產品應用
Sinuofuhong
此文檔將提供應用開發使用電容器(EDLC)基本使用指南。若在開發使用過程中遇到問題且在此文件中找不到解決答案時請與我們聯系。
This document provides basic guidelines for application development using capacitors, also known as EDLC. If questions arise during your development process and are not answered in this document, please contact us.
壽命Life Time
EDLC具有比二次電池更長久的壽命,其壽命可達數十萬次以上。EDLC基本的壽命終止失效模式為等效串聯電阻(ESR)升高和/或容量的降低。實際的壽命終止標準取決于應用要求。長期置于高溫下,高電壓和超電流將會導致ESR升高和容量降低。這些參數的降低將可延長超級電容器的壽命。一般來說,圓筒型EDLC具有與電解電容器相類似的構造,有電解液、鋁殼和膠粒。多年使用后,EDLC內電解液也會干涸,如同電解電容器一樣,導致ESR升高,壽命終止。
EDLC has a longer life time than secondary batteries, Their cycle life can reach hundreds of thousands of times. The basic end-of-life failure mode for an EDLC is an increase in equivalent series resistance (ESR) and/or a decrease in capacitance. The actual end-of-life criteria are dependent on the application requirements. Prolonged exposure to elevated temperatures, high applied voltage and excessive current will lead to increased ESR and decreased capacitance. Reducing these parameters will lengthen the life time of a supercapacitor. In general, cylindrical EDLC have a similar construction to electrolytic capacitors, having a liquid electrolyte inside an aluminum can sealed with a rubber bung. Over many years, the EDLC will dry out, similar to an electrolytic capacitor, causing high ESR and eventually end-of-life.
電壓Voltage
EDLC是有額定的工作電壓的。電壓值是基于其最高額定溫度下最長壽命來設定的。如果使用電壓超出了推薦電壓,其結果將會導致壽命縮短。如果電壓長期過高,EDLC內將會產生氣體,導致漏液或防爆閥破裂。EDLC是可以承受短期過電壓的。
EDLC are rated with a nominal recommended working or applied voltage. The values provided are set for long life at their maximum rated temperature. If the applied voltage exceeds this recommended voltage, the result will be reduced life time. If the voltage is excessive for a prolonged time period, gas generation will occur inside the EDLC and may result in leakage or rupture of the safety vent. Short-term over voltage can usually be tolerated by the EDLC.
極性Polarity
EDLC的設計是有相對稱的電極,即兩極具有相類似的成分。在EDLC初次組裝時,任一電極都可定為正極或負極。一旦EDLC在100%質量測試時第一次充電,其電極將會形成極性化。每-EDLC都有負極框或符號來標識極性。盡管其可以降低到零電壓,其電極還是會保留非常少的電荷。雖然之前充電的EDLC會放電至-2.5V且在容量或ESR方面至極低,但還是不能進行反極使用。
EDLC are designed with symmetrical electrodes, meaning they are similar in composition. When an EDLC is first assembled, either electrode can be designated positive or negative. Once the EDLC is charged for the first time during the 100% QA testing operation, the electrodes become polarized. Every EDLC either has a negative stripe or sign denoting polarity. Although they can be shorted to zero volts, the electrodes maintain a very small amount of charge. Reversing polarity is not recommended, however previously charged EDLC have been discharged to -2.5V with no measurable difference in capacitance or ESR.
注:在一方向上保留的電荷越久,EDLC就越變的極性化。如果在一方向上長期充電后再進行反向充電,EDLC的壽命將會大大的縮減。
Note:The longer they are held charged in one direction,the more polarized they become.If reversely charged after prolonged chargeing in one direction,the life of the EDLC may be shortened.
