因雷擊、繼電保護(hù)誤動或拒動而短路，低壓開關(guān)柜短路電流的強(qiáng)烈沖擊可能損壞變壓器，因此應(yīng)從各方面努力提高變壓器的短路耐受能力。

How can MNS low-voltage drawer cabinet avoid short circuit fault? It can be seen from the slight difference of amplitude-frequency characteristics of each phase at the high voltage side that if the amplitude of the main frequency is relatively large, the harmonic test of no-load vibration characteristics of another 300MVA power supply shows that the power grid is often short-circuited due to lightning strikes, relay protection maloperation or refusal to operate, and the strong impact of the short-circuit current of the low-voltage switchgear may damage the transformer, so efforts should be made to improve the short-circuit withstand capacity of the transformer from all aspects.

短路事故統(tǒng)計結(jié)果表明，絕緣距離會發(fā)生變化，固體絕緣被破壞，導(dǎo)致局部放電。當(dāng)施加雷電過電壓時，有可能發(fā)生匝間、餅擊穿，導(dǎo)致突發(fā)絕緣事故。即使在正常工作電壓下，局部放電的長期作用也可能導(dǎo)致絕緣擊穿事故。80%左右是MNS低壓抽屜柜造成的，只有10%左右是運維造成的。

The statistical results of short circuit accidents show that the insulation distance will change and the solid insulation will be damaged, leading to partial discharge. When lightning overvoltage is applied, inter-turn and cake breakdown may occur, resulting in sudden insulation accidents. Even under normal working voltage, the long-term effect of partial discharge may lead to insulation breakdown accidents. About 80% is caused by MNS low-voltage drawer cabinet, and only about 10% is caused by operation and maintenance.

在維修過程中，一方面要盡量減少短路故障，減少沖擊次數(shù)，另一方面，要及時檢測繞組的變形，防止其發(fā)生危險。高低壓側(cè)的振動特性不同，積極開展繞組變形測試和診斷，通常廠家遭受短路故障電流沖擊后，繞組會發(fā)生局部變形，即使不立即損壞，也可能留下嚴(yán)重隱患。

In the process of maintenance, on the one hand, it is necessary to minimize short circuit faults and reduce the number of shocks; on the other hand, it is necessary to detect the winding deformation in time to prevent its occurrence of danger. The vibration characteristics of the high and low voltage sides are different, and the winding deformation test and diagnosis are actively carried out. Usually, after the manufacturer is impacted by the short-circuit fault current, the winding will have local deformation, which may leave serious hidden dangers even if it is not immediately damaged.

頻域中三相高壓側(cè)相同位置的振動信號的幅值出現(xiàn)在相同的頻率位置，即高壓側(cè)在400Hz然而，頻域中低壓側(cè)的振動信號的振幅是100Hz。

In the frequency domain, the amplitude of the vibration signal at the same position of the three-phase high-voltage side appears at the same frequency position, that is, the amplitude of the vibration signal at the high-voltage side is 400Hz. However, in the frequency domain, the amplitude of the vibration signal at the low-voltage side is 100Hz.

高低壓側(cè)同一位置的振動信號的基頻和各次諧波的幅值在一個數(shù)量級，即頻域特性基本相同，變壓器的、經(jīng)濟(jì)、可靠運行和輸出取決于其自身的制造質(zhì)量、運行環(huán)境和維護(hù)質(zhì)量，可有效防止操作和維護(hù)過程中突發(fā)故障的措施。更多相關(guān)內(nèi)容就來我們網(wǎng)站http://www.hua155.com做咨詢吧！

The amplitude of the fundamental frequency and each harmonic of the vibration signal at the same position of the high and low voltage sides is in the same order of magnitude, that is, the frequency domain characteristics are basically the same. The safe, economic, reliable operation and output of the transformer depend on its own manufacturing quality, operating environment and maintenance quality, which can effectively prevent sudden failures during operation and maintenance. Come to our website for more relevant content http://www.hua155.com Do consulting!