三相四线制系统中基于等功率法的谐波检测

有源电力滤波器(APF)补偿性能的好坏很大程度上取决于系统的谐波检测算法。介绍了三相四线制系统中的3种谐波检测法,即以瞬时无功功率理论为基础的d-q法、有功分离法和基于功率平衡的等功率法,重点阐述了等功率法。在系统电压畸变和无畸变、负荷对称和不对称4种组合情况下利用PSCAD/EMTDC软件对系统的谐波检测进行仿真,在此基础上对3种检测法在补偿效果、实时性等方面作详细比较,分析各自特性。比较可知,等功率法不需要大量的计算,程序设计简单,且在补偿效果、实时性、直流侧电压利用率方面均取得其他2种方法难以比拟的效果,且易于硬件实现。实验结果表明,等功率法实用价值高。

Harmonic detection based on equal power method in three-phase four-wire system

The compensation performance of active power filter depends on harmonic detection mostly.Three methods of harmonic detection in three-phase four-wire system are introduced:d-q method based on instantaneous inactive power theory,active power separation method and equal power method based on power equilibrium.The basic principle of equal power method is emphasized,for which simulations with PSCAD / EMTDC are made in four combinatorial instances of distorted / normal voltage and symmetrical / dissymmetrical load.The compensation effect and real-time performance of three harmonic detection methods are compared based on the simulations,which shows that,the equal power method is the best in compensation effect,real-time performance and DC voltage utilization efficiency.It has less calculation,simple saftware design and hardwaree implementation,and high practicability.