溫度Ambient Temperature
SEE系列電容的標準溫度范圍為-25℃~70℃。SEL系列電容的標準溫度范圍為-40℃~60℃。溫度及電壓會對EDLC壽命有影響。一般來說,環境溫度每提升10℃,EDLC壽命就會縮短一半。因此,建議盡可能在規定溫度范圍內使用EDLC以降低內部劣化與ESR升高。在低于正常室溫環境下,可使用稍高于額定工作電壓而不造成內部劣化和壽命縮短。在低溫下提升使用電壓將可抵銷ESR的升高。高溫下ESR的升高會導致EDLC永久性劣化/電解液分解。在低溫下,因電解液粘性的提升及離子的緩性移動緣故,ESR升高只是一種短暫現象。
The standard temperature rating is -25℃ to 70℃ for SEE series or -40℃ to 60℃ for SEL series. Temperature in combination with voltage can affect the life time of an EDLC. In general, raising the ambient temperature by 10℃ will decrease the life time of an EDLC by a factor of two. As a result, it is recommended to use the EDLC at the Specified temperature range possible to decrease internal degradation and ESR increase. At temperature lower than normal room temperature, it is possible to apply voltages slightly higher than the recommended working voltage without significant increase in degradation and reduction in life time. Raising the applied voltage at low temperatures can be useful to offset the increased ESR seen at low temperatures. Increased ESR at higher temperatures is a result of permanent degradation/electrolyte decomposition inside the EDLC. At low temperatures, however, increased ESR is only a temporary phenomenon due to the increased viscosity of the electrolyte and slower movement of the ions.
放電特性Discharge Characteristics
EDLC放電時電壓是呈斜線的。在確定應用時的容量與ESR要求時,考慮耐壓放電和電容性放電成分是很重要的。在高脈沖電流應用時,內阻值是最為關鍵的。在低電流長時間應用時,電容放電特性是最為關鍵的。
EDLC discharges with a sloping voltage curve. When determining the capacitance and ESR requirements for an application, it is important to consider both the resistive and capacitive discharge components. In high current pulse applications, the resistive component is the most critical. In low current, long duration applications, the capacitive discharge component is the most critical.
在I電流下放電t(秒)時電壓降低Vdrop公式為:
Vdrop = I(R+t/C)
The formula for the voltage drop, Vdrop, during a discharge at I current for t seconds is:
Vdrop = I(R+t/C)
在脈沖電池應用時,須使用低ESR(R值)EDLC以減低電壓降幅。
To minimize voltage drop in a pulse application, use an EDLC with low ESR(R value).
在低電流應用時,應使用高容量(C值)EDLC。
To minimize voltage drop in a low current application, use an EDLC with large capacitance(C value).
充電方法Charge Methods
EDLC可用各種方法進行充電,包括恒定電流、恒定功率、恒定電壓或與能量儲存器,如電池、燃料電池、直流轉換器等進行并聯。如果EDLC與電池并聯,加一個低阻值串聯電阻將會提升電池的壽命。如果使用串聯電阻,須確保EDLC輸出電壓輸出端是直接與應用器連接而不是通過電阻與應用器連接,否則EDLC的低ESR將無效。在高脈沖電流放電時,許多電池系統壽命縮短均會縮短。
EDLC can be charged using various methods including constant current, constant power,constant voltage or by paralleling to an energy source, i.e. battery, fuel cell, DC converter, etc. If an EDLC is configured in parallel with a battery, adding a low value resistor in series will increase the life of the battery. If a series resistor is used, ensure that the voltage outputs of the EDLC are connected directly to the application and not through the resistor; otherwise the low ESR of the EDLC will be nullified. Many battery systems exhibitdecreased life time when exposed to high current discharge pulses.
EDLC最大建議充電電流I應按以下方式計算,Vw為充電電壓,R為EDLC ESR:
I= Vw/5R
The maximum recommended charge current l, for an EDLC where Vw is the charge voltage and R is the EDLC ESR is calculated as below:
I = Vw/5R
持續大電流或高電壓充電,EDLC將會過度發熱。
過度發熱將會導致ESR提升,氣體產生,壽命縮短,漏液,防爆閥破裂。
如果要使用高于額定值的電流或電壓充電請與生產廠商聯系。
Overheating of the EDLC can occur from continuous over current or overvoltage charging.
Overheating can lead to increased ESR, gas generation, decreased life time, leakage, venting or rupture.
Contact the factory if you plan to use a charge current or voltage higher than specified.
