1364907 九、發明說明： 【發明所屬之技術領域】 本發明關於一種電源轉換領域之直流對直流轉換裝 置，-尤指一種以兩組並聯操作的直流對直流轉換器及辅助電 感元件所組成之新聖柔性切換電路。 【先前技術】 隨著工業發展及儀器設備的日趨精密，對於各種電子 設備或儀器的電源供應品質需求提高；另外，能源的逐漸 匱乏，使得能源使用效率格外受到注目發展。職此之故， 具有高轉換效率及高功率密度的轉換器是有其迫切之市場 需要。一般而言，提高轉換器的切換頻率可以提升系統整 體的功率密度。然而在提升頻率的同時，會伴隨著產生較 大的電磁干擾(EMI)，且增加開關元件的切換損失，損失的 能量絕大部份會以熱的形式釋出。由於提高功率密度的結 果’使得散熱更加困難’造成元件因高溫而降低電壓及電 流的耐受度，進一步造成系統的損壞。 為解決開關在高頻切換時所帶來的問題，一般採用柔 性切換技術。早期應用的柔性切換技術是所謂的準諧振式 (Quasi-resonant)零電壓或零電流轉換器電路，WKwang-Hwa Liu and Fred C. Y. Lee, “Zero-Voltage Switching Technique in DC/DC Converters,J, IEEE Trans, on Power Electronics, Vol.5, No.3, Jul. 1990, pp.293-304。這類電路雖 然能夠有效達成零電壓切換的目的，但其代價是開關元件 5 1364907 必須承受因為諧振所帶來的高電流。另外如增加另一個輔 助開關元件及其他被動元件所達成的所謂主動式零電壓切 換電路，見於 Ching-Jung Tseng and Chem-Lin Chen，“Novel ZVT-PWM Converters with Active Snubbers；5 IEEE Trans, on Power1364907 IX. Description of the Invention: [Technical Field] The present invention relates to a DC-to-DC converter device in the field of power conversion, in particular, a new DC-DC converter and auxiliary inductor components operating in parallel with two groups St. flexible switching circuit. [Prior Art] With the development of industry and the increasingly sophisticated equipment, the demand for power supply quality of various electronic equipment or instruments has increased. In addition, the gradual lack of energy has made energy efficiency particularly attractive. For this reason, converters with high conversion efficiency and high power density have their urgent market needs. In general, increasing the switching frequency of the converter can increase the overall power density of the system. However, while increasing the frequency, it is accompanied by a large electromagnetic interference (EMI), and the switching loss of the switching element is increased, and most of the lost energy is released in the form of heat. As a result of increasing the power density, the heat dissipation is made more difficult, causing the component to withstand high voltages and current tolerance, which further causes damage to the system. In order to solve the problem caused by the switch switching at high frequency, a flexible switching technique is generally adopted. The early application of flexible switching technology is the so-called Quasi-resonant zero-voltage or zero-current converter circuit, WKwang-Hwa Liu and Fred CY Lee, "Zero-Voltage Switching Technique in DC/DC Converters, J, IEEE Trans, on Power Electronics, Vol.5, No.3, Jul. 1990, pp.293-304. Although such a circuit can effectively achieve the purpose of zero voltage switching, the price is that the switching element 5 1364907 must withstand resonance The high current is brought in. In addition, the so-called active zero voltage switching circuit realized by adding another auxiliary switching element and other passive components is found in Ching-Jung Tseng and Chem-Lin Chen, "Novel ZVT-PWM Converters with Active Snubbers; 5 IEEE Trans, on Power
Electronics, Vol. 13, No. 5, Sep. 1998, pp. 861-869;以及 Chien-Ming Wang，“Novel Zero-Voltage-Transition PWM DC-DC Converters，，， IEEE Trans, on Industrial Electronics, Vol. 53, No. 1, Feb. 2006, pp. 254-262 。Electronics, Vol. 13, No. 5, Sep. 1998, pp. 861-869; and Chien-Ming Wang, "Novel Zero-Voltage-Transition PWM DC-DC Converters,,, IEEE Trans, on Industrial Electronics, Vol. 53, No. 1, Feb. 2006, pp. 254-262.
