电力系统谐波与不平衡污染程度评估指标的研究

Research on evaluation indexes of harmonic and unbalance pollution level in power system

在电力系统中,谐波与不平衡会导致线损增加、设备被损坏、电能计量不准确等诸多问题。但是目前并没有一套固定的指标来对谐波与不平衡污染程度进行评估。针对该问题,根据IEEE Std 1459-2010功率理论和其对视在功率的分解方法,提出了一套适用于非正弦不平衡条件下新的谐波与不平衡污染程度评估指标。对传统评估指标的合理性进行了分析;针对传统评估指标的缺点,分别给出了单相系统和三相系统中新评估指标的定义;最后在Matlab/Simulink中搭建仿真模型,比较传统指标与新指标的评估效果。分析结果表明,新指标能够准确和全面地对谐波和不平衡污染程度进行评估。

In power system,the harmonic and unbalance will lead to the increase of line losses,damage of equipments,inaccuracy in electric energy metering and many other problems.However,there is not a set of fixed indexes to evaluate the level of harmonic and unbalanced pollution at present.Aiming at this problem,according to the IEEE Std 1459-2010 power theory and its decomposition method for apparent power,a set of new evaluation indexes of harmonic and unbalance pollution level under non-sinusoidal unbalanced condition is proposed in this paper.Firstly,the rationality of traditional evaluation indexes is analyzed.And then,based on the shortcomings of the traditional evaluation indexes,the definitions of the new evaluation indexes in the single phase system and the three-phase system are given respectively.Finally,a simulation model is built in Matlab/Simulink to compare the evaluation effects of the traditional indexes and the new indexes.The results of the analysis indicate that the new indexes can accurately and comprehensively evaluate the level of harmonic and unbalance pollution.