1299589 九、發明說明： 【發明所屬之技術領域】 本發明為一種二次電池的保護方法與裝置，特別是一種針 對二次電池的使用情形提供一電流限制，用以限制該二次電池 之電流的一次電池保護方法。 【先前技術】 一次電池是藉由電池的陰陽極進行氧化還原反應，用以將 化學能轉換為電能或將電能轉換成化學能，要能長久維持二次 電池的使用效能，主要的關鍵在維持二次電池内部材料的組 成。然而二次電池的使用往往為滿足產品的需要而有不當使用 的隋心’例如過局的壞境溫度、過南或過低的充放電電壓或充 放電電流過大等等，這些都可能造成電池内部材料變質，產生 電池性能早期衰退的主要原因。因此為保護二次電池的使用， 電池供應商會要求使用者在使用上維持電池的溫度或電壓在電 池的正常使用範圍之内。以鋰鈷系列電池為例，一般建議的正 '吊使用範圍疋·充電截止電壓在4.15V〜4.35V之間，放電截止 電壓在2.35V〜3.0V之間，充放電的溫度在6〇。〇内。 一般二次電池所提供的限制多半是在充放電電壓及電池本 體溫度上，但在實際應用上，二次電池的輸出電流對於二次電 池的保護更是息息相關。舉例來說，二次電池為了因應負載的 需求而被迫輸出大電流時，就可能造成二次電池本身的電壓迅 速下降和二次電池本體溫度快速上升，而二次電池本體溫度上 升又會影響二次電池内部的化學反應，如此一來因為沒有針對 一次電池的使用情形進行電流限制或電流限制的條件設定不 佳，使得二次電池迅速達到功率崩潰，造成實際應用上的效率 0178-A20770TWF(N2)；P05930Q35TW；brent 5 1299589 =1知⑽解決二次電池的充放電電流 =理機制:,用以限制二次電池的電流大小，以避免上:情 t發f。以目賴有產品對電流的限制條件往往以定電^ 试，求仔該應用產品可能使用的最大電流後，再 數所這樣的限㈣流往往只可能發生在負載異常短路“ 形=仔限制電机的貫質意義上較接近於短路保護開關盘 二次電池保護無關。 ^ 由於產品内各項裝置的不同，對於二次電池的輸出 電7也有很大的影響’例如筆記型電腦的電池在開機時，為啟 減種轉子裝置（如光碟機，硬雜等），瞬_要較大的電流 夕卜，八餘時間都維持在一定用電量，雖然期間可能有許多脈波， ”峰負載與平時負載差異只有卜2倍。又以電動機車為 歹j，電動機車在啟動時需要較大的電流，之後平順加速時用電 較低，電流輸出減小，直到高速行駛時輸出電流才又上升。如 果電動機車是在市區内行駛，可能因為路況需求而對電動機車 快速加速、減速或起動，造成對二次電池需求的電流快速變化， 而，二次電池快速老化，減少使用壽命。如果以目前使用的定 電^呆護方式的話’可能設定的限制電流值過高，僅只能達到 "人電池的短路保護’而無法真正針對二次電池的應用需求進 行電流的限制，冑到二次電池的保護效果。 【發明内容】 為了改善習知以定電流方式作為二次電池保護方法的缺 點;’本發明提供一種二次電池的電流限制機制作為二次電池的 保β蔓方去包括·提供一二次電池；提供該二次電池的開迴路 電堅’、殘電各里的關係曲線；提供該二次電池之一放電截止電 〇178-A20770TWF(N2)；P〇593〇〇35TW;brent 1299589 壓，彳貞測該二次電池目前的一開迴路電壓，並根據該二次電池 的開迴路電壓與殘電容量的關係曲線求得該二次電池目前的一 殘電容量值；提供該二次電池之一直流放電阻抗；以及根據該 二次電池的殘電容量值與該直流放電阻抗，計算在一第一預定 時間内’不使該二次電池到達該放電截止電壓之複數個電流值 中一最大電流值，且根據該最大電流值，限制該二次電池之輸 出電流。 本發明亦提供另一種二次電池電流限制機制作為二次電池 的保護方法’包括：提供一二次電池；提供該二次電池之一限 制溫度值與一熱阻係數；提供該二次電池之一直流放電阻抗與 一直流充電阻抗。偵測該二次電池之溫度與一環境溫度。根據 該熱阻係數、該直流放電阻抗、該直流充電阻抗、該二次電池 之溫度與該環境溫度，計算在一第一預定時間内，該二次電池 進行充電或放電動作其中之一時，不使該二次電池的溫度到達 該限制溫度值的複數個電流值中一最大電流值，用以限制該二 次電池之電流。 此外，本發明更提供一二次電池的保護裝置，包括：一偵 測單元，用以偵測一二次電池之一開迴路電壓、一環境溫度與 一二次電池溫度，並輸出該開迴路電壓、該環境溫度與該二次 電池溫度。一保護機制單元，紀錄該二次電池之複數個參數， 並根據該等參數、該開迴路電壓、該環境溫度與該二次電池溫 度，該二次電池之一殘電容量值，計算在一第一預定時間内， 不使該二次電池到達-放電截止電壓之複數個電流值中一最大 電流值，或計算再-第二預定時間内，使該二次電池進行充電 或放電動作其中之—時，不㈣二次電池的溫度到達m 度之複數個電流中之一最大電流值。一電源管理單元，根據該 〇178-A20770TWF(N2)；P05930035TW；brent 7 Ϊ299589 保護機制單元所得之最大電流值，限制該二次電池之電流 【實施方式】 本發明提出一種二次電池的保護方法及袭置，特別是藉由 :次電池在不同的使用情形時，偵測二次電池的特性狀態，提 供二次電池的充放電電流限制，以取代傳統方式t以電池的設 ^電流容量或異常短料固定數據為限難时法。本發明提 出之二次電池保護方法包括三項電流限制的機制，包括：一、 在放電期間避免放電電流過大，造成二次電池電壓快速到達放 電截止電壓。—、避免二次電池在充電或放電期間，電流過大 使：電池本體的溫度到達預定的限制溫度。三、在二次電池充 電避免充電電流過大使得二次電池的電壓超過充電截止電 為了推异則述二次電池保護方法中電流限制機制的第一] :第三項，我們必須隨時計算二次電池的開迴路電壓，以及: 次電池的充電阻抗與放電阻抗等參數。直接量測二次電池的具 迴路電壓必須先將二次電池靜置—段時間，等到二次電池中力 ，物的離子分佈濃度穩定後才能量測到穩㈣開迴路電壓，^ ，在實際應用上有執行上的困難。由於二次電池的開迴路電属 疋由參與電池氧化還原反映的離子濃度比例所決定的，因 們由殘餘電容量（亦就是尚餘可參與反應物的多寡）來推曾_ 次電池的開迴路電肢較為理想的。此外二次電池的充電^ ^放電阻抗分職應進行充電和放電過程_電子移動與離子移 t所遇到的阻礙，因此可預期會受到電池溫度、殘電容量和電 t老化以後材料組成的改變等等的影響。在此我們可以以電池 出薇時的標準阻抗值來作計算，必要時在加人溫度 0178-A20770TWF(N2)；P05930035TW；brent 81299589 IX. Description of the Invention: [Technical Field] The present invention relates to a method and apparatus for protecting a secondary battery, and more particularly to providing a current limit for limiting the current of the secondary battery for use of the secondary battery A primary battery protection method. [Prior Art] The primary battery is subjected to a redox reaction by the anode and cathode of the battery to convert chemical energy into electrical energy or convert electrical energy into chemical energy. To maintain the performance of the secondary battery for a long time, the main key is to maintain The composition of the internal material of the secondary battery. However, the use of secondary batteries often has the disadvantage of improper use for satisfying the needs of the product, such as excessive ambient temperature, excessive or too low charge/discharge voltage, or excessive charge and discharge current, etc., which may cause the battery. Deterioration of internal materials creates the main cause of early battery degradation. Therefore, in order to protect the use of the secondary battery, the battery supplier will require the user to maintain the temperature or voltage of the battery within the normal use range of the battery. Taking lithium-cobalt series batteries as an example, the general recommended range of 'hanging range' is 4.1. The charge cut-off voltage is between 4.15V and 4.35V, the discharge cut-off voltage is between 2.35V and 3.0V, and the charge and discharge temperature is 6〇. Inside. Generally, the limitation provided by the secondary battery is mostly on the charge and discharge voltage and the temperature of the battery body. However, in practical applications, the output current of the secondary battery is closely related to the protection of the secondary battery. For example, when the secondary battery is forced to output a large current in response to the demand of the load, the voltage of the secondary battery itself may rapidly drop and the temperature of the secondary battery body may rise rapidly, and the temperature rise of the secondary battery body may affect. The chemical reaction inside the secondary battery, because the conditions for current limiting or current limiting are not set well for the use of the primary battery, so that the secondary battery quickly reaches the power collapse, resulting in practical efficiency of 0178-A20770TWF ( N2); P05930Q35TW; brent 5 1299589 =1 know (10) to solve the charge and discharge current of the