MOSFET开关变换电路换流过程的瞬态磁场能量密度的计算

为进一步明确电力电子电路开关瞬态过程的干扰特性 ,基于传输线理论 ,首先解决了瞬态电流环路磁矢量势计算中所遇到的难题 ,并在此基础上提出了一种瞬态场时域解析模型 .在进行高精度计算时 ,该模型与数值方法相比具有高效的特点 .最后以MOSFET开关电路为例 ,计算了该开关在关断瞬间瞬态磁场的变化规律 ,并计算了瞬态磁场能量密度 .本模型的建立为电力电子电路的电磁兼容性设计提供了依据 .计算结果与实际结果均表明 ,瞬态电流在本文所提出的实验回路中的传输时延虽为纳秒级 ,但应在瞬态模型中给予充分考虑

Computation of Transient Magnetic Energy Density of the Commuting Process for MOSFET Converter Circuits

For further characterizing the interference properties of the transient switching process of the power electronic circuits, a transient magnetic time domain analytical model is proposed on the basis of the TLM(Transmission Line Method). The magnetic vector potential of the loop circuits is first presented. The model is characterized in its high efficiency as compared with the numerical methods especially for the high precision computation. The dynamic magnetic field at the cutoff instant of the MOSFET as well as the magnetic field energy density is computed. The objective of the model is to provide the principle for the EMC design of the power electronic circuits. The results of the computation as well as that of the experiments show that though the propagation delay of the transient current in the loop circuit is in the order of several nanoseconds, it must be fully taken into consideration in the transient mode.