To ensure optimum operation with the stochastic nature sources, it is essential to develop an eff... more To ensure optimum operation with the stochastic nature sources, it is essential to develop an efficient forecasting model for wind and solar power generation. A hybrid Markov chain is used to forecast solar radiation as it is suitable for modelling discrete process. While, auto regressive integrated moving average (ARIMA) model is used to predict wind speed as a continuous process. Renewable forecasting methods which built in this paper was compared with the other forecasting models and found that the recommended model in this research more accurate, simpler and faster than other models. Wind speed and solar radiation are forecasted at local sites in Egypt. Based on the forecasting outcomes, it would be possible to perform unit commitment to ensure optimal operation with the presence of renewable energy. Unit committed objective for the Eastern Portion of the Egyptian electrical grid is obtained. Also, to overcome the variation and error of renewable forecasting in unit commitment, ...
Powerline communication is gaining momentum with the rise of the smart grid, the Internet of Thin... more Powerline communication is gaining momentum with the rise of the smart grid, the Internet of Things as part of the 4th industrial revolution and associated applications such as transportation and energy efficiency. Coupling and channel characterization are essential parts of a power-line communication system. Therefore, understanding these components allows performance evaluation and prediction of the system. This paper presents an entire review of couplers and channel characterization modeling techniques used in narrow and broadband power-line communication systems. Types and applications of different couplers are presented; a review of different power-line communication channel modeling techniques and the fundamentals allows a clear understanding of factors influencing or affecting the signal propagation through the channel. The purpose of this review is to guide researchers and system designers looking for literature resources on couplers and channel characterization for power-li...
International Conference on Renewable Power Generation (RPG 2015), 2015
Nowadays, economic and environmental requirements are increased. Therefore, this paper presents a... more Nowadays, economic and environmental requirements are increased. Therefore, this paper presents a proposed solution of the unit commitment problem for a multi-area grid, which contains conventional and renewable energy sources and storage units. To ensure optimum and economic operation with the stochastic nature sources, it is essential to develop an efficient forecasting model for renewable power generation. Forecasting model was built by using a hybrid Markov to forecast solar power, while, auto regressive integrated moving average model is used to predict wind power. Unit commitment problem incorporate with forecasting model to develop probabilistic unit commitment. The proposed formulation is subject to multi-constraints. To overcome the variation and error of renewable power forecasting, the reserve coefficient is modified to develop two new reserves; up reserve and down reserve. The optimization algorithm used to solve probabilistic unit commitment is Dynamic programming based on Neural Network. The system under study in this paper is a standard IEEE 30, with wind speed and solar radiation data are based on the available data of the city of Florida in USA.
International Journal of Electrical Power & Energy Systems, 2016
Abstract In future electric grids it is expected that the share of power produced by renewable en... more Abstract In future electric grids it is expected that the share of power produced by renewable energy systems will increase to supply large deficits in power demand. Wind energy is one of the most important sources of renewable energy generation systems. With increased penetration level of wind energy conversion systems in modern electric grid, the quality of power will inevitably be affected. Power quality (PQ) indices are used to quantify the quality of the power. They serve as the basis for comparing negative impacts of different disturbances on power networks. Previous research of PQ indices with electric grids including wind energy sources was mainly based on fixed wind speed. Therefore, the PQ indices were calculated as instantaneous values that do not reflect the overall power quality impact of the grid connected wind energy systems. The main objective of this paper is to propose new probabilistic PQ indices for electric grids including wind energy systems. The proposed PQ indices combine both the probabilistic nature of wind speed using discrete Markov analysis and the electric grid behavior. The main PQ indices proposed are those concerning harmonics, flicker, and voltage sag. The developed indices are suitable for electric grids that include high penetration level of wind based power sources. The method used is general and can be applied to other power quality indices or power system performance indices.
The depletion of conventional energy sources, the global quest to reduce greenhouse emissions, an... more The depletion of conventional energy sources, the global quest to reduce greenhouse emissions, and the exponential increase in fossil fuel prices are a few reasons that there is more focus on renewable energy resources. Solar and Microhydropower (MHP) is a good solution for rural electrification to alleviate poverty by promoting socio-economic development. The challenge with one renewable resource is when operating independently does not guarantee continuous power flow due to its intermittent nature and the high initial cost. The effectiveness of the system requires more than one resource hence the development of hybrid systems. This paper presents a hybrid system to cater for the 180kW load in the rural area. The PV irradiance fluctuation is mimicked to test the robustness of the system with constant power from MHP. MHP uses a synchronous generator with the excitation system to maintain the required voltage, PV array control is done by the constant current controller and DC/DC/AC converters are employed to interface the PV system and MHP. Results show that when the irradiance is 1000w/m2 and flowrate is 0.27m3 /s the system meets the load demands, but the fluctuation of the irradiance leads to the load being shed to avoid a blackout.
Due to the latest advancements in innovative communication technologies, Energy Cyber-physical Sy... more Due to the latest advancements in innovative communication technologies, Energy Cyber-physical Systems (ECPS) have gradually transformed from a conventional simple type of system into a heterogeneous and more complex system incorporating computational and communication abilities that enables various embedded devices to monitor, communicate, sense and control the physical world. As a system with huge computational and storage needs, cloud computing seems to be a promising solution offering several possibilities and functionalities coupled with access to unlimited resources in a virtualized and scalable manner. Cloud computing has the ability to create an on-demand facility to gain admission into networks coupled with several integrated computational resources that can be promptly delivered with least managerial effort or little or no interaction from service providers. In this work, the role cloud computing plays in an energy cyber-physical system is explored with a view to analyzing...
