1252589 玖、發明說明： 【發明所屬之技術領域】 本發明主旨為發展具電壓箝制及柔性切換機制之高效 率燃料電池高昇壓比換流器。燃料電池利用電化學反應原 理發電，具低電壓及高電流輸出特性，然而高電壓輸出之 燃料電池組體積大且堆疊不易，除此之外，燃料電池輸出 電壓易隨負載變動而造成影響，因應高電壓需求之應用場 合，具高效率及高昇壓比特性之換流器為燃料電池電力調 節不可或缺項目之一。本發明之具電壓箝制及柔性切換機 制之高效率燃料電池高昇壓比換流器，運用電壓箝制及柔 性切換技術，減少半導體開關元件切換損失及降低導通損 失，提高轉換效率，並突破傳統昇壓式換流器之昇壓比以 及克服高匝數比耦合電感漏感之問題，運用閉迴路控制機 制106，增加本發明之換流器靈敏度及系統頻寬，解決燃 料電池輸出電壓易隨負載變動之問題，達成高效率燃料電 池高昇壓比換流器輸出電壓穩定之效果。本發明所發展之 具電壓箝制及柔性切換機制之高效率燃料電池高昇壓比換 流器，大幅提昇能源利用率及增加供電穩定度，可運用於 大功率反流器之高壓直流匯流排或直接提供負載，本發明 之技術亦可發展為各式低壓電源發電系統調節為穩定高壓 直流之電源轉換裝置。 【先前技術】 自然界的能源並非取之不盡、用之不竭的資源，且伴 隨能源開發造成的環境污染，是地球上萬物共同面臨的危 1252589 機。除此之外，一般傳統能源的轉換效率並不高，因此在 面臨能源短缺的前提下，提高能源轉換效率是刻不容緩的 課題。燃料電池是利用電化學反應原理直接將化學能轉換 為電能，發電過程無噪音且產出物無任何污染，因此其發 電效能優於傳統内燃機系統。燃料電池並非是真正所謂的 電池，而是一種環保式發電機，相較於一般的電池，雖然 同樣都是藉由電化學反應將化學能轉換為電能，但燃料電 池的反應物非密閉在反應器中，而必須自外界源源不斷的 供應至電極才能持續發電，因此理論上而言，燃料電池的 壽命是無限制的。然而燃料電池發電具低電壓高電流發電 特性，且其輸出電壓易隨負載變化而改變，因此需一具高 昇壓比特性之換流器及閉迴路控制機制106，提高並穩定 燃料電池之輸出電壓，以提供穩定之高壓直流供應。 另一方面，傳統昇壓式換流器，如圖2(a)所表示，可 藉由調整開關之責任週期（Duty Cycle)，控制輸出電壓昇 壓比例，然而換流器中功率半導體開關並非理想開關，功 率半導體開關導通與戴止暫態期間内，流經功率半導體開 關之電流與功率半導體元件兩端電壓乘積造成高切換損 失，此不具有柔性切換之換流器，不利操作於高頻切換， 為了降低電路中漣波電壓及電流，只有選取較大電容與電 感值，被動元件體積與重量因而增加；再者，當應用於高 昇壓比之情況下，責任週期需要調整至極大值，然而換流 器中電感之等效電阻（ESR)導致昇壓比有所限制，故傳統 昇壓式換流器無法操作於高昇壓比之範圍。當傳統昇壓式 1252589 換流器之功率半導體開關截止時，兩端電壓值為輸出電 壓，此局於輸入電壓數倍之跨壓，迫使功率半導體開關需 選擇高耐壓之MOSFET，然而其具有較大導通電阻值 (Rdswn}) ’形成較咼之導通損失。除此之外，傳統昇壓式 換流器中二極體存在逆向回復(Reverse_Recove^)之問題， 二功率半導體開關導通之暫態期間，傳統昇壓式換流器之 电谷电I對功率半導體開關及二極體造成反向電流突波並 ίί功率、，。基於以上所述，發展出具耦合電感之昇壓式換 *叩，改善其中部分缺點，該換流器架構如圖2(b)所表示， 運用轉合=感使昇壓比例提高，當該換流器之功率半導體 開=戴止日守，耦合電感二次側建立電壓，功率半導體開關 又相§於輪出端之高電壓，具電壓箝制之效果，但 =Α感漏感之電流在功率半導體開關截止暫態期間内， 111電流延遲截止, 而對功率半導體開關兩端造成較高電壓突 波’需額外加裂雷曰Μ ^ ^ 日日體、、友振電路（Snubber Circuit) ’在母個1252589 发明, INSTRUCTION DESCRIPTION: TECHNICAL FIELD OF THE INVENTION The present invention is directed to the development of a high efficiency fuel cell high step-up ratio converter with voltage clamping and flexible switching mechanisms. The fuel cell uses the principle of electrochemical reaction to generate electricity with low voltage and high current output characteristics. However, the fuel cell stack with high voltage output is bulky and difficult to stack. In addition, the output voltage of the fuel cell is easily affected by load fluctuations. For applications with high voltage requirements, inverters with high efficiency and high boost ratio characteristics are one of the indispensable items for fuel cell power regulation. The high-efficiency fuel cell high-boost ratio converter with voltage clamping and flexible switching mechanism of the invention uses voltage clamping and flexible switching technology to reduce switching loss of semiconductor switching elements and reduce conduction loss, improve conversion efficiency, and break through traditional boost The boost ratio of the converter and the problem of overcoming the leakage inductance of the coupled inductor with high turns ratio, using the closed loop control mechanism 106, increasing the sensitivity of the converter and the system bandwidth of the present invention, and solving the fuel cell output voltage is easy to change with load The problem is to achieve high efficiency fuel cell high boost ratio converter output voltage stability effect. The high-efficiency fuel cell high-boost ratio converter with voltage clamping and flexible switching mechanism developed by the invention greatly improves energy utilization and increases power supply stability, and can be applied to high-voltage DC busbar of high-power inverter or directly Providing the load, the technology of the present invention can also be developed into a power conversion device that regulates various high-voltage direct current power generation systems to stabilize high-voltage direct current. [Prior Art] The energy of nature is not an inexhaustible resource, and the environmental pollution caused by energy development is a common threat to all things on the planet. In addition, the conversion efficiency of traditional energy sources is not high. Therefore, in the face of energy shortage, improving energy conversion efficiency is an urgent task. The fuel cell directly converts chemical energy into electrical energy by using the principle of electrochemical reaction. The power generation process is noise-free and the output is free from any pollution, so its power generation efficiency is superior to that of the conventional internal combustion engine system. The fuel cell is not really a so-called battery, but an environmentally-friendly generator. Although the chemical energy is converted into electrical energy by electrochemical reaction, the reactants of the fuel cell are not sealed in the reaction. In the device, it must be continuously supplied to the electrode from the outside to continue power generation. Therefore, in theory, the life of the fuel cell is unlimited. However, fuel cell power generation has low voltage and high current power generation characteristics, and its output voltage is easy to change with load changes. Therefore, a converter with high step-up ratio characteristics and a closed loop control mechanism 106 are required to improve and stabilize the