针对现有磁复位技术存在变压器励磁能量利用率低等问题，提出一种副边串联LCD实现励磁能量转移的新型副边磁复位正激变换器，提升了正激变换器电气性能，对正激变换器的推广应用具有重要的指导意义。

对所提变换器的工作原理进行详细分析，指出开关管能够实现低电压关断，同时根据励磁电感、正激电感及附加电感电流是否连续，将变换器划分为8种不同组合工作模式。分析不同组合工作模式的能量传输过程，发现在给定的输入电压和负载变化范围内，励磁电感CCM/附加电感DCM/正激电感CCM时，开关管低电压关断程度最深，并且其低电压关断程度随着附加电容的减小而不断加深，但与附加电感的取值无关。推导了该模式下变换器的输入输出关系、附加电容最大电压、附加电感和正激电感峰值电流的解析表达式，并指出附加LCD电路仅传输变压器励磁能量，不会影响正激电感工作模式，有利于实现变换器的高效率和大功率输出。根据该模式的能量传输过程，在保证变压器可靠磁复位的前提下，尽可能地加深开关管低电压关断程度，提出了附加电容和附加电感的参数设计方法；结合输出纹波电压分析，确保变换器在给定的动态变化范围内，均能满足输出纹波电压要求，提出了正激电感的设计方法；依据不同阶段能量传输过程的等效电路，推导出各功率器件电压、电流应力的解析表达式，给出了相应元器件的选型方法。

根据所提出的设计方法，研制出一台48V/10A的实验样机，并进行仿真分析及实验研究，结果表明：样机各项电气技术指标均满足预期设计要求，验证了理论分析的正确性及设计方法的可行性。

Aiming at the problems of low transformer excitation energy utilization in the existing magnetic reset technology, a new type of secondary side magnetic reset forward converter with secondary side series LCD to realize excitation energy transfer was proposed, which improves the electrical performance of the forward converter has an important guiding significance for the promotion and application of the forward converter.

The working principle of the proposed converter was analyzed in detail, and it was pointed out that the switch can realize low-voltage turn-off. At the same time, the converter was divided into 8 different combined working modes according to whether the magnetizing inductance, forward inductance and additional inductor current are continuous. Analyzing the energy transmission process of different combined working modes, it was found that within the given input voltage and load variation range, when the magnetizing inductance CCM/additional inductance DCM/forward inductance CCM, the switch has the deepest low-voltage turn-of and the degree of low-voltage turn-off continues to deepen as the additional capacitance decreases, but it has nothing to do with the value of the additional inductance. The analytical expressions for the input and output relationship of the converter, the maximum voltage of the additional capacitor, and the peak current of the forward inductor and the additional inductance were deduced in this mode, and it was pointed out that the additional LCD circuit only transmits the transformer excitation energy and does not affect the working mode of the forward inductor. It is beneficial to realize the high efficiency and high power output of the converter. According to the energy transmission process of this mode,on the premise of ensuring the reliable magnetic reset of the transformer and deepen the low-voltage turn-off degree of the switch as much as possible, the parameter design method of additional capacitance and additional inductance was proposed; Combined with output ripple voltage analysis to ensure that the converter can meet the output ripple voltage requirements within a given dynamic range, and a design method for forward inductance was proposed; According to the equivalent circuit of the energy transmission process at different stages, and the analytical expression of the power device voltage and current stress were derived, gives the selection method of power devices.

According to the proposed design method, a 48V/10A experimental prototype is developed, and the simulation analysis and experimental research are carried out. The results show that the electrical technical indexes of the prototype meet the expected design requirements, which verifies the correctness of the theoretical analysis and the feasibility of the design method.

[1]周国华, 赵泓博, 毛桂华, 等. 开关变换器调制技术的分类与综述[J]. 中国电机工程学报, 2018, 38(21): 6383-6400+6501.

[2]刁明君. 开关电源的研究发展综述[J]. 通信电源技术, 2018, 35(07): 89+93.

[3]刘树林, 刘健著. 开关变换器分析与设计[M]. 北京: 机械工业出版社, 2010.

[4]周国华, 许建平. 开关变换器调制与控制技术综述[J]. 中国电机工程学报, 2014, 34(06): 815-831.

[5]李红梅, 张恒果, 崔超. 车载充电PWM软开关DC-DC变换器研究综述[J]. 电工技术学报, 2017, 32(24): 59-70.

[6]刘昌咏, 赵晋斌, 毛玲, 等. 一种高降压比DC-DC变换器[J]. 电工技术学报, 2019, 34(20): 4264-4271.

[7]鲁信秋. 高可靠性同步整流控制技术的研究与实现[D]. 成都: 电子科技大学, 2018.

[8]黄亚峰, 陈剑, 刘俊峰, 等. 正反激倍压DC-DC变换器机理分析与仿真[J]. 东北电力大学学报, 2018, 38(04): 35-39.