在先前技藝中’如中華民國專利公報第1271918號提出具 相對較少元件之柔性切換直流/直流轉換器。該發明在轉換 器中加上輔助開關、電感及二極體，藉以使主要開關達到 零電壓切換的目的。但是該輔助電路並不負擔功率傳送的 任務，且辅助開關本身為PWM切換。另外如中華民國專利 公報申請案號第94122765號提出的柔性切換之直流_直流轉 換器，該發明係在一降壓式(buck)轉換器中，加入—組輔助 ，順向式（forward)轉換器或是推挽式（push_pull)轉換器 $，利用該輔助轉換器的動作來達成降壓式轉換器的零電 壓切換。同樣的，該辅助轉換器仍然僅扮演能量的轉移， 達成柔性切換的目的；而不提供能量傳遞至負載的功能。 由以上的討論可知，通常為了達成柔性切換的目的， 所付出的代價是增加許多額外的電路元件，甚至是開關元 =。如此的安排，使得電路分析及控制方法更增添了許= 複雜度，甚至於增加了許多成本。 。夕 6 1364907 . 【發明内容】 鑒於上述相關技藝之情況，為了達成柔性切換的目的必 -須增加許多額外的電路元件，使得電路分析及控制方法更 .增添了許多複雜度，甚至於增加了許多成本。 有鑑於此，本發明之主要目的係提供一種簡易的並聯式直 .流對直流轉換裝置，即可降低開關在導通時的切換損失。 本發明之並聯式直流對直流轉換裝置中具有兩並聯之同 性貝之直流對直流轉換器，同時由輸入端汲取能量；一控制 藝電路供應一調節信號確保兩並聯之直流對直流轉換器傳遞 能量至輸出端；一輔助電感確保降低兩並聯之直流對直流轉 換器内主動開關的切換損失。 【實施方式】 第1圖表示本發明所提出的並聯式直流對直流轉換裝 置（1)的架構圖，由兩組相同的直流對直流轉換器（10)，(20) • 加以並聯操作，並加上一個輔助電感（30)，經由一組控制 電路(40)產生調節信號控制兩組直流對直流轉換器傳遞能 里至輸出端，配合輸出穩壓電容(5〇)穩定輸出端電壓量。 第2圖表示本發明之第一較佳實施例，以升壓式直流對直 "IL轉換裳置（1 )為貫施對象。一組轉換器元件包含了主動開 關（101)、主電感（102)、主二極體（1〇3)和調節信號(4〇1)，另 一組轉換器元件亦包含主動開關（2〇1)、主電感（202)、主二極 體（203)和調節信號(402)。主動開關（1〇1)及（2〇1)上分別有反 背接二極體（1〇4)及（204)與寄生電容（1〇5)及（205) 〇直流輸 7 1364907 入電壓為（νώ)，經由並聯之直流對直流轉換器（10)，(20)對輸 出穩壓電容(50)充電及傳送能量給輸出負載(RL)。兩個主動 開關之間的輔助電感（30)，其主要目的為釋放兩個主動開關 (101)及(201)在導通前儲存於寄生電容（105)及（205)上的電 荷，使得兩個主動開關（101)及(201)能零電壓導通(ZVS)，因 而提升轉換器的效率。 接下來為了方便探討並聯式直流對直流轉換裝置（1)的工 作原理’在此電路分析前我們假設： 1. 輸出穩壓電容(50)值足夠大，因此輸出電壓(V。)漣波可忽 略0 2. 忽略主動開關（1〇1)及(2〇1)及主二極體(1〇3)及(2〇3)導通時 的壓降。 3. 主電感（102)和（202)的值很大，電感電流可視為定值。 第3圖為簡化後的等效電路圖，兩個主動開關(1〇1)以及(2〇1) 由脈波寬度調變（pulse-width-modulation ; PWM)控制調節信號 (401)及(402)。兩主動開關皆工作在相同的操作頻率，二者的調 節旮號有一固定相移，且彼此調節信號之導通部份重疊，開關 5周節彳§號(401)及(402)波形如第4圖所示。在電路方程式推導過 程中，輔助電感(30)的電感值以表示，而寄生電容(1〇5)與(2〇5°) 的電容值酿設轉，且〇；喊示。此電路分析共可分為八個模 式’第5圖及第6圖分別為其等效電關形及理論波形。 a.模式〈屹第5圖问7 在此模式前’主動開關(洲上的閘極調節信號(術)已降為 8 1364907 零，~時，主動開關(20/)上的Fz垃跨壓上升至κσ，電流匕也升至 零’原本流經主動開關(20/)上的電流全部流入主二極體(203)，對 負載提供能量，而L此時的電流皆流到輔助電感(30)中。這個階 段’由於外^的電壓為零，輔助電感(30)上的跨壓為匕，因此電流 b以F。/4的斜率線性減少，同時主動開關(川7)上的電流呈線性 增加。當L降至零，的電流便流入主動開關(;07)上，此時主二 極體電流如等於主電感電流/^。接者，l的電流開始換向同時 與//ji/IL入主動開關(70/)上’當L持續反向增加時，主二極體電 流心2也漸漸減少至零，直到輔助電感電流L等於_一時，主二極 體(203)截止，此模式結束。 電流Lb和k如以下方程式所示In the prior art, a flexible switching DC/DC converter having relatively few components is proposed as disclosed in the Republic of China Patent Publication No. 1271918. The invention adds an auxiliary switch, an inductor and a diode to the converter to achieve the purpose of zero voltage switching of the main switch. However, the auxiliary circuit does not carry the task of power transfer, and the auxiliary switch itself is PWM switching. In addition, a flexible switching DC-DC converter proposed in the Republic of China Patent Gazette No. 94122765, which incorporates a group-assisted, forward-forward conversion in a buck converter. The push-pull converter ($) or the push-pull converter ($) uses the action of the auxiliary converter to achieve zero-voltage switching of the buck converter. Similarly, the auxiliary converter still only plays the role of energy transfer for the purpose of flexible switching; it does not provide the function of energy transfer to the load. As can be seen from the above discussion, in general, for the purpose of achieving flexible switching, the price paid is to add many additional circuit components, even switching elements =. This arrangement makes the circuit analysis and control method even more complicated and even adds a lot of cost. .