Fuzzy time domain and Z-transform for modeling of harmonic electric loads

This paper demonstrates the application of fuzzy systems and Z-transform for electric load modeling in the presence and/or absence of harmonics. The problem is formulated as one of linear optimization, where the objective is to minimize the spread of the model parameters. A triangular membership function is chosen for each load parameter. Having identified the fuzzy load parameters, the fuzzy admittance of the load is formulated in the frequency domain. The proposed algorithm is tested using simulated and actual recorded data for nonlinear loads having different characteristics. The results obtained are reported in the pape

Long-term electric peak load forecasting for power system planning: A comparative study

A comparative study between two static estimation algorithms, namely least error squares (LES) and least absolute value (LAV) algorithm was presented. The proposed algorithm used the past history data for the load and the influence factors. Different models were developed and tested for long-term peak load power forecasting. It was shown that the LES algorithm produces better-predicted results than the LAV algorithm in the time-dependent model

Fuzzy linear parameter estimation algorithms: A new formulation

In this paper, we present a new formulation of a fuzzy linear estimation problem as one of the linear programming where the objective is to minimize the spread of the data points, subject to constraints on each measurement point to guarantee that the original membership is included in the estimated membership. Different models are developed based on fuzzy triangular membership as well as fuzzy numbers of LR-type, and applied to different examples in fuzzy linear regression and finally we apply these models for estimating the electrical load on a substation busbar. It is demonstrated that since the nature of the load is characterized by uncertainty, the proposed technique is well suited to apply for electrical load estimation.Scopu