secondary battery = mechanism: to limit the current of the secondary battery to avoid: f: f. In order to determine the current limit of the product, it is often determined by the power supply. After the maximum current that the application product may use, the number of such (4) flows may only occur in the load abnormal short circuit. The quality of the motor is relatively close to the secondary battery protection of the short-circuit protection switch disk. ^ Due to the different devices in the product, it also has a great influence on the output power of the secondary battery. At the time of starting up, in order to start and reduce the rotor device (such as CD player, hard memory, etc.), it is necessary to maintain a certain amount of power for more than eight hours, although there may be many pulse waves during the period," The difference between the peak load and the usual load is only 2 times. In addition, the electric motor car is 歹j, and the electric motor car needs a large current when starting, and then the power consumption is lower when the smoothing is accelerated, and the current output is reduced until the output current rises again at high speed. If the electric motor vehicle is driving in an urban area, the electric motor vehicle may be rapidly accelerated, decelerated or started due to the demand of the road condition, causing a rapid change in the current required for the secondary battery, and the secondary battery rapidly ages and reduces the service life. If the current limit of the current limit is too high, the limit current value that can be set is too high, and only the short circuit protection of the human battery can be achieved, and the current limit cannot be truly applied to the application requirements of the secondary battery. The protective effect of the secondary battery. SUMMARY OF THE INVENTION In order to improve the conventional method of using a constant current as a secondary battery protection method, the present invention provides a current limiting mechanism for a secondary battery as a secondary battery to include a secondary battery. Providing a relationship curve between the open circuit and the residual current of the secondary battery; providing one of the secondary batteries with a discharge cutoff voltage of 178-A20770TWF (N2); P〇593〇〇35TW; brent 1299589, Detecting a current open circuit voltage of the secondary battery, and determining a current residual capacity value of the secondary battery according to a relationship curve between the open circuit voltage and the residual current of the secondary battery; providing the secondary battery a DC discharge impedance; and calculating, according to the residual capacity value of the secondary battery and the DC discharge impedance, one of a plurality of current values that does not cause the secondary battery to reach the discharge cutoff voltage within a first predetermined time The maximum current value, and the output current of the secondary battery is limited according to the maximum current value. The present invention also provides another secondary battery current limiting mechanism as a method for protecting a secondary battery 'including: providing a secondary battery; providing a limit temperature value and a thermal resistance coefficient of the secondary battery; providing the secondary battery A DC discharge impedance and a constant current charging impedance. The temperature of the secondary battery and an ambient temperature are detected. Calculating, according to the thermal resistance coefficient, the DC discharge impedance, the DC charging impedance, the temperature of the secondary battery, and the ambient temperature, when the secondary battery performs one of charging or discharging operations within a first predetermined time, And a maximum current value of the plurality of current values of the secondary battery reaching the limit temperature value for limiting the current of the secondary battery. In addition, the present invention further provides a secondary battery protection device, comprising: a detecting unit for detecting an open circuit voltage, an ambient temperature and a secondary battery temperature of a secondary battery, and outputting the open circuit Voltage, the ambient temperature, and the temperature of the secondary battery. a protection mechanism unit that records a plurality of parameters of the secondary battery, and calculates a residual capacity value of the secondary battery according to the parameters, the open circuit voltage, the ambient temperature, and the temperature of the secondary battery, In the first predetermined time, the secondary battery is not caused to reach a maximum current value of the plurality of current values of the discharge-discharge voltage, or the second predetermined time is calculated to cause the secondary battery to perform charging or discharging operations. - When, the temperature of the secondary battery does not reach one of the plurality of currents of m degrees. A power management unit limits the current of the secondary battery according to the maximum current value obtained by the protection mechanism unit of the 〇178-A20770TWF(N2); P05930035TW; brent 7 Ϊ 299589. [Embodiment] The present invention provides