ΙΪ64898 九、發明說明： 【發明所屬之技術領域】 本發明係關於一種具最大功率追蹤〔Maximum Power PointΙΪ64898 IX. Description of the Invention: [Technical Field of the Invention] The present invention relates to a maximum power tracking (Maximum Power Point)
Tracking ’ MPPT〕功能之獨立型〔stand-alone〕發電系統之蓄電池 充電裝置及其方法；特別是關於應用於風力、太陽能發電或其他 再生能源發電等需要具最大功率追蹤功能之獨立型發電系統之蓄 電池充電裝置及其方法，該蓄電池充電裝置包含一直流/直流轉換 器及一控制電路；更特別是該控制電路以四個工作模式〔operation mode〕控制該直流/直流轉換器，並依風力或太陽能發電輸出功率 及蓄電池狀態條件選擇啟動該四個工作模式之一，以提高風力、 太陽能或其他再生能源發電系統輸出能量之利用率。 【先前技術】 傳統小型獨立型風力或太陽能發電系統係指將該發電系統所 產生之電力直接輸出供應至負載使用，而再將多餘電力儲存於電 池。當該發電系統之輸出電力不足時，則由該電池進行供電。此 類型發電系統通常採用較小設備容量，故其相對適用於輸配電系 統無法供電之偏遠地區，且使用此類型發電系統之區域也大部份 處於缺乏電力資源供應的環境，故有必要儘可能提高此類型發電 系統的能量利用率。 由於獨立型風力或太陽能發電系統之輸出功率不穩定，且有 些時間可能低於負載所需，因此一般獨立型風力或太陽能發電系 統均配備有蓄電池及其充電裝置。為了有效運用蓄電池在發電系 統内儲存能量的功能，因而必須充分利用發電系統產生的能量進 行快速充電至該蓄電池，以做為負載的電源。然而，若蓄電池進 5 行不當快速充電時，易導致損壞蓄電池，即縮短電池壽命。 傳統蓄電池充電方法主要包含：定電流充電法〔constant current charging method〕、定電壓充電法〔constant v〇ltage charging method〕、混合定電流/電壓充電法〔c〇nstant current/ constant voltage charging method〕及脈衝電流充電法〔pulse current charging method〕等0 事實上，前述充電方法仍各自具有技術優點及缺點。例如： 小電流定電流充電法具有充電時間過長的缺點；大電流定電流充 電法具有因過度充電而損壞蓄電池的缺點》定電壓充電法具有如 因過度放電而導致蓄電池端電壓過低時，在開始充電時，因產生 過大充電電流而損壞蓄電池的缺點。混合定電流/電壓充電法仍無 法改善因大電流充電導致彳貝壞蓄電池的缺點。至於脈衝電流充電 法，其對蓄電池的損壞較小。 一般而言，習用具最大功率追蹤功能之獨立型發電系統〔例 如：風力或太陽能發電系統〕之蓄電池充電方法大都採用定電流 與定電壓兩段式充電’即採用混合定電流/電壓充電法。當該發電 系統之輸出電能小於負載所需能量〔Pa，負載功率〕及蓄電池充 電所需能量〔Pb，蓄電池最大定電流之充電功率〕時，該發電系 統進入最大功率追縱模式；當該發電系統之輸出電能大於負載所 需能量及蓄電池充電所需能量之總和〔Pa+Pb〕時，為了防止過大 之充電電流損害蓄電池’將該發電系統之輸出電能限制低於該負 載所需能量及最大充電電流之設定值之和，亦即必須停止該發電 系統之最大功率追蹤機制；此時，該發電系統無法輸出最大功率 ，其所能產生之多餘能量無法完全有效的被輸出利用。 j 3*64898Tracking 'MPPT' function stand-alone power generation system battery charging device and method thereof; especially for independent power generation systems requiring maximum power tracking functions such as wind power, solar power generation or other renewable energy power generation a battery charging device and method thereof, the battery charging device comprising a DC/DC converter and a control circuit; more particularly, the control circuit controls the DC/DC converter in four operating modes, and depending on the wind or The solar power output and battery state conditions select one of the four operating modes to increase the utilization of the output energy of wind, solar or other renewable energy power generation systems. [Prior Art] A conventional small independent wind power or solar power generation system refers to a direct output of the power generated by the power generation system to a load, and then the excess power is stored in the battery. When the output power of the power generation system is insufficient, power is supplied from the battery. This type of power generation system usually uses a small equipment capacity, so it is relatively suitable for remote areas where power transmission and distribution systems cannot supply power, and most of the areas using this type of power generation system are in an environment lacking power supply, so it is necessary to Improve the energy efficiency of this type of power generation system. Since the output power of a stand-alone wind or solar power system is unstable and some time may be lower than that required by the load, a typical stand-alone wind or solar power system is equipped with a battery and its charging device. In order to effectively use the function of the battery to store energy in the power generation system, it is necessary to make full use of the energy generated by the power generation system for rapid charging to the battery as a power source for the load. However, if the battery is improperly charged in 5 lines, it will easily cause damage to the battery, which will shorten the battery life. The conventional battery charging method mainly includes: a constant current charging method, a constant voltage charging method, a constant current/constant voltage charging method, and Pulse current charging method, etc. In fact, the foregoing charging methods still have their own technical advantages and disadvantages. For example: The small current constant current charging method has the disadvantage of excessive charging time; the large current constant current charging method has the disadvantage of damaging the battery due to overcharging. The constant voltage charging method has a battery terminal voltage that is too low due to excessive discharge. When charging is started, the battery is damaged due to excessive charging current. The mixed constant current/voltage charging method still cannot improve the disadvantages of the mussel bad battery caused by the large current charging. As for the pulse current charging method, the damage to the battery is small. In general, the independent charging system of the maximum power tracking function (for example, wind power or solar power generation system) uses a constant current and constant voltage two-stage charging, that is, a mixed constant current/voltage charging method. When the output energy of the power generation system is less than the required energy of the load [Pa, load power] and the energy required for charging the battery [Pb, the charging power of the maximum constant current of the battery], the power generation system enters a maximum power tracking mode; When the output power of the system is greater than the sum of the energy required by the load and the energy required for charging the battery (Pa+Pb), in order to prevent the excessive charging current from damaging the battery, the output power of the power generation system is limited to the energy required by the load and the maximum The sum of the set values of the charging current, that is, the maximum power tracking mechanism of the power generation system must be stopped; at this time, the power generation system cannot output the maximum power, and the excess energy that can be generated cannot be completely and effectively utilized for output. j 3*64898