[9]夏炎冰. 自磁复位正激式变换器研究[D]. 南京: 南京航空航天大学, 2012.

[10]侯庆会. 高性能小功率DC/DC模块电源研究[D]. 杭州: 浙江大学, 2018.

[11]Mirzaei Amin, Rezvanyvardom Mahdi. High voltage gain soft switching full bridge interleaved flyback DC-DC converter for PV applications[J]. Solar Energy, 2020, 196(05): 217-227.

[12]李洪珠, 刘歆俣, 李洪璠, 等. 正激变换器磁集成分析与设计准则[J]. 中国电机工程学报, 2019, 39(12): 3667-3676.

[13]王洪宝. 单端高效正激变换器的研究[D]. 锦州: 辽宁工业大学, 2015.

[14]Myung Ho Kim, Seung Hoon Lee, Boom Seok Lee, et al. Double-ended active-clamp forward converter with low DC offset current of transformer[J]. IEEE Transactions on Industrial Electronics, 2020, 67(2): 1036-1047.

[15]Ming H, Bin O. A hybrid control strategy for forward flyback converter with improved efficiency as an interface to low voltage renewable sources[C]// 2nd IEEE Conference on Energy Internet and Energy System Integration, 2018: 1-5.

[16]Hyeon-Seok Lee, Hyung-Jin Choe, Seok-Hyeong Ham, et al. High-efficiency asymmetric forward-flyback converter for wide output power range[J]. IEEE Transactions on Power Electronics, 2017, 32(1): 433-440.

[17]刘树林, 张海亮, 王航杰, 等. 抑制输出能量倒灌的二次侧自复位正激变换器的能量传输过程分析[J]. 电工技术学报, 2020, 35(S2): 477-483.

[18]Jian Cao, Shulin Liu, Liqian Yan, et al. Research on power transmission characteristic of forward flyback converter[C]// 2018 13th IEEE Conference on Industrial Electronics and Applications (ICIEA). IEEE, 2018: 1342-1346.

[19]Shijia Yang, Zhaoming Qian, Qian Ouyang, et al. An improved active-clamp ZVS forward converter circuit[C]// 2008 Twenty-Third Annual IEEE Applied Power Electronics Conference and Exposition, 2008: 318-322.

[20]Jingyuan Lin, Sih Yi Lee, Chung Yi Ting, et al. Active-clamp forward converter with lossless-snubber on secondary-side[J]. IEEE Transactions on Power Electronics, 2019, 34(8): 7650-7661.

[21]宁平华, 陈乐柱, 丁鑫龙, 等. 双RCD箝位的双管正激变换器研究[J]. 电源学报, 2016, 14(03): 124-130.

[22]王国礼, 金新民. 采用LCD箝位电路的正激DC-DC变换器[J]. 电工技术杂志, 2000(12): 24-26.

[23]Xiaoqing Qin, Haibing Hu, Hongfei Wu, et al. A series-input forward converter with shared RCD cell for high-reliability and wide input voltage range applications[C]// Energy Conversion Congress and Exposition. IEEE, 2013:154-158.

[24]顾亦磊, 顾晓明, 吕征宇, 等. 一种新颖的宽范围双管正激型DC/DC变换器[J]. 中国电机工程报, 2005, 25(02): 47-51.

[25]谢小高, 赵晨, 郑凌蔚, 等. 有源钳位正反激变流器的第三绕组与电流型混合同步整流驱动方案[J]. 中国电机工程学报, 2012, 32(33): 31-36+172.

[26]李学峰, 吴德军, 王仕韬. 一种变模态恒定磁芯复位电压双管正激变换器[J]. 电源学报, 2018, 16(01): 19-23.

[27]Han Shin Youn, Jae ll Baek, Jae Kuk Kim. Interleaved active clamp forward converter with extended operating duty ratio by adopting additional series-connected secondary windings for wide input and high current output applications[J]. IEEE Transactions on Power Electronics, 2019, 34(5): 4423-4433.

[28]Xiaoguang Jin, Lanruo Wan, Jun Xu, et al. Dual-switch forward converter with an additional reset capacitor for hold-up operation[J]. The Journal of Engineering, 2019, 2019(16): 2593-2596.

[29]刘树林, 曹剑, 胡传义, 等. 正-反激组合变换器的能量传输模式及输出纹波电压分析[J]. 电工技术学报, 2019, 34(08): 1647-1656.

[30]马培松, 许皓. 基于SG3525的双管正激变换器的研制[J]. 电气开关, 2018, 56(04): 59-62.

[31]魏应冬, 吴建德, 顾亦磊. 一种新型双管正-反激直流变换器[J]. 中国电机工程学报, 2005, 25(20): 50-55.

[32]Lee J, Lee C, Han S. Two-switch reset winding forward converter with Low input current ripple[C]// IECON 2018 44th Annual Conference of the IEEE Industrial Electronics Society, Washington, DC, USA, 2018: 1543-1549.