a protection method for a secondary battery And the attack, in particular, by: detecting the characteristic state of the secondary battery in different use cases, providing the charge and discharge current limit of the secondary battery, instead of the conventional method, the current capacity of the battery or Abnormal short-term fixed data is a difficult time method. The secondary battery protection method proposed by the present invention includes three current limiting mechanisms, including: 1. Avoiding excessive discharge current during discharge, causing the secondary battery voltage to quickly reach the discharge cutoff voltage. - To prevent the secondary battery from being overcharged during charging or discharging. The temperature of the battery body reaches a predetermined limit temperature. Third, in the secondary battery charging to avoid the charging current is too large, so that the voltage of the secondary battery exceeds the charging cut-off power. In order to push the difference, the current limiting mechanism in the secondary battery protection method is the first]: the third item, we must calculate twice at any time. The open circuit voltage of the battery, and the parameters such as the charging impedance and discharge impedance of the secondary battery. Direct measurement of the secondary battery with the loop voltage must first set the secondary battery to rest - the time, wait until the force in the secondary battery, the ion concentration of the object is stable before measuring the stable (four) open loop voltage, ^, in practice There are implementation difficulties in the application. Since the open circuit of the secondary battery is determined by the proportion of the ion concentration reflected by the redox reaction of the battery, the residual capacity (that is, the amount of reactants that can be involved in the reaction) is used to push the battery. Loop electric limbs are ideal. In addition, the charging of the secondary battery ^ ^ discharge impedance should be carried out in the charging and discharging process _ electronic movement and ion transfer t encountered obstacles, so it can be expected to be affected by battery temperature, residual capacity and electrical t aging material Change and so on. Here we can calculate the standard impedance value when the battery is out, if necessary, add the temperature 0178-A20770TWF (N2); P05930035TW; brent 8
V 1299589 修正。 數也是必要的。通常f:阻抗和放電阻抗外，電池的散熱係 數已經綠定，變=二!池在出廢後電池芯與外界的熱阻係 參數來作計算 衫大，因此我們就讀商提供的數值為 模组書中即以供以—電動自行車馬達電力來源的-電池 核、，且為只施例’說明前述二次電池保護方 限制機制，苴中爷雷姊伊,、, 貝电也電/瓜 ^該電繞组以七個18Ah鋰鈷系二次 =二電截止電μ 2·8ν。在本實施例中，以不同的制單 凡、-人電池的電;1、電流和溫度彳貞測’並以開迴路電壓與電 流積分的方式’隨時計算電池的殘餘電容量，並隨時計算以不 同的放電電流在-分鐘後各單元電池的電壓，以求得不使達到 放電截止電壓的最大電流。 為了求彳于一開始二次電池的殘電容量的初始值，每次使用 二次電池前，先假定電池已經靜置足夠時間，使得從二次電池 置知的端電壓即為開迴路電壓。藉由量得的開迴路電壓對照一 殘電容量與開迴路電壓關係曲線，求得初始的殘電容量值。一 旦電池開始充放電後，電池的開迴路電壓就必須以殘電容量計 算，而殘電容量的求得則是以殘電容量初始值減去放電的電流 積分或加上充電的電流積分所得。底下則先以上述二次電池保 護方法中電流限制機制的第一項放電電流限制，計算在連續放 電一分鐘的限制下，提供二次電池的電源管理裝置的最大放電 電流。 第1圖為本實施例所使用的UAh鋰鈷系二次電池的殘電 容量與開迴路電壓的對照圖。第2圖則是該1.8Ah鋰鈷系二次 電池在不同的殘電容量狀態下，以一定電流分別放電3秒鐘、 0178-A20770TWF(N2)；P05930035TW；brent 9 1299589 1 〇 f;/鐘和1分鐘的情形下求得的電池直流阻抗曲線圖。第3圖 則是表示在不同的殘電容量下，以不同的放電電流求得直流阻 抗的關係圖’特別是在低容量狀態時，直流阻抗會有較大的差 異。本實施例即以二次電池的殘電流量為2〇%時，計算可連續 放電一分鐘而不到達放電截止電壓的最大電流。在此我們先計 算從0.2C(C為表示二次電池所提供的電流，在此為h8Ah，〇 2c = 〇·36Α)到3.0C (5.4A)，每隔0.2C的各種電流經過一分鐘放 電後的殘電容量值。例如以3〇c電流放電一分鐘的放電容量為 5% ’那就可以得知以其他電流放電一分鐘後，二次電池的開迴 路電壓會落在第1圖中殘電容量15%到2〇%之間的對應電壓 值。另外直流阻抗造成的電壓影響部份，則由第2圖與第3圖 所構成的二維阻抗函數及6〇 (s=s〇c%，〗）乘上放電電流來求 知。除此之外，在計算之前二次電池可能會因為充電或放電造 成電池端電壓與開迴路電壓的差異部分，經過一分鐘後仍有殘 餘效果，必須併入計算。二次電池的殘餘電壓差是以指數形式 衰減，其衰減的時間函數可由電池出廠前測量所得。綜合上述 可得下列方程式，用以估計以定電流放電一分鐘後的電池端電 壓： 匕w)-(]^—)^exp(—60/^^60(^)(第一式） 其中I為放電期間的定電流，s為放電前的殘電容量（以％ 表示），S，為以電流〗放電一分鐘後的殘電容量，可表示為 b匕為二次電池的開迴路電壓，匕。為二次電池 的開迴路電壓的初始值，0為二次電池的端電壓的初始值，丁則 疋-次電池衰減的時間常數。放電電》Z越大，放電—分鐘後 的殘電容量s’就越小’開迴路電壓❻，)也越小，但直流阻抗 及V，/)也因此變大。第一式為本實施例中以一分鐘為例的方程 0178-A20770TWF(N2)；P05930035TW；brent 10 1299589 = = :方程式，可計算不同時間，定電流放電後的電 間’才能到達給定的開迴路電壓。其中t為電時:放 Γ ⑺一 FVexpH/z·) 一/·心，^。（第二式） 曰為了說月第一式的计算，我們以第4a圖與第4b圖來做說 明。第43圖為一放電深度與開迴路電壓對照圖，第4b圖為第 如圖中46的放大圖，表示在放電深度到達8〇%(放電深度（％ ) 等们_減去殘電容量（％))時，以定電流放錢的開迴路 電壓值。其中a為表示二次電池電壓回復，b為二次電池容量減 少，c為放電阻抗產生的二次電池端電壓的變化。可分別以下列 數學式表示： β = -(^〇°-F°).exp(-60/r) b=zVoc(s’)-V〇c(S) c = -I •i?60^',/) 因此可藉由炉⑺ > 匕^ (放電截止電壓）來求出最大電流。 在第4b圖中，45為表示放電深度到達80%的位置。4〇則表示 在放電深度到達80%後，就停止放電（以〇c放電），在經過8 分鐘後’因二次電池的特性而有電池電壓回復的情形，所以電 壓會較原先電壓高。41則是表示以%c放電8分鐘後，二次電 池的殘電容量與對應開迴路電壓。42則是表示以%〔放電8分 鐘後，二次電池的殘電容量與對應開迴路電壓。43則是表示以 %(：放電8分鐘後，二次電池的殘電容量與對應開迴路電壓。44 則是表示以1C放電8分鐘後，二次電池的殘電容量與對應開迴 路電壓。 第5圖為一二次電池以定電流放電的電壓對照圖，表示二 〇178-A20770TWF(N2)；P05930035TW；brent 11 1299589 久電池在放電ί朱度8 Ο %後靜置一段時間後’以不同的電流放電 一分鐘内，二次電池的端電壓變化曲線圖，其中圖上的虛線為 預測以不同電流放電一分鐘時，二次電池的電壓曲線圖。其中 51為二次電池在放電深度80%後，以一極小電流放電所得之電 壓變化曲線，52為以0.2C放電一分鐘所得之電壓變化曲線，53 為以0.6C放電一分鐘所得之電壓變化曲線，54為以i〇c放電 一分鐘所得之電壓變化曲線，55為以1.4C放電一分鐘所得之電 壓變化曲線’ 56為以1.8C放電一分鐘所得之電壓變化曲線，57 為以2.2C放電所得之電壓變化曲線，58為以2_6C放電一分鐘 所付之電壓變化曲線’ 59為以3 .OC放電一分鐘所得之電壓變化 籲 曲線。由圖上可得知，當二次電池以26C内的電流放電一分鐘 後’不會使二次電池的電壓達到放電截止電壓2·8ν，若二次電 池以3C的電流放電一分鐘，則會使二次電池的電壓低於放電截 * 止電壓。同理我們可以在二次電池不同的放電深度，作對應電 池容量的最大電流限制值的預測。第6圖為二次電池在不同的 放電课度時，以不同的定電流放電一段時間後，二次電池的電 壓變化曲線圖。其中62為二次電池放電深度8〇%時，以不同電 流放電-分鐘時，二次電池的電壓變化曲線，已經在第5圖說 明過。61為二次電池放電深度60%時，以不同電流放電一分鐘籲 犄’一-人電池的電壓變化曲線，63為二次電池放電深度卯％時， 以不同電桃放電一分鐘時，二次電池的電壓變化曲線。其中在 二次電池放電深度60%時H 2(：和3C對二次電流放電， 由於電池的放電阻抗較低，造成的壓降較小，因此都不會到達 放，截止電壓。