output voltage of the fuel cell. To provide a stable high voltage DC supply. On the other hand, the conventional boost converter, as shown in Fig. 2(a), can control the output voltage boost ratio by adjusting the duty cycle of the switch. However, the power semiconductor switch in the converter is not The ideal switch, during the conduction and the transient period of the power semiconductor switch, the current flowing through the power semiconductor switch and the voltage across the power semiconductor component cause high switching loss, which does not have a flexible switching converter, which is disadvantageous for high frequency operation. Switching, in order to reduce the chopping voltage and current in the circuit, only the larger capacitance and inductance value are selected, and the passive component volume and weight are increased. Moreover, when applied to the high boost ratio, the duty cycle needs to be adjusted to the maximum value. However, the equivalent resistance (ESR) of the inductor in the converter results in a limited boost ratio, so the conventional boost converter cannot operate in the high boost ratio range. When the power semiconductor switch of the conventional boost 1252589 converter is turned off, the voltage at both ends is the output voltage, and the voltage across the input voltage is several times, forcing the power semiconductor switch to select a high withstand voltage MOSFET, however, A larger on-resistance value (Rdswn}) 'forms a lower conduction loss. In addition, there is a problem of reverse recovery (Reverse_Recove^) in the diode of the conventional boost converter, and the power of the conventional boost converter during the transient period of the two-power semiconductor switch is turned on. Semiconductor switches and diodes cause reverse current surges and power. Based on the above, the development of a boosted converter with a coupled inductor improves some of the disadvantages. The converter architecture is shown in Figure 2(b), using the turn-in = sense to increase the boost ratio when the switch The power semiconductor of the current device is turned on and off, the secondary side of the coupled inductor establishes the voltage, and the power semiconductor switch is § § at the high voltage of the wheel end, with the effect of voltage clamping, but the current of the leakage inductance is at the power During the off-state of the semiconductor switch, the 111 current delay is turned off, and a higher voltage surge is caused to both ends of the power semiconductor switch. 'Additional cracking thunder is required ^ ^ Sikki, Snubber Circuit' Mother
’、月中消耗_馬合雷A 用的電曰一扭感漏感所儲存之能量，然而換流器所使 其轉換效率。 峪將f造成额外之切換損失，因而降低 性切換機制之^進一步，研究學者發展出具耦合電感及柔 開關電路取女Γ壓式換流器，如圖2(c)所表示，利用Η型 串聯二極體再早:功率半導體開關，並在耦合電感二次側 導體開關、、並聯電容’其中Η型開關電路由兩個功率半 路的兩個功^個:極體及一個電容所組成。當開關電 串聯二極骱； '半導體開關截止時，並聯於耦合電感二次側 笔各’提供另一路徑使漏感電流流向輸出負 10 1252589 載，克服高匝數比耦合電感漏感所造成的問題，不藉由電 晶體缓振電路消耗耦合電感漏感所儲存之能量，並保有原 電壓箝制之效果，此時該換流器的Η型開關電路之電容與 耦合電感漏感發生諧振，因此Η型開關電路的兩個功率半 導體開關截止時具零電壓切換（Zero Voltage Switching， ZVS)機制；當Η型開關電路的兩個功率半導體開關導通 時，將Η型開關電路中電容儲存之能量傳導至耦合電感一 次側，諸振電流由零遞增，Η型開關電路中兩個功率半導 體開關導通時具零電流切換(Zero Current Switching，ZCS) 機制，但因其不具有零電壓切換機制，功率半導體開關之 寄生電容電壓造成内部短路電流，導致功率半導體開關發 愛並增加功率損失，且低耐壓之功率半導體開關具有較高 寄生電容，切換損失因而大幅增加，況且，使用兩個功率 半導體開關串聯於Η型開關電路中會額外增加導通損失， 為其效率不彰之主要因素。 為了改善上述習用之昇壓式換流器缺點，本發明發展 具電壓箝制及柔性切換機制之高效率燃料電池高昇壓比換 流器，此換流器使用柔性切換電路102，其主要功能是透 過柔性切換電路102之功率半導體開關之切換，使得柔性 切換電路102之諧振電容C；上電壓，對一次侧電路1〇3之 耦合電感一次侧造成電壓反向，並配合柔性切換電路102 之諧振電感4，於一次侧電路1〇3之功率半導體開關&導 通前，利用諸振方式達成一次側電路103之功率半導體開 關&導通時具有零電壓及零電流切換特性，其中柔性切換 1252589 電路102之功率半導體開關心及心之導通時間很短，不 造成較高之環流使導通損失增加。相較於傳統昇壓式換流 器，本發明運用耦合電感，不僅可箝制開關電壓，亦可使 其昇壓比例提高，同時利用耦合電感漏感之特性，減輕二 次侧電路之二極體逆向回復之問題；相較於具耦合電感 及柔性切換機制之昇壓式換流器，本發明具有導通時零電 壓及零電流切換特性，在每週期内將一次側電路之功率半 導體開關4上之寄生電容能量反饋至直流輸入電路101之 濾波電容ς.，減少功率半導體開關内部損失，使用單一功 率半導體開關於一次侧電路103，大幅降低導通損失，進 而提高本發明所揭示具電壓箝制及柔性切換機制之高效率 燃料電池高昇壓比換流器之轉換效率。 【發明内容】 圖1表示本發明所揭示具電壓箝制及柔性切換機制之 高效率燃料電池高昇壓比換流器方塊圖。本發明乃利用燃 料電池作為直流電源，將發電過程所產出低電壓高電流特 性之電能，經本發明所揭示之具電壓箝制及柔性切換機制 之高效率燃料電池高昇壓比換流器電源轉換後，大幅昇高 燃料電池直流輸出電壓F/，可應用於高電壓需求時之場 合；本發明之閉迴路控制機制106，解決燃料電池直流輸 出電壓易隨負載變動之問題，穩定直流輸出電路105之輸 出電壓。利用柔性切換電路102，達成一次側電路103之 功率半導體開關X具有零電壓以及零電流切換特性，進而 提高轉換效率。當一次侧電路103之功率半導體開關導通 12 1252589 時，先將燃料電池產出之能量傳導之一次侧電路103之耦 合電感一次侧;當一次側電路103之功率半導體開關截 止時，將燃料電池產出之能量、儲存於一次侧電路103之 耦合電感一次侧以及二次侧電路之電容C2能量，於一次側 電路103之二極體導通時，將三者串聯之能量導至直流輸 出電路105，提昇燃料電池直流輸出電壓。 本發明改善先前技術之原理及對照功效如下： 1.電源供應由燃料電池所提供：本發明運用燃料電池發電 所產出之能量，具有潔淨及高效率之特點，有別於傳統 石化燃料，本發明之換流器將燃料電池直流輸出電壓大 幅昇高，可應用於大功率反流器之高壓直流匯流排中。 2· —次侧電路103及二次侧電路104提高昇壓比例、箝制 功率半導體開關\電壓以及解決耦合電感漏感問題：利 用耦合電感匝數與電壓成比例之特性，本發明之裝置具 高昇壓比之特性，提供較高於傳統昇壓式換流器之昇壓 比例；運用二次侧電路104之電容C2，解決高匝數比耦 合電感漏感所產生之問題，不使用電晶體缓振電路消耗 漏感能量，以利於轉換效率之提昇；二次側電路104之 耦合電感二次侧4所建立之電壓，分擔一次側電路103 之功率半導體開關兩端之跨壓，使此電壓低於直流輸出 電路105之輸出電壓，使其具有電壓箝制之特性。 3·電壓箝制特性降低導通損失：一次侧電路103之功率半 導體開關兩端之跨壓被箝制於低壓範圍，可以選用較低 耐壓值之MOSFET，因其具較低之導通電阻可減低導通 13 1252589 損失，進而提升轉換效率。 4. 柔性切換電路102降低切換損失並使功率半導體開關可 操作於高頻切換：柔性切換電路102利用諧振原理，在 一次側電路103之功率半導體開關\導通前，將一次侧 電路103之功率半導體開關上寄生電容之能量，反饋至 直流輸入電路101之輸出濾波電容Cz，使一次侧電路103 之功率半導體開關導通時兼具零電壓及零電流切換特 性，而低壓之MOSFET具較大之寄生電容，所反饋功 率大於柔性切換電路102功率半導體開關上之導通損失 與切換損失之總和，因此可提昇電源轉換效率；另一方 面，此柔性切換特性亦可使功率半導體開關切換頻率提 高，降低被動元件之體積與重量，提高功率密度。 5. 