Ayman Faza | Princess Sumaya University for Technology (PSUT) (original) (raw)

Papers by Ayman Faza

Dynamic pricing in electrical systems is a promising tool that could be used in future power grid... more Dynamic pricing in electrical systems is a promising tool that could be used in future power grids to modify the overall shape of the daily demand. This can have enormous benefits for utility companies, which can use different demand shaping techniques to modify the shape of the demand in ways that can reduce the overall cost of generation or increase their revenue. By appropriately introducing real-time pricing schemes, utility companies can effectively reshape the daily load profile, to reduce the peak load or fill the early morning demand valleys. In this paper, two different dynamic pricing schemes are evaluated in terms of the way revenue is procured. While in some cases, revenue is increased by the simple reduction in generation cost; in other cases, the higher price premiums yield an increased revenue to the utility companies. Results show that different schemes, as well as different customer flexibility and awareness levels, can significantly contribute to the amount and type of revenue utility companies can procure.

Distributed Generation (DG) sources such as solar and wind power sources are gaining an increased... more Distributed Generation (DG) sources such as solar and wind power sources are gaining an increased popularity due to the various advantages they provide over the traditional fossil-fuel-based power generation sources. However, their effects on the system operation, while expected to be positive, are not yet fully understood. In this paper, we study the effect of adding DG sources to the grid on the overall system reliability. We simulate the effect of gradually injecting limited amount of real power at the load buses of the IEEE 14 bus system, and combine that with a single-transmission line contingency to study the effect of the DG sources on improving the operation of the grid in terms of reducing the stress on the transmission network, and reducing the total number of and the amount of overloads that could possibly occur in the transmission lines, due to the line contingencies. Our results show a general improvement in the operation of the power grid, due to the addition of the DG sources, but also shows that the amount of injected power has to be limited to generally small values, and in some cases should be planned in a way that keeps in mind the capacities of the lines in the transmission network.

The effectiveness of virtual environments depends largely on how efficiently they recreate the re... more The effectiveness of virtual environments depends largely on how efficiently they recreate the real world. In the case of auditory virtual environments, the importance of accurate recreation is enhanced since there are no visual cues to assist perception, as in the case of audiovisual virtual environments. In this paper, we present the Immersive Audio Environment (IAE), an easily constructible and portable structure, which is capable of 3-D sound auralization with very high spatial resolution. A novel method for acoustically positioning loudspeakers in space, which is required by the IAE for simulation of sound sources, is presented in this paper. We also present a method to calibrate loudspeakers in an audio system in the case when the loudspeakers are not of the same type. Our contribution is the creation of a system that uses existing and modifications of existing techniques; Vector Based Amplitude Panning (VBAP), in order to recreate an audio battle environment. The IAE recreates the audio effects of battle scenes and can be used as a virtual battle environment for training soldiers. The results of subjective tests show a very low error standard deviation for azimuth and elevation angles and a high correlation between user responses and true angles.

Wireless sensor networks are becoming a basis for a rapidly increasing range of applications. Hab... more Wireless sensor networks are becoming a basis for a rapidly increasing range of applications. Habitat, flood, and wildfire monitoring are interesting examples of such applications. Each application has different requirements in terms of node functionalities, network size, complexity and cost; therefore, it is worthwhile time investment to design and implement a general purpose framework for wireless sensor networks that would be adaptable to any monitoring application of interest with a minimum amount of effort. In this manuscript, we propose a basic structure for such a framework and highlight a number of challenges anticipated during the course of this doctoral research.

Sustainable Cities and Society, Nov 1, 2019

Advances in the technologies of smart grids has made it possible to monitor and control the deman... more Advances in the technologies of smart grids has made it possible to monitor and control the demand side of the power grid in ways that were not possible in the past. Thanks to the advances in information and communication technologies (ICT), Demand Side Management (DSM) is now possible, and promises more efficient and reliable power grids. This paper presents a study of different dynamic pricing techniques that are used as means to shape the demand in ways that minimize generation cost or maximize profit. This is achieved by using a fuzzy logic model that takes into account the different types of customers in the system. The paper further uses Particle Swarm Optimization (PSO) algorithm to generate the parameters that can achieve optimal grid operation. Results show that when customers are actively engaged in DSM schemes, and with the proper Dynamic Pricing scheme, optimal results can be obtained that benefit both the customers and the utility company, not to mention the savings in energy production and its impact on the sustainability of our cities. The results show that savings up to 12% in generation cost and a three times increase in profit can be achieved using an optimized DSM scheme.

