參與過(guò)電機(jī)試驗(yàn)，或者是電機(jī)的實(shí)際使用者，可能都遇到過(guò)一種情況，就是電機(jī)在啟動(dòng)或斷電過(guò)程中，可能會(huì)發(fā)生抖動(dòng)，這個(gè)問(wèn)題也有粉絲提出過(guò)，今天我們針對(duì)該現(xiàn)象與大家進(jìn)行簡(jiǎn)單交流。

電機(jī)試驗(yàn)過(guò)程中，如果采用調(diào)壓或調(diào)頻方式起動(dòng)，電機(jī)的起運(yùn)過(guò)程相對(duì)平衡，相反，當(dāng)電機(jī)按照正常運(yùn)行電壓起動(dòng)時(shí)，電機(jī)會(huì)有比較明顯的抖動(dòng)現(xiàn)象；同樣，正常運(yùn)行的電機(jī)，突然斷電了，也有類(lèi)似現(xiàn)象發(fā)生，有時(shí)候還會(huì)伴有比較明顯的噪聲。

機(jī)械共振作用

當(dāng)電機(jī)運(yùn)行中的機(jī)械系統(tǒng)所受激勵(lì)的頻率，與該系統(tǒng)的某個(gè)階段的固有頻率相接近時(shí)，將會(huì)發(fā)生明顯的共振現(xiàn)象，出現(xiàn)明顯的位移共振，有時(shí)會(huì)因?yàn)檎駝?dòng)作用而產(chǎn)生比較明顯的聲音。電機(jī)啟動(dòng)或斷電運(yùn)行過(guò)程中，所發(fā)生的“抖動(dòng)”就是一種共振的具體表現(xiàn)。

該類(lèi)問(wèn)題在變頻電機(jī)的使用過(guò)程中也時(shí)有發(fā)生，變頻電機(jī)可能在某些頻段的運(yùn)行效果特別好，而在其他頻段可能存在明顯的電磁噪聲，其根本的原因是由于電磁共振的作用。

慣性狀態(tài)改變的具體表現(xiàn)

電機(jī)啟動(dòng)過(guò)程及停止過(guò)程都是一種慣性改變的過(guò)程，改變慣性的過(guò)程，即運(yùn)行對(duì)象受力改變的過(guò)程，改變的時(shí)間越短、受力越大，狀態(tài)改變即越明顯，直接的物理表象為人的直覺(jué)可以感受到的振動(dòng)，對(duì)于電機(jī)產(chǎn)品而言，可能是聲音和位移的變化。

為此，電機(jī)安裝使用過(guò)程中的固定非常必要，例如通過(guò)電機(jī)底腳面、端蓋法蘭面與安裝基準(zhǔn)進(jìn)行固定，必要時(shí)增加其他限位措施。在電機(jī)運(yùn)行過(guò)程中，會(huì)因?yàn)殡y以規(guī)避的振動(dòng)問(wèn)題發(fā)生固定的松動(dòng)問(wèn)題，因而定期的保養(yǎng)和維護(hù)特別必要。

Those who have participated in motor tests or are actual users of motors may have encountered a situation where the motor may shake during startup or power outage. This issue has also been raised by fans. Today, we will have a brief discussion with everyone about this phenomenon.
During the motor testing process, if voltage or frequency regulation is used to start the motor, the starting process of the motor is relatively balanced. On the contrary, when the motor is started at the normal operating voltage, there will be a noticeable vibration phenomenon in the motor; Similarly, when a normally running motor suddenly loses power, similar phenomena occur, sometimes accompanied by noticeable noise.
Mechanical resonance effect
When the excitation frequency of the mechanical system in operation of the motor is close to the natural frequency of a certain stage of the system, obvious resonance phenomenon will occur, with obvious displacement resonance, and sometimes more obvious sound will be produced due to vibration. The vibration that occurs during the starting or power-off operation of the motor is a specific manifestation of resonance.
This type of problem also occurs during the use of variable frequency motors. Variable frequency motors may have particularly good operating effects in certain frequency bands, while there may be obvious electromagnetic noise in other frequency bands, and the fundamental reason is due to the effect of electromagnetic resonance.
The specific manifestation of inertia state change
The process of starting and stopping a motor is a process of inertia change, which refers to the process of changing the force on the operating object. The shorter the time of change and the greater the force, the more obvious the state change. The direct physical appearance is the vibration that can be felt by human intuition. For motor products, it may be the change in sound and displacement.
Therefore, it is necessary to fix the motor during installation and use, such as by fixing the motor foot surface, end cover flange surface with the installation reference, and adding other limiting measures if necessary. During the operation of the motor, fixed looseness may occur due to unavoidable vibration issues, so regular maintenance and upkeep are particularly necessary.