夕6 1364907. SUMMARY OF THE INVENTION In view of the above-mentioned related art, in order to achieve the purpose of flexible switching, it is necessary to add many additional circuit components, which makes the circuit analysis and control method more complicated, and even increases a lot. cost. In view of this, the main object of the present invention is to provide a simple parallel direct current-to-DC conversion device, which can reduce the switching loss of the switch when it is turned on. The parallel DC-DC converter device of the present invention has two parallel-parallel DC-to-DC converters, and draws energy from the input terminal; a control art circuit supplies an adjustment signal to ensure energy transfer between the two parallel DC-DC converters. To the output; an auxiliary inductor ensures that the switching losses of the active switches in the two parallel DC-to-DC converters are reduced. Embodiment 1 FIG. 1 is a block diagram showing a parallel DC-DC converter (1) according to the present invention, in which two sets of identical DC-DC converters (10), (20) are connected in parallel, and An auxiliary inductor (30) is added to generate an adjustment signal via a set of control circuits (40) to control the two sets of DC-to-DC converters to transfer energy to the output, and the output voltage regulator (5〇) to stabilize the output voltage. Fig. 2 is a view showing a first preferred embodiment of the present invention, in which a boost type direct current "IL conversion skirting (1) is applied. A set of converter components includes an active switch (101), a main inductor (102), a main diode (1〇3), and an adjustment signal (4〇1), and another set of converter components also includes an active switch (2〇) 1), main inductor (202), main diode (203) and adjustment signal (402). The active switches (1〇1) and (2〇1) respectively have anti-backup diodes (1〇4) and (204) and parasitic capacitances (1〇5) and (205) 〇DC input 7 1364907 input voltage For (νώ), the output regulator capacitor (50) is charged and the energy is delivered to the output load (RL) via the parallel DC-to-DC converters (10), (20). The auxiliary inductor (30) between the two active switches, whose main purpose is to release the charges stored on the parasitic capacitances (105) and (205) of the two active switches (101) and (201) before turning on, so that two The active switches (101) and (201) are capable of zero voltage conduction (ZVS), thereby increasing the efficiency of the converter. Next, in order to facilitate the discussion of the working principle of the parallel DC-to-DC converter (1), we assume that before this circuit analysis: 1. The output voltage regulator (50) is large enough, so the output voltage (V.) ripple can be Ignore 0 2. Ignore the voltage drop when the active switches (1〇1) and (2〇1) and the main diodes (1〇3) and (2〇3) are