MNS低压抽屉柜如何避免短路故障？从高压侧各相幅频特性的细微差别可以看出，如果主频的幅值相对较大，另一台300MVA电源的空载振动特性谐波试验表明，电网经常因雷击、继电保护误动或拒动而短路，低压开关柜短路电流的强烈冲击可能损坏变压器，因此应从各方面努力提高变压器的短路耐受能力。

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.

短路事故统计结果表明，绝缘距离会发生变化，固体绝缘被破坏，导致局部放电。当施加雷电过电压时，有可能发生匝间、饼击穿，导致突发绝缘事故。即使在正常工作电压下，局部放电的长期作用也可能导致绝缘击穿事故。80%左右是MNS低压抽屉柜造成的，只有10%左右是运维造成的。

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.

在维修过程中，一方面要尽量减少短路故障，减少冲击次数，另一方面，要及时检测绕组的变形，防止其发生危险。高低压侧的振动特性不同，积极开展绕组变形测试和诊断，通常厂家遭受短路故障电流冲击后，绕组会发生局部变形，即使不立即损坏，也可能留下严重隐患。

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.

频域中三相高压侧相同位置的振动信号的幅值出现在相同的频率位置，即高压侧在400Hz然而，频域中低压侧的振动信号的振幅是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.

高低压侧同一位置的振动信号的基频和各次谐波的幅值在一个数量级，即频域特性基本相同，变压器的安全、经济、可靠运行和输出取决于其自身的制造质量、运行环境和维护质量，可有效防止操作和维护过程中突发故障的措施。更多相关内容就来我们网站 //www.aqfitlab.com做咨询吧！

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 //www.aqfitlab.com Do consulting!