一种用于PWM逆变器的非对称T型滤波器的设计方法

针对以体积最小为目的的PWM逆变器用非对称T型滤波器的参数设计中会出现高次多元方程，难以获得有用的解析解的实际问题，提出了一种采用三维数据可视化技术的设计方法：在保证低通滤波器衰减特性的前提下，分别绘出纯电阻负载和阻感负载时系统功率因数的曲面，再依次考量电力电子器件中的电流负担、电压应力等因素，从空间曲面到空间曲线，再到平面曲线，逐步地缩小取值范围。最后对电感器的结构进行了优化设计。实验验证了该方法的正确性和实用价值。

A METHOD FOR DESIGNING NON-SYMMETRY T-NET WORK FILTER USED IN PWM INVERTERS

The difficulty in obtaining practical analytic solution for high order polynomial equations when designing the Non-symmetry T-network Filter of PWM inverter leads to the 3D visual technique proposed in this paper. On the premise that the attenuation characteristic of the low-pass filter is guaranteed, the curved surfaces presenting the power factor of the system under different load conditions are drawn first, then,under the considerations of the current allowance and voltage allowance and etc of power electronic devices, available range for the parameters is reduced--from 3D surface to 3D curve,and from 3D curve to 2D curve. The structure of the filter is optimized at last. Experiments have testified the validity and use value of this method.