turned on. 3. The values of the main inductors (102) and (202) are large, and the inductor current can be regarded as a fixed value. Figure 3 is a simplified equivalent circuit diagram. Two active switches (1〇1) and (2〇1) are adjusted by pulse-width-modulation (PWM) control signals (401) and (402). ). Both active switches operate at the same operating frequency, and the adjustment apostrophes of the two have a fixed phase shift, and the conduction portions of the adjustment signals overlap each other, and the waveforms of the switches 5 and 401 (401) and (402) are as shown in the fourth The figure shows. In the circuit equation derivation process, the inductance value of the auxiliary inductor (30) is expressed, and the capacitance values of the parasitic capacitance (1〇5) and (2〇5°) are turned, and 〇; This circuit analysis can be divided into eight modes. The fifth and sixth figures are their equivalent electrical and theoretical waveforms. a. Mode <屹 Figure 5 Q7 Before this mode' active switch (the gate adjustment signal on the continent has been reduced to 8 1364907 zero, ~, the Fz cross over the active switch (20/) Ascending to κσ, the current 升 also rises to zero. 'The current flowing through the active switch (20/) flows all the way into the main diode (203), supplying energy to the load, and the current at L flows to the auxiliary inductor ( 30) In this stage, 'the voltage across the external voltage is zero, and the voltage across the auxiliary inductor (30) is 匕, so the current b decreases linearly with the slope of F./4, while the current on the active switch (Chuan 7) It increases linearly. When L drops to zero, the current flows into the active switch (;07). At this time, the main diode current is equal to the main inductor current /^. The current of l starts to commutate simultaneously with // Ji/IL enters the active switch (70/). When L continues to increase in reverse, the main diode current core 2 also gradually decreases to zero until the auxiliary inductor current L is equal to _, the main diode (203) is cut off. , this mode ends. The currents Lb and k are as shown in the following equation
hs ft) = vtt Ζ·£)_2〇 •丨 JLt n ⑴ (2)(3) b·模式//{ ί; < ί ，第5圖⑼} 由於主二極體(朋)截止，輸出穩壓電容⑽)上的電壓將不再 箝位於&，電流Ζ·Ζ2流入輔助電感⑽且輸出穩壓電容(應)開始 放電，放電電流會流經輔助電感⑽使電流&會有 口 當主動開關⑽上的電壓恤2降至零，將結束此模乙二口。 及電流L可表示如下 ^ VDS2 9 (14) 1364907 輸入電流與負載電流的關係為 Ι〇~η "&sIin =77i^/,n 由(13)、（14)式，輸出功率可表示為： (15) ρ〇=^η2=υ2^ιίη2Hs ft) = vtt Ζ·£)_2〇•丨JLt n (1) (2)(3) b·Mode //{ ί; < ί , Figure 5 (9)} Since the main diode (pen) is cut off, the output The voltage on the Zener capacitor (10) will no longer clamp to & the current Ζ·Ζ2 flows into the auxiliary inductor (10) and the output regulator capacitor (should) start to discharge. The discharge current will flow through the auxiliary inductor (10) to make the current & When the voltage shirt 2 on the active switch (10) drops to zero, the module will end. And the current L can be expressed as follows: VDS2 9 (14) 1364907 The relationship between the input current and the load current is Ι〇~η "&sIin =77i^/,n by (13), (14), the output power can be expressed For: (15) ρ〇=^η2=υ2^ιίη2