第1圖揭示習用具最大功率追蹤功能之獨立型發電系統之輸 出功率曲線圖。當該獨立型發電系統為太陽能發電系統時，其輸 出功率特性曲線PI、P2 P3及P4分別代表在不同日照度下該太 陽能發電系統輸出功率與其輸出端電壓之關係，其中曲線P4之曰 照度最強’而祕P1之日照度最弱。另外，當該獨立型發電系統 為風力發電系統時，其輸出功率特性曲線PI、P2、p3及P4分別 代表在不同風力下該風力發«統輸“率與其發電機之轉速關 係，其中曲線P4之風速最強、曲線P3之風速次強、曲線p2之風 速次弱及曲線P1之風速最弱。請參照第i圖所示，其中當曲線p3 及P4之最大功率區域大於負載所需能量及蓄電池充電所需能量之 總和〔Pa+Pb〕時，將限制該獨立型發電系統之輸出功率在負載所 需能量及蓄電池》電所需能量之總和〔Pa+Pb〕，因而導致其無法 完全有效個關立型發電系統之輸㈣率〔如第〖圖之網㈣ 域所示〕。Figure 1 is a graph showing the output power of a stand-alone power generation system with the maximum power tracking function of the appliance. When the independent power generation system is a solar power generation system, the output power characteristic curves PI, P2 P3 and P4 respectively represent the relationship between the output power of the solar power generation system and the voltage of the output terminal under different illumination degrees, wherein the curve P4 has the strongest illumination. 'And the secret of P1 is the weakest. In addition, when the independent power generation system is a wind power generation system, the output power characteristic curves PI, P2, p3, and P4 respectively represent the relationship between the speed of the wind power generation and the speed of the generator under different wind powers, wherein the curve P4 The wind speed is the strongest, the wind speed of curve P3 is strong, the wind speed of curve p2 is weak, and the wind speed of curve P1 is the weakest. Please refer to the figure i, where the maximum power area of curves p3 and P4 is greater than the energy required by the load and the battery When the sum of the energy required for charging [Pa+Pb], the output power of the independent power generation system and the sum of the energy required for the battery (Pa+Pb) are limited, so that it cannot be completely effective. The transmission rate of the Guanli type power generation system (four) is shown in the figure (Fig.
另-省用太陽能脈衝式充電裝置，如中華民國專利第娜州 號，其揭^電方法與前述充電方法相似m具最大功率 追縱功能之充電裝置之充電方法，如美國公開專利第細雜卿 號，其揭不太陽能發電系統充電裝置 -充電裝置輸出—穩定電壓後，再輸出二== 出功率小於蓄電池充電及負載消耗功率之總和時，該=置: 執行最大辨追蹤機制；反之，若其 、了 負載消耗功率之總㈣，作„奸^4大於畜電池充電及 維持輸出一固定電壓.，該充電方法為定電壓法。；、和以 7 顯然，該第2006/0174939號雖然可輸出穩定電壓，以避免該 輸出電壓之劇烈變動而損害負載，並進一步簡化系統結構，但是 當蓄電池處於低儲能狀態時，其電壓較低；此時，若該充電裝置 開始啟動在定電壓充電模式時，由於蓄電池與充電裝置之電壓差 距過大，因而產生過大的充電電流，該過大充電電流除了減短蓄 電池之使用壽命之外，亦可能損壞該充電裝置。簡言之，該第 2006/0174939號之充電方法仍有必要進一步改善其缺點，以避免 損壞該充電裝置及蓄電池；換言之，當將具最大功率追蹤功能之 充電裝置之充電法與其他充電方法進行整合時，亦仍有必要適當 改善其缺點。 中華民國專利公開公報第200825278號揭示具最大功率追蹤 功能之風力發電系統之蓄電池充電方法，但該方法需使用一直流/ 直流轉換器及一脈衝控制〔產生〕電路，且該風力發電系統之蓄 電池充電方法包含五種工作模式。因此’無論硬體控制電路或控 制方式皆具有較複雜的缺點。 有鑑於此’本發明為了改良上述缺點，本發明能提供一種具 最大功率追蹤功能之獨立型發電系統之蓄電池充電裝置，該裝置 包含一直流/直流轉換器及一控制電路，該控制電路控制該直流/ 直流轉換器形成四個工作模式’當獨立型發電系統之輸出功率較 小時，啟動最大功率追蹤功能，其充電電流為一連續電流，若該 發電系統之輸出功率小於負載功率時’由該發電系統及蓄電池共 同供應電力至該負載，當該蓄電池電壓低於一預定最小放電電墨 值時，切離該負載；當該獨立型發電系統之輪出功率大於該負載 功率及蓄電池最大定電流之充電功率之總和時，其改採用脈衝充 ΙΪ64898 電方法，並在未超過該負載功率及預設最大脈衝充電功率之總和 下’其能持續執行該最大功率追縱功能；一旦該獨立型發電系統 之輸出功率超過該負載功率及預設最大脈衝充電功率之總和時， 中止執行該最大功率追蹤功能，當該蓄電池電壓超過一預定之定 電壓充電電壓時，採用定電壓充電，如此本發明能達成有效提升 獨立型發電系統之輸出功率之目的。 【發明内容】 本發明之主要目的係提供一種具最大功率追蹤功能之獨立型 發電系統之蓄電池充電裝置，該蓄電池充電裝置包含一直流/直流 轉換器及一控制電路；該控制電路控制該直流/直流轉換器，以便 該直流/直流轉換器具有四個工作模式，該四個工作模式包含最大 功率追蹤功能、脈衝充電功能、定電壓充電功能或其組合’以達 成簡化硬體電路及充電模式之目的。 本發明之另一目的係提供一種具最大功率追蹤功能之獨立型 發電系統之蓄電池充電方法，當該獨立型發電系統之輸出功率較 小時，啟動最大功率追蹤功能，其充電電流為一連續電流；當該 獨立型發電系統之輸出功率較大時，其採用脈衝充電方法’並在 未超過負載功率及預定蓄電池最大脈衝充電功率之總和下，其能 持續執行該最大功率追蹤功能；一旦該獨立型發電系統之輸出功 率大於負載功率及預定最大脈衝充電功率之總和時，中止執行該 最大功率追蹤功能；及一旦當該蓄電池電壓超過一預定之定電壓 充電電壓時，採用定電壓充電。 本發明之另一目的係提供一種具最大功率追蹤功能之獨立型 發電系統之蓄電池充電方法，其提供四個工作模式，當獨立型發 9 Π'64898 電系統之輸出功率較小時，啟動最大功率追蹤功能，其蓄電池之 •'充電電流為一連續電流’若該發電系統之輸出功率小於負載功率 時，由該發電系統及蓄電池共同供應電力至該負載，當該電池電 壓低於一預定最小放電電壓值時’切離該負載；當該獨立型發電 系統之輸出功率大於該負載功率及蓄電池最大定電流之充電功率 之總和時，其改採用脈衝充電方法，並在未超過該負載功率及預 定蓄電池最大脈衝充電功率之總和下，其能持續執行該最大功率 追敞功能；一旦該獨立型發電系統之輸出功率超過該負載功率及 φ 預定蓄電池最大脈衝充電功率之總和時，中止執行該最大功率追 蹤功能，當該蓄電池電壓超過預定定電壓充電電壓時，採用定電 壓充電，以防止該蓄電池過度充電，以達成有效提升獨立型發電 系統輸出功率之利用率之目的。 為了達成上述目的，本發明具最大功率追蹤功能之獨立型發 電系統之蓄電池充電裝置包含一直流/直流轉換器及一控制電路， 其蓄電池充電方法包含： 當發電系統之輸出功率較小時，該控制電路控制該直流/直流 • 轉換器啟動最大功率追蹤功能，其蓄電池之充電電流為一連續電 流，若該發電系統之輸出功率小於負載功率時，由該發電系統及 蓄電池共同供應電力至該負載，當該蓄電池電壓低於一預定最小 放電電壓值時，切離該負載·， 當該發電系統之輪出功率大於該負載功率及蓄電池最大定電 流之充電功率之總和時’該控制電路控制該直流丨直流轉換器採用 脈衝充電方法’並在未超過該負載功率及預定蓄電池最大脈衝充 電功率之總和下’其能持續執行該最大功率追蹤功能； 10 1264898 一旦該發電系統之輸出功率大於該負載功率及預定蓄電池最 大脈衝充電功率之總和時，該控制電路控制該直流/直流轉換器中 止執行該最大功率追蹤功能，該控制電路亦控制該直流/直流轉換 器維持在該預定蓄電池最大脈衝充電功率下進行充電；及 當該蓄電池電壓超過一預定定電壓充電電壓時，該控制電路 控制該直流/直流轉換器採用定電壓充電，以防止該蓄電池過度充 電。 本發明之充電方法利用該控制電路及直流/直流轉換器依該 發電系統之輸出功率及蓄電池狀態選擇最大功率追蹤功能、脈衝 充電功能、定電壓充電功能或其組合，以達成有效提升獨立型發 電系統輸出功率之利用率之目的。 【實施方式】 為了充分瞭解本發明’於下文將例舉較佳實施例並配合所附 圖式作詳細說明，且其並非用以限定本發明。 本發明較佳實施例之具最大功率追蹤功能之獨立型發電系統 之蓄電池充電裝置可應用於風力發電'太陽能發電或其他再生能 源發電，其並非用以限定本發明。 第2圖揭示本發明較佳實施例之具最大功率追縱功能之獨立 型發電系統及蓄電池充電裝置之方塊圖。請參照第2圖所示，本 發明較佳實施例具之最大功率追蹤功能之獨立型發電系統之電池 充電裝置包含一獨立型發電系統卜一直流/直流轉換器2、一控制 電路3、一蓄電池4及一開關6。該獨立型發電系統i用以提供一 直流電源，該獨立型發電系統1選擇為太陽能蓄電池或經整流之 風力發電系統。該直流/直流轉換器2之輸入連接至該獨立型發電 I364898 系統1之輸出，該直流/直流轉換器2之輸出則並聯連接至該蓄電 池4，該蓄電池4經該開關6並聯連接至一負載5，以供應電能至 該負載5。該控制電路3連接至該直流/直流轉換器2，其用以控制 該直流/直流轉換器2，使其具有最大功率追縱功能、脈衝充電功 能及定電壓充電功能等。該控制電路3依該獨立型發電系統〖之 輸出功率及s玄蓄電池4之狀態選擇執行最大功率追蹤功能、脈衝 充電功能、定電壓充電功能或其組合，以達成有效提升獨立型發 電系統輸出功率之利用率之目的。該蓄電池4可用以儲存或釋放 電能。當該獨立型發電系統1之輸出功率較小時，該控制電路3 控制β亥直流/直流轉換器2我行該最大功率追縱功能，以期利用該 獨立型發電系統1之最大輸出功率；此時，該蓄電池4之充電功 率為該獨立型發電系統1之最大輸出功率與該負我5之功率之差 ，其充電電流為一連續電流；此時’採用連續電流對該蓄電池4 充電可較脈衝充電充入更大之能量，而若該獨立型發電系統1之 輸出功率小於該負載5之功率時，則由該蓄電池4與該獨立型發 電系統1共同供應電力至該負載5’當該蓄電池4之電壓低於一預 定最小放電電壓值時，則打開該開關6切離該負載5。當該獨立型 發電系統1之輸出功率大於該蓄電池4之最大定電流之充電功率 及該負載5之功率之總和時，該控制電路3控制該直流/直流轉換 器2執行脈衝充電方法’並在未超過該負載5之功率及蓄電池4 之預定最大脈衝充電功率總合下，執行最大功率追蹤功能，以期 充分利用該獨立型發電系統1之最大輸出功率。