对电能质量进行归一量化并进行综合评估是衡量电能质量优劣与电价制定的依据之一，也是电力市场的要求。文中首先将电能质量的暂态指标量化并将其考虑到综合评估指标中，然后将基于相似理论的智能评估方法引入电能质量综合评估中，提出了新的基于粒子群算法的理想区间法来综合评估电能质量。实践证明，此方法能够在同一电能质量等级内更加精确地评价电能质量的优劣，从而给出更加全面、准确的评估结果。

The unitary quantification and synthetic evaluation of power quality are the basis of power quality assessment and electricity pricing, in the same time it is also the requirement of electricity market. In this paper, firstly the transient index of power quality is quantified and brought into the synthetic evaluation of power quality; then the intelligent evaluation method based on similarity theory is led into power quality synthetic evaluation and a new ideal interval method based on particle swarm optimization (PSO) is proposed to synthetically evaluate power quality. Practical effect proves that the proposed method can evaluate power quality difference more precisely within the same power quality grade.