閉迴路控制機制：燃料電池輸出電壓隨負載變化，可以 藉由閉迴路控制機制106穩定直流輸出電路105之輸出 電壓。 【實施方式】 圖3表示本發明所揭示之換流器電壓電流示意。其中 耦合電感利用理想變壓器、激磁電感4及漏感4表示，理 想變壓器一次側與二次侧之匝數分別為7V以及7V，將耦 p ^ 合電感一次侧表示為理想變壓器之一次側、激磁電感以 及漏感，耦合電感二次侧4表示為理想變壓器之二次側， 定義理想變壓器之匝數比7V及耦合係數尺如下： N 二 NJNp (1) 14 1252589 ^Lm +Lk) (2) 其中一次側跨壓為％ ’假設二次側電路104之電容仏夠 ^可視眷為定電壓源，並將直流輸人電路1G5簡化為輸入電 壓C。圖4表示本發明所揭示之換流器電路工作模式圖， 圖5表7Γ电壓及電流波形時序。圖4電路工作模式 如下： 模式一丨&〜j : 容“w，二極心、狀偏，譜振電 值致使柔性切換電路102中二極- 充電。 此時輸入電壓對激磁電感4及漏感4線^ 模式二[6〜]: 田日守間丨時，功率半導體 漏感之電流對功率半導體開關《之寄生電容充Γ兹電感及 壓近似線性上升。 玍包奋充電，兩端跨 模式三[G〜G ]: 當時間气日寺，功率半導體開關 升至F-v ，二;1 可生電谷電壓> ^ ^ ° C2 一極體Θ導通，激磁電减及叙入^^、 上 之電流流向直流輪出電路i05， 電感漏感上 電；理想變屢器透過磁轉合的方/ = q對負载放 導至耦合電感二次側z，電 古“、电感上能量傳 利用克希荷夫電壓定律，可^導=向直流輪出電路105。 Κ，+ι)·%+κ VC2 二 Ν·νΝρ (3) 15 (4) 1252589 在此期間，激磁電感及漏感上電流同時對柔性切換電路102 中之諧振電容C；充電，二極體、Ρ/ϊ2導通，諧振電流呈 正弦函數波形，二極體導通時具零電流切換機制， 諧振電容電壓上升，此時柔性切換電路102之功率半 導體開關&及&2跨壓等於諧振電容之電壓。 模式四[〜G】： 當時間戸ί3時，柔性切換電路102之諧振結束，此時 言皆振電容上電壓略為大於激磁電感及漏感上之電壓總和， 使二極體及仏2逆偏，諧振電流呈正弦函數遞減至零， 二極體截止時亦具零電流切換機制，而激磁電感 及耦合電感漏感上之電流則持續流向直流輸出電路105。 當時間介於ί2〜ί4，耦合電感一次側之能量轉移至耦合電 感二次侧，另一方面，激磁電感利用漏感電流連續之特性， 將輸入電壓、耦合電感一次側及二次侧電路之電容C2上之 能量經由二極體A導至直流輸出電路105。 模式五[〜ί5 ]: 當時間ί=ί4時，漏感電流近似線性降至零值，二極體 Α截止時具零電流切換之特性，不造成反向電流突波，減 輕此二極體逆向回復之問題，並因漏感上電流變化率為 零，漏感上兩端電壓為零，使功率半導體開關&電壓降低， 該功率半導體開關之箝制電壓值可表示為‘, mid-month consumption _ Ma Helei A used to charge the energy stored by the sense of leakage, but the converter makes its conversion efficiency.峪 f f 造成 造成 造成 造成 造成 造成 造成 造成 造成 造成 造成 造成 额外 额外 额外 额外 额外 额外 额外 额外 额外 额外 额外 额外 额外 额外 额外 额外 额外 额外 额外 额外 额外 额外 额外 额外 额外 额外 额外 额外 额外 额外 额外 额外 额外 额外 额外 额外The diode is early: the power semiconductor switch, and the secondary side conductor switch of the coupled inductor, and the shunt capacitor', wherein the Η type switch circuit is composed of two power half paths: a pole body and a capacitor. When the switch is electrically connected in series with two poles; when the semiconductor switch is turned off, the parallel connection to the secondary side of the coupled inductor provides another path for the leakage current to flow to the output negative 10 1252589, overcoming the leakage inductance of the high inductance ratio coupling inductor. The problem is that the transistor damping circuit consumes the energy stored in the coupling inductance leakage inductance and retains the effect of the original voltage clamping. At this time, the capacitance of the converter type switching circuit resonates with the coupling inductance leakage inductance. Therefore, the two power semiconductor switches of the 开关-type switching circuit have a Zero Voltage Switching (ZVS) mechanism when turned off; when the two power semiconductor switches of the 开关-type switching circuit are turned on, the energy stored in the capacitance of the 开关-type switching circuit is stored. Conducted to the primary side of the coupled inductor, the oscillator currents are incremented by zero, and the two current semiconductor switches in the Η-type switching circuit have a Zero Current Switching (ZCS) mechanism, but because they do not have a zero voltage switching mechanism, the power The parasitic capacitance voltage of the semiconductor switch causes an internal short-circuit current, which causes the power semiconductor switch to love and increase power loss, and Power semiconductor switch having high breakdown voltage of the parasitic capacitance, and therefore a substantial increase in switching losses, moreover, the use of two semiconductor switches connected in series with a power switching circuit Η extra conduction loss increases, the main factor for the efficiency not been apparent. In order to improve the disadvantages of the conventional boost converter, the present invention develops a high efficiency fuel cell high step-up ratio converter with voltage clamping and flexible switching mechanism. The converter uses a flexible switching circuit 102 whose main function is to transmit The switching of the power semiconductor switch of the flexible switching circuit 102 causes the resonant capacitor C of the flexible switching circuit 102; the upper voltage causes a voltage reversal on the primary side of the coupled inductor of the primary side circuit 1〇3, and cooperates with the resonant inductance of the flexible switching circuit 102. 4. Before the power semiconductor switch & of the primary side circuit 1〇3 is turned on, the power semiconductor switch of the primary side circuit 103 is achieved by the vibration mode, and has zero voltage and zero current switching characteristics when turned on, wherein the flexible switching 1252589 circuit 102 The power semiconductor switching center and the conduction time of the core are short, and no high circulation is caused to increase the conduction loss. Compared with the conventional boost converter, the present invention uses the coupled inductor to not only clamp the switching voltage, but also increase the boost ratio, and at the same time, utilize the characteristic of the leakage inductance of the coupled inductor to reduce the diode of the secondary circuit. The problem of reverse recovery; compared with a boost converter with a coupled inductor and a flexible switching mechanism, the present invention has zero-voltage and zero-current switching characteristics during turn-on, and the power semiconductor switch 4 of the primary side circuit is applied during the weekly period. The parasitic capacitance energy is fed back to the filter capacitor 直流 of the DC input circuit 101 to reduce the internal loss of the power semiconductor switch, and the single-power semiconductor switch is used in the primary side circuit 103 to greatly reduce the conduction loss, thereby improving the voltage clamping and flexibility disclosed in the present invention. Switching mechanism for high efficiency fuel cell high boost ratio converter conversion efficiency. