The impact of load modeling on power flow studies for the cyprus power system

Models for the electrical equipment of the generation, transmission and distribution systems, which are required for power system analysis, may be available by the manufacturers and contractors or can be estimated by on-site tests or mathematical analysis. Due to the fact that the system load is characterized by randomness and time-varying physical properties, load representation in practical applications continues to be an area of uncertainty and the issue of load modeling remains an important and challenging research topic. The main task of this paper is the establishment of a method for estimating the parameter values for a nonlinear relationship between voltage and active and reactive load powers for medium voltage feeders in transmission substations. An application that employs the ZIP load model and determines parameter values based on real-time measurements is proposed. The impact of the established voltage-dependent load model on the power flow studies for practical systems is investigated. In order to verify its efficacy, the proposed load modeling methodology is applied on the isolated power system of Cyprus.