A novel analytical model for electrical loads comprising static and dynamic components

Abstract

This paper is concerned with modeling of electrical loads. It presents a detailed analytical approach for modeling static and dynamic loads. Specific individual loads such as heating loads, filament lamps, fluorescent lamps and induction motors are represented using the proposed model. The aggregate load models are derived taking into consideration their nonlinear properties. Good agreement is obtained between the theoretical values using the proposed model and available published experimental results. The outcome of this study gives a simple and detailed load model that will be valuable for different simulation studies especially in the area of transient stability.

Introduction

The importance of power system load characteristics in power system planning and operation is increasing, especially in the competitive industrial environment today. Thus in performing power system analysis, accurate models must be developed for all pertinent system components. Security assessment is even more important than ever, in endeavoring to realize cost-effective power system planning and operation with sufficient reliability. However, the representation of loads continues to be an area of greater uncertainty [1], [2], [3] where knowledge of the demand side of power system is less than that of the supply side. This is quite natural because power system loads consist of a huge number of electric devices geographically distributed and operated at the customers’ own will. Furthermore, little attempt has been made by the various utilities to determine the composition of their loads under present or projected peak conditions. Because of these uncertainties, an accurate representation of loads presents a formidable problem. Electric utility analysts and their management require evidence of the benefits of improved load representation in order to justify the effort and expense of collecting and processing load data and, perhaps, modifying computer program load models.

In this paper, a novel approach is introduced, which results in detailed expressions for the characteristic parameters of electrical loads. The load estimation and aggregation according to its components will help to define the transmission network loading.