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a block diagram of a high efficiency fuel cell high step-up ratio converter with voltage clamping and flexible switching mechanisms as disclosed herein. The invention utilizes a fuel cell as a direct current power source to convert the low-voltage high-current characteristic electric energy generated by the power generation process, and the high-efficiency fuel cell high-boost ratio converter power supply with voltage clamping and flexible switching mechanism disclosed by the present invention is converted. The DC output voltage F/ of the fuel cell is greatly increased, and can be applied to the occasion of high voltage demand; the closed loop control mechanism 106 of the present invention solves the problem that the DC output voltage of the fuel cell easily changes with the load, and stabilizes the DC output circuit 105. The output voltage. With the flexible switching circuit 102, the power semiconductor switch X of the primary side circuit 103 is realized to have zero voltage and zero current switching characteristics, thereby improving conversion efficiency. When the power semiconductor switch of the primary side circuit 103 is turned on 12 1252589, the coupled inductor of the primary side circuit 103 of the energy conducted by the fuel cell is firstly coupled to the primary side; when the power semiconductor switch of the primary side circuit 103 is turned off, the fuel cell is produced. The energy, the primary side of the coupled inductor stored in the primary side circuit 103, and the capacitance C2 energy of the secondary side circuit, when the diode of the primary side circuit 103 is turned on, directs the energy of the three series in series to the DC output circuit 105. Increase the DC output voltage of the fuel cell. The invention improves the principle and the control efficacy of the prior art as follows: 1. The power supply is provided by the fuel cell: the energy produced by the fuel cell power generation of the invention has the characteristics of cleanness and high efficiency, and is different from the traditional petrochemical fuel. The inventor of the invention greatly increases the DC output voltage of the fuel cell and can be applied to the high voltage DC bus of the high power inverter. 2. The secondary side circuit 103 and the secondary side circuit 104 increase the boost ratio, clamp the power semiconductor switch \ voltage, and solve the coupling inductance leakage inductance problem: the device of the present invention has a high rise by utilizing the characteristic that the coupled inductor turns are proportional to the voltage. The ratio of the voltage ratio provides a higher boost ratio than the conventional boost converter; the capacitor C2 of the secondary side circuit 104 is used to solve the problem caused by the leakage inductance of the high inductance ratio coupled inductor, and the transistor is not used. The vibration circuit consumes leakage inductance energy to facilitate the improvement of the conversion efficiency; the voltage established by the secondary side 4 of the coupled inductor of the secondary side circuit 104 shares the voltage across the power semiconductor switch of the primary side circuit 103, so that the voltage is low. The output voltage of the DC output circuit 105 is such that it has the characteristics of voltage clamping. 3. Voltage clamping characteristics reduce conduction loss: the voltage across the power semiconductor switch of the primary side circuit 103 is clamped in the low voltage range, and a MOSFET with a lower withstand voltage value can be selected, because the lower on-resistance can reduce the conduction 13 1252589 Loss, which in turn increases conversion efficiency. 4. The flexible switching circuit 102 reduces switching loss and enables the power semiconductor switch to operate at high frequency switching: the flexible switching circuit 102 utilizes the resonance principle to power the power semiconductor of the primary side circuit 103 before the power semiconductor switch of the primary side circuit 103 is turned on. The energy of the parasitic capacitance on the switch is fed back to the output filter capacitor Cz of the DC input circuit 101, so that the power semiconductor switch of the primary side circuit 103 has a zero voltage and zero current switching characteristic when turned on, and the low voltage MOSFET has a large parasitic capacitance. The feedback power is greater than the sum of the conduction loss and the switching loss on the power semiconductor switch of the flexible switching circuit 102, thereby improving the power conversion efficiency; on the other hand, the flexible switching characteristic can also increase the power semiconductor switching frequency and reduce the passive component. The volume and weight increase the power density. 