二次電池在放電深度90%時，由於二次電池的 容量接近截止’二次電池的直流組抗較大，因此以1C、2C或 3C的電流放電都會得到較大的壓降。以本實施例提供的第一式 0178-A20770TWF(N2)；P〇5930035TW；brent 12 1299589 與各項參數計算後，可得到二次電池在放電深度6〇%時的限制 電流值為3.6C，二次電池放電深度90%時的限制電流值為 1.8C，便可根據該限制電流值限制二次電池的輸出電流。 除了放電的電流限制外，本發明也可以應用在充電時的充 電電流限制，以避免過度充電的情形。或是以定電流充電的充 電時間的估算也可以利用第二式求得。我們可以藉由二次電池 的殘電容量在不同狀態時，估計以不同的定電流充電一特定時 間後’二次電池的殘電容量變化或是開迴路電壓的變化。或是 估^在-特定時間内，不使二次電池超過充電截止電壓的最大 =流。又或是以一固定電流值對二次電池充電，估計需要多少 w才能使二次電池到達充電截止電麼。藉由這些資訊提供給 電源管理單元供作電源㈣的限制’或是提供給使用者得知。 ^除了避免m電流過大使得：次電池無預警的到達放電截止 電塵、，或是超過充電截止電壓外，本發明所提供之二次電池保 遵方法更包含利用不同放電電流狀況下的溫度上升預測，來限 制電池電流。以本實施例中的：次電池在殘電容量㈣時為 例’此時二次電池的直流阻抗約為14_，限制溫度值為砍， =境溫度為饥。計算電池的溫度是否到達限制溫度時，必須 =到總熱量的產生量與熱量的產生速率。由基本熱力學原理 可侍到下列兩個數學式： 生熱量(第三式） 务熱功率 ：p = Aj7及 甘^ (第四式） 為二次電池的比熱，約為麵焦耳/公斤；M為二 二人電池的質量，約為h5公斤 了為連績放電時間，單位為秒， 設定的相心。分鐘（_秒）；〜為二次電 池内部到外部之間的熱傳導阻抗， H·人電 匕έ包裝外殼的傳導熱阻以 〇178-A2077〇TWF(N2)；P〇5930035TW；brent 13 1299589 及外殼表面到外部環境之間的對流熱阻，在本實施例中，外殼 的熱傳導阻抗是由表面積1050平方公分，厚度2.5mm，外殼材 質為PVC的熱傳導係數為0.16W/m.K。此外，電池外殼亦受到 對流散熱的影響，以本實施例之電動自行車來說，車速的快慢 對於對流散熱是有一定的.影響。以自行車車速14公里為例，風 速約每秒4公尺，二次電池在外部接觸的長度為20公分，對流 熱阻約0.483K/W，因此綜合前兩項的熱阻可得4為.1.97K/W。 在不知道二次電池的溫度的時候，為計算不使二次電池到 達限制溫度的最大電流，我們分別假定二次電池此時的溫度為 室溫25°C與限制溫度65°C的情形下去計算。我們先以第三式來 計算在室溫25°C下，假定二次電池的初始溫度亦為25°C，二次 電池的限制溫度為65°C，則二次電池的電流超過限制溫度的條 件為： 12> ΑΤ·Ορ·Μ/ΙΙ·Τ = 714 (亦即最大電流為 26_7A) 另一方面，我們假定二次電池此時的溫度為65°C，室溫25°C 時，則由第四式可以求出維持二次電池内部溫度在65°C的發熱 功率與對應電流值為： P= AT/Rh = 40 /1.97 = 20.3w = Ι2·0.14 ( 1=12.04Α) 由上述得知，當二次電池的内部溫度到達限定溫度 65V 時，二次電池的電流必須維持12A才可使二次電池内部溫度維 持在65°C (與外界溫差為40°C )。若二次電池内部的初始溫度 與外界溫度同為25°C，則必須要超過26.7A的電流才能在10分 鐘内，使二次電池的内部到達限制溫度65°C。因此在二次電池 溫度未知，室温25°C時，避免二次電池在1〇分鐘内到達限制溫 度，電池管理系統應將二次電池的電流限制在26.7A以下。 若是已知二次電池的初始溫度為60°C，外部溫度同樣為 0178-A20770TWF(N2)；P05930035TW；brent 14 1299589 25°C，以第三式計算得知，需9.45A的電流才可在十分鐘之後 使二次電池達到65°C的限制溫度，因此電池管理系統對二次電 池的電流限制應為9.45A。 第7圖為一二次電池與保護裝置之功能架構圖，其中保護 裝置70計算一限制電流值後，用以限制二次電池72的輸出或 輸入電流。偵測單元73用以偵測二次電池72的各項數值，例 如電壓大小，溫度高低，電流大小等等。將這些數值傳送給保 護機制單元74作數學運算後得到一限制電流值，並傳送給電源 管理單元75 ,電源管理單元75則根據該限制電流值限制二次電 池72的電流輸出。當負載71從二次電池72汲取的電流值小於 該限制電流值時，二次電池72輸出負載71所需之電流值。當 負載71從二次電池72汲取的電流值大於該限制電流值時，則 電源管理單元75控制二次電池72的輸出電流為該限制電流值。 第8圖為本發明之一流程圖。在步驟S81時，偵測二次電 池的各項狀態數值，如電壓、溫度或是電流等等。在步驟M2 時，根據步驟S81仙到的狀態數值與二次電池本身的參數如 直μ阻抗、熱阻係數或殘電容量與開迴路電壓對照圖等等，計 算出限制電流值。在步驟S83時，根據步驟S82計算出的限 制電流值限制二次電池的輸出電流，並回到步驟s8卜持續計算 新的限制電流值。 ' μ由土述的說明可使得本發明更易於了冑，藉由本發明也可 使得推算二次電池的限制電流值更為準確，而且也可推算以定 電机充放電所需的時間。藉由以本發明提出的二次電池保護方 =電流限制機制求得的限制電流，可使得二次電池的限制電 机更為準確，也可以適時的根據二次電池的使用情形作改變， 相車乂於習知以定電流的限制，依據本發明所提出的二次電池保 0178-A20770TWF(N2)；P05930035TW；brent 1299589 電流’其實用性明顯較習 護方法中f流限制卿所求得的限制 知技藝來的好。 κ竹内*，而並非將本發明狹義地限定於該實施 歹|，壬可熟習此技藝者，在不脫離本發明之精神和範圍内，卷 =些=之更動與潤飾，因此本發明之保護範圍當視後附之: 凊專利範圍所界定者為準。 〒 0178-A20770TWF(N2);P05930035TW;brent 16 1299589 【圖式簡單說明】 第1圖為一 1.8Ah鋰鈷系二次電池的殘電容量與開迴路電 壓的對照圖。 第2圖為一 1.8Ah鋰鈷系二次電池在不同的殘電容量狀態 下，以一定電流放電3秒鐘、10秒鐘和1分鐘的情形下求得的 電池直流阻抗曲線圖。 第3圖則是表示在不同的殘電容量下，以不同的放電電流 求得的直流阻抗曲線圖。 第4a圖為一放電深度與開迴路電壓對照圖。 第4b圖為第4a圖中46的放大圖。 φ 第5圖為一二次電池以定電流放電的電壓對照圖。 第6圖為二次電池在不同的放電深度時，以不同的定電流 放電一段時間後，二次電池的電壓變化曲線圖。 、 第7圖為一二次電池與保護裝置之功能架構圖。 / 第8圖為本發明之一流程圖。 【主要元件符號說明】 40〜二次電池放電深度到達80%後，靜置8分鐘後的殘電容 量與對應電壓； ® 41〜二次電池放電深度到達80%後，以)放電8分鐘後的 殘電容量與對應電壓； 42〜二次電池放電深度到達80%後，以放電8分鐘後的 殘電容量與對應電壓； 43〜二次電池放電深度到達80%後，以放電8分鐘後的 殘電容量與對應電壓； 44〜二次電池放電深度到達80%後，以1C放電8分鐘後的 0178-A20770TWF(N2)；P05930035TW；brent 17 1299589 殘電容量與對應電壓； 45〜二次電池放電深度到達80%的殘電容量與對應電壓； 46〜二次電池放電深度到達80%後的局部放大圖； 51為二次電池在放電深度80%後，以一極小電流放電所得 之電壓變化曲線； 52為以0.2C放電一分鐘所得之電壓變化曲線； 53為以0.6C放電一分鐘所得之電壓變化曲線； 54為以1.0C放電一分鐘所得之電壓變化曲線； 55為以1.4C放電一分鐘所得之電壓變化曲線； 56為以1.8C放電一分鐘所得之電壓變化曲線； 57為以2.2C放電所得之電壓變化曲線； 58為以2.6C放電一分鐘所得之電壓變化曲線； 59為以3.0C放電一分鐘所得之電壓變化曲線 61〜二次電池放電深度60%時，以不同電流放電所得之電壓 曲線， 62〜二次電池放電深度80%時，以不同電流放電所得之電壓 曲線； 63〜二次電池放電深度90%時，以不同電流放電所得之電壓 曲線； 70〜保護裝置； 71〜負載； 72〜二次電池； 73〜偵測單元； 74〜保護機制單元； 75〜電源管理單元； S81〜偵測二次電池的狀態數值； 0178-A20770TWF( N2) ； P05930035TW； brent 18 1299589 S82〜根據二次電池本身的參數及狀態數值，計算一限制電 流值； S83〜根據步驟S82求得的限制電流值，限制二次電池的輸 出電流。 0178~A20770TWF(N2)；P05930035TW；brent 19Corrected by V 1299589. The number is also necessary. Usually f: impedance and discharge impedance, the heat dissipation coefficient of the battery has been green, change = two! After the battery is out of waste, the thermal resistance of the battery core and the outside is calculated to calculate the large size, so the value provided by our readers is the model. In the group book, the battery core of the electric bicycle motor power source is supplied, and the above-mentioned secondary battery protection party restriction mechanism is described for the case only, 苴中爷雷姊伊,,, 贝电也电/瓜^ The electrical winding is seven times 18Ah lithium cobalt secondary = two electrical cutoff electricity μ 2·8ν. In this embodiment, the residual capacity of the battery is calculated at any time by using different methods, the power of the human battery, the current and the temperature, and the integral of the open circuit voltage and current. The voltage of each unit cell after - minute after different discharge currents is obtained to obtain the maximum current that does not reach the discharge cutoff voltage. In order to find the initial value of the residual capacity of the secondary battery at the beginning, before using the secondary battery, it is assumed that the battery has been left for a sufficient time, so that the terminal voltage known from the secondary battery is the open circuit voltage. The initial residual capacity value is obtained by comparing the measured open circuit voltage with a residual current capacity and open