本文针对三相四线制低压配电网中存在的谐波污染严重、中性线电流较大的问题,提出了一种基于无谐波检测的三相四线制有源电力滤波器(Active Power Filter,简称APF)控制策略。建立了电容中点型三相四线制APF的数学模型,并给出了其中电感、电容主要参数的设计方法。在对比分析谐波检测和无谐波检测控制方法的基础上,选取了更有优势的无谐波检测控制策略,并针对系统中存在的负序以及零序电流分量分别设计了比例谐振(Proportional Resonant,简称 PR)控制器。在Matlab/Simulink环境下搭建了三相四线制APF的仿真模型,对谐波补偿和抑制中性线电流作了仿真测试,效果显著。最后,以TI公司的TMS320F28377为控制器单元核心搭建了实验平台,证实了所提控制策略的可行性。
英文摘要:
This paper focusing on the three-phase four-wire distribution system with serious harmonics pollution and larger unbalanced neutral harmonic current, presents a three-phase four-wire active power filter i.e. APF based on the control strategy of non-harmonic detection. It establishes the mathematical model of three-phase four-wire APF with mid-point capacitor, and gives the design method of main parameters of inductance and capacitance. Control strategy of harmonic detection and non-harmonic detection are analyzed, and non-harmonic detection method is selected as the main control strategy finally. Controller of proportional resonant i.e. PR is designed to eliminate negative harmonic and the zero sequence current. Simulation of the three-phase four-wire APF is build in Matlab/Simulink environment to test the result for harmonic compensation and suppression of neutral line current, and it shows the remarkable effect of comprehensive improvement. Finally, an experimental platform taking TI TMS320F28377 as the main controller is build to verify the feasibility of the control strategy.