自放電與漏電流Self Discharge and Leakage Current
以不同方法進行測量時自放電和漏電流在本質上是相同的,因為EDLC在構造上,從正極到負極具備高的耐電流特性。也就是說為保留電容電荷,是需要少量的額外電流,此稱為漏電流。當充電電壓移除,電容不在負荷時,額外的電流會促使EDLC放電,此稱為自放電電流。
Self discharge and leakage current are essentially the same thing measured in different ways. Due to the EDLC construction, there is a high-resistance internal current path from the anode to the cathode. This means that in order to maintain the charge on the capacitor a small amount of additional current is required. During charging this is referred to as leakage current. When the charging voltage is removed, and the capacitor is not loaded, this additional current will discharge the EDLC and is referred to as the self discharge current.
為測量實際的漏電流或自放電數值,也因為構造原因,EDLC須充電100小時以上。EDLC可模擬為幾個并聯的電容器,每一個都有不同的串聯電阻值。低串聯電阻值的電容器能迅速充電從而提升終端電壓達到充電電壓值的同一水平。但在充電電壓移除時,如果這些并聯的電容器之中有未完全充電的話,電容器將會放電到具有較高串聯電阻的并聯電容器中。結果就是終端電壓將會降低,形成高自放電電流。須注意容量越高,完全充電時間就越久。
In order to get a realistic measurement of leakage or self discharge current the EDLC must be charge for in excess of 100 hours. This again is due to the capacitor construction. The EDLC can be modeled as several capacitors connected in parallel, each with an increasing value of series resistance. The capacitor with low values of series resistance is charged quickly thus increasing the terminal voltage to the same level as the charge voltage. However, if the charge voltage is removed these capacitors will discharge into the parallel capacitors with higher series resistance if they are not fully charged. The result of this is that the terminal voltage will fall, giving the impression of high self discharge current. It should be noted that the higher the capacitance value, the longer it will take for the device to be fully charged.
EDLC系列設置Series Configurations of EDLC
單個SEE系列EDLC電壓限制為2.5V,SEL系列EDLC電壓限制為2.7V。因許多應用領域要求高電壓.EDLC可以設置為串聯以提升工作電壓。確保單一的EDLC電壓不超過其最大的額定工作電壓是很重要的,否則會導致電解液分解,氣體產生,ESR升高,壽命縮短。
Individual EDLC is limited to 2.5V for SEE series or 2.7V for SEL series. As many applications require higher voltages, EDLC can be configured in series to increase the working voltage. It is important to ensure that the individual voltage of any single EDLC does not exceed its maximum recommended working voltage as this could result in electrolyte decomposition, gas generation, ESR increase and reduced life time.
予充電和放電時,在穩態下因容量差異和漏電流差異,電容器電壓不平衡現象將會產生。在充電時,串聯電容器將起到電壓分配作用,因此高容值單體將會承受更大的電壓。例如:2個1F電容器進行串聯,一個電容器容量為+20%,另一個容量為-20%,電壓通過電容器的最差性況為:
Vcap2= Vsupply x (Ccapl/(Ccapl+Ccap2))
其中Ccapl具備+20%容量,則 Vsupply= 5V。
Vcap2= 5V x (1.2/(1.2+0.8))=3V
Capacitor voltage imbalance is caused, during charge and discharge, by differences in capacitance value and, in steady state, by differences in capacitor leakage current. During charging series connected capacitors will act as a voltage divider so higher capacitance devices will receive greater voltage stress. For example if two 1F capacitors are connected in series, one at +20% of nominal capacitance the other at -20% the worst-case voltage across the capacitors is given by:
Vcap2 = Vsupply x (Ccapl/(Ccapl+Ccap2))
where Ccapl has the +20% capacitance. So for a Vsupply = 5V.
Vcap2 = 5V x (1.2/(1.2+0.8)) = 3V
從上可以看出,為避免超出3V的EDLC浪涌電壓范圍,串聯電容器的容值應在±20%的公差范圍內。在選擇上,一個合適的主動電壓平衡電路可用來降低因容值不平衡而產生的電壓不平衡。需注意到大多數的電壓平衡方法都取決于具體的應用。
From this it can be seen that, in order to avoid exceeding the EDLC surge voltage rating of 3V, the capacitance values of series connected parts must fall in a +20% tolerance range. Alternatively a suitable active voltage balancing circuit can be employed to reduce voltage imbalance due to capacitance mismatch. It should be noted that the most appropriate method of voltage balancing will be application specific.