circuit voltage. Once the battery begins to charge and discharge, the open circuit voltage of the battery must be calculated as the residual capacity, and the residual capacity is obtained by subtracting the current integral of the residual current from the initial value of the residual capacity or adding the current integral of the charge. Under the above, the first discharge current limit of the current limiting mechanism in the above secondary battery protection method is first calculated, and the maximum discharge current of the power management device of the secondary battery is provided under the limit of one minute of continuous discharge. Fig. 1 is a view showing a comparison between the residual capacity and the open circuit voltage of the UAH lithium cobalt secondary battery used in the present embodiment. The second figure shows that the 1.8Ah lithium-cobalt secondary battery is discharged at a constant current for 3 seconds under different residual capacity conditions, 0178-A20770TWF (N2); P05930035TW; brent 9 1299589 1 〇f; And the DC impedance curve of the battery obtained in 1 minute. Fig. 3 is a graph showing the relationship between the DC impedance and the different discharge currents at different residual capacities. In particular, in the low-capacity state, the DC impedance is greatly different. In the present embodiment, when the residual current of the secondary battery is 2%, the maximum current which can be continuously discharged for one minute without reaching the discharge cutoff voltage is calculated. Here we calculate from 0.2C (C is the current provided by the secondary battery, here h8Ah, 〇2c = 〇·36Α) to 3.0C (5.4A), and each current of 0.2C passes for one minute. Residual capacity value after discharge. For example, if the discharge capacity of one minute of discharge at 3 〇c is 5% ', it can be known that after one minute of discharge with other currents, the open circuit voltage of the secondary battery will fall in the residual capacity of 15% to 2 in FIG. The corresponding voltage value between 〇%. In addition, the voltage-affected portion due to the DC impedance is multiplied by the two-dimensional impedance function and 6 〇 (s = s 〇 c%, y) formed by the second and third figures. In addition, before the calculation, the secondary battery may cause a difference between the battery terminal voltage and the open circuit voltage due to charging or discharging. After one minute, there is still a residual effect, which must be incorporated into the calculation. The residual voltage difference of the secondary battery is exponentially attenuated, and the time function of the decay can be measured by the battery before leaving the factory. In summary, the following equation can be obtained to estimate the battery terminal voltage after one minute of discharge at a constant current: 匕w)-(]^-)^exp(-60/^^60(^)(first formula) where I For the constant current during discharge, s is the residual capacity before discharge (in %), and S is the residual capacity after one minute of discharge by current, which can be expressed as b匕 is the open circuit voltage of the secondary battery.为. is the initial value of the open circuit voltage of the secondary battery, 0 is the initial value of the terminal voltage of the secondary battery, and the time constant of the attenuation of the secondary battery. The larger the discharge, the larger the Z, the after-discharge The smaller the capacitance s' is, the smaller the open circuit voltage ❻, but the DC resistance and V, /) are also increased. The first formula in this embodiment takes one minute as an example. Equation 0178-A20770TWF(N2); P05930035TW;brent 10 1299589 == : Equation, which can calculate different time, after the constant current discharge, the electric room can reach the given Open loop voltage. Where t is electricity: put Γ (7) a FVexpH/z·) a / heart, ^. (Second type) 曰 In order to calculate the first type of calculation, we will make a description in Figures 4a and 4b. Figure 43 is a comparison of the discharge depth and the open loop voltage, and Fig. 4b is an enlarged view of the figure 46, showing that the discharge depth reaches 8〇% (discharge depth (%), etc. _ minus the residual capacity ( %)), the open circuit voltage value of the current with a constant current. Where a is the secondary battery voltage recovery, b is the secondary battery capacity reduction, and c is the secondary battery terminal voltage change due to the discharge impedance. They can be expressed in the following mathematical formulas: β = -(^〇°-F°).exp(-60/r) b=zVoc(s')-V〇c(S) c = -I •i?60^ ', /) Therefore, the maximum current can be obtained by the furnace (7) > 匕^ (discharge cutoff voltage). In Fig. 4b, 45 is a position indicating that the depth of discharge reaches 80%. 4〇 indicates that after the discharge depth reaches 80%, the discharge is stopped (discharged at 〇c), and after 8 minutes elapsed, the battery voltage is restored due to the characteristics of the secondary battery, so the voltage is higher than the original voltage. 41 is the residual capacity of the secondary battery and the corresponding open circuit voltage after 8 minutes of discharge at %c. 42 indicates the residual capacity of the secondary battery and the corresponding open circuit voltage after 8 minutes of discharge. 