永久免费观看的毛片手机视频-日韩精品无码一区二区三区-国产精品一区在线观看你懂的-亚洲学生妹高清av-久久香综合精品久久伊人

Hello! Welcome to the website of Dongguan Youchen Electronic Technology Co., Ltd.

Youchen Technology

Chip Capacitor/Electrolytic Capacitor/Ceramic Capacitor Supplier
18929295505
admin@dgyouchen.com
Current Page: Home > News > Common problem
News

Factors Influencing the Life of Electrolytic capacitor (I)

2019-07-25

Electrolytic capacitor are widely used in different fields of power electronics, mainly for smoothing, energy storage or filtering after AC voltage rectification, and also for non precision timing delay. In the MTBF prediction of switching power supply, the model analysis results show that Electrolytic capacitor is the main factor affecting the life of switching power supply, so it is very important to understand and influence the factors of capacitor life.

1. The life of Electrolytic capacitor depends on its internal temperature.

Therefore, the design and application conditions of Electrolytic capacitor will affect the life of Electrolytic capacitor. From the design point of view, the design method, materials and processing technology of Electrolytic capacitor determine the life and stability of the capacitor. For the application, the service voltage, ripple current, switching frequency, installation form, heat dissipation mode, etc. all affect the life of Electrolytic capacitor.

2. Abnormal failure of Electrolytic capacitor

Some factors may cause the Electrolytic capacitor to fail, such as extremely low temperature, capacitor temperature rise (welding temperature, ambient temperature, AC ripple), excessive voltage, instantaneous voltage, Very high frequency or reverse bias voltage; Among them, the temperature rise is the biggest factor affecting the working life (Lop) of Electrolytic capacitor.

The conductivity of capacitance is determined by the ionization capacity and viscosity of electrolyte. When the temperature decreases, the viscosity of the electrolyte increases, resulting in a decrease in ion mobility and conductivity. When the electrolyte freezes, the ion mobility is very low, resulting in a very high resistance. On the contrary, excessive heat will accelerate the evaporation of the electrolyte, and when the amount of electrolyte decreases to a certain limit, the lifespan of the capacitor will also end. When working in cold areas (generally below -25 ℃), heating is required to ensure the normal working temperature of Electrolytic capacitor. For example, outdoor UPS is equipped with heating plates in Northeast China.

Capacitors are prone to breakdown under overvoltage conditions, while surge voltage and instantaneous high voltage are common in practical applications. Especially in China, which has a vast territory and complex power grids in various regions, the AC power grid is very complex, often exceeding 30% of the normal voltage, especially for single-phase input. Phase deviation will exacerbate the normal range of AC input. The test shows that the commonly used 450V/470uF105 ℃ imported ordinary 2000 hour Electrolytic capacitor will leak and emit gas after 2 hours under 1.34 times of the rated voltage, and the top will burst. According to statistics and analysis, the failure of the Electrolytic capacitor output from the communication switching power supply PFC close to the grid is mainly due to the grid surge and high-voltage damage. The voltage of aluminum Electrolytic capacitor is generally selected for secondary derating, and it is more reasonable to reduce it to 80% of the rated value.

3. Analysis of Life Impact Factors

In addition to abnormal failure, the life of Electrolytic capacitor has an exponential relationship with temperature. Because of the use of non solid electrolyte, the life of the Electrolytic capacitor also depends on the evaporation rate of the electrolyte, resulting in a reduction in electrical performance. These parameters include capacitance, leakage current and Equivalent series resistance (ESR).

Refer to the formula for the expected life of RIFA company:

PLOSS=(IRMS) ² XESR (1)

Th=Ta PLOSSxRth (2)

Loop=Ax2Hours (3)

B=reference temperature value (typical value is 85 ℃)

A=capacitor life at reference temperature (varies depending on the diameter of the capacitor)

C=Number of degrees of temperature rise required to reduce capacitor life by half

From the above formula, we can clearly see that there are several direct factors affecting the life of Electrolytic capacitor: ripple current (IRMS) and Equivalent series resistance (ESR), ambient temperature (Ta), and total thermal resistance (Rth) transferred from the hot spot to the surrounding environment. The point where the internal temperature of the capacitor is the highest is called the hot spot temperature (Th). The hot spot temperature value is the main factor affecting the working life of capacitors. The following factors determine the external temperature (ambient temperature Ta) of the hot spot temperature value in practical applications, the total thermal resistance (Rth) transmitted from the hot spot to the surrounding environment, and the energy loss caused by AC current (PLOSS). The internal temperature rise of a capacitor is linearly related to energy loss.

During capacitor charging and discharging, the current flowing through the resistor causes energy loss, and the change in voltage also causes energy loss when passing through the dielectric. In addition, the energy loss caused by leakage current leads to an increase in the internal temperature of the capacitor.

Previous Page:Causes affecting the life of Electrolytic capacitor (II)

Next Page:Life of aluminum Electrolytic capacitor
Youchen Technology
Dongguan Youchen Electronic Technology Co., Ltd
Tel: 0769-85328400 8533526885336465
Fax: 0769-85308615
Email: admin@dgyouchen.com
Website: m.sh-hongtu.com
Address: Floor 3, No. 7 Xinfeng Road, Shangsha Fourth Industrial Zone, Chang'an Town, Dongguan City, Guangdong Province
Yue ICP Bei No. 13008404
All rights reserved:Dongguan Youchen Electronic Technology Co., Ltd
In-line aluminum electrolytic capacitor manufacturer, SMT aluminum electrolytic capacitor manufacturer, direct sales, brand selection, model selection, price
Follow us:

Do you need our help? Welcome to leave your email!
Subscription
18929295505  
2324774509
admin@dgyouchen.com
主站蜘蛛池模板: 蜜臀亚洲av无码精品国产午夜.| 麻豆av一区二区三区久久| 国产成人麻豆亚洲综合无码精品| 亚洲日韩国产精品乱-久| 啦啦啦免费视频播放在线观看 | 亚洲爆乳无码专区| 日韩精品久久久肉伦网站| 欧美男生射精高潮视频网站| 国产精品多p对白交换绿帽| 99热久久这里只精品国产www| 亚洲无线码高清在线观看| 无码人妻精品一区二区三区蜜桃| 亚洲av无码久久| 老熟女高潮一区二区三区| 岛国av无码免费无禁网站| 亚洲国产精品18久久久久久| 国产精品亚洲а∨无码播放不卡| 狼人大香伊蕉国产www亚洲| 亚洲人成无码www久久久| 奇米777四色影视在线看| 亚洲av色区一区二区三区| 人人添人人澡人人澡人人人人| 九一九色国产| 精品国产亚洲一区二区三区| 奇米在线7777在线精品| 在线观看亚洲av日韩av| 亚洲性无码av在线欣赏网| 免费无码又爽又刺激高潮的视频 | 抽搐一进一出gif免费动态| 日日噜噜噜夜夜爽爽狠狠| 国产md视频一区二区三区| 精品视频一区二区三三区四区| 久久久久国产一区二区三区| 精品国产18久久久久久| 亚洲风情亚aⅴ在线发布| 无码av中文一区二区三区桃花岛| 国产成人亚洲精品无码车a| 最近中文字幕mv免费高清在线 | 免费能直接看黄的视频| 亚洲av色影在线| 啦啦啦中文在线观看日本|