被動電壓平衡Passive Voltage Balancing
被動電壓平衡可用電壓分配電阻與每一EDLC并聯來實現。這可讓電流從高電壓的EDLC上流至低電壓的EDLC上從而實現電壓的平衡。最重要是選擇平衡電阻值以提供EDLC更高電流的流動而不增加 EDLC的漏電流。須記住在高溫下漏電流是會上升的。
Passive voltage balancing uses voltage-dividing resistors in parallel with each EDLC. This allows current to flow around the EDLC at a higher voltage level into the EDLC at a lower voltage level, thus balancing the voltage. It is important to choose balancing resistor values that provide for higher current flow than the anticipated leakage current of the EDLC, bearing in mind that the leakage current will increase at higher temperatures.
被動電壓平衡只在不經常進行EDLC充放電使用和使用能承受平衡電阻的額外電流負載時推薦使用。建議所選擇的平衡電阻應能提供最差EDLC漏電流50倍以上的額外電流(根據最高使用溫度選擇3.3 KΩ~22kΩ的電阻)。盡管更大阻值的平衡電阻在大多數情況下也能工作,但其不可能在不匹配的電容器串聯時起到保護作用。
Passive voltage balancing is only recommended for applications that don't regularly charge and discharge the EDLC and that can tolerate the additional load current of the balancing resistors. It is suggested that the balancing resistors be selected to give additional current flow of at least 50 times the worst-case EDLC leakage current (3.3kΩ t0 22kΩ depending on maximum operating temperature). Although higher values of balancing resistor will work in most cases they are unlikely to provide adequate protection when significantly mismatched parts are connected in series.
主動電壓平衡Active Voltage Balancing
主動電壓平衡電路能使串聯的EDLC上的電壓與額定電壓驅同而不管有多少電壓不平衡產生。同時確保在穩態情況下準確的電壓平衡電路能有效地降低電流,而且只在電容電壓發生不平衡時才要求更大的電流。這些特性使得主動電壓平衡電路是EDLC頻繁充放電及如電池等能量組件使用的最理想電路。
Active voltage balancing circuits force the voltage at the nodes of series connected EDLC to be the same as a fixed reference voltage, regardless of how any voltage imbalance occurs. To ensure accurate voltage balancing, active circuits typically draw much lower levels of current in steady state and only require larger currents when the capacitor voltage goes out of balancing. These characteristics make active voltage balancing circuits ideal for applications that charge and discharge the EDLC frequently as well as those with a finite energy source such as a battery.
反極性保護Reverse Voltage Protection
當串聯EDLC迅速放電,容量值低的電容器之上的電壓將潛在地變為負電壓。如之前的解釋,此是不希望出現的且會縮短EDLC的工作壽命。一種簡單的防護逆向電壓的方法是在電容器上增加一個二極管。使用適當的額定的限流二極管替代標準的二極管,還可以保護EDLC出現過電壓現象。需要謹慎的是確保二極管能承受電源的峰值電流。
When series connected EDLC are rapidly discharged, the voltage on low capacitance value parts can potentially go negative. As explained previously, this is not desirable and can reduce the operating life of the EDLC. One simple way of protecting against reverse voltage is to add a diode across the capacitor,configured so that it is normally reverse bias. By using a suitably rated zener diode in place of a standar diode the EDLC can also be protected against overvoltage events. Care must be taken to ensure that the diode can withstand the available peak current from the power source.
焊接信息 Soldering Information
過熱會導致EDLC電性能的退化,漏液或內壓升高。焊接應遵循以下具體指示:
Excessive heat may cause deterioration of the electrical characteristics of the EDLC, electrolyte leakage or an increase in internal pressure. Follow the specific instructions listed below:
另外:
1.不要把EDLC浸入已熔解的焊錫中。
2.只在EDLC導針上粘上焊劑。
3.確保EDLC套管不直接與PCB或其它組件接觸。過高的焊錫溫度會導致套管收縮或破裂。
4.避免EDLC在裸露的電路板之下工作以防止短路發生。
In addition
1.Do not dip EDLC body into melted solder.