43 indicates that the residual capacity of the secondary battery and the corresponding open circuit voltage after 8 minutes of discharge. 44 indicates the residual capacity of the secondary battery and the corresponding open circuit voltage after discharging at 1 C for 8 minutes. Figure 5 is a voltage comparison diagram of a secondary battery with a constant current discharge, indicating that the second battery 178-A20770TWF (N2); P05930035TW; brent 11 1299589 long battery after a period of discharge ί Zhudu 8 Ο% after a period of time The current voltage change curve of the secondary battery in one minute of different current discharge, wherein the dotted line on the graph is a voltage curve of the secondary battery when the discharge is predicted to be performed at different currents for one minute, wherein 51 is the discharge depth of the secondary battery. After 80%, the voltage change curve obtained by discharging at a very small current, 52 is a voltage change curve obtained by discharging at 0.2 C for one minute, 53 is a voltage change curve obtained by discharging at 0.6 C for one minute, and 54 is discharging at i〇c. The voltage change curve obtained in one minute, 55 is a voltage change curve obtained by discharging at 1.4 C for one minute, '56 is a voltage change curve obtained by discharging at 1.8 C for one minute, and 57 is a voltage change curve obtained by discharging at 2.2 C. 58 is a voltage change curve '59 paid by discharging at 2_6 C for one minute is a voltage change curve obtained by discharging at 3. OC for one minute. It can be seen from the figure that when the secondary battery is discharged for one minute in a current of 26 C, 'Do not let the voltage of the secondary battery reach the discharge cut-off voltage of 2·8 ν. If the secondary battery is discharged at a current of 3 C for one minute, the voltage of the secondary battery will be lower than the discharge cut-off voltage. Similarly, we can The different discharge depths of the secondary battery are predicted as the maximum current limit value corresponding to the battery capacity. Fig. 6 is the voltage of the secondary battery after the secondary battery is discharged at different constant currents for different periods of time. The variation curve, wherein 62 is the discharge depth of the secondary battery of 8〇%, the voltage change curve of the secondary battery when discharging at different currents - minute has been described in Fig. 5. 61 is the secondary battery discharge depth 60% When the current is discharged at different currents for one minute, the voltage curve of the one-person battery is taken, and 63 is the voltage change curve of the secondary battery when the discharge of the secondary battery is 卯%, when the electric peach is discharged for one minute. In the case where the discharge depth of the secondary battery is 60%, H 2 (: and 3C discharge to the secondary current, since the discharge impedance of the battery is low, the voltage drop is small, and therefore the discharge voltage is not reached. At a discharge depth of 90%, since the capacity of the secondary battery is close to the cutoff 'the DC group resistance of the secondary battery is large, a large voltage drop is obtained by discharging the current at 1 C, 2 C or 3 C. The present embodiment provides the pressure drop. The first type 0178-A20770TWF (N2); P〇5930035TW; brent 12 1299589 and after calculation of various parameters, the limit current value of the secondary battery at the discharge depth of 6〇% is 3.6C, and the secondary battery discharge depth is 90. When the limit current value at % is 1.8 C, the output current of the secondary battery can be limited according to the limit current value. In addition to the current limitation of the discharge, the present invention can also be applied to the charging current limitation at the time of charging to avoid overcharging. Or the estimation of the charging time of charging with a constant current can also be obtained by the second equation. When the residual capacity of the secondary battery is in different states, it is estimated that the residual current capacity of the secondary battery or the change of the open circuit voltage after charging for a specific period of time with a different constant current is estimated. Or estimate that the secondary battery does not exceed the maximum current of the charge cut-off voltage for a certain period of time. Or it is to charge the secondary battery with a fixed current value, and it is estimated how many w is needed to make the secondary battery reach the charge cut-off power. This information is provided to the power management unit for use as a power source (4) limit or provided to the user. ^ In addition to avoiding the m current being too large, the secondary battery reaches the discharge cutoff dust without warning, or exceeds the charge cutoff voltage, and the secondary battery protection method provided by the present invention further includes using the temperature rise under different discharge current conditions. Predict to limit battery current. In the present embodiment, the secondary battery is in the case of the residual capacity (four) as an example. At