5. Closed loop control mechanism: The fuel cell output voltage varies with load, and the output voltage of the DC output circuit 105 can be stabilized by the closed loop control mechanism 106. Embodiments Fig. 3 is a view showing the voltage and current of an inverter disclosed in the present invention. The coupled inductor is represented by an ideal transformer, a magnetizing inductance 4 and a leakage inductance 4, and the number of turns of the primary side and the secondary side of the ideal transformer are 7V and 7V, respectively, and the primary side of the coupling p ^ combined inductance is expressed as the primary side of the ideal transformer, and the excitation is performed. Inductance and leakage inductance, the secondary side of the coupled inductor 4 is represented as the secondary side of the ideal transformer. The turns ratio of the ideal transformer is defined as 7V and the coupling coefficient is as follows: N II NJNp (1) 14 1252589 ^Lm +Lk) (2) The primary side voltage is %'. It is assumed that the capacitance of the secondary circuit 104 is sufficient to be a constant voltage source, and the DC input circuit 1G5 is simplified to the input voltage C. Fig. 4 is a view showing the operation mode of the inverter circuit disclosed in the present invention, and Fig. 5 shows the timing of the voltage and current waveforms. The mode of operation of the circuit of Figure 4 is as follows: Mode 丨 &~j: Capacitance "w, dipole, bias, spectral voltage value causes the two poles of the flexible switching circuit 102 - charging. At this time the input voltage is to the magnetizing inductance 4 and Leakage sense 4 lines ^ Mode 2 [6~]: When Tian Rishou is smashing, the current leakage inductance of the power semiconductor to the power semiconductor switch "The parasitic capacitance of the power semiconductor switch and the voltage rises approximately linearly. Cross-mode three [G~G]: When time Qiri Temple, power semiconductor switch rises to Fv, two; 1 can generate electricity valley voltage> ^ ^ ° C2 one pole body Θ conduction, excitation power reduction and reversal ^^ The current flows to the DC output circuit i05, and the inductance leakage inductance is powered; the ideal converter passes the magnetic coupling side / = q to the load to the secondary side of the coupled inductor z, the electric ", the energy transfer on the inductor Utilizing Kirchhoff's voltage law, the circuit 105 can be turned to the DC. Κ, +ι)·%+κ VC2 二Ν·νΝρ (3) 15 (4) 1252589 During this period, the magnetizing inductance and the leakage inductance simultaneously charge the resonant capacitor C in the flexible switching circuit 102; charging, diode Ρ/ϊ2 is turned on, the resonant current is a sinusoidal function waveform, and the diode has a zero current switching mechanism when the diode is turned on, and the resonant capacitor voltage rises. At this time, the power semiconductor switch && 2 span voltage of the flexible switching circuit 102 is equal to the resonant capacitor. The voltage. Mode 4 [~G]: When the time 戸ί3, the resonance of the flexible switching circuit 102 ends. At this time, the voltage on the capacitor is slightly larger than the sum of the voltages on the magnetizing inductance and the leakage inductance, so that the diode and the 仏2 are reverse biased. The resonant current is reduced to zero by a sinusoidal function, and the zero current switching mechanism is also applied when the diode is turned off, and the current on the leakage inductance of the magnetizing inductance and the coupled inductor continues to flow to the DC output circuit 105. When the time is between ί2 and ί4, the energy of the primary side of the coupled inductor is transferred to the secondary side of the coupled inductor. On the other hand, the magnetizing inductor uses the continuous leakage current characteristic to input the input voltage, the coupled inductor primary side and the secondary side circuit. The energy on capacitor C2 is conducted via diode A to DC output circuit 105. Mode 5 [~ί5 ]: When time ί=ί4, the leakage current is approximately linearly reduced to zero value, and the diode is switched to zero current switching characteristic, which does not cause reverse current surge, and the diode is lightened. The problem of reverse recovery, and the current change rate on the leakage inductance is zero, the voltage across the leakage inductance is zero, and the power semiconductor switch & voltage is lowered, and the clamp voltage value of the power semiconductor switch can be expressed as
