基于谐波配比优化的Φ_(2)类逆变器设计研究

Design method for classΦ_(2)inverter based on optimal harmonic weighting

为了降低Φ_(2)类逆变器中功率开关器件的电压应力并简化其谐振参数设计过程,提出了一种基于谐波配比优化的参数设计方法.首先对Φ_(2)类逆变器开关节点电压(vds)频谱进行了分析,以降低开关器件电压应力为导向推导了优化的谐波配比和目标vds.然后基于目标vds实现了对Φ_(2)类逆变器微分方程的退耦合求解,得到了各支路的电流并进行了完整的量化分析.进一步结合开关节点电压和开关电流的频谱特征,推导了Φ_(2)类逆变器谐振槽的阻抗幅度与相位约束,以此为依据提出了直接确定电路谐振参数的方法.最后搭建了27.12 MHz的原理样机,和传统设计方法相比,开关电压应力降低了10.2%,效率提升了7.2%.

To minimize the switch voltage stress and simplify the design procedure of very high frequency classΦ_(2) inverter,a design strategy was proposed based on optimal harmonic weighting method.Firstly,the switching node voltage spectrum was analyzed to obtain the main harmonic components.Then,the optimal harmonic weighting and target drain voltage were derived by taking the voltage stress as the optimization objective.Based on the derived voltage,differential equations of classΦ_(2) inverter were decoupled to solve branch current and provide fully quantitative analysis.Furthermore,combining the spectrum characteristics of the switching node voltage and switch current,impedance magnitude and phase constrains of the resonant tank were obtained,where the circuit parameters were calculated directly.Finally,a 27.12 MHz prototype is built,compared with the conventional design,10.2%reduction in voltage stress and 7.2%improvement in efficiency are achieved.