this time, the DC resistance of the secondary battery is about 14 mm, the limit temperature value is chopped, and the ambient temperature is hungry. When calculating whether the temperature of the battery reaches the limit temperature, it must be = the total amount of heat generated and the rate of heat generation. The basic two thermodynamics can be applied to the following two mathematical formulas: heat generation (third type) heat power: p = Aj7 and Gan ^ (fourth formula) is the specific heat of the secondary battery, about the surface joule / kg; M For the quality of the battery of two or two people, about h5 kg is the continuous performance discharge time, the unit is second, set the phase. Minutes (_sec); ~ is the thermal conduction resistance between the inside and outside of the secondary battery, H. The conduction thermal resistance of the package of the electrician is 〇178-A2077〇TWF(N2); P〇5930035TW;brent 13 1299589 And the convective thermal resistance between the surface of the outer casing and the external environment. In this embodiment, the thermal conduction resistance of the outer casing is 1050 square centimeters of surface area, 2.5 mm thick, and the thermal conductivity of the outer casing material is 0.16 W/mK. In addition, the battery casing is also affected by convection heat dissipation. In the electric bicycle of this embodiment, the speed of the vehicle has a certain influence on convection heat dissipation. Taking the bicycle speed of 14 kilometers as an example, the wind speed is about 4 meters per second, the length of the secondary battery in the external contact is 20 cm, and the convective thermal resistance is about 0.483 K/W, so the thermal resistance of the first two items can be obtained as four. 1.97K/W. When the temperature of the secondary battery is not known, in order to calculate the maximum current that does not cause the secondary battery to reach the limit temperature, we assume that the temperature of the secondary battery at this time is 25 ° C at room temperature and 65 ° C at a limit temperature. Calculation. We first calculate in the third formula at room temperature 25 ° C, assuming that the initial temperature of the secondary battery is also 25 ° C, the limit temperature of the secondary battery is 65 ° C, then the current of the secondary battery exceeds the limit temperature The condition is: 12> ΑΤ·Ορ·Μ/ΙΙ·Τ = 714 (that is, the maximum current is 26_7A) On the other hand, we assume that the secondary battery has a temperature of 65 ° C at this time and a room temperature of 25 ° C. From the fourth formula, the heating power and the corresponding current value for maintaining the internal temperature of the secondary battery at 65 ° C can be obtained: P = AT / Rh = 40 / 1.97 = 20.3w = Ι 2 · 0.14 (1 = 12.04 Α) It is known that when the internal temperature of the secondary battery reaches a limit temperature of 65 V, the current of the secondary battery must be maintained at 12 A to maintain the internal temperature of the secondary battery at 65 ° C (40 ° C from the outside). If the initial temperature inside the secondary battery is 25 °C, the current must exceed 26.7A to reach the limit temperature of 65 °C within 10 minutes. Therefore, when the temperature of the secondary battery is unknown and the room temperature is 25 °C, the secondary battery is prevented from reaching the limit temperature within 1 minute, and the battery management system should limit the current of the secondary battery to 26.7A or less. If the initial temperature of the known secondary battery is 60 ° C, the external temperature is also 0178-A20770TWF (N2); P05930035TW; brent 14 1299589 25 ° C, calculated by the third formula, the current of 9.45A is required. After ten minutes, the secondary battery was brought to a limit temperature of 65 ° C, so the battery management system should have a current limit of 9.45 A for the secondary battery. Fig. 7 is a functional block diagram of a secondary battery and a protection device, wherein the protection device 70 calculates a limit current value for limiting the output or input current of the secondary battery 72. The detecting unit 73 is configured to detect various values of the secondary battery 72, such as a voltage level, a temperature level, a current level, and the like. These values are transferred to the protection mechanism unit 74 for mathematical operation to obtain a limited current value, which is transmitted to the power management unit 75, and the power management unit 75 limits the current output of the secondary battery 72 based on the limited current value. When the current value drawn by the load 71 from the secondary battery 72 is less than the limit current value, the secondary battery 72 outputs the current value required for the load 71. When the current value drawn by the load 71 from the secondary battery 72 is greater than the limit current value, the power management unit 75 controls the output current of the secondary battery 72 to be the limited current value. Figure 8 is a flow chart of the present invention. In step S81, various state values of the secondary battery, such as voltage, temperature or current, are detected. At the step M2, the limit current value is calculated