一旦該獨立型發 電系統1之輸出功率大於該負載5之功率及蓄電池4之預定最大 脈衝充電功率之總和時’該控制電路3控制該直流/直流轉換器2 12 ΙΪ64898 中止執行該最大功率追蹤功能，該控制電路3亦控制該直流/直流 轉換器2將該獨立型發電系·统1之輸出功率限制在該負載5之功 率及畜電池4之預定最大脈衝充電功率之總和，此時該控制電路3 控制該仍持續控_直流/直流轉絲2仍持續執行脈衝充電功能 以脈衝方式對該蓄電池4充電。當該蓄電池4之電壓大於一預 定之定電壓充電電壓值時，該控制電路3終止脈衝充電功能，此時 該控制電路3㈣該直流/直雜換ϋ 2執狀電壓充電功能，以 定電壓對該蓄電池4進行充電。 第2Α至2C圖揭示本發明較佳實施例之具最大功率追蹤功能 之獨立型發電系統之蓄電池充電裝置中採用直流/直流轉換器之電 路圖。β月參照第2Α至2C圖所示，本發明可採用非隔離式直流/ 直流轉換器充電架構，其選自第2Α圖之降壓式轉換器〔buck converter〕、第2B圖之升壓式轉換器〔b〇〇st⑶旧咐沉〕或第2C 圖之升-降赋職H〔 buek.boost converter·〕#，其並刺以限定 本發明之範圍。該降壓式轉換器、升壓式轉換器及升·降壓式轉換 器之架構係m直流/直流轉換器充電架構，於此不予贅述。該 控制電路3即用以控制該直流/直流轉換器2〔降壓式轉換器 '升 壓式轉換n或升-降壓式轉換器〕之電力f子開關元件，以執行最 大功率追蹤、脈衝充電、定電壓充電等功能或其組合。 第3圖揭示本發明較佳實施例之具最大功率追蹤功能之獨立 型發電系統之蓄電池充電方法輸出功㈣線圖。當該獨立型發電 系統1為太陽能發電系統時，其輸出功率特性曲線ρι、、P3及 P4分別代表在*同日照度下社陽歸電祕輸出功率與其輸出 端電墨之關係，其中曲線P4之日照度最強，而曲線ρι之日照度 13 1364898 最弱。另外，當該獨立型發電系統1為風力發電系統時，其輸出 功率特性曲線pi、P2、P3及P4分別代表在不同風力下該風力發 電系統輸出功率與其發電機之轉速關係，其中曲線P4之風速最強 ，而曲線P1之風速最弱。請參照第3圖所示，其標示一第一限制 功率Pa、一第二限制功率Pa+Pb及一第三限制功率Pa+Pc ;其中 Pa為負載功率、Pb為蓄電池最大定電流之充電功率，pc為預定蓄 電池最大脈衝充電功率，且第三限制功率pa+pc大於第二限制功 率Pa+Pb。在曲線P4之最大功率區域〔如第3圖之網格區域所示 〕大於該第三限制功率Pa+Pc，因而其僅在太陽光照度或風力很強 導致產生之功率曲線P4時’無法執行最大功率追蹤功能。將第3 圖相較於第1圖時’本發明無法完全有效利用該獨立型發電系統1 之輸出功率部分遠小於習用獨立型發電系統之充電裝置〔如第1 圖所示〕；因此，本發明之具最大功率追蹤功能之獨立型發電系 統之蓄電池充電裝置相對於習用獨立型發電系統之充電裝置更能 有效利用s玄獨立型發電系統1之輸出能量，以加速蓄電池充電速 率及縮短蓄電池充電時間。 請再參照第2及3圖所示，本發明較佳實施例之具最大功率 追蹤功能之獨立型發電系統之蓄電池充電裝置提供四個工作模式 ，以執行最大功率追蹤、脈衝充電、定電壓充電或其組合。當該 獨立型發電系統1之輸出功率等於或大於該第一限制功率Pa、但 小於第二限制功率Pa+Pb時，執行一第一工作模式，該控制電路3 控制該直流/直流轉換器2執行最大功率追蹤功能，以期利用該獨 立型發電系統1之最大輸出功率；此時，該賴6為閉合，輸出 -功率至該負載5 ’該蓄電池4之充電功率為該獨立型發電系統】 IJ64898 之最大輸出功率與該負載5功率之差’其充電電流為一連續電流 ，此時採用連續電流對該蓄電池4充電可較脈衝充電充人更大之 能量；而當該獨立型發電系統i之輪出功率小於該第—限制功率 Pa時，該控制電路3控制該直流/直流轉換器2執行該最大功率追 蹤功能，此時該獨立型發電系統1與該蓄電池4共同供應電力至 該負載5。-旦該蓄電池4之電壓低於—預定最小放電電壓值時， 藉由控制該開關6形成開路’而切離該負載$，以避免該蓄電池4 過度放電；在切離該負載5後’仍利用該獨立型發電系統i之輸 出功率充電該蓄電池4’該蓄電池4之較佳預定最小電壓值由蓄電 池廠建議之最低放電電壓值獲得。 請再參照第2及3圖所示’當該獨立型發電系統丨之輸出功 率大於該第二限制功率Pa+Pb、但小於第三限制功率pa+pc時執 行-第二工作模式，此時該f電池4不宜再採科續電流充電， 否則該蓄電池4可能過熱而影響壽命，在第二卫作模式下該控制 電路3控制該直流/直流轉換器2執行脈衝充電方法，並持續執行 最大功率追蹤功能，以期利用該獨立型發電系統i之最大輸出功 率；此時’該開關6為閉合’以輸出一功率至該負載5。 請再參照第2及3圖所示，當_立型發電系統丨之輸出功 率大於該第三限制功率Pa+Pe _，執行―第三卫作模式，此時不 宜再執行最大功率追蹤功能，否則會縮短該蓄電池4之壽命。在 第三工作模式下’雛制電路3中止執行最大功率追蹤功能，該 控制電路3控制該直流/直流轉換器2將該獨立 出功率限制在該負載5之功率及蓄電池4之預定二充= 率之總和，此時該控制電路3仍持續執行脈衝充電功能以脈衝 15 此時，該開關6為閉合，以輸出一 方式對該蓄電池4進行充電； 功率至該負載5。 厭右Φ ··…第2圖所不’ 蓄電池4之電壓大於一預定定電 壓充電電壓值〔A1〕時，執行 β T “工作模式，此時不宜再利用 $、'電流充電方式對讀蓄電池4充電，否則造成該蓄 電池4過充電而縮短該蓄電池4之壽命。在第四工作模式下，該 控制電路3終止脈衝充電功能，此時該控制電路3控制該直流/直 肌轉換器2執行定電壓充電功能，以定電壓對該蓄電池4進行充 電。錄佳預定定電壓充電電壓值〔Α1〕由蓄電池廠之建議值獲 得。此時，該開關ό為閉合，以輸出一功率至該負載5。 第4圖揭示本發明較佳實施例之具最大功率追蹤功能之獨立 型發電系統之蓄電池充電方法之流程圖。 請再參照第2至4圖所示，首先，本發明較佳實施例之具最 大功率追蹤功能之獨立型發電系統之蓄電池充電方法判斷該蓄電 池4之電壓是否小於一預定定電壓充電電壓值〔Α1〕^若該蓄電 池4之電壓不小於該預定定電壓充電電壓值〔Α1〕時，直接執行 第四工作模式，該控制電路3控制該直流/直流轉換器2執行定電 壓充電功能，以定電壓對該蓄電池4進行充電；若該蓄電池4之 電壓小於該預定定電壓充電電壓值〔Α1〕時，選擇執行第一工作 模式、第二工作模式或第三工作模式。 當該蓄電池4之電壓小於該預定定電壓充電電壓值〔A1〕時 ，判斷該獨立型發電系統1之輸出功率是否小於第二限制功率 Pa+Pb;若該獨立型發電系統1之輸出功率小於第二限制功率 Pa+Pb時’執行第一工作模式，由該控制電路3控制該直流/直流 丄允4898Another-provincial solar pulse type charging device, such as the Republic of China patent No. Nazhou, whose charging method is similar to the foregoing charging method, and the charging method of the charging device having the maximum power tracking function, such as the US public patent Qing, it is not the solar power system charging device - charging device output - after the stable voltage, and then output two = = the output power is less than the sum of the battery charging and the load power consumption, the = set: the maximum discriminating mechanism is implemented; If it is the total power consumption of the load (4), the gong ^4 is greater than the battery charge and maintain a fixed voltage. The charging method is the constant voltage method.;, and 7 is obvious, although the 2006/0174939 The stable voltage can be output to avoid the violent fluctuation of the output voltage to damage the load, and further simplify the system structure, but when the battery is in a low energy storage state, the voltage is low; at this time, if the charging device starts to start at a constant voltage In the charging mode, because the voltage difference between the battery and the charging device is too large, an excessive charging current is generated, and the excessive charging current is In addition to the service life of the short battery, the charging device may also be damaged. In short, the charging method of No. 2006/0174939 still needs to further improve its shortcomings to avoid damage to the charging device and the battery; in other words, when When the charging method of the charging device of the maximum power tracking function is integrated with other charging methods, it is still necessary to appropriately improve the shortcomings. The Republic of China Patent Publication No. 200825278 discloses a battery charging method for a wind power generation system having a maximum power tracking function. However, the method requires a DC/DC converter and a pulse control [generation] circuit, and the battery charging method of the wind power system includes five working modes. Therefore, no matter the hardware control circuit or the control method is complicated. Disadvantages. In view of the present invention, in order to improve the above disadvantages, the present invention can provide a battery charging device for a stand-alone power generation system with maximum power tracking function, the device comprising a DC/DC converter and a control circuit, the control circuit Control the DC/DC converter to form four Working mode 'When the output power of the independent power generation system is small, the maximum power tracking function is activated, and the charging current is a continuous current. If the output power of the power generation