高效能返馳式電源供應器

High Efficient Flyback Switching Power Supply

謝慶星(Ching-Hsing Hsieh)

指導教授 ： 林登彬

大同大學/電機資訊學院/電機工程學系所/碩士(2005年)

摘要

本論文主要為研製一種具準諧振模式(Quasi-Resonant Mode)的省電返馳式轉換器, 利用返馳式轉換器準諧振模式的柔性切換將電流設計在不連續導通的型態，使變壓器在能量完全釋放時，藉由電感、MOSFET CDS 的雜散電容產生諧振，使 VDS 在 MOSFET 關閉情形下，因 CDS 諧振作用,VDS 會由高壓降至一個很低的電壓,例如降到零。由 IC 偵測波谷，尋找在多個波谷中的最低點打開 MOSFET 。利用較少元件的回授控制，做過電壓保護、過電流保護、過溫度保護及過功率保護, 根據轉換器的動作原理做詳細的討論與分析。最後以設計實例完成一個輸入電壓變動範圍90Vac / 47Hz ~ 264Vac / 63Hz,輸出電壓32V電流2.344A、最高效率為88%、非常低的待機功率，例如在無負載時, 264V的輸入電壓待機功率0.45W。符合IEA( International Energy Agency)協會對電源轉換器 ( Adapter ) 的待機規定，本論文完成一個低切換損失、高效率的省電轉換器。

關鍵字

待機功率。 ； 不連續導通 ； 返馳式轉換器 ； 準諧振模式

並列摘要

This thesis presents the design and implement a high efficiency of low power consumption Flyback converter that designs Quasi-Resonant mode soft switching in discontinuous conduction mode (DCM). Discontinuous conduction mode transformer delivers the energy that uses inductor(L) and MOSFET’s Coss to generate resonant in MOSFET “ OFF ” status. That VDS will be reduced to low voltage (ZVS) (Even to 0V).The pulse width modulation (PWM) IC will sense the valley and turn on MOSFET in the lowest voltage valley point. This PWM IC (TEA1532) can use little components to design the Feedback control, over voltage protection (OVP), over current protection (OCP), over temperature protection (OTP) and over power protection (OPP). Finally, We will design a switching power supply with input voltage of 90Vac / 47Hz ~ 264Vac / 63Hz, Output voltage of 32Vdc and output current from Imin 0A to Imax 2.344 A ( 75W),efficiency of about 88% typical in 230Vac / 50Hz, Standby power of Pin = 0.45W @ 264Vac / 50Hz at no load that use in printer adapter and can match IEA ( International Energy Agency ) standard requirements. This thesis present a low switching loss and high efficiency green power.

並列關鍵字

Discontinuous conduction mode ； Flyback converter ； Quasi-Resonant mode ； Standby power

參考文獻

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