[33]Heinicke, H. Apparatus for converting D.C. voltage[P]. United States Patents: 392105418, 1975.

[34]定超. 正反激组合变换器的分析与设计[D]. 西安: 西安科技大学, 2016.

[35]V C Van. Properites of DC-to-DC converters for switch-mode power supplies[J]. Philips Application Information 472, 1975: 8-10.

[36]陈道炼, 陈卫昀, 严仰光. RCD箝位正激变换器的分析研究[J]. 南京航空航天大学学报, 1997(02): 111-115.

[37]Wolf G. Mains isolating switch-mode power supply[J]. Philips Electronic Applications Bulleting, 1973, 32(1).

[38]Carsten B. High power smps require intrinsic reliability. Power Conversion International (PCI) [J]. proceedings, 1981: 118-133.

[39]胡海兵, 吴红飞, 刘薇, 等. 一族有源钳位正激变换器[J]. 电工技术学报, 2013, 28(12): 245-250+261.

[40]吴琨, 钱挺, 王浩. 一种开关频率固定的输出可调型有源钳位正激双向谐振变换器[J]. 电工技术学报, 2018, 33(20): 4771-4779.

[41]杨银平. 高边有源钳位反激式UPS充电器的研究设计[J]. 佳木斯大学学报(自然科学版), 2019, 37(05): 739-742.

[42]D H Park, H J Kim, Y S Sun. A development of the off-line active clamp ZVS forward converter for telecommunication applications[J]. Proceedings of Power and Energy Systems in Converging Markets, 1997: 271-276.

[43]Tian Jian, Reimann T, Scherf M, D Li, et al. Influences of magnetic inductance, leakage inductance and saturable inductance on an active clamp forward converter[C]// 2007 European Conference on Power Electronics and Applications, 2007: 1-8.

[44]Bor-Ren Lin, Huann-Keng Chiang, Chien-En Huang, et al. Analysis of an active clamp forward converter[C]// 2005 International Conference on Power Electronics and Drives Systems, 2005: 140-145.

[45]E H Wittenbreder, V D Baggerly, H-C Martin. A duty cycle extension technique for single ended forward converters[J]. IEEE Applied Power Electronics Conference(APEC) proceedings, 1992: 51-57.

[46]Murakami N, Yamasaki M. Analysis of a resonant reset condition for a single-ended forward converter[J].1988:1018-1023.

[47]Wei Qin, Bo Zhu, Xu Zhang, et al. A novel current-feed soft-switching two-switch forward resonant DC-DC Transformer (DCX)[C]// international power electronics and application conference and exposition, 2014: 126-130.

[48]王玉杰, 陈霞, 刘士军. 车载空调用谐振去磁正激电源的分析与设计[J]. 技术与市场, 2018, 25(11): 21-24.

[49]宁平华. 基于双RCD箝位电路和饱和电抗器的多输出开关电源研究[J]. 齐齐哈尔大学学报(自然科学版), 2016, 32(03): 1-6.

[50]顾晓明, 顾亦磊, 杭丽君, 等. 谐振复位软开关双管正激型DC/DC变换器[J]. 电力系统自动化, 2005, 29(02):67-71.

[51]J N Park, T R Zaloum, M A Cambridge. A dual mode forward/flyback converter[C]// IEEE Power Electronics Specialists conference, 1982: 3-13.

[52]Zaloum Thomas Raymond. An analysis of a dual mode forward/flyback converter[D]. M.A. Thesis, Massachusett Institute of Technology, 1982: 1-95.

[53]王国礼, 金新民. 一种正-反激组合变换器的研究[J]. 电力电子技术, 2001, 35(2): 4-6.

[54]彭银乔, 刘树林, 吴浩, 等. 正-反激组合变换器变压器的优化设计[J]. 电工技术学报, 2020, 35(S2): 470-476.

[55]R R Khorasani, A Ehsan. ZVT resonant core reset forward converter with a simple auxiliary circuit[J]. IEEE Transactions on Industrial Electronics, 2018, 65(1): 242-250.

[56]石健将, 洪峰, 严仰光. 双管正-反励组合变换器研究[J]. 电工技术学报, 2003, 18(5): 87-90.

[57]李晓高, 洪峰. 双管双变压器正-反激组合变换器研究[J]. 电力电子技术, 2007, 41(11): 26-28.

[58]严亮. 全激变换器的研究[D]. 燕山大学, 2017.

[59]Lahooti Eshkevari Alireza, Ali Mosallanejad, Sepasian Mohammadsadegh.

Design, modelling, and implementation of a modified double-switch

flyback-forward converter for low power applications[J]. Power

Electronics Iet, 2019, 12(4):739-748.

[60]Shulin Liu, Chuanyi Hu, Jian cao, et al. Research on the PFC mechanism of forward-flyback converter[J]. IOP Conference Series: Materials Science and Engineering, 2019, 533(1): 311-318.