초록 열기/닫기 버튼
This paper presents a novel method to assess voltage sags by taking into account the voltage tolerance characteristic of loads. In general, the tolerance characteristic is expressed in the form of a two-dimensional curve of voltage magnitude and duration. Also, the shape of characteristic curves depend on the type of loads. In order to estimate the expected sag frequency affecting sensitive loads, it is necessary to perform a voltage sag assessment considering the voltage tolerance curves of loads. However, because most existing methods of voltage sag assessment only focus on voltage sag magnitudes, these methods have limitations in reflecting various types of tolerance curves. In this paper, an effective method for reflecting various thresholds of sag magnitude and duration is proposed. The proposed method performs voltage sag assessment based on the area of vulnerability for given voltage thresholds and sag durations are estimated using a probability model on the historical operation data of protection system. In addition, we propose an effective assessment scheme based on the concept of measuration by division for a slope-shape tolerance curve.
