In this paper the overvoltage on a transformer terminated at a transmission line through a cable is considered. Also, the effects of the length and size of the cable on the amplitude of overvoltage and its harmonics are investigated. Simulations are performed using EMTP and their results show the longer cable the less amplitude of overvoltage on the terminal of the transformer.

In this paper, reactive power compensation through the tertiary winding of an auto transformer, is presented, as an alternative to support voltage variation resulting from the UPFC action. Thereafter, the load flow analysis and application over part of the 230/138 kV brazilian system, was realised. An analysis of the CTEEP system was needed, due chiefly to the features it presents currently as a result of the grid expansion occurred in recent years. The simulations performed to control the transformers' terminal voltages, were done utilising the ATP/EMTP program.

Results concerning the effectiveness of the tertiary winding reactive power injection of the UPFC shunt converter as well as the load flow control of the referred system, are presented in the paper.

The growing demand for reduced cost of power and increased reliability of power system in a liberalized market is pushing the need for more decentralized power generation units that will feed directly into the distribution and low voltage networks. The evaluation of operating reserve is needed for designing a system which can reliably meet the load demand for an area or population. The expected load is predicted and a sufficient generation is planned accordingly. Reserve generation is scheduled in order to account for load forecast uncertainties and possible outages of generation plant. Energy storage is designed and included in the system to accept energy generated by a power generation system, which when not utilized is converted into a form suitable for storage. Since output dispatch from reserve generating units varies from several hours to a few minutes, stored energy is effective due to its instantaneous availability. The need for excessive generation to meet peak load demand is further reduced by the introduction of distributed generation facilities close to the load centers in addition to the storage devices. This significantly reduces reserve generation cost for spinning reserve installations. Most of the power is produced by large centralized power generation plants which are built on the basis of economy, security and quality of supply. This centralized structure is operated by hierarchical control centers and allows the system to be monitored, controlled and adjusted on the basis of very elaborate load forecasting models. Modern scheduling approaches are now utilized which are either deterministic or probabilistic in nature. Short term scheduling in a changed scenario is much dependent on the approach being adopted in accordance to the principles of systems engineering. This approach gives us the most optimum scheduling method for any situation that is being considered and is cost effective. Life cycle cost analysis is carried out while it is being planned, designed and operated. Life cycle cost is included as a parameter in the systems engineering process to design for economic feasibility. The life cycle is tailored to specific systems being addressed, such as research & development, installation, operations, retirement and disposal costs. Defining the lifetime, availability and investment interest rate, a case study design is formulated with renewable resources as the distributed generation capacity and chemical batteries as the storage facility. The thermal generation units are considered as the primary sources of power generation, which includes the operating and spinning reserve. The aspect of operations and maintenance are considered for determining the economic feasibility of the scheduling methods being considered. The systems engineering management plan serves as a focal point for the overall program planning process and establishes a relationship between reliability, maintenance, logistic support, integrated test, quality assurance etc. It also provides an integrating role in the planning of engineering activities. The objective function for the realization of total cost for scheduling methodology considered is dependent on a number of constraints in each subsystem of storage, distributed generation and thermal generation. The optimization is performed by Lagrangian Relaxation method and the results are compared with the results obtained by using HOMER optimization tools available from NREL. The advantage of the designed short term scheduling method is that it gives us more than one possibility and route to reach a best possible optimized solution depending upon the constraints and inputs.

This paper investigates experimental testing as well as numerical results relating to inverse magnetostrictive effects in an electrical steel sample. This is based upon the 3d magnetoelastic formulation. The magnetic field causes elastic deformation and mechanical stress changes the magnetic properties. It is found that an increase in the mechanical stress causes the material to contain more flux density. This result has the promise of increased power density inside the electrical device on stressing the material. Also the numerical results enable us to determine the field intensity at any point inside and outside the sample.

In the power production and distribution industry; there is a growing and continuous demand for increasing reliability and safety of electric current measurements, especially in high voltage application. Also the complexity of control systems used in the power transmission networks require more fixed points of measurement and a wider range of measurement situations. Magnetostriction is a property of ferromagnetic materials such as iron, nickel, and cobalt. When placed in a magnetic field, these materials change size and/or shape. Coating a short period Fiber Bragg Gratings (FBG) sensor with a ferromagnetic material makes the sensor sensitive to electromagnetic fields, hence a measurement value of the electric current can be obtained. In this paper an electromagnetic field sensor based on short period FBG is introduced and its mathematical model developed.