Lts J^s • 本專利所提出的並聯式直流對直流轉換裝置的架構， 可以應用於其他基本形式的直流對直流轉換器裝置=，如 降壓式(buck)、降升壓式（buck-boost) ’其操作原理和控制方 式與前例所述極為相似。如第7圖所示，為本發明第二較:實施 例，此為降壓式直流對直流轉換裝置的電路架構；如第8圖所示= 為本發明第三較佳實施例，此為升降壓式直流對直流轉換裝^的 電路架構。本發明所提出的電路架構重點在於負載高功率需 求的應用，任-種並聯式直流對直流轉換裝置可提供的功率會 籲有所限制’可以才木用第9圖所示，為本發明第四較佳實施例， 以相同形式之直流對直流轉換器進行並聯連接，得以進三步擴大 輸出功率的範®，且;至於導致整體電路效率降低。 13 1364907 【圖式簡單說明】 第1圖 並聯式直流對直流轉換裝置的架構圖。 第2圖 本發明第一較佳實施例。 第3圖 本發明第一較佳實施例的簡化電路圖 第4圖 本發明第一較佳實施例的開關調節信號波形圖。 第5圖(a)〜(d)本發明第一較佳實施例的各模式的等效電路圖。 第6圖 本發明第一較佳實施例的理論波形圖。 第7圖 本發明第二較佳實施例。 第8圖 本發明第三較佳實施例。 第9圖 本發明第四較佳實施例。 【主要元件符號說明】 (7):並聯式直流對直流轉換裝置 (U :直流輸入電壓 (/0)、（20):直流對直流轉換器 (30):輔助電感 (70/)、（207):主動開關 (702)、（202):主電感 (7M)、（2W):主二極體 (7料）、（2糾）：反背接二極體 (705)、（205):寄生電容 (401)、（402):調節信號 (40):控制電路 (•50):輸出穩壓電容 14 1364907 〇Rz):輸出負載 (K):直流輸出電壓Lts J^s • The architecture of the parallel DC-DC converter proposed in this patent can be applied to other basic forms of DC-DC converter devices = such as buck and buck- Boost) 'The operating principle and control method are very similar to those described in the previous example. As shown in FIG. 7, it is a second embodiment of the present invention, which is a circuit structure of a buck DC-DC converter; as shown in FIG. 8 = a third preferred embodiment of the present invention, this is The circuit structure of the buck-boost DC-to-DC converter. The circuit architecture proposed by the present invention focuses on the application of high power demand, and the power that can be provided by any parallel DC-to-DC converter can be limited. In the fourth preferred embodiment, the DC-to-DC converters of the same form are connected in parallel, and the output power is expanded in three steps, and the overall circuit efficiency is lowered. 13 1364907 [Simple description of the diagram] Figure 1 Schematic diagram of the parallel DC-to-DC converter. Figure 2 shows a first preferred embodiment of the invention. Figure 3 is a simplified circuit diagram of a first preferred embodiment of the present invention. Figure 4 is a waveform diagram of a switching adjustment signal of a first preferred embodiment of the present invention. Fig. 5 (a) to (d) are equivalent circuit diagrams of respective modes of the first preferred embodiment of the present invention. Figure 6 is a theoretical waveform diagram of a first preferred embodiment of the present invention. Figure 7 shows a second preferred embodiment of the invention. Figure 8 is a third preferred embodiment of the present invention. Figure 9 is a fourth preferred embodiment of the present invention. [Explanation of main component symbols] (7): Parallel DC-to-DC converter (U: DC input voltage (/0), (20): DC-to-DC converter (30): Auxiliary inductor (70/), (207 ): Active switch (702), (202): main inductor (7M), (2W): main diode (7 material), (2 correction): anti-backup diode (705), (205): Parasitic capacitance (401), (402): adjustment signal (40): control circuit (•50): output voltage regulator 14 1364907 〇Rz): output load (K): DC output voltage
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