based on the state value obtained in the step S81 and the parameters of the secondary battery itself such as the direct μ impedance, the thermal resistance coefficient or the residual current capacity and the open circuit voltage map, and the like. At the step S83, the output current of the secondary battery is limited in accordance with the limit current value calculated in the step S82, and the process returns to the step s8 to continuously calculate the new limit current value. The description of μ can make the present invention easier to make, and the present invention can also make it more accurate to estimate the current limit value of the secondary battery, and can also estimate the time required to charge and discharge the motor. By limiting the current obtained by the secondary battery protection side=current limiting mechanism proposed by the present invention, the limiting motor of the secondary battery can be made more accurate, and can also be changed according to the use condition of the secondary battery in a timely manner. According to the limitation of constant current, the secondary battery according to the present invention is guaranteed by the secondary battery protection 0178-A20770TWF (N2); P05930035TW; brent 1299589 current's utility is obviously higher than that of the f flow restriction The limitations of knowing the skills come. 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 The scope is attached as follows: 界定 The scope defined by the patent scope shall prevail. 〒 0178-A20770TWF(N2); P05930035TW;brent 16 1299589 [Simple description of the diagram] Fig. 1 is a comparison diagram of the residual capacity and open circuit voltage of a 1.8Ah lithium-cobalt secondary battery. Fig. 2 is a graph showing the DC impedance curve of a battery obtained by discharging a 1.8 Ah lithium-cobalt secondary battery under a state of residual current with a constant current for 3 seconds, 10 seconds, and 1 minute. Figure 3 is a graph showing the DC impedance obtained with different discharge currents at different residual capacities. Figure 4a is a comparison of the depth of discharge and the open loop voltage. Figure 4b is an enlarged view of 46 in Figure 4a. φ Fig. 5 is a voltage comparison diagram of a secondary battery discharged at a constant current. Fig. 6 is a graph showing the voltage variation of the secondary battery after a period of discharge of the secondary battery at different discharge depths for a certain period of time. Figure 7 is a functional architecture diagram of a secondary battery and protection device. / Figure 8 is a flow chart of the present invention. [Description of main component symbols] 40~ After the discharge depth of the secondary battery reaches 80%, the residual capacity and corresponding voltage after standing for 8 minutes; ® 41~ After the discharge depth of the secondary battery reaches 80%, after 8 minutes of discharge, Residual capacity and corresponding voltage; 42~ After the discharge depth of the secondary battery reaches 80%, the residual capacity after discharge for 8 minutes and the corresponding voltage; 43~ After the discharge depth of the secondary battery reaches 80%, after discharging for 8 minutes Residual capacity and corresponding voltage; 44~ secondary battery discharge depth reaches 80%, after 1C discharge for 8 minutes, 0178-A20770TWF (N2); P05930035TW; brent 17 1299589 residual capacity and corresponding voltage; 45~ twice The discharge depth of the battery reaches 80% of the residual capacity and the corresponding voltage; 46~ the partial amplification of the secondary battery after the discharge depth reaches 80%; 51 is the voltage obtained by discharging the secondary battery with a very small current after the discharge depth is 80%. Change curve; 52 is a voltage change curve obtained by discharging at 0.2 C for one minute; 53 is a voltage change curve obtained by discharging at 0.6 C for one minute; 54 is a voltage change curve obtained by discharging at 1.0 C for one minute; 55 is at 1.4 C Discharge The voltage change curve obtained in one minute; 56 is the voltage change curve obtained by discharging at 1.8 C for one minute; 57 is the voltage change curve obtained by discharging at 2.2 C; 58 is the voltage change curve obtained by discharging at 2.6 C for one minute; 59 is When the voltage change curve 61 obtained by discharging at 3.0 C for one minute is 60% when the discharge depth of the secondary battery is 60%, the voltage curve obtained by discharging at different currents, and the voltage curve obtained by discharging at different currents when the discharge depth of the secondary battery is 80% 63~ secondary battery discharge depth 90%, the voltage curve obtained by different current discharge; 70~ protection device; 71~ load; 72~ secondary battery; 73~ detection unit; 74~ protection mechanism unit; Power management unit; S81~ detects the state value of the secondary battery; 0178-A20770TWF(N2); P05930035TW; brent 18 1299589 S82~ calculates a limiting current value according to the parameters and state values of the secondary battery itself; S83~ according to the steps The limiting current value obtained by S82 limits the output current of the secondary battery. 0178~A20770TWF(N2); P05930035TW;brent 19