2.Only flux the leads of the EDLC.
3.Ensure that there is no direct contact between the sleeve of the EDLC and the PC board or any other component. Excessive solder temperature may cause sleeve to shrink or crack.
4.Avoid exposed circuit board runs under the EDLC to prevent electrical shorts.
手工焊接Manual Soldering
不可讓EDLC外部套管與焊棒接觸,否則套管會熔化或破裂。焊嘴溫度建議低于350℃,焊接持續時間少于4秒鐘。應使烙鐵與EDLC導針直接接觸時間最小化,因為導針過熱會提高等效串聯電阻值(ESR)。
Do not touch the EDLC's external sleeve with the soldering rod or the sleeve will melt or crack. The recommended temperature of the soldering rod tip is less than 350℃ and the soldering duration should be less than 4 seconds. Minimize the time that the soldering iron is in direct contact with the terminals of the EDLC as excessive heating of the leads may lead to higher equivalent series resistance (ESR).
波峰焊Wave Soldering
最多給PCB預熱60秒鐘,浸錫達0.8mm或更厚。預熱溫度極限應低于100℃。
Use a maximum preheating time of 60 seconds for PC boards 0.8mm or thicker. Preheating temperature should be limited to less than 100℃.
以下表格信息只用于導針的波峰焊接:
Use the following table for wave soldering on leads only:
焊錫溫度(℃) |
建議焊錫時間 |
最大焊接時間 |
220℃ |
7 |
9 |
240℃ |
7 |
9 |
250℃ |
5 |
7 |
260℃ |
3 |
5 |
回流焊接Reflow Soldering
除非EDLC有明確的額定耐回流焊接溫度,否則不應對EDLC使用回流焊接而應使用紅外線或傳送烤爐加熱方法進行焊接。
Do not use reflow soldering on EDLC using infrared or convection oven heating methods unless the EDLC is specifically rated to withstand reflow soldering temperature.
紋波電流Ripple Current
盡管EDLC相對于其它超級電容來說有很低的電阻,其還有比鋁電解電容器更高的電阻且在紋波電流之中容易受內部熱量的影響而使ESR升高,壽命縮短。為確保長久的壽命,推薦的最大紋波電流不應使EDLC表面溫度提升高于3℃。
Although EDLC have very low resistance in comparison to other supercapacitors, they do have higher resistance than aluminum electrolytic capacitors and are more susceptible to internal heat generation when exposed to ripple current. Heat generation leads to electrolyte decomposition, gas generation, increased ESR and reduced life time. In order to ensure long life time, the maximum ripple current recommended should not increase the surface temperature of the EDLC by more than 3℃.
電路板設計Circuit Board Design
盡量避免清潔電路板,如果要進行電路板清潔,應使用標準電路板清潔液通過無靜電或超音波浸漬方法進行清潔,時間不超過5分鐘,最高溫度不高于60℃。之后要徹底沖洗和風干。一般來說,應將EDLC如同鋁電解電容器一樣對待。
Avoid cleaning of circuit boards, however if the circuit board must be cleaned use static or ultrasonic immersion in a standard circuit board cleaning fluid for no more than 5 minutes and a maximum temperature of 60℃. Afterwards thoroughly rinse and dry the circuit boards. In general, treat EDLC in the same manner you would an aluminum electrolytic capacitor.
長期貯存Long Term Storage
不要在以下環境中貯存EDLC:
1.局溫/高濕度下貯存
2.直接與腐蝕性材料、酸、堿金屬或有毒氣體接觸
3.陽光直射
4.粉塵環境
5.沖擊和/或振動環境
Do not store EDLC in any of the following environments:
1.High temperature and/or high humidity
2.Direct contact with corrosive materials, acids, alkalis or toxic gases
3.Direct exposure to sunlight
4.Dusty environment
5.Environment subject to excessive shock and/or vibration
運輸信息Transportation Information
EDLC未受到US DOT(運輸部)和IATA的規定。正確的國際運輸描述是“電子產品-電容器”。
EDLC are non-regulated by the US DOT (Department of Transport) and IATA. The correct international shipping description is “Electronic Parts – Capacitors”.
