Practical issues in load modeling for voltage stability studies

Abstract

Load modeling has become a critical component fur the comprehensive and accurate analysis of power systems. In particular, voltage stability limits derived from simulations may be highly influenced by load models used in both static and dynamic analysis. While data for must transmission and generation elements is either well established or can he readily determined from measurement, good load data and models remain difficult to reliably ascertain. This paper discusses the requirements of load models, current approaches, and provides a practical approach to develop models for use in voltage stability analysis. Based on billing data or load inventory surveys, the load is classified into broad types such as residential, industrial, and commercial load and each is subdivided into more sperilic components including induction motors and other elements. Time-domain simulations are used to establish the load characteristics and general purpose models are synthesized from the results for use in static analysis. Examples of this approach are presented in case studies Index Terms-Load modeling, stability analysis, voltage stability, dynamic simulation.

Static Load Characteristic of Complex Load Node with Allowance for Automation

“…The value of U Q G G for industrial enterprises lies within the range of 3.2 -6.4 [1,2]. The regulating effect of SLC1 lies in the mentioned range while the regulating effect of SLC 2 is greater than the upper limit of the range.…”

“…At the same time the simplified load models or the standard static characteristics are used under network calculation. These models don't reflect the real interrelation between the condition parameters and the load value [1]. This paper concentrates on techniques of SLC identification (identification of the static load characteristics) for the purpose of further using the obtained load models to improve the mathematical model of a power system in the task of calculation of the steady-state conditions.…”

Modelling the short-term and long-term aggregate response of multiple loads fed through a sub-transmission network

“…The a ij and α ij coefficients can be obtained by fitting the model (1) in the least-square sense to a set of (V i , P i ) points obtained from a detailed model of the load [5]. The b ij and β ij coefficients are obtained in the same way from (V i , Q i ) points.…”

“…Considerable attention has been paid to deriving practical models of either individual or composite loads at distribution level [3], [4], [5]. Further efforts should be also devoted to improving load models at the transmission level [6], [7].…”

Probabilistic ranking of power system loads for voltage stability studies in networks with renewable generation

“…The modelling of power system components has a remarkable influence on voltage stability assessment, and load models in particular [16]. If the load model is not accurate, the power system may operate under a condition that leads to voltage instability [17].…”