system is less than the load power, the power supply system and the battery are jointly supplied. Power to the load, when the battery voltage is lower than a predetermined minimum discharge ink value, the load is cut off; when the wheel-out power of the independent power generation system is greater than the sum of the load power and the maximum rated current of the battery , which adopts the pulse charging method 64898 electric method, and can continuously perform the maximum power tracking function without exceeding the sum of the load power and the preset maximum pulse charging power; once the output power of the independent power generation system exceeds the When the sum of the load power and the preset maximum pulse charging power is performed, the maximum power tracking function is suspended, and when the battery voltage exceeds a predetermined constant voltage charging voltage, the constant voltage is charged, so that the present invention can effectively improve the independent power generation. The purpose of the output power of the system. SUMMARY OF THE INVENTION The main object of the present invention is to provide a battery charging device for a stand-alone power generation system with maximum power tracking function, the battery charging device comprising a DC/DC converter and a control circuit; the control circuit controls the DC/ a DC converter such that the DC/DC converter has four operating modes including a maximum power tracking function, a pulse charging function, a constant voltage charging function, or a combination thereof to achieve a simplified hardware circuit and a charging mode purpose. Another object of the present invention is to provide a battery charging method for a stand-alone power generation system with maximum power tracking function. When the output power of the independent power generation system is small, the maximum power tracking function is started, and the charging current is a continuous current. When the output power of the independent power generation system is large, it adopts the pulse charging method', and under the sum of the load power and the maximum pulse charging power of the predetermined battery, it can continuously perform the maximum power tracking function; once the independent When the output power of the power generation system is greater than the sum of the load power and the predetermined maximum pulse charging power, the maximum power tracking function is suspended; and once the battery voltage exceeds a predetermined constant voltage charging voltage, constant voltage charging is employed. Another object of the present invention is to provide a battery charging method for a stand-alone power generation system with maximum power tracking function, which provides four operating modes, and when the output power of the independent type 9 Π '64898 electric system is small, the maximum startup is performed. Power tracking function, the 'charging current of the battery is a continuous current'. If the output power of the power generation system is less than the load power, the power generation system and the battery jointly supply power to the load when the battery voltage is lower than a predetermined minimum When the discharge voltage value is 'cut off the load; when the output power of the independent power generation system is greater than the sum of the load power and the maximum fixed current of the battery, the pulse charging method is adopted, and the load power is not exceeded. The maximum power chasing function can be continuously performed under the sum of the maximum pulse charging power of the predetermined battery; once the output power of the independent power generating system exceeds the sum of the load power and the maximum pulse charging power of the predetermined battery, the maximum is suspended. Power tracking function, when the battery voltage exceeds the predetermined power When the charging voltage, charging using the constant voltage, to prevent overcharging the battery, in order to achieve the purpose of independent power generation system effectively improve the utilization of the output power. In order to achieve the above object, the battery charging device of the independent power generation system with maximum power tracking function of the present invention comprises a DC/DC converter and a control circuit, and the battery charging method comprises: when the output power of the power generation system is small, The control circuit controls the DC/DC converter to activate a maximum power tracking function, wherein the charging current of the battery is a continuous current. If the output power of the power generation system is less than the load power, the power generation system and the battery jointly supply power to the load. When the battery voltage is lower than a predetermined minimum discharge voltage value, the load is cut off, and when the power output of the power generation system is greater than the sum of the load power and the maximum rated current of the battery, the control circuit controls the The DC-DC converter adopts a pulse charging method' and can continuously perform the maximum power tracking function without exceeding the sum of the load power and the predetermined maximum pulse charging power of the battery; 10 1264898 Once the output power of the power generation system is greater than the load Power and scheduled battery maximum The control circuit controls the DC/DC converter to suspend execution of the maximum power tracking function, and the control circuit controls the DC/DC converter to