Dissimilarities of Physical Meaning between Loss of Load indices based on Load Curve Types

摘要

This paper proposes a conversion function and a method to transform LOLEd (days/year) using daily peak load curve into LOLE_H (hours/year) using hourly load curve and describes a relationship between LOLEd and LOLEh The indices cannot only be just transformed arithmetically but also have different characteristics physically because of using their different load curves. The conversion function is formulated as variables of capacity and a forced outage rate of generator, hourly load daily load factor, daily peak load yearly load factor and etc. Therefore, the conversion function (γ = Φ(·)) is not simple. In this study, therefore, the function is formulated as linear times of separated two functions. One is an exponential formed conversion function of daily load factor and the other is a formulated with an exponential typed conversion function of daily peak load yearly load factor. Furthermore, this paper presents an algorithm and a flow chart for transforming LOLE_D into LOLE_H. The proposed conversion function is applied to the actual KPS (Korea Power System) in 2015. The exponent coefficients of the conversion functions are assessed using the proposed method. Finally, assessment errors using the conversion function for case study of the actual system are evaluated to certify as a first proposed method.