Vs \ — clamp - + VNp (5) 此時激磁電感儲存之能量透過理想變壓器，對二次侧電路 104之電容C2充電，能量以耦合電感二次侧之電流呈現。 16 1252589 模式六[]: 當時間ί=ί5時，柔性切換電路102之功率半導體開關 心以及導通’諧振電容上電壓造成理想變壓器一次侧 電壓反向’並對激磁電感與漏感充電’輛合電感一次侧電 流k遞增，流經理想變壓器之電流L遞減；另一方面，諧 振電容與開關寄生電容上電壓和大於輸入電壓，透過諧振 電容與諧振電感諧振之特性，反饋能量於輸入電壓，開關 跨壓迅速降至零值，在諧振電流流經一次侧電路103之功 率半導體開關\之基體二極體(Body Diode)時，給予觸發 訊號，使導通時兼具有零電壓及零電流切換機制。一次侧 電路103之功率半導體開關導通後，激磁電感電壓與漏感 電壓之和等於輸入電壓，輸入電壓對激磁電感及漏感充 電。 模式七u〜心]: 當時間戸L時，理想變壓器之電流降為零值，耦合電 感二次側電流亦為零，所有能量轉移至耦合電感一次側， 輸入電壓對其充電。當柔性切換電路102之功率半導體開 關心以及上諧振電流流經其基體二極體時，將觸發訊 號截止，截止時具零電壓及零電流切換特性。 假設所有元件均為理想，利用激磁電感上在一週期内 之平均電壓為零，令一次側電路103之功率半導體開關& 責任週期d，可推導出昇壓比例及一次側電路103之功率 半導體開關&箝制電壓為 V0 _l + d^N K " \-d (6) 17 1252589 S\_ clampVs \ — clamp - + VNp (5) At this time, the energy stored in the magnetizing inductance is transmitted through the ideal transformer, and the capacitor C2 of the secondary side circuit 104 is charged, and the energy is presented by the current on the secondary side of the coupled inductor. 16 1252589 Mode six []: When time ί=ί5, the power semiconductor switching core of the flexible switching circuit 102 and the voltage on the conducting 'resonant capacitor cause the ideal transformer primary side voltage reversal' and charge the magnetizing inductance and leakage inductance The current k of the inductor increases, and the current L flowing through the ideal transformer decreases. On the other hand, the voltage on the resonant capacitor and the parasitic capacitance of the switch is greater than the input voltage, and the resonant capacitor and the resonant inductor resonate, and the feedback energy is applied to the input voltage. The voltage across the voltage rapidly drops to zero. When the resonant current flows through the body diode of the power semiconductor switch of the primary side circuit 103, the trigger signal is given, so that the zero voltage and zero current switching mechanism is provided when the current is turned on. . After the power semiconductor switch of the primary side circuit 103 is turned on, the sum of the magnetizing inductance voltage and the leakage inductance voltage is equal to the input voltage, and the input voltage charges the magnetizing inductance and the leakage inductance. Mode seven u~heart]: When the time is 戸L, the current of the ideal transformer drops to zero, and the secondary side current of the coupled inductor is also zero. All energy is transferred to the primary side of the coupled inductor, and the input voltage is charged. When the power semiconductor of the flexible switching circuit 102 is concerned and the upper resonant current flows through its base diode, the trigger signal is turned off, and the zero voltage and zero current switching characteristics are turned off. Assuming that all components are ideal, the average voltage of the magnetizing inductor in one cycle is zero, and the power semiconductor switch & duty cycle d of the primary side circuit 103 can be used to derive the boosting ratio and the power semiconductor of the primary side circuit 103. Switch & clamping voltage is V0 _l + d^NK " \-d (6) 17 1252589 S\_ clamp
K l + d-N ⑺ 由方程式（6)可得知，此電路之昇壓比例高於傳統昇壓式 換流器，可藉由調整匝數比彌補傳統昇壓式換流器昇壓比 例之不足；由方程式（7)可得知，一次侧電路103之功率 半導體開關&上箝制電壓小於直流輸出電路105之輸出電 壓，即可選用耐壓低且導通電阻小之MOSFET，降低導通 損失，進而提高轉換效率。 圖6表示本發明所揭示之具電壓箝制及柔性切換機制 之高效率燃料電池高昇壓比換流器實施例之一，燃料電池 之實測電壓及電流特性曲線。（a)為電壓及功率對電流之特 性曲線；（b)為電流及功率對電壓之特性曲線。由上述實 測結果，當燃料電池輸出電流愈大時，意即輸出功率愈大 時，輸出電壓亦隨之下降。 本實施例配合燃料電池輸出之電壓電流規格以及直流 輸出電路105輸出200伏特直流電壓，適當選取本發明所 揭示具電壓箝制及柔性切換機制之高效率燃料電池高昇壓 比換流器元件，一次侧電路之功率半導體開關&選用 IRFPS3810 (100V，RDS(0N)=9mQ)，具較高之寄生電容， 柔性切換電路之功率半導體開關心及心為IRF540 (100V，RDS(ON)=77mQ)，具較低寄生電容值，可降低柔性 切換電路之功率半導體開關之切換損失，A、以及从2 選用為蕭特基二極體SR20100,可減少其導通跨壓以利於 提升效率，/¾選用為SFA1608，閉迴路控制機制106使用 TL494脈波寬度調變控制晶片，功率半導體開關元件頻率 18 1252589 操作於100kHz，輸出功率為40〜200瓦特，本實施例詳細 之規格如下 f· : 28〜35V V0 ： 200V 尺·· 200〜1000Ω c2 ： 47 /zF Cr : 68 nF Cl ： 2200 β¥ C0 ： 220 βΥ Lr · 0.3 β Η Lp ： 52 //Η 4, ： 1340 //Η iY ： 5.1 Κ ： 0.98 圖7表示本發明所揭示之具電壓箝制及柔性切換機制 之高效率燃料電池高昇壓比換流器實施例操作於輸出功率 160瓦特之實測波形響應：（a)表示一次侧電路103之功率 半導體開關\之電壓電流波形，圖中顯示出該功率半導體 開關導通時負向電流流經基體二極體，兼具零電壓及零電 流切換機制；功率半導體開關截止時寄生電容充電，功率 半導體開關兩端電壓上升，箝制電壓約為60伏特；（b)表 示柔性切換電路102之功率半導體開關心及&2電壓電流 波形，為了降低環流及導通損失，選取較小之諧振電容及 諧振電感值，使諧振頻率提高，降低柔性切換電路102之 19 1252589 功率半導體開關導通時間，利用諧振電流由零遞增之特 性’其導通時具零電流切換機制，電流流經基體二極體時 將其截止，截止時具零電壓及零電流切換特性；（c)、（d)K l + dN (7) It can be known from equation (6) that the boost ratio of this circuit is higher than that of the conventional boost converter, and the boost ratio of the conventional boost converter can be compensated by adjusting the turns ratio. It can be known from equation (7) that the power semiconductor switch & upper clamp voltage of the primary side circuit 103 is smaller than the output voltage of the DC output circuit 105, and a MOSFET with low withstand voltage and small on-resistance can be selected to reduce the conduction loss, and further Improve conversion efficiency. Figure 6 is a graph showing the measured voltage and current characteristics of a fuel cell with one of the embodiments of the high efficiency fuel cell high step-up ratio converter with voltage clamping and flexible switching mechanism disclosed in the present invention. (a) is the characteristic curve of voltage and power versus current; (b) is the characteristic curve of current and