大功率整流系统谐波功率特性及其对电能计量的影响和节能分析

Analysis of Energy Saving and Harmonic Power Characteristics and Its Effects on Electric Energy Measurement in High Power Rectifier System

为解决现有大功率整流系统在计及谐波情况下电能计量及节能等方面遭遇的现实问题,本文对谐波功率特性及其对系统电能计量与效率的影响进行了研究。首先介绍了基波电能计量方案,以三相整流电路为例,研究了功率流向及功率计算,并探讨了电源含与不含谐波情形下系统总有功功率与基波功率的关系。其后,研究了无滤波、网侧滤波及感应滤波下谐波功率的特点及其对系统电能质量与效率的影响。仿真与工程试验结果表明:谐波是由基波转化而来,其回送功率必然引起总功率与基波功率的不平衡;感应滤波方式在谐波抑制、减小系统谐波损耗及节能方面具有优势。

In order to solve the practical problems of electric energy measurement and energy saving in the current high power DC power systems including harmonics, the characteristics of harmonic power and their impact on electric energy measurement and efficiency are studied in this paper. Firstly, the scheme of fundamental power measurement is introduced. Taking three-phase rectifier circuit for example, the flow directions and calculation of power are presented, and the relation of the system＇s total reactive power and the fundamental power under the conditions of the source with and without the harmonics are analyzed. Then, the characteristics of harmonic power and their effects on the energy measurement and efficiency are analyzed by the no filtering, grid side filtering and inductive filtering methods. The simulation and projective test results show that harmonic is converted from fundamental current, which results the imbalance of the total active power and the fundamental power on the process of looking back to the grid side; the inductive filtering method has the advantages of good harmonic suppression, less losses of the key power supply equipment and energy saving.