應急程序 Emergency Procedures
如果發現EDLC過熱或是聞到香的氣味,應立即斷開與EDLC連接的電源或負載。讓EDLC降溫,然后進行正確處理。不可讓臉或手接觸過熱的EDLC。如果EDLC發生漏液或防爆閥破裂請與生產廠商聯系索取材料安全資料表。
If an EDLC is found to be overheating or if you smell a sweet odor, immediately disconnect any power or load to the EDLC. Allow the EDLC to cool down, then dispose of properly. Do not expose your face or hands to an overheating EDLC. Contact the factory for a Material Safety Date Sheet if an EDLC leaks or vents.
如果有漏液情況:
皮膚接觸:用肥皂和水沖洗皮膚。
眼睛接觸:用水清洗眼睛15分鐘,看醫生。
吸?。汉扰D?水并吐出,看醫生。
If exposed to electrolyte:
Skin Contact: Wash exposed area thoroughly with soap and water.
Eye Contact: Rinse eyes with water for 15 minutes and seek medical attention.
ngestion: Drink milk/water and induce vomiting; seek medical attention.
一般性安全考慮General Safety Considerations
如果過度充電,反向充電,焚燒或高于150℃加熱,EDLC有可能發生防爆閥爆裂。不要壓擠,損傷,壓釘或拆解EDLC。濫用EDLC可能導致鋁殼上高溫(燒傷)。
EDLC may vent or rupture if overcharged, reverse charged, incinerated or heated above 150℃. Do not crush, mutilate, nail penetrate or disassemble. High case temperature (burn hazard) may result from abuse of EDLC.
廢棄處理程序。
Disposal Procedures.
不要隨便丟棄。應根據當地法律法規進行處理。
Do not dispose of unit in trash. Dispose of according to local regulations
溫度表現 Thermal Performance
使用時能量貯存單位上低內阻會使得低熱量產生。電子產品使用溫度越低,其工作時間越久。大多數使用領域自然空氣對流都能提供足夠的冷卻環境。在惡劣環境中使用,還要求有最長的使用壽命則需要添加一些空氣對流設備。
Low internal resistance of the energy storage units enables low heat generation within the units during use. As with any electronic components the cooler the part operates the longer the service life. In most applications natural air convection should provide adequate cooling. In severe application requiring maximum service life some forced airflow may be required.
針對耐熱來說,測量產品的Rth需在環境溫度(-25℃)下進行并允許自然對流。數據表上的Rth值對確定產品工作極限值是有用的。利用Rth值,可計算出任何電流和工作循環下的溫升。
The thermal resistance, Rth of the units has been experimentally determined assuming free convection at ambient (-25℃). The Rth value provided on the data sheet is useful for determining the operating limits for the units. Using the Rth value a module temperature rise can be determined based upon any current and duty cycle.
溫度升高值可按以下等式算出:
△T = Dc*Rth*I2*Resr
其中:Dc=工作循環
I=AC/DC電流
Rth=耐熱性(℃/W)
Resr=等效串聯電阻,(Ohms)(使用直流電)
The temperature rise can be expressed by the following equation:
△T = De*Rth*I2*Resr
Where:Dc=Duty Cycle
I=Current AC/DC(A)
Rth=Thermal Resistance(℃/W)
Resr=Equivalent Series Resistance,(Ohms)(DC value used)
特性Features:
1.可用作充電電池及后備電源。
2.具備數十萬次充電/放電循環次數,免卻廢物處理。
3.不含有毒材料,如鎳及鎘。
1.Can be used as a rechargeable battery and ideal for backing up purpose.
2.Capable of several hundreds of thousands of charge/discharge cycles; free from throwaway disposal.
3.Does not contain toxic materials such as nickel and cadmium.
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