power versus voltage. From the above measured results, when the fuel cell output current is larger, the output voltage is also decreased as the output power is increased. In this embodiment, in combination with the voltage and current specifications of the fuel cell output and the DC output circuit 105 outputting 200 volts DC voltage, the high-efficiency fuel cell high-boost ratio converter component with voltage clamping and flexible switching mechanism disclosed in the present invention is appropriately selected, and the primary side is The power semiconductor switch & selects IRRPS3810 (100V, RDS(0N)=9mQ) with high parasitic capacitance. The power semiconductor switch core and core of the flexible switching circuit are IRF540 (100V, RDS(ON)=77mQ). The lower parasitic capacitance value can reduce the switching loss of the power semiconductor switch of the flexible switching circuit, A, and the Schottky diode SP20100 selected from 2, which can reduce the conduction voltage across the tube to improve the efficiency, /3⁄4 is selected as SFA1608, closed loop control mechanism 106 uses TL494 pulse width modulation control chip, power semiconductor switching element frequency 18 1252589 operates at 100kHz, output power is 40~200 watts, the detailed specifications of this embodiment are as follows f: 28~35V V0 : 200V ruler · 200~1000Ω c2 : 47 /zF Cr : 68 nF Cl : 2200 β¥ C0 : 220 βΥ Lr · 0.3 β Η Lp : 52 //Η 4, : 1340 //Η iY : 5.1 Κ : 0.98 Figure 7 shows the measured waveform response of a high efficiency fuel cell high step-up ratio converter with voltage clamping and flexible switching mechanism operating at 160 watts of output power: (a ) indicates the voltage and current waveform of the power semiconductor switch of the primary side circuit 103. The figure shows that the negative current flows through the base diode when the power semiconductor switch is turned on, and has a zero voltage and zero current switching mechanism; the power semiconductor switch is turned off. When the parasitic capacitance is charged, the voltage across the power semiconductor switch rises, and the clamping voltage is about 60 volts; (b) represents the power semiconductor switching center of the flexible switching circuit 102 and the voltage and current waveforms of the & 2, in order to reduce the circulation and conduction losses, select The small resonant capacitor and the resonant inductor value increase the resonant frequency, reducing the on-time of the 19 1252589 power semiconductor switch of the flexible switching circuit 102, utilizing the characteristic that the resonant current is incremented by zero, and the zero current switching mechanism is turned on when the conduction is performed, and the current flows through the substrate. When the diode is turned off, it has zero voltage and zero current switching characteristics when it is turned off; (c), ( d)
與（e)分別表示二極體An、A與Z)2電壓電流波形，由圖 中可顯示其均具有柔性切換之特性，並顯示一次侧電路103 之二極體A在截止時，無反向電流突波，減輕其逆向回復 之問題；（f)表示諧振電容C；電壓與諧振電感夂電流波形， 由圖中可得知，其諧振頻率較功率半導體開關之切換頻率 _ 高，諧振之週期亦較短；（g)表示耦合電感一次侧電流與 耦合電感二次侧電流波形，在耦合電感能量傳遞時之響 應；（h)表示直流輸出電路105之輸出電壓&、直流輸出電 路105之輸出電流忍與燃料電池之直流輸入電流//，在輸 出功率40瓦特至160瓦特間負載變化時之響應，在配合 閉迴路控制機制106及高頻操作下，燃料電池之直流輸入 電流及直流輸出電路105之輸出電壓之漣波很小，使燃料 電池穩定工作並輸出直流電壓200伏特。 I 本發明所揭示具電壓箝制及柔性切換機制之高效率燃 料電池高昇壓比換流器具有另一種實施方式，如圖8所 · 示，將柔性切換電路102整理為單開關柔性切換電路801， 並將閉迴路控制機制106整理為使用單開關柔性切換電路 之閉迴路控制機制802。單開關柔性切換電路801利用諧 振原理，在一次侧電路103之功率半導體開關&導通前， 觸發單開關柔性切換電路801之功率半導體開關，該 電路中電感心2與電容Cr2發生諧振之前半週期，將一次侧 20 1252589 電路103之功率半導體開關X上寄生電容之能量，反饋至 直流輸入電路101之電容C；.，使一次側電路103之功率半 導體開關Α導通時兼具零電壓與零電流切換特性，提昇轉 換效率，而諧振之後半週期，由燃料電池經單開關柔性切 換電路801中，功率半導體開關之基體二極體對該電 路之電容C；2充電，其餘操作之原理與圖1電路相同。 【圖式簡單說明】 圖1表示本發明所揭示具電壓箝制及柔性切換機制之高效 率燃料電池高昇壓比換流器方塊圖。 圖2表示習用之昇壓式換流器：（a)傳統昇壓式換流器；（b) 具耦合電感之昇壓式換流器；（c)具耦合電感及柔性 切換機制之昇壓式換流器。 圖3表示本發明所揭示之具電壓箝制及柔性切換機制之高 效率燃料電池高昇壓比換流器電壓及電流方向示意。 圖4表示本發明所揭示之具電壓箝制及柔性切換機制之高 效率燃料電池高昇壓比換流器，電路工作模式圖。 圖5表示本發明所揭示之具電壓箝制及柔性切換機制之高 效率燃料電池高昇壓比換流器，電壓及電流之波形時 序。 圖6表示本發明所揭示具電壓籍制及柔性切換機制之高效 率燃料電池高昇壓比換流器實施例之一，燃料電池之 實測電壓及電流特性曲線。（a)為電壓及功率對電流之 特性曲線；（b)為電流及功率對電壓之特性曲線。 圖7表示本發明所揭示具電壓箝制及柔性切換機制之高效 21 1252589 率燃料電池高昇壓比換流器實施例之一，電壓電流實 測之響應波形：（a) —次側電路之功率半導體開關& 跨壓％與電流心；（b)柔性切換電路之功率半導體開關 心跨壓〜i與電流; (c)柔性切換電路之二極體乃/^跨 壓％/^1與電流b/a ;(d) 一次侧電路之二極體A跨壓％與 電流/D1 ; (e)二次侧電路之二極體乃2跨壓vD2與電流^ ; (f)諧振電容Cr之電壓vCr與諧振電感之電流k ; (g)耦 合電感一次侧電流k與耦合電感二次侧電流L ; (h)負載變 動下，直流輸出電路之輸出電壓G、直流輸出電路之 輸出電流與燃料電池直流輸出電流//。 圖8表示本發明所揭示具電壓箝制及單開關柔性切換機制 之高效率燃料電池高昇壓比換流器方塊圖。 