G.B. Jasmon

Distribution network reduction for voltage stability analysis and loadflow calculations

Abstract This paper presents an innovative technique for loadflow calculations and voltage instability analysis of distribution networks. A method for reducing a radial network into a single line equivalent has been developed which simplifies lengthy calculations of an unreduced network. This reduced network also enables the fast computation of loadflow solutions of distribution networks. The conditions for voltage collapse to occur are easily derived from the single line equivalent. In all the calculations, no voltage computation is required as all the voltages are eliminated from the governing equations. Test results indicate the superiority of the technique compared to other known methods.

Maximizing voltage stability in distribution networks via loss minimization

Abstract Distribution networks have to be operated under conditions that minimize system loss due to economic reasons. This paper shows that besides economic considerations, there is an added advantage in operating distribution networks at minimum loss conditions. This advantage is in the form of increased voltage stability. It is shown that maximum voltage stability in a distribution network is achieved when the system is operated at minimum loss conditions.

Optimum Simultaneous DG and Capacitor Placement on the Basis of Minimization of Power Losses

and the results will also be discussed in detail.

Optimum multi DG units placement and sizing based on voltage stability index and PSO

Optimum DG placement and sizing is one of the current topics in restructured power system. Most of the authors have worked out on their optimum placement base on the power losses reduction concept. However, the improvement on power losses value in the network will not guarantee to the planner to have lower voltage stability index (VSI) for the system. This paper proposes a new approached for multi DG placement and sizing for distribution systems which is based on a voltage stability index. The most optimum DG size will be found out using several types of PSO optimization algorithm. The output results will also compared with EPSO, REPSO, and IPSO. The proposed algorithm is tested on 12-bus, modified 12-bus and 69-bus radial distribution networks.

Modeling and simulation of digital negative sequence relay for unbalanced protection of generator

Modeling tools are useful for educational and industrial use. Such tools help the new engineers to simulate the power system under normal and faulty conditions. This paper presents the design and various data conversion steps of a digital negative sequence relay. The digital relay has a superiority over electromechanical relay in terms of accuracy and speed. The detection of negative sequence current and appropriate action is useful for protection of power system components. The operation of relay should be fast and reliable for minimum outage of power system in case of abnormality or electrical fault. In this paper, the relay performance under different system dynamics is also visualized on MATLAB / SIMULINK® considering a 400V power system.

Modeling and simulation of reverse power relay for generator protection

Modeling tools are useful for basic understanding of power system, particularly for new engineers. Such tools help the new engineers to modulate the system under normal and faulty conditions. This paper presents the modeling and simulation of digital reverse power relay on MATLAB/Simulink®. Various data conversion steps in digitization of a signal are also discussed. In the past, electromechanical relays were commonly used, now such relays have been replaced with high accuracy and high speed digital relays. Fast operation of relay is desirable, particularly for such type of faults which could lead to system blackout. Digital relays offer other advantages also, in term of multiple variable settings and compact size. In this paper, the relay performance is tested on 11kV synchronous generator, connected with 220kV through a step up transformer.

Fast stability achievement through fuzzy logic based non-linear excitation control of synchronous generator

Power System Controllers are most commonly used for stabilized operation of power system under different operating conditions. Different conventional controller exists for excitation control to maintain power system voltages, for synchronism and stability. Many controllers work satisfactorily under steady state conditions, but needed their fast action under transient conditions. In this paper the impact of fuzzy logic controller on system performance observed through non-linear excitation control of synchronous generator under transient condition. The results of fuzzy logic controller are also compared with the conventional controller (PID).

Message from the Vice Chancellor (University of Malaya)

It is my great pleasure to present the first issue of the Journal of International and Comparative Education (JICE). This journal serves as a platform for the dissemination of original and high quality research in the field of International and Comparative Education.