本論文完成交流端連續電流功率因數修正之自振式LLC LED驅動電路。相較於他激式電路，自振式電路可高頻操作，且不須使用控制電路IC及其輔助電源，成本因而較低。自振式LLC諧振電路，其開關能軟切換操作，降低開關損失，提高效率。由於自振式電路之輸出電流會隨著輸入電壓增加而增加，故須加入定電流控制機制，以穩定輸出電流。
傳統直流端不連續功率因數修正電路，因其輸入電流操作在不連續導通模式，有較高之輸入電流di/dt、元件電流應力及開關損失，使電路效率降低。故須使用交流端連續電流功率因數修正機制，提高功率因數，降低輸入電流總諧波失真，以符合IEC61000-3-2 Class C之輸入電流諧波規範。
本論文已研製100W雛型電路，完成系統總成測試，驗證輸入電流的各次諧波，均可符合IEC61000-3-2 Class C之諧波規範。其功率因數為0.99及輸入電流總諧波失真率為9.5%。當輸入交流電壓從100V增加至110V時，定電流控制電路可有效降低LED電流變化率達8%，且電路效率皆在84%以上。

The design and implementation of AC-side continuous-conduction-mode (CCM) power-factor-correction (PFC) self-oscillating LLC LED driver has been completed and verified successfully.
Compared to IC-controlled inverters, usually, self-oscillating inverters are able to operate at high frequency without the need of the control IC and auxiliary power supply for lower component cost. The switches of the self-oscillating LLC resonant inverter achiceve soft-switching to reduce switching losses and increase efficiency. Since the load current of the self-oscillating LLC resonant inverter increases as the input voltage increases, the constant current control scheme is required to regulate the load current.
The conventional DC-side discontinuous-conduction-mode (DCM) PFC inverters have high di/dt, high current stress and high switching losses to cause low circuit efficiency. To meet the IEC61000-3-2 Class C Standard, the AC-side CCM PFC mechanism is used have high power factor and low input current harmonics.
A 100W prototype circuit has been designed and implemented to verify input current harmonics for the fulfillment of IEC61000-3-2 Class C standard. The measured power factor (PF) is 0.99 and total harmonic distortion (THD) is 9.5%. When the AC voltage ranges from 100V to 110V, the variation of LED current with the constant load current control is 8% less than that without the constant load current control. The circuit efficiencies are all above 84%.

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