maintain charging at the maximum pulse charging power of the predetermined battery; When the battery voltage exceeds a predetermined constant voltage charging voltage, the control circuit controls the DC/DC converter to charge with a constant voltage to prevent the battery from being overcharged. The charging method of the present invention uses the control circuit and the DC/DC converter to select a maximum power tracking function, a pulse charging function, a constant voltage charging function or a combination thereof according to the output power and the battery state of the power generation system, so as to achieve an effective improvement of independent power generation. The purpose of the utilization of the system output power. The present invention is described in detail below with reference to the accompanying drawings, and is not intended to limit the invention. The battery charging device of the independent power generation system having the maximum power tracking function according to the preferred embodiment of the present invention can be applied to wind power generation 'solar power generation or other regenerative energy source power generation, which is not intended to limit the present invention. Fig. 2 is a block diagram showing a stand-alone power generation system and a battery charging device having a maximum power tracking function according to a preferred embodiment of the present invention. Referring to FIG. 2, a battery charging device for a stand-alone power generation system having a maximum power tracking function according to a preferred embodiment of the present invention includes a stand-alone power generation system, a DC/DC converter 2, and a control circuit 3. Battery 4 and a switch 6. The stand-alone power generation system i is for providing a DC power source, and the stand-alone power generation system 1 is selected as a solar battery or a rectified wind power generation system. The input of the DC/DC converter 2 is connected to the output of the independent power generation I364898 system 1, and the output of the DC/DC converter 2 is connected in parallel to the battery 4, and the battery 4 is connected in parallel to a load via the switch 6. 5, to supply electrical energy to the load 5. The control circuit 3 is connected to the DC/DC converter 2 for controlling the DC/DC converter 2 to have a maximum power tracking function, a pulse charging function, and a constant voltage charging function. The control circuit 3 selects and executes the maximum power tracking function, the pulse charging function, the constant voltage charging function or a combination thereof according to the output power of the independent power generation system and the state of the sinusoidal battery 4, so as to achieve an effective improvement of the output power of the independent power generation system. The purpose of utilization. The battery 4 can be used to store or release electrical energy. When the output power of the independent power generation system 1 is small, the control circuit 3 controls the maximum power tracking function of the beta DC/DC converter 2 in order to utilize the maximum output power of the independent power generation system 1; The charging power of the battery 4 is the difference between the maximum output power of the independent power generation system 1 and the power of the negative power 5, and the charging current is a continuous current; at this time, the battery 4 can be charged by using a continuous current. The pulse charging is charged with a larger amount of energy, and if the output power of the independent power generation system 1 is less than the power of the load 5, the battery 4 and the independent power generation system 1 jointly supply power to the load 5' when When the voltage of the battery 4 is lower than a predetermined minimum discharge voltage value, the switch 6 is turned on to cut off the load 5. When the output power of the independent power generation system 1 is greater than the sum of the maximum constant current charging power of the battery 4 and the power of the load 5, the control circuit 3 controls the DC/DC converter 2 to perform a pulse charging method 'and Under the sum of the power of the load 5 and the predetermined maximum pulse charging power of the battery 4, the maximum power tracking function is performed to fully utilize the maximum output power of the independent power generation system 1. Once the output power of the stand-alone power generation system 1 is greater than the sum of the power of the load 5 and the predetermined maximum pulse charge power of the battery 4, the control circuit 3 controls the DC/DC converter 2 12 ΙΪ 64898 to suspend the execution of the maximum power tracking function. The control circuit 3 also controls the DC/DC converter 2 to limit the output power of the independent power generation system 1 to the sum of the power of the load 5 and the predetermined maximum pulse charging power of the battery 4, and the control is performed at this time. The circuit 3 controls the still-continuous control_DC/DC wire 2 to continue to perform the pulse charging function to charge the battery 4 in a pulsed manner. When the voltage of the battery 4 is greater than a predetermined constant voltage charging voltage value, the control circuit 3 terminates the pulse charging function. At this time, the control circuit 3 (4) the DC/straight ϋ 2 执 执 voltage charging function, with a constant voltage pair The battery 4 is charged. 