Load flow study is an important component of power system planning and operation. The power system is represented by a set of nonlinear algebraic equations, and several methods are available for solving the load flow equations like the Newton-Raphson method, Fast Decoupled Load Flow method, etc. In certain situations, these methods give convergence problems. Sharma and Satyavir Singh in their paper, “A Reliable Method for the Solution of the Load Flow Problem”, present a method for the solution of the load flow problem that does not cause convergence problems. They illustrate the method with a two-bus power system.

The paper, “Hybrid Speed Control of Sensorless Brushless DC Motor with Fuzzy-Based Estimation”, by Mahesh Kumar et al. deals with the control of the Brushless DC Motor (BLDC) for electric drive applications. To control these machines, it is generally required to measure the speed and position of rotor by using complicated sensors. The authors describe a method for the estimation of the speed and rotor position using a fuzzy-based observer. A Proportional Integral (PI) controller is used, whose parameters are tuned by fuzzy logic technique.

In pattern recognition, clustering algorithms are used. The Fuzzy C-Means (FCM) algorithm is a typical clustering algorithm used in a wide range of engineering applications. In the paper, “Biometric Fingerprint Segmentation Using Kernel Fuzzy C-Means Clustering on Level Set Method”, a new algorithm is presented by Tara Saikumar et al.. It is shown that KFCM method, combined with the level set methods, can be used for the segmentation of low contrast images and medical images.

Distribution Generation (DG) refers to the small generation units, usually of less than 10 MW capacity, installed in distribution systems. Distributed generators are installed near the customer side, and so they have a great impact on the reliability of the power system especially on distributed system side. Reliability evaluation is an important issue in power system, analysis. In the paper, “Reliability Evaluation of a Distribution System”, by Sreenivas et al., a reliability model is developed to assess the impact of DG using certain reliability indices. Analysis is carried out without DG, with DG, and swapping two DGs. It is shown that the DG has the ability of improving the reliability of distribution system and customers.

In the paper, “ANN Controller-Fed PMDC Drive for Paper Mills”, the authors Sankar and Ramareddy present the design of a neural network controller to enhance the performance and dynamics of the permanent magnet DC motor used in industries like paper mills, textile mills, etc. The simulation results show that the proposed ANN Controller is a robust and insensitive controller and is well suited for systems with uncertain and unknown variations in plant parameters.

-- MSR Murty
Consulting Editor