摘要
由于LLC(谐振变换器电路中的谐振电感L_(r)、励磁电感L_(m)、谐振电容C_(r),统称LLC)谐振变换器在DC-DC变换中具有良好的特性,但在间歇控制模式下,仍存在每个控制周期内开关管的第一次开启过程会产生硬开关现象,限制了谐振变换器在轻载条件下进一步提高运行效率的可能性。为了解决这些问题,提出了一种全新的四脉冲模式间歇控制策略。该策略在三脉冲模式的基础上在副边侧设计了一个新脉冲来进行驱动,目的是将副边的能量返流到原边,通过原边开关管在结电容返流完成且体二极管导通时,发出的触发信号,实现原边开关管在第一个触发脉冲导通,从而将变换器运行在效率最优轨迹中。实验结果表明,所提出的控制策略在电压降低工况下可进一步提高了变换器的轻载运行效率,证明此策略的有效性。
Because the LLC(resonant inductor L_r,excitation inductor L_m,resonant capacitor C_r,collectively referred to as LLC)resonant converter exhibits excellent characteristics in DC-DC conversion,yet in the intermittent control mode,a hard switching phenomenon still exists during the first turn-on of the switching tube in each control cycle.The potential for further enhancing the operational efficiency of the resonant converter under light load is limited.To address these issues,a novel four-pulse mode intermittent control strategy is put forward.Based on the three-pulse mode,a new pulse is designed on the secondary side for driving,with the aim of backflowing the energy of the secondary side to the primary side.Once the junction capacitor backflow is completed and the body diode is turned on,the trigger signal sent by the primary side switching tube can enable the primary side switching tube to be turned on in the first trigger pulse,allowing the converter to operate in the optimal efficiency trajectory.The experimental results demonstrate that the proposed control strategy can further enhance the light-load operational efficiency of the converter under the voltage reduction condition,thereby verifying the effectiveness of this strategy.
作者
马胜国
赵玉珂
古展基
曹才具
陈文
赵晓曦
Ma Shengguo;Zhao Yuke;Gu Zhanji;Cao Caiju;Chen Wen;Zhao Xiaoxi(China Gridcom Co.,Ltd.,Shenzhen,Guangdong 518109,China)
出处
《机电工程技术》
2024年第7期269-274,共6页
Mechanical & Electrical Engineering Technology
基金
深圳市国电科技通信有限公司科技项目基金资助(546808220007)。
关键词
LLC谐振变换器
轻载
寄生电容
间歇控制
能量回馈
LLC resonant converter
light load
parasitic capacitance
burst control
energy feedback
