Cost Estimation of Voltage Sag Mitigation Based on Improved Severity Index

The voltage sag mitigation is a non-standardized, due to the lack of customer side details, treatment capacity estimation difficulties, easy to cause excessive or inadequate treatment. This paper studies the identification of the tolerance and capacity of the mitigated devices, and proposes an improved severity index that considers the severity of voltage sag’s residual voltage and duration. And the treatment capacity identification method based on the improved sag severity index and object capacity ratio is put forward and then estimates the required treatment costs. Based on the actual monitoring data of a city power grid, the empirical analysis results show that the proposed method is effective and reasonable.