2A to 2C are diagrams showing a circuit diagram of a DC/DC converter in a battery charging device of a stand-alone power generation system having a maximum power tracking function according to a preferred embodiment of the present invention. Referring to Figures 2 to 2C, the present invention can employ a non-isolated DC/DC converter charging architecture selected from the buck converter of Figure 2 and the boost of Figure 2B. The converter [b〇〇st (3) old sinking] or the 2C graph rising-lowering H [buek.boost converter·]#, which is punctured to define the scope of the invention. The structure of the buck converter, boost converter, and step-up converter is a m DC/DC converter charging architecture, which will not be described here. The control circuit 3 is used to control the power f sub-switching element of the DC/DC converter 2 (buck converter 'boost converter n or step-up converter) to perform maximum power tracking and pulse Charging, constant voltage charging, etc. or a combination thereof. Fig. 3 is a diagram showing the output power (four) line diagram of the battery charging method of the independent power generation system with the maximum power tracking function according to the preferred embodiment of the present invention. When the independent power generation system 1 is a solar power generation system, the output power characteristic curves ρι, P3, and P4 respectively represent the relationship between the output power of the social positivity and the output ink at the output of the same day illuminance, wherein the curve P4 The sun shines the strongest, while the daylight of the curve ρι 13 1364898 is the weakest. In addition, when the independent power generation system 1 is a wind power generation system, the output power characteristic curves pi, P2, P3, and P4 respectively represent the relationship between the output power of the wind power generation system and the speed of the generator under different wind powers, wherein the curve P4 The wind speed is the strongest, while the curve P1 has the weakest wind speed. Referring to FIG. 3, it indicates a first limiting power Pa, a second limiting power Pa+Pb, and a third limiting power Pa+Pc; wherein Pa is the load power, and Pb is the maximum constant current charging power of the battery. , pc is the maximum pulse charging power of the predetermined battery, and the third limiting power pa+pc is greater than the second limiting power Pa+Pb. The maximum power region of the curve P4 (shown as the grid region of FIG. 3) is greater than the third limiting power Pa+Pc, so that it cannot perform the maximum only when the solar illuminance or the wind force is strong resulting in the power curve P4. Power tracking function. Comparing Fig. 3 with Fig. 1 'the invention cannot fully utilize the output power of the stand-alone power generation system 1 much less than the charging device of the conventional stand-alone power generation system [as shown in Fig. 1); therefore, this The battery charging device of the independent power generation system with the maximum power tracking function is more effective than the charging device of the conventional independent power generation system, and can effectively utilize the output energy of the s-separate power generation system 1 to accelerate the battery charging rate and shorten the battery charging. time. Referring to FIGS. 2 and 3 again, the battery charging device of the independent power generation system with maximum power tracking function according to the preferred embodiment of the present invention provides four operating modes for performing maximum power tracking, pulse charging, and constant voltage charging. Or a combination thereof. When the output power of the independent power generation system 1 is equal to or greater than the first limited power Pa but smaller than the second limited power Pa+Pb, a first operating mode is performed, and the control circuit 3 controls the DC/DC converter 2 Performing the maximum power tracking function to utilize the maximum output power of the independent power generation system 1; at this time, the Lai 6 is closed, and the output-power is to the load 5 'The charging power of the battery 4 is the independent power generation system] IJ64898 The difference between the maximum output power and the power of the load 5' is that the charging current is a continuous current. At this time, charging the battery 4 with continuous current can be more energy than the pulse charging; and when the independent power generation system i When the wheel power is less than the first limit power Pa, the control circuit 3 controls the DC/DC converter 2 to perform the maximum power tracking function, and the independent power generation system 1 and the battery 4 jointly supply power to the load 5 . - when the voltage of the battery 4 is lower than the predetermined minimum discharge voltage value, the load is cut away by controlling the switch 6 to form an open circuit 'to avoid excessive discharge of the battery 4; after cutting off the load 5' Charging the battery 4' with the output power of the stand-alone power generation system i The preferred predetermined minimum voltage value of the battery 4 is obtained from the lowest discharge voltage value recommended by the battery manufacturer. Please refer to the second and third working modes when the output power of the independent power generation system is greater than the second limited power Pa+Pb but less than the third limited power pa+pc, as shown in the second and third figures. The f battery 4 is not suitable for continuous current charging, otherwise the battery 4 may overheat and affect the life. In the second