基于简化时域模型的CLLC直流变换器参数设计

Parameter Design Method of CLLC DC-DC Converter Based on Simplified Time Domain Model

CLLC直流变换器的谐振腔参数设计是其稳定运行的保障,但现有的基于基波分析的设计方法并不能实现参数设计的准确与高效。该文从设计的角度出发,首先分析了基波分析在设计上的局限性,接着在CLLC直流变换器时域分析结果的基础上,选取设计中需要考虑的运行模式进行分析,并通过简化处理,建立CLLC直流变换器的简化时域模型,导出了可以用于参数设计的增益公式与边界条件,并讨论不同控制目标下的设计依据。根据该文方法得到的设计公式形式简洁,准确度高,大大简化了设计的步骤。在此基础上,该文给出一套完整的设计思路,并应用该方法设计了一台5kW的CLLC直流变换器样机,仿真与实验的结果均证明了该方法的正确性。

The resonant cavity parameters design of CLLC DC-DC converter is the guarantee of its stable operation, but the existing design method based on first harmonic approximation(FHA) can not achieve accuracy and efficiency. From the point of view of design, this paper firstly analyzed the limitation of FHA. Then, based on the results of time domain analysis of CLLC DC-DC converter, a simplified time domain model of CLLC DC-DC converter was established by reasonably simplifying the waveforms. The gain formula and boundary conditions were derived and the design basis under different load conditions was discussed. The design formulas obtained by this method were simple and accurate,which greatly simplify the design process. On this basis, this paper presented a complete design process and a 5 kW CLLC DC-DC converter prototype was made. The simulation and experimental results proved the correctness of the theory.