cas1402206(cas21准则)

摘要

图1：电网电压FOT调制PFC升压转换器(左); FSW对电网电压(右)

图 2 所示是我们提出的调制器(黑色的是FOT调制器，绿色的是COT调制器)，其中Q代表功率开关管栅极驱动逻辑信号，END-TOFF (END-TON)是调制器的输出，其上升沿是TOFF (TON)时长;IR1和IR2恒定电流发生器。采用与图[1]相同的符号表示法，VTH_RAMP和VRAMP电压可以表示为2πfline t 的函数， T(θ)= TON(θ) TFW(θ) TR(θ)=TON(θ) TOFF(θ)是开关周期。

图 3：创新调制器的实验波形：230Vac 满载(左);115Vac轻载(右)

图4：实验数据比较: 230Vac轻载(DCM工作模式)

结束语和未来研究

本文提出一个创新的采用FOT/COT方法实现恒定开关频率的自适应PWM调制器，并通过仿真和实验方法验证了这个概念。在摘要中，我们介绍了这个调制器设计的工作原理。这篇论文的正文部分还将探讨非理想因素(例如，Ct2 电容上的纹波)的重要影响和调制器小信号模型，以及更多信息和仿真验证实验结果。

参考文献

[1] C. Adragna, "Fixed-Off-Time Control of PFC Pre-regulators", 10th European Conference on Power Electronics and Applications, EPE 2003, Toulouse, France, paper 382.

[2] C. Adragna, S. De Simone and G. Gattavari, "New Fixed-Off-Time PWM modulator provides constant frequency operation in boost PFC pre-regulators", International Symposium on Power Electronics, Electrical Drives, Automation and Motion, SPEEDAM 2008, pp. 656-661.

[3] H.C.Lin, B.C Fung and T.Y Chang, "A Current Mode Adaptive On-Time Control Scheme for Fast Transient DC-DC Converters", International Symposium on Circuits and Systems, ISCS 2008, pp. 2602 - 2605.

[4] L.F.Shi and L.Y.Xu, "Frequency compensation circuit for adaptive on-time control buck regulator" IET Power Electron, 2014, Vol. 7, Iss.7, pp. 1805–1809.

[5] W.C.Chen, H.C.Chen, M.W.Chien, Y.W.Chou, K.H.Chen, Y.H. Lin, T.Y Tsai, S.R Lin, and C.C.Lee “Pseudo-Constant Switching Frequency in On-Time Controlled Buck Converter with Predicting Correction Techniques”, IEEE Transactions on Power Electronics, Vol. 31, Iss.5, pp. 3650 – 3662, May 2016.

[6] X. Xu, X. Wu and X. Yan, "A Quasi Fixed Frequency Constant On-Time Controlled Boost Converter", International Symposium on Circuits and Systems, ISCS 2008, pp. 2206-2209.

[7] M.C.Lee, X. Jing and P.K.T.Mok, "A 14V-Output Adaptive-Off-Time Boost Converter with Quasi-Fixed-Frequency in Full Loading Range", International Symposium of Circuits and Systems, ISCAS 2011, pp. 233-236.

[8] "400 W FOT-controlled PFC pre-regulator with the L6563", STMicroelectronics Application Note, AN2485.