互感耦合式紧凑型多调谐滤波器的设计

陈柏超 周兴隆 罗垚 朱远哲

Abstract：Aiming at the problem of large volume and large floor space of traditional multi-tuned passive filters， a design method of compact multi-tuned filter considering the coupling between coils was proposed. Starting from the function of complex impedance， the circuit form of the traditional multi-tuned passive filter was obtained， and the circuit with the coupling relationship between the inductors equivalent to the former was established. Through the decoupling of the coupled inductor and the equivalent relationship with the traditional filter circuit， the nonlinear equations of the coil geometric parameters were established， and the design result of the compact three-tuned filter with coils coaxially placed was obtained. The simulation of the designed compact filter was carried out and the experimental prototype was fabricated. The simulation and experimental results show that this compact multi-tuned filter reduces the area occupation of the coils and also has good filtering performance.

Keywords：harmonic analysis; passive filters; Cauer filters; coupled circuits; inductance; nonlinear equations

0 引 言

近年來，由于电力电子装置等非线性设备大量接入电力系统，电力谐波问题越来越突出，谐波治理成为了一个重要话题。在众多的谐波治理手段中，安装电力滤波器是目前效果最显著、应用最广泛的方案[1-6]。虽然有源滤波器具有良好的谐波抑制和动态补偿效果，但其价格昂贵、安装容量受开关容量的限制，不适合在高电压、大容量的场合使用，因此在很多场合中仍然需要使用到传统的无源滤波器进行谐波治理[7-9]。而在目前较为流行的混合型滤波装置中，无源滤波部分也是十分重要的一个环节[10-12]，因此无源滤波器的设计仍然是电力滤波器研究中的重要部分。

LC滤波器是电力系统中最常用的无源滤波器，其结构简单、价格低廉、效果良好。传统的LC滤波器通常由调谐多个频率的LC支路构成，电路拓扑中含有多个电感线圈。在设计传统的多调谐滤波器时，通常不会将线圈间的互感考虑进去，并且在实际工程布置的过程中，采取了将线圈分开布置的方式（如品字形布置），以消除线圈间互感，保证滤波器的滤波效果[13-15]。本文提出了一种互感耦合式多调谐滤波器设计思路，在设计过程中考虑了电感线圈间的耦合，恰当地安排线圈间的互感关系，使得整组线圈可集中布置，在保持优良的滤波性能的同时，很大程度地减小了滤波器占地面积，粗略估计，对于一组n调谐滤波器，其电感线圈的占地面积仅需传统方案的1/n。……