With the rapid emergence of mobile commerce, numerous issues challenging its development have come to the highlight over the past few years. Two major ones are first ,handling long lived transactions while preserving database consistency and concurrency during transactions, and second, the description of an efficient model for dealing with cell to cell "hopping" that is typical during a transaction execution in mobile environment. Numerous models with varied efficiencies have been suggested so far to address the issues, albeit independently. The objective of this paper is to modify an existing model called the kangaroo transaction model and incorporate the advanced concept of "sagas" to make it more efficient in dealing long lived transactions over mobile networks.

The Bluetooth protocols have been developed to support wireless transmission within personal area networks; primarily serving as a cable replacement technology for mobile devices. The standard protocol provides support for synchronous transmission of audio and asynchronous transmission of data. In general, the standard was developed to use synchronous connection-oriented (SCO) channels to transmit real-time audio communication and asynchronous connectionless (ACL) channels to transmit non-real-time data communication. No preexisting support exists for the transmission of real-time, asynchronous communication.

This paper introduces research to model and adapt the Bluetooth technology so that it can provide for the deterministic transmission of real-time, asynchronous data within a Bluetooth piconet; hence supporting the transmission of real-time data within low-power, limited-range distributed systems. This approach is well suited to the transmission of real-time sensor data within various mobile and portable control systems. The paper documents the motivation, preliminary analysis, and initial results of an on-going research project supporting the viability of the use of Bluetooth within "hard" real-time and "soft" real-time control systems.

An important problem is to extract speech signal (or any information- carrying signal) from noisy speech, which was corrupted by additive background noise. Background noise is encounter in such environments as airplanes (commercial or military), helicopters, automobiles, tanks just to name a few.

Adaptive noise canceling device (ANC) consists of two microphones: a primary one detecting the noise-corrupted speech (signal) and a reference microphone detecting only a correlated component of the noise, which is present in the primary microphone. The noise in the reference microphone is processed by an adaptive filter, which generates a replica of the noise component in the primary input. The difference between the primary microphone output and the output of the adaptive filter will result in a less noisy speech signal.

Ideally, one would like to make a computationally simple and numerically robust adaptive filter with high rate of convergence and small misadjustment. As in any engineering problem, these desirable characteristics, in most cases, are incompatible with each other and some kind of trade off is needed. For example, the widely used LMS filer is computationally simple and numerically robust, but converges slowly, especially if the noise is colored. One the other hand, the well known recursive least squares (RLS) algorithm exhibits fast convergence, but it is very complex and is known to have numerical problems. These two cases may be considered to represent two extreme cases of the "trade-off spectrum".

The proposed approach is based on the estimation of speech signal power from which the signal to noise ratio is calculated and the magnitude of the step size is controlled. This approach facilitates the rapid convergence of the filter and reduces signal distortion. Simulations show that the signal power monitoring during adaptation is very important for noise reduction. Furthermore, the relative position of the two microphones was also studied.

Annotated digital video is likely to be a useful source of documentation for evaluation of the higher education classroom, for both conventional and distance learning environments. At the University of Technology, Jamaica, a study of several small classroom sessions of 20-30 students were carried out by analysing classroom interactions that were recorded using multiple video camera sources. Sessions consisted of a lecture including review of a test, a tutorial session, one session delivered remotely over a one-way video conferencing link via cable television and two (2) UWIDEC teleconferencing sessions. Paper annotations were produced for each session, by observing the video recording and marking different categories of interactions at fixed time intervals, and including these alongside the lecturer’s material. Positive responses from participants suggest that such annotation material will be a useful self-evaluation tool for lecturers, and could form part of a multimedia document for this purpose.

This paper introduces a novel method for complex number representation. The proposed, Redundant Complex Binary Number System (RCBNS) is developed by combining a Redundant Binary Number and a complex number in base (-1+j). Donald [1] and Walter Penny [2,3] represented complex numbers using base -j and (-1+j) in the classified algorithmic models. A Redundant Complex Binary Number System consists of both real and imaginary-radix number systems that form a redundant integer digit set. This system is formed by using complex radix of (-1+j) and a digit set of = 3, where assumes a value of -3, -2, -1, 0, 1, 2, 3. The arithmetic operations of complex numbers with this system treat the real and imaginary parts as one unit. The carry-free addition has the advantage of Redundancy in number representation in the arithmetic operations. Results of the arithmetic operations are in the RCBNS form. The two methods for conversion from the RCBNS form to the standard binary number form have been presented. In this paper the RCBNS reduces the number of steps required to perform complex number arithmetic operations, thus enhancing the speed.