전압의 주파수 변화를 이용한 동기탈조 검출 알고리즘에 관한 연구

A Study on the Out-of-Step Detection Algorithm using Voltage Frequency Variation

The protection against transient instability and consequent out-of-step condition is a major concern for the utility. The unstable system may cause serious damage to system elements such as generators and transmission lines. Therefore, out-of-step detection is essential to operate a system safely. This paper presents the Out-of-Step detection algorithm using voltage frequency variation. The digital filters based on Discrete Fourier Transforms (DFT) to calculate the frequency of a sinusoid voltage are used, and the generator angle is estimated using the variation of the calculated voltage frequency. The proposed out-of-step algorithm is based on the assessment of a transient stability using equal area criterion. The proposed out-of-step algorithm is verified and tested by using EMTP MODELS.