mode, the control circuit 3 controls the DC/DC converter 2 to perform a pulse charging method, and continues to perform the maximum The power tracking function is to utilize the maximum output power of the independent power generation system i; at this time, the switch 6 is closed to output a power to the load 5. Please refer to the second and third figures. When the output power of the _ vertical power generation system is greater than the third limit power Pa+Pe _, the third-level mode is executed. At this time, the maximum power tracking function should not be executed. Otherwise, the life of the battery 4 will be shortened. In the third mode of operation, the "presence circuit 3 suspends the execution of the maximum power tracking function, and the control circuit 3 controls the DC/DC converter 2 to limit the independent output power to the power of the load 5 and the predetermined two charge of the battery 4 = At the same time, the control circuit 3 continues to perform the pulse charging function to pulse 15. At this time, the switch 6 is closed, and the battery 4 is charged in an output manner; power is applied to the load 5.厌右Φ··...Fig. 2 does not 'when the voltage of the battery 4 is greater than a predetermined constant voltage charging voltage value [A1], the β T "operation mode is executed, and it is not appropriate to use the $, 'current charging mode to read the battery at this time. 4 charging, otherwise causing the battery 4 to overcharge and shortening the life of the battery 4. In the fourth mode of operation, the control circuit 3 terminates the pulse charging function, at which time the control circuit 3 controls the DC/DC muscle converter 2 to perform The constant voltage charging function charges the battery 4 with a constant voltage. The predetermined fixed voltage charging voltage value [Α1] is obtained from the recommended value of the battery factory. At this time, the switch is closed to output a power to the load. 5. Figure 4 is a flow chart showing a method of charging a battery of a stand-alone power generation system having a maximum power tracking function according to a preferred embodiment of the present invention. Referring again to Figures 2 to 4, first, a preferred embodiment of the present invention. The battery charging method of the independent power generation system with maximum power tracking function determines whether the voltage of the battery 4 is less than a predetermined constant voltage charging voltage value [Α1]^ if the battery When the voltage of 4 is not less than the predetermined constant voltage charging voltage value [Α1], the fourth operating mode is directly executed, and the control circuit 3 controls the DC/DC converter 2 to perform a constant voltage charging function, and performs the voltage on the battery 4 at a constant voltage. Charging; if the voltage of the battery 4 is less than the predetermined constant voltage charging voltage value [Α1], selecting to perform the first working mode, the second working mode or the third working mode. When the voltage of the battery 4 is less than the predetermined constant voltage charging When the voltage value [A1] is determined, it is determined whether the output power of the independent power generation system 1 is less than the second limited power Pa+Pb; if the output power of the independent power generation system 1 is less than the second limited power Pa+Pb, the first execution is performed. Working mode, controlled by the control circuit 3, the DC/DC 489 489 489
轉換器2執行^:大功率追縱功能，以_利用該獨立型發電系統i 之最大輸出功率；此時，該_ 6為閉合，輸出—功率至該負載5 ’該蓄電池4之充電功率為該獨立型發電系統i之最大輸出功率 、該負載5之功率之差’其充電電流為1續電流，若該獨立型 發電系統1之輸出功率小於該第—限制:力率pa時，該f電池4進 2放電，該蓄電池4與鶴立型發電_〗制提供該負載5所 需之功率。因此，在執行該第—工作模式時，判斷該蓄電池4之The converter 2 performs a high power tracking function to utilize the maximum output power of the independent power generation system i; at this time, the _ 6 is closed, and the output power is to the load 5 'the charging power of the battery 4 is The difference between the maximum output power of the independent power generation system i and the power of the load 5 is that the charging current is 1 continuous current. If the output power of the independent power generation system 1 is less than the first limit: the force rate pa, the f The battery 4 is discharged into 2, and the battery 4 and the stand-up power generation system provide the power required for the load 5. Therefore, when the first working mode is executed, the battery 4 is judged
，壓是否低賊駭⑸、職值；若简電池*之電壓低於該預 定最小電難時，藉岭制該關6形成開路而切離該負載5 ’以避免該蓄電池4過度放電，並_該獨立型發電系統i之輸 出功率充電該蓄電池4。 接著亥獨立型發電系統i之輸出功率大於或等於第二限 制功率Mb時，再判斷該獨立型發電系統i之輸出功率是否小 於第三限制功率Pa+Pc。 若D玄獨立發電系統（之輸出功率小於第三限制功率Whether the pressure is low or not (5), the value; if the voltage of the battery* is lower than the predetermined minimum power, the bridge 6 is formed to open the circuit and cut off the load 5' to avoid the battery 4 being over-discharged, and The output power of the independent power generation system i charges the battery 4. When the output power of the independent power generation system i is greater than or equal to the second limited power Mb, it is determined whether the output power of the independent power generation system i is smaller than the third limited power Pa+Pc. If D Xuan independent power generation system (the output power is less than the third limit power
Pa+PcPa+Pc
