薄膜電容器在使用過(guò)程中出現(xiàn)問(wèn)題怎么辦?電解電容廠家根據(jù)多年從事電子元器件行業(yè)的經(jīng)驗(yàn)發(fā)現(xiàn),薄膜電容器常見(jiàn)問(wèn)題的故障有以下3個(gè)原因。
How to deal with the problems in the use of thin film capacitors? According to years of experience in electronic components industry, electrolytic capacitor manufacturers found that there are three reasons for common problems of thin film capacitors.
一、環(huán)境溫度高
High ambient temperature
由于薄膜電容器的工作環(huán)境整體通風(fēng)條件差,室內(nèi)溫度高達(dá)48C以k,由此可見(jiàn)環(huán)境溫度過(guò)高是引起電容爆炸的原因之。
Due to the poor ventilation condition of the working environment of the thin film capacitor, the indoor temperature is as high as 48c to K. It can be seen that the high ambient temperature is the cause of capacitor explosion.
二、電壓極不穩(wěn)定
The voltage is extremely unstable
從公式QC=2π fCV2中可以看出:電容器的無(wú)功容量與電壓的平方成正比。當(dāng)電壓降低時(shí),電容器的無(wú)功容輦將按電樂(lè)的平方成正比地相應(yīng)減少,即電容器的容量得不到充分利用。當(dāng)運(yùn)行電壓升高時(shí)會(huì)使電容器的溫升增加,甚至使電容器的熱T衡破壞而引起電容器爆炸。因此因標(biāo)規(guī)定:電容器允許在1.1倍額定電壓下長(zhǎng)期運(yùn)行,但每24h內(nèi)在1.15倍額定電壓下運(yùn)行的時(shí)間不得超過(guò)30min.
From the formula QC = 2 π fcv2, it can be seen that the reactive capacity of capacitor is directly proportional to the square of voltage. When the voltage decreases, the reactive power capacity of the capacitor will be reduced in proportion to the square of the electric music, that is, the capacity of the capacitor can not be fully utilized. When the operating voltage increases, the temperature rise of the capacitor will increase, and even the thermal balance of the capacitor will be damaged, which will cause the capacitor explosion. Therefore, according to the standard, the capacitor is allowed to operate under 1.1 times of rated voltage for a long time, but the operation time under 1.15 times of rated voltage within 24 hours shall not exceed 30 minutes
壓極不穩(wěn)定,電壓波動(dòng)范圍為0. 9Ue - 1.15Ue (Ue為額定電壓400V),用電時(shí)常在450V左右,運(yùn)行時(shí)間長(zhǎng)達(dá)Th,這是造成電容爆炸燒壞的原因。
The voltage pole is unstable, the voltage fluctuation range is 0.9ue-1.15ue (UE is the rated voltage of 400V), the power consumption is often about 450V, and the operation time is as long as th, which is the cause of capacitor explosion and burning.
三、諧波電流的存在
The existence of harmonic current
諧波電流的存在常使電容器發(fā)生異常的響聲,嚴(yán)重時(shí)引起電容器膨脹,這是引起電容器保炸的原因之三。發(fā)生這種情況的主要原因是:
The existence of harmonic current often causes abnormal noise of capacitor, and even causes capacitor expansion when serious, which is the third reason of capacitor explosion. The main reasons for this are as follows:
(1)高次諧波電流疊加于基波電流,使電容器總電流增大:
When the higher harmonic current is superimposed on the fundamental current, the total current of the capacitor increases
(2)某一高次諧波在系統(tǒng)感抗和電容器容抗之間引起并聯(lián)諧振,使流入電容器的電流成信增長(zhǎng):
A higher harmonic causes parallel resonance between the system inductance and capacitor capacitance reactance, which makes the current flowing into the capacitor increase
(3)電容器內(nèi)部對(duì)某一高次諧波發(fā)生局部串聯(lián)諧振,從而引起過(guò)負(fù)荷。
The internal part of the capacitor is in series resonance to a certain higher harmonic, which causes overload.
處理措施
Treatment measures
為了防止這些情況發(fā)生,可以在補(bǔ)償電容器組的每相內(nèi)串按一個(gè)空心電抗器來(lái)限制電流。使電容電路的合成電抗對(duì)于高次諧波而言,變?yōu)楦行噪娍?。若選擇串聯(lián)電抗器的電抗使5次諧波諧振時(shí),則5次諧波被短路,對(duì)5飲諧鈹以上的高次諧波,因電容回路變?yōu)殡姼行?,所以波形被改善,從而根本上消除了產(chǎn)生諧振的可能。
In order to prevent these situations, a air core reactor can be connected in series in each phase of the compensation capacitor bank to limit the current. The synthetic reactance of capacitor circuit is changed into inductive reactance for higher harmonic. If the reactance of the series reactor is selected to make the fifth harmonic resonance, the fifth harmonic will be short circuited. For the higher harmonic above the fifth harmonic beryllium, the waveform will be improved because the capacitance circuit becomes inductive, thus eliminating the possibility of resonance.
當(dāng)然,我們?cè)谂袛?a href="http://www.whweier.com" target="_self">薄膜電容器故障原因之前,都會(huì)根據(jù)薄膜電容的工作環(huán)境以及電路情況進(jìn)行綜合的分析而進(jìn)行判斷,從而制定出合理的解決方案。
Of course, before we judge the cause of the failure of the film capacitor, we will make a comprehensive analysis of the working environment and circuit conditions of the film capacitor to make a reasonable solution.