Lecture Notes in Computer Science, 2007

The advanced electric power grid promises a self-healing infrastructure using distributed, coordi... more The advanced electric power grid promises a self-healing infrastructure using distributed, coordinated, power electronics control. One promising power electronics device, the Flexible AC Transmission System (FACTS) device, can modify the power flow locally within a power grid. Embedded computers within the FACTS devices, along with the links connecting them, form a communication and control network that can dynamically change the advanced electric power grid to achieve higher dependability. The goal is to reroute power distribution in the event of transmission line failure. Such a system over a widespread area, is a cyber-physical system. The overall reliability of the advanced electric power grid is function of the respective reliabilities of its two major subsystems, namely, the FACTS network and the physical components that comprise the power grid. This paper presents a mathematical model based on the Markov chain imbeddable structure that utilizes a priori knowledge of reliability estimates for the FACTS devices and the communications links among them to predict the overall reliability of the power grid.

The advanced electric power grid is a cyber-physical system comprised of physical components such... more The advanced electric power grid is a cyber-physical system comprised of physical components such as power generators and transmission lines, and cyber components that control the operation of the grid. The objective of the proposed doctoral research is to develop a reliability model for the grid that reflects interdependencies among cyber and physical failures, through capturing the semantics of the system operation. We investigate several failure modes for devices that carry out cyber control of the grid, and examine the effect of their failure in terms of physical power flow in the grid. We propose the use of fault injection into the software of the cyber layer to refine the model, as well as the development of statistical methods to determine confidence levels for our model.

ABSTRACT Load flow analysis is the backbone of the power system studies and design, and through i... more ABSTRACT Load flow analysis is the backbone of the power system studies and design, and through it the voltage magnitude and phase angle at each bus and the complex power flowing in each transmission line can be obtained. In this paper, we use the load-flow to perform a sensitivity analysis of the IEEE 30 bus system. We find the maximum complex power flowing in each transmission line in case of no fault and in case of a single transmission line fault in the steady state condition. The results of this analysis helps identify the most critical lines in the system, which can help better plan the capacities of such lines, and minimize the probability of potential cascading failures.

Sustainable Cities and Society, 2019

Demand side management is an important aspect of the newly established smart grid concept. Conseq... more Demand side management is an important aspect of the newly established smart grid concept. Consequently, real-time pricing plays a crucial role in controlling the power demand in the grid, as it encourages customers to shift their timeinsensitive loads to off-peak periods. However, most solutions do not address the realistic behavior of customers. In this paper, customers' behavior is modeled based on two main factors; their awareness to the concept of real-time pricing, and their flexibility in shifting their consumption patterns. A Fuzzy logic Customer Response Prediction Model is presented to predict the customers' demand based on the aforementioned factors and the level of motivation offered by the utility company in terms of a change in price.Unlike most of the research in the field which is concerned with predicting the demand, the core of this model lies in predicting how different customers will behave in a realtime pricing environment based on their levels of flexibility, awareness, and the added motivation, which in turn will shape the overall future demand. Using the presented model, it is expected that customers with higher awareness and flexibility would respond better to dynamic price changes.

Reliability Engineering & System Safety, Mar 1, 2018

International Journal of Intelligent Transportation Systems Research, Jul 18, 2023

Operation of long EHVAC cable interconnectors requires controlling voltage/reactive power profile... more Operation of long EHVAC cable interconnectors requires controlling voltage/reactive power profiles. With reference to a hypothetical 200 km long 400 kV-50 Hz cable system, connecting to the grid three large OWFs with 2 GW total capacity, the paper compares results yielded by a dedicated algorithm with those of a standard OPF software. A parametric study of the interconnector was carried out, considering different dispatch scenarios and boundary conditions (network connection point voltages). Several cases were ran for an enlarged, meshed test system including the interconnector. Results show that solutions yielded by OPF and by the authors' algorithm are very close, confirming the effectiveness of the latter but also its possible replacement by a standard OPF when dealing with non-radial cable system topologies.

The Smart Grid is a cyber-physical system comprised of physical components, such as transmission ... more The Smart Grid is a cyber-physical system comprised of physical components, such as transmission lines and generators, and a network of embedded systems deployed for their cyber control. Our objective is to qualitatively and quantitatively analyze the reliability of this cyber-physical system. The original contribution of the approach lies in the scope of failures analyzed, which crosses the cyber-physical boundary by investigating physical manifestations of failures in cyber control. As an example of power electronics deployed to enhance and control the operation of the grid, we study Flexible AC Transmission System (FACTS) devices, which are used to alter the flow of power on specific transmission lines. Through prudent fault injection, we enumerate the failure modes of FACTS devices, as triggered by their embedded software, and evaluate their effect on the reliability of the device and the reliability of the power grid on which they are deployed. The IEEE118 bus system is used as our case study, where the physical infrastructure is supplemented with seven FACTS devices to prevent the occurrence of four previously documented potential cascading failures.