執行第工作模式，在第二工作模式下該控制電路3控制該 直流/直流轉換H 2執行脈衝充電方法，並持續執行最大功率追縱 功能，以期利用該獨立型發電系統1之最大輸出功率；此時，該 開關6為閉合’輸出_功率至該負載5。除了執行脈衝充電功能外 另動只控制電路3另控制該直流/直流轉換器2仍執行最大功 反之 右獨立型發電系統1之輸出功率大於或等於第三限 制功率Pa+Pe時，執行第三工作模式，在第三4模式下，該控 制電路3中止執仃最大功率追縱魏，該控制電路3控制該直^ 17 直机轉換器2將該獨立型發電系統 功率及蓄電池4之預定最大脈衝充電功限^該負载5 路3仍持庐轴一Β^ 之〜和，此時該控制電 1執仃脈衝充電功能以脈衝方式對該蓄電池4 ’此時’該開關6為閉合，輸出—功率至該負載5 及第接著，在執行第-工作模式、第二卫作模式、第三工作模式 定ιΓ模式後，再返回躺該蓄電池4之電壓Η小於一預 。疋歧電電壓值〔Α1〕之方塊’以重新執行工作模式之判斷 型發電第林料難實施敗綠切率魏魏之獨立 丄:之蓄電池充電裝置中控制電路使用之最大功率追蹤流 ^制，其採时任週期擾動方絲追㈣獨立型發電⑽i之 T ’責任職為該錢/直流轉換器2之電力電子開關導通 日^與切換週期之比，然其並非用以限定本發明之。請參照 第5圖所P最大辨追蹤絲機㈣先讀取賴立型發電系統i 輸出電麼〔v_ee〕及電流〔Is_〕，並計算其功率〔卩⑽似⑷ 〕，再經由前-次功率（ρ_㈣〕和本次計算功率〔Ps_(n) 的比較方式判斷其責任週期擾動方向，當本次計算功率〔 ⑻〕大於前一次功率時，表示責任週期擾動方 向正確’不須改變責任週期擾動方向，即D (k+i) =D (k) + △ D田本-人计异功率〔Ps〇urce⑻〕小於前—次功率〔p丽e(n_ j)〕時 ’表示責任遇期擾動方向不正破，需改變責㈣期擾動方向，因 此先執行△!) x⑷，再執行D(k+1)=D(k)+ ad，如此一 直重複以上步驟便可順利達到最大功率點，並停留在最大功率點 附近來回擾動。 13:64898 前述較佳實施例僅舉例說明本發明及其技術特徵，該實施例 之技術仍可適當進行各種實質等效修飾及/或替換方式予以實施； 因此，本發明之權利範圍須視後附申請專利範圍所界定之範圍為 I3S4898 【圖式簡單說明】 第1圖：習用具最大功率追蹤功能之獨立塑發電系統之輸出 功率曲線圖。 第2圖：本發明較佳實施例之具最大功率追蹤功能之獨立型 發電系統及蓄電池充電裝置之方塊圖。 第2A至2C圖：本發明較佳實施例之具最大功率追蹤功能之 獨立型發電系統之蓄電池充電裝置中採用直流/直流轉換器之電略 圖。 第3圖：本發明較佳實施例之具最大功率追蹤功能之獨立型 發電系統之蓄電池充電方法輸出功率曲線圖。 第4圖：本發明較佳實施例之具最大功率追蹤功能之獨立型 發電系統之蓄電池充電方法之流程圖。 第5圖：本發明較佳實施例之具最大功率追蹤功能之獨立型 發電系統採用最大功率追蹤方法之流程圖。 【主要元件符號說明】 2 直流/直流轉換器 5負載 1獨立型發電系統 3 控制電路 4蓄電池 6開關 20Performing a working mode, in which the control circuit 3 controls the DC/DC conversion H 2 to perform a pulse charging method, and continuously performs a maximum power tracking function, in order to utilize the maximum output power of the independent power generation system 1; At this time, the switch 6 is closed 'output_power' to the load 5. In addition to performing the pulse charging function, only the control circuit 3 controls the DC/DC converter 2 to perform the maximum power, and when the output power of the right independent power generation system 1 is greater than or equal to the third limited power Pa+Pe, the third execution is performed. In the working mode, in the third mode 4, the control circuit 3 suspends the execution of the maximum power tracking, and the control circuit 3 controls the straight-line converter 2 to maximize the power of the independent power generation system and the predetermined state of the battery 4. Pulse charging power limit ^ The load 5 way 3 still holds the Β axis Β^~ and, at this time, the control electric 1 performs the pulse charging function to pulse the way to the battery 4 'At this time' the switch 6 is closed, the output - Power to the load 5 and then, after performing the first mode of operation, the second mode of operation, and the mode of operation of the third mode of operation, the voltage returned to the battery 4 is less than a predetermined value.疋 电 电 电 Α Α Α Α ' 以 以 以 以 以 以 重新 重新 重新 重新 重新 重新 重新 重新 以 判断 判断 判断 判断 判断 判断 判断 判断 判断 判断 判断 判断 判断 魏 魏 魏 魏 魏 魏 魏 魏 魏 魏 魏 魏 魏 魏 魏The timing of the current cycle is disturbed by the square wire. (4) The independent power generation (10) i of the T' responsibility is the ratio of the power electronic switch conduction time of the money/DC converter 2 to the switching cycle, but it is not intended to limit the present invention. . Please refer to Figure 5 for the maximum discriminating tracer (4). First read the output power of the Lai Li type power generation system i [v_ee] and current [Is_], and calculate the power [卩(10) like (4)], then pass the pre-time The power (ρ_(four)) and the current calculation power [Ps_(n) are compared to determine the direction of the duty cycle disturbance. When the current calculation power [(8)] is greater than the previous power, the duty cycle disturbance direction is correct. No need to change the duty cycle. Disturbance direction, that is, D (k+i) = D (k) + △ D field-personal power [Ps〇urce (8)] is less than the front-time power [p 丽e(n_ j)] If the disturbance direction is not broken, you need to change the direction of disturbance (4), so first execute △!) x(4), then execute D(k+1)=D(k)+ ad, so you can repeat the above steps to reach the maximum power point. And stay in the vicinity of the maximum power point to disturb. 13:64898 The foregoing preferred embodiments are merely illustrative of the present invention and its technical features, and the techniques of the embodiments can be carried out with various substantial equivalent modifications and/or alternatives as appropriate; The scope defined by the scope of the patent application is I3S4898 [Simple description of the drawing] Figure 1: The output power curve of the independent plastic power generation system with the maximum power tracking function of the appliance. Figure 2 is a block diagram of a stand-alone power generation system and a battery charging device with maximum power tracking functionality in accordance with a preferred embodiment of the present invention. 2A to 2C are diagrams showing a schematic diagram of a DC/DC converter used in a battery charging device of a stand-alone power generation system having a maximum power tracking function according to a preferred embodiment of the present invention. Figure 3 is a graph showing the output power of a battery charging method for a stand-alone power generation system having a maximum power tracking function in accordance with a preferred embodiment of the present invention. Figure 4 is a flow chart showing a method of charging a battery of a stand-alone power generation system having a maximum power tracking function in accordance with a preferred embodiment of the present invention. Figure 5 is a flow chart showing the maximum power tracking method for a stand-alone power generation system having a maximum power tracking function in accordance with a preferred embodiment of the present invention. [Main component symbol description] 2 DC/DC converter 5 load 1 independent power generation system 3 Control circuit 4 battery 6 switch 20