M. W. Mustafa

A novel method for ATC computations in a large-scale power system

In a restructured power system, it is the responsibility of the independent system operator (ISO) to control the power transactions and avoid overloading of the transmission lines beyond their thermal loading megavolt-ampere (MVA) limits. For this, ISO has to update periodically a real-time index termed available transfer capability (ATC). The methods reported to date for ATC determination are unable to cater to either the accuracy or the online CPU time requirements when the system is a large one. This paper proposes a novel method with the full details for determining ATC in a large power system from only three input variables through fuzzy modeling. The method is validated through extensive simulation tests on the standard IEEE 24-bus reliability test system (RTS), and comparison with an ac load flow-based conventional method using the same array of transactions, base cases, and generation/line outages.

Prediction of salt contamination on high voltage insulators in rainy season using regression technique

The severity of contamination on the high voltage insulator surfaces is the significant factor in determining the level of outdoor insulation and in choosing the types of insulators. In the equatorial region, the most dangerous kind of contamination is salt contamination. A regression technique has been used to develop a modified equivalent salt deposit density (ESDD) mathematical model with respect to meteorological conditions. This model provides a useful way for predicting contamination level and for determining frequency of washing the insulators in a given contaminated area.

A Parallel Bees Algorithm for ATC Enhancement in Modern Electrical Network

This paper presents a parallel-based methodology for placement of Flexible AC Transmission Systems (FACTS) devices in order to reduce the time it takes to reach a solution while maximizing the available transfer capability (ATC) of a given power system. The Parallel Bees Algorithms (PBA) simultaneously searches the location, size and types of FACTS devices to enhance ATC between the source and sink area. Four types of emerging FACTS devices are used namely, Thyristor Controlled Series Compensator (TCSC), Static Var Compensator (SVC), Unified Power Flow Controller (UPFC) and Thyristor Controlled Phase Shift Tranformer (TCPST). The IEEE118 Bus system is used to illustrate the applicability of the proposed algorithm to enhance ATC effectively. The results obtained are very encouraging and compared to a Bees Algorithm (BA), Genetic Algorithm (GA) and Parallel Genetic Algorithms (PGA). The results show that parallel computing technique can be used effectively to reduce time to reach a solution for large scale network and FACTS devices have proven their utility for ATC improvement.

An overview of Non-intrusive load monitoring methodologies

Load monitoring is essential in every energy consuming system. Traditional load monitoring system, which used to be intrusive in nature require the installation of sensor to every load of interest which makes the system to be costly and time consuming. Nonintrusive load monitoring (NILM) system uses the aggregated measurement at the utility service entry to identify and disaggregate the appliances connected in the building, which means only one set of sensors is required and it does not require entrance into the consumer premises. Having studied much and working in the area, this paper aim to provide a comprehensive review of the state of art of NILM, the different methods applied by researchers so far, before concluding with the future research direction, which include automatic home energy saving using NILM.

Classification of electricity load forecasting based on the factors influencing the load consumption and methods used: An-overview

Electrical energy consumption is affected by many parameters. These includes the variables related to power system itself, weather and climatic factors and socio-economic being of the energy consumers. In this paper, two components of load forecasting are classified. The parameters that influence the energy consumption and the methods used to forecast the energy consumption are reviewed. It is observed that, many factors have great influence on the energy consumption, and the forecasting accuracy depends on the amount of data used. Also the methods applied contribute in the forecasting accuracy and complexity of the method. It is therefore important to use large data, and apply an appropriate method (technique) while forecasting electrical energy. A lot of methods are reviewed, from time series method to artificial intelligence with varying parameters, most of which are weather related, demography of the area, economy class of the consumers and the history of electrical energy consumed.

Analysis of fuzzy Power System Stabilizer using various defuzzification interface for Takagi-Sugeno fuzzy logic

Power System Stabilizer (PSS) is well known to provide damping in low-frequency oscillation and improve power system stability. This paper discussed the use of Takagi-Sugeno (TS) fuzzy logic to design the PSS controller and the performance is tested on single machine infinite bus (SMIB) system. The generator represented by the standard K-coefficients as second order system. The mechanism to determine the rule is describe and the performance is being investigated for both conventional PSS and proposed TS fuzzy PSS (FPSS) with different type of defuzzification for changes in mechanical input in the system. The angular speed deviation and its acceleration are being taken as the input parameters and the stabilize voltage signal as output. The system is simulated in MATLAB/SIMULINK environment. The superior response for FPSS proved the ability of Takagi-Sugeno fuzzy controller to enhance the stability of the system in comparison of the conventional one.

SMS conflict detection traffic light

Damage to the traffic light is normal. However, this can lead to the hassle and unsafe situation to road users. This project is creating a new paradigm in the monitoring system of traffic lights. This system has the ability to send multiple SMS to the contractor, the traffic police and local council if faulty traffic lights. Normally, road users has to call a contractor based on the information displayed on poles traffic light. With the existing system, the time it will take to repair traffic light depending on the time taken by road users to report to the contracting parties. Monitoring system for damage traffic light will address this problem by shortening the time taken in action of this project, the system can identify a damaged condition, namely Green Conflict. Upon receiving the signal Green Conflict occurs SMS will be sent to the parties mentioned above for further action. Green Conflict occurs when the green light at an intersection simultaneously with each other. Where in when there is a breakdown in these high probability of an accident occurring. Micro controller analyzes the nature of the damage and send signals to the module GSM. GSM module will send details including the location and types of damage. For this project, SMS system is used to identify the corresponding damage.

An algorithm for power components measurement in a harmonic load rich system using digitized walsh function

In the measurement of power components using the conventional method, electric utility companies lose income for power conveyed to current harmonic producing consumers whose equipment introduces distortion of current waveform. This paper proposed enhanced method for quantifying three-phase power components using the Walsh function approach. It harnesses the advantages of the approach in investigation of non-linear load problems with the view to enhance the reliability and accuracy of measuring instrument. The approach does not necessitate phase shift between current and voltage signals. The proposed algorithm can also measure reactive power for effective charge of consumers with non-linear harmonic load.

Novel adaptation of the critical clearing angle formula for faults on a three phase and a six phase line

Enhanced power transfer through polyphase conversion of a transmission line, specially three to six phase, as an alternative to upgrading the conventional three phase power transmission voltage is becoming an area of growing interest in the power industry. Among others this conversion will have an impact on the system stability. While the well-known symmetrical component method has been found suitable in modeling the unsymmetrical faults of a three phase system for transient stability analysis it appeared as difficult-to-apply for six phase system. In this paper a new technique has been proposed to determine the stability in terms of critical clearing angles for both three and six phase line faults. The method has been validated by applying it first for the faults on a 132 kV three phase double circuit line of a given practical power system and comparing the results with those obtained through the symmetrical component method. Then it has been applied for the faults on the same line but considered to have been converted into a 132 kV six phase single circuit line. The method, though an approximate one, is straightforward, simpler and faster than the symmetrical component method and provides sufficiently accurate results.