圖不主要部分之編"5虎代表意義如下· 101 :直流輸入電路 102 :柔性切換電路 103 : —次侧電路 104 :二次側電路 105 :直流輸出電路 106 :閉迴路控制機制 801 :單開關柔性切換電路 802 :使用單開關柔性切換電路之閉迴路控制機制 22And (e) respectively represent the voltage and current waveforms of the diodes An, A, and Z) 2, which can be shown to have the characteristics of flexible switching, and show that the diode A of the primary side circuit 103 is turned off, and there is no opposite. To the current surge, to reduce the problem of reverse recovery; (f) represents the resonant capacitor C; voltage and resonant inductor 夂 current waveform, as can be seen from the figure, its resonant frequency is higher than the switching frequency of the power semiconductor switch _ high, resonance The period is also short; (g) represents the primary side current of the coupled inductor and the secondary side current waveform of the coupled inductor, the response of the coupled inductor energy transfer; (h) represents the output voltage of the DC output circuit 105 & DC output circuit 105 The output current is forbearant and the DC input current of the fuel cell //, the response when the output power varies between 40 watts and 160 watts. Under the closed loop control mechanism 106 and high frequency operation, the DC input current and DC of the fuel cell The output voltage of the output circuit 105 is small, so that the fuel cell operates stably and outputs a DC voltage of 200 volts. The high-efficiency fuel cell high-boost ratio converter with voltage clamping and flexible switching mechanism disclosed in the present invention has another embodiment. As shown in FIG. 8, the flexible switching circuit 102 is organized into a single-switch flexible switching circuit 801. The closed loop control mechanism 106 is organized into a closed loop control mechanism 802 that uses a single switch flexible switching circuit. The single-switch flexible switching circuit 801 uses the resonance principle to trigger the power semiconductor switch of the single-switch flexible switching circuit 801 before the power semiconductor switch of the primary-side circuit 103 is turned on, in which the inductor core 2 and the capacitor Cr2 resonate before the half-cycle The energy of the parasitic capacitance on the power semiconductor switch X of the primary side 20 1252589 circuit 103 is fed back to the capacitance C of the DC input circuit 101; so that the power semiconductor switch of the primary side circuit 103 is turned on and has zero voltage and zero current. Switching characteristics, improve conversion efficiency, and the second half of the resonance, by the fuel cell through the single-switch flexible switching circuit 801, the base diode of the power semiconductor switch charges the capacitor C; 2, the principle of the rest of the operation and Figure 1 The circuit is the same. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a block diagram showing a highly efficient fuel cell high step-up ratio converter with voltage clamping and flexible switching mechanism according to the present invention. Figure 2 shows a conventional boost converter: (a) a conventional boost converter; (b) a boost converter with a coupled inductor; (c) a boost with a coupled inductor and a flexible switching mechanism Inverter. Fig. 3 is a view showing the voltage and current directions of a high-efficiency fuel cell high step-up ratio converter with a voltage clamping and flexible switching mechanism according to the present invention. Fig. 4 is a view showing the operation mode of the high-efficiency fuel cell high-boost ratio converter with voltage clamping and flexible switching mechanism according to the present invention. Fig. 5 is a diagram showing the waveform sequence of voltage and current of a high efficiency fuel cell high step-up ratio converter with voltage clamping and flexible switching mechanism according to the present invention. Fig. 6 is a view showing a measured voltage and current characteristic curve of a fuel cell with one of the embodiments of the high-boosting fuel cell high-boost ratio converter having a voltage system and a flexible switching mechanism according to the present invention. (a) is a characteristic curve of voltage and power versus current; (b) is a characteristic curve of current and power versus voltage. FIG. 7 is a diagram showing an embodiment of a high-boost 21-252589-rate fuel cell high step-up ratio converter with voltage clamping and flexible switching mechanism according to the present invention. The response waveform of the voltage and current measurement is: (a) the power semiconductor switch of the secondary side circuit & cross voltage % and current core; (b) power switching center of the flexible switching circuit across the voltage ~ i and current; (c) the diode of the flexible switching circuit is / ^ cross voltage % / ^ 1 and current b / a; (d) the diode voltage A of the primary side circuit and the current / D1; (e) the diode of the secondary circuit is the voltage across the voltage vD2 and the current ^; (f) the voltage of the resonant capacitor Cr vCr (k) coupled inductor primary side current k and coupled inductor secondary side current L; (h) load variation, DC output circuit output voltage G, DC output circuit output current and fuel cell DC Output current//. Figure 8 is a block diagram of a high efficiency fuel cell high step-up ratio converter with voltage clamping and single switching flexible switching mechanisms as disclosed herein. The figure is not the main part of the code "5 tiger representative meaning is as follows · 101: DC input circuit 102: flexible switching circuit 103: - secondary side circuit 104: secondary side circuit 105: DC output circuit 106: closed loop control mechanism 801: single Switching flexible switching circuit 802: closed loop control mechanism using a single switch flexible switching circuit 22