| 引用本文: | 袁义生,张钟艺,梅相龙,张金克.三电平LLC谐振变换器关断损耗的优化设计[J].电力自动化设备,2020,40(2): |
| YUAN Yisheng,ZHANG Zhongyi,MEI Xianglong,ZHANG Jinke.Optimal design of switching-off loss in three-level LLC resonant converters[J].Electric Power Automation Equipment,2020,40(2): |
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| 摘要: |
| 开关管关断损耗是三电平LLC谐振变换器高频工况下的主要损耗，是一个与谐振电感Lr、谐振电容Cr、励磁电感Lm以及电压增益Gv密切关联的变量。首先用时域分析法，建立了开关管关断电流Ioff与电感比k、归一化频率 fn 和品质因数Q之间的解析函数；并结合开关管关断过程特点，建立了关断损耗Psw-off与[k, fn, Q]之间的解析函数。然后构建出[Ioff, k, fn, Q]和[Psw-off, k, fn, Q]2个四维图形，分析参数之间的规律。在此基础上，推导了在电压增益的需求和开关管零电压导通的实现2个约束条件下来优化Psw-off的[k, fn, Q]参数取值空间，进而采用粒子群优化算法求解关断损耗优化下的[k, fn, Q]值。最后设计了一个200 V输入、130 V输出、负载电阻48.4 Ω、额定功率350 W的实验样机，并对比分析了所提方法与降低谐振电流有效值来减少导通损耗的传统优化方法分别在满载与半载条件下的关断损耗，证明了所提优化方法在降低开关管关断损耗、提高变换器效率方面效果明显。 |
| 关键词: 三电平LLC谐振变换器 关断损耗 优化设计 时域分析 粒子群优化算法 |
| DOI：10.16081/j.epae.202001021 |
| 分类号:TM46 |
| 基金项目:国家自然科学基金资助项目(51467005)；江西省自然科学基金资助项目(20181BAB206033) |
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| Optimal design of switching-off loss in three-level LLC resonant converters |
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YUAN Yisheng, ZHANG Zhongyi, MEI Xianglong, ZHANG Jinke
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School of Electrical and Automation Engineering, East China Jiaotong University, Nanchang 330013, China
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| Abstract: |
| Switching-off loss is the major loss of three-level LLC resonant converter under high frequency condition, which is closely related to resonant inductance Lr, resonant capacitance Cr, magnetizing inductance Lm and voltage gain Gv. Firstly, the analytic function between switching-off current Ioff and inductance ratio k, normalized frequency fn and quality factor Q is built by time domain analysis method, and the analytic function between switching-off loss Psw-off and [k, fn, Q] is built by combining the feature of the switching-off process. Then two four-dimension graphs about [Ioff, k, fn, Q] and [Psw-off, k, fn, Q] are pictured and the laws among parameters are analyzed. Based on the above analysis, the solving space of [k, fn, Q] is derived under the constraints of voltage gain requirement and ZVS(Zero Voltage Switching) realization condition. Furthermore, the final [k, fn, Q] values are achieved by PSO(Particle Swarm Optimization) algorithm for optimal switching-off loss. Finally, a prototype with 200 V input voltage, 130 V output voltage and 48.4 Ω load resistance, 350 W rated power is built. Under the conditions of full load and half load, the experimental results of the switching-off loss Psw-off are compared between the proposed method and the traditional optimal method of reducing the effective value of resonant current to decrease the conduction loss of the circuit, which verifies that the proposed optimal design method can effectively reduce the switching-off loss and improve the converter efficiency. |
| Key words: three-level LLC resonant converter switching-off loss optimal design time domain analysis PSO algorithm |
