Impact Of Load Models Research Articles

Distribution State Estimation and Its Impact of Load Modeling

To maintain system security and other essential parameters like reliability and quality, continuous monitoring of the system is very important. Considering the distribution network, state estimation (SE) methods can be adopted. The purpose of the method is to identify and estimate unknown variables based on the online measurements of test data. The primary objectives considered in this paper are: To choose the exact SE method and the artificial neural network (back propagation algorithm), which can be used for determination in the islanding mode of distribution network states, the composite load model is considered for the estimation of states and further enhancement. By adopting the system, state variables in terms of error are measured in the 12-bus distribution network with precise measurements and compared with practical values. The SE proposed includes results with the load flow backward-forward sweep method to satisfy the system state variables. Numerical results indicate that the model performs better for error measurement data with states and in the case of state forecasting.

Impact of load models in energy management using combined approach of Volt–Var control and distributed generation

Impact of load models in energy management using combined approach of Volt–Var control and distributed generation

Assessment of Effect of Load Models on Loss-of-Life Calculation of a Transformer Using a Point Estimation Method

The study of the impact of load models on transformer insulation life is essential for the truthful aging calculation. In most of the studies related to the assessment of transformer aging, distribution loads are treated as constant power type. However, the practical loads are of mix type (combination of constant power, constant current, constant impedance). Moreover, the residential, commercial, and industrial loads comprise the different percentages of constant power, constant current, and constant impedance loads. In this article, different load models are investigated to quantify their impact on the aging calculation of a transformer under various loading scenarios and environmental conditions. The study includes different classes of the loads with corresponding load shapes, ambient temperatures, determined for a typical week of each season. It considers highly unbalanced transformer loading conditions and network configurations. The study also considers the effect of harmonics on the transformer aging. Aging acceleration rate and percentage loss of life of the substation transformer connected to IEEE 13-bus system have been calculated for different loading and climatic conditions. The same procedure has been adopted for the modified IEEE 123-bus system, and the trends of the results have been compared with the IEEE 13-bus system. It has been shown that the load models make a considerable effect on life calculation of a transformer. Therefore, selection of an appropriate load model is important for accurate estimation of aging of a transformer.

An Efficient and Simple Load Flow Approach for Radial and Meshed Distribution Networks

The main contribution of this paper is: (i) proposing a new efficient and simple load flow method for balanced radial and meshed distribution systems, (ii) impact of load models, different X/R ratios, load growth and tolerance levels to check robustness of proposed load flow method, (iii) impact of number of loops on meshed distribution systems, (iv) Comparison of radial and mesh distribution for voltage profile, total power losses, and number of iterations. The convergence ability of the proposed load flow method is evaluated under these conditions. Computer program has been developed to implement the power flow solution scheme in MATLAB and successfully applied to several practical distribution networks with radial and mesh structure. The convergence ability is quantitatively evaluated for different loading conditions, load growth, R/X ratios, and tolerance levels. Moreover, the effects of static load modeling on the convergence characteristics of the proposed algorithm are also investigated. Effectiveness of the proposed load flow method has been tested on IEEE 33 bus and IEEE 69 bus radial and meshed distribution networks. The proposed load flow method is compared with existing load flow methods, Ghosh et al. [6], Aravindhababu et al. [7], and J.H.Teng [16] to demonstrate its effectiveness.

Reactive Security Study of a Large Power System

This paper presents results of a reactive security study of the New South Wales main grid. System modeling is focused on the effect of load dynamics. A composite dynamic load model is used. The reactive security study reported here is based on a steady-state approach. A general method for steady-state voltage stability analysis is used to compute the saddle-node bifurcation point and the relevant security margin. The reactive security in the studied area is evaluated for the system under various scenarios. The impact of load models on the security margin is studied in detail.