A new approach to load modelling for a power electronics‐based load structure

Abstract

This paper presents a new non-linear complex load structure that consists of two induction motors, a DC motor, a static load and electric vehicle charging stations. The proposed structure covers modern power system loads behaviour. Additionally, there is a need for an automatic method of load modelling that is accurate and suitable for new loads. This paper proposes an automated load modelling (ALM) method for a new composite load structure based on a software tool. This paper presents two new load models besides the conventional load models. All load models are simultaneously used in each sliding window in the proposed ALM, and the best load model is chosen by the root mean square error (RMSE) criterion. It makes the proposed method to be more accurate than other similar methods. Because in this case, the proposed method becomes independent of variations in load composition, in contrast to other methods. This paper also discusses the length of the sliding window, which, unfortunately, has not been sufficiently covered in published articles on load modelling. The proposed load structure is applied to the New England 39-bus system in DIgSILENT POWER FACTORY software. MATLAB/curve fitting toolbox is used for an optimization problem.