Due to the increased dependence on the power grid, it is important to look for solutions that wil... more Due to the increased dependence on the power grid, it is important to look for solutions that will relieve the grid from its increasing amount of stress. The reliability of the grid can be improved by adding distributed generation (DG) sources in various locations in it, which can potentially reduce the amount of power flowing in its transmission network, and partially supply that power locally through the various DG sources. In this paper, we evaluate the effect of adding wind powered DG sources at selected locations in the grid, and measure the effect of this addition on the overall grid reliability. Results show that, the addition of DG sources will improve the grid reliability, if the location of the DG sources was chosen properly. In addition, we show that constant power at the location of DG sources provides a better performance than variable power. A characteristic of wind generation, variable power can still provide a significant improvement in grid reliability.

ABSTRACT The Immersive Audio Environment (IAE) was designed to provide an effective military trai... more ABSTRACT The Immersive Audio Environment (IAE) was designed to provide an effective military training facility. It's efficacy at synthesizing sounds from desired directions and also the ability to synthesize moving sounds has been previously reported. This paper discusses the addition of a tracking system to evaluate subject training performance. Numerous tracking systems have been developed for tracking in immersive environments. Some examples include using head mounted web cams, visible light cameras mounted on the support structure, or even single camera tracking as in commercially available entertainment. Our system uses a combination of an existing infrared tracking system and a specially designed system of inertial tracking. This paper presents tests and results to evaluate the accuracy of the tracking system with respect to our application and verifies the efficacy of using the IAE for training enhancement.

Springer eBooks, Sep 19, 2008

Analyzing the reliability of the power grid is a computationally intensive task, due to its scale... more Analyzing the reliability of the power grid is a computationally intensive task, due to its scale and complexity and large number of interconnected components. For a system of n components, where each component can either fail or func-tion, the number of system ...

A cyber-physical system is the integration of a physical infrastructure with a cyber infrastructu... more A cyber-physical system is the integration of a physical infrastructure with a cyber infrastructure, which provides control over its physical counterpart. The goal is to improve certain aspects of the physical infrastructure, such as its reliability. The Smart Grid, in which intelligent cyber control is added to improve the operation of the traditional power grid, is a prime example of a cyber-physical system. Quantitative models are needed in order to better understand the benefits and risks of adding intelligence to physical systems. To this end, we have developed an integrated cyber-physical reliability model, with a focus on the Smart Grid as our case study. By understanding operational semantics of the Smart Grid, we analyzed the effects of failures in both the physical and cyber infrastructures. Moreover, for the cyber infrastructure, we studied several failure modes, which reflect the various ways in which the cyber components can fail, both in hardware and in software. We further refined our model by using software fault injection in the cyber infrastructure, which revealed additional failure modes. The original contribution of this dissertation is the development of a quantitative reliability model for the Smart Grid, which reflects the effect of physical failures (transmission line outages) and cyber failures (software errors) in a unified model. This work can be extended to other cyber-physical critical infrastructure systems, and serves as a first step towards development of a generalized quantitative reliability model for cyber-physical systems --Abstract, page iii

International Journal of Applied Power Engineering (IJAPE)

Due to the increased demand on electric power, power systems have become highly stressed. This ha... more Due to the increased demand on electric power, power systems have become highly stressed. This has caused the frequent occurrence of cascading failures, where the failure of one line leads to a series of failures causing a system blackout. Adding high speed control of different electrical parameters of the power system can help improve the reliability of the power system and relieve some of that stress. In this research, the effects of adding static VAR compensators (SVCs) and distributed generation units has been studied from a reliability perspective. Since installing this equipment can be expensive, an algorithm has been developed to obtain the optimal bus location to install such devices, such that reliability is improved. Furthermore, Monte Carlo simulation is used to provide a measure for the improvement in system reliability in the presence of transmission line failures. Results show that injecting real and reactive power generally improves system reliability. However, increa...

Solar power generation, mainly from photovoltaic (PV) systems, has been rapidly growing in Jordan... more Solar power generation, mainly from photovoltaic (PV) systems, has been rapidly growing in Jordan. However, increased PV penetration in distribution systems can cause multiple technical issues; namely, overvoltage at grid buses and overloading at the substation transformers in case of excessive reverse power flow. Thus, it is vital to be able to estimate the capacity of distribution systems for distributed generation (DG); and gradually find methods to increase it to allow for more integration of on-grid PV systems. In this paper, a simple deterministic method to estimate the PV capacity of distribution systems is presented, utilizing incremental increase in PV power injection. This method, which does not require detailed knowledge of the distribution grid's load profile, can be used to estimate how much installed PV power can be incorporated into the distribution system without violating certain power quality constraints. The proposed method is applied to a 73-node 33 kV distri...

2021 IEEE Jordan International Joint Conference on Electrical Engineering and Information Technology (JEEIT), 2021