Decentralized Generation (DG) is expected to play a vital role in the future of electric power sy... more Decentralized Generation (DG) is expected to play a vital role in the future of electric power system. The power electronics interfaced microturbine generation systems are currently attracting lot of attention to meet different needs both at end consumers and the distribution utility levels. Dynamic modelling of the microturbine is a challenging process because manufacturers do not readily provide model data, if any exist at all. In this paper a proposed microturbine DG dynamic model is developed in Matlab-Simulink and implemented using a test system built with SimpowerSystem block set. The proposed model is interfaced with the electrical system using a simplified Voltage Source Inverter (VSI) model. This model supports power system applications as long as harmonics are not the main concern. For many techno-economical reasons, the amount of DG systems is expected to increase rapidly, especially for rural electrification. Therefore, this paper investigates the autonomous operation of...
2016 International Conference on the Industrial and Commercial Use of Energy (ICUE), 2016
Variable Speed Wind Turbine (VSWT) employing Permanent Magnet Synchronous Generator (PMSG) uses f... more Variable Speed Wind Turbine (VSWT) employing Permanent Magnet Synchronous Generator (PMSG) uses full scale back- to-back converter that totally decouples the rotating parts of the wind turbine and the generator from the electrical network. Therefore, there is no inertial contribution from the PMSG VSWT for primary frequency regulation. The modern trend is to synthesize active power control (APC) capability which benefits from the fast response of the converter to change the active power production during a frequency disturbance. This paper introduces a proposed APC algorithm for PMSG VSWT in order to imitate the response of a conventional synchronous generator. The proposed APC method uses two auxiliary torque control loops; the first is the emulated inertia control loop based on the effective inertia constant which depends on the wind power produced, and the second is the droop control loop. Those two loops extract the instantaneous active power needed for primary frequency regulat...
Wind power plants with Permanent Magnet Synchronous Generators (PMSG) employ full scale back to b... more Wind power plants with Permanent Magnet Synchronous Generators (PMSG) employ full scale back to back converter that totally isolates the rotating system of the wind power plant from the electrical network. Therefore, there is no inertial contribution from wind power plant for primary frequency regulation. While the produced power of a WPGS is based on wind speed operating regimes, this power can be transiently increased with proper control action of the power electronics converter on the generator side. It is essential to design a centralized controller that manages the wind output power during normal operation mode, and that can be switched to the frequency contingency mode to support the network frequency. For normal operation mode, this paper proposes an adjustable controller with a dual objective of energy maximization and loading exertion minimization. For frequency contingency mode a transient active power control algorithm is proposed in order to imitate the response of a con...
In modern electric power systems, the dependence on solar power is increasing. The grid connected... more In modern electric power systems, the dependence on solar power is increasing. The grid connected applications are very important with deficit in conventional power stations due to fuel shortage. The design of the control strategy to connect photovoltaic (PV) systems to the electric distribution grid is a challenging issue. This paper focuses on a controller design and its implementation in grid connected PV systems for power factor correction in distribution power systems. The first step is modeling of the components of the PV system, mainly; the PV source, the DC-DC converter, and the grid interface inverter with the appropriate filter. PSCAD is used for simulating this study. The proposed controller is then designed. The proposed control strategy targets the design of the Maximum Power Point Tracking (MPPT) algorithm, and the control of injected active and reactive power. The control of the reactive power is addressed in this paper to equip the PV system with power factor correct...
2018 International Conference on the Industrial and Commercial Use of Energy (ICUE), 2018
Many remote communities in developing countries suffer from lack or weak grid connection. A relia... more Many remote communities in developing countries suffer from lack or weak grid connection. A reliable electric energy system is essential for the residential and small industrial applications. In modern smart grids, the concept of virtual utility is used to describe a cluster of hybrid Distributed Generation (DG) and storage systems. The optimum cluster of DG and storage systems within a virtual utility is essential for a reliable energy management system, to effectively supply the load demands. This requires the minimization of the Net Present Cost (NPC) of the cluster’s investment. Among various economic evaluation software tools, very effective software according to recent research and projects is the Hybrid Optimization Model for Electric Renewables (HOMER). In this paper, a remote load is used as a case study for economic evaluation of a cluster of DG resources. The available resources for the case study include PV arrays, small wind turbines, and a Hydrogen Fuel cell system alo...
The performance deviation of a PV/Water pumping system is inevitable due to the serious effect ca... more The performance deviation of a PV/Water pumping system is inevitable due to the serious effect caused by major ambient factors. Those factors are mainly the partial shading condition (PSC) of the PV array, the angle of incidence (AOI) of the solar beam, the air mass (AM), and the dust. This paper develops an aggregated irradiance model that incorporates the effects of all the major ambient factors. This model is developed by estimating the hourly global irradiance on the tilted surface, then dividing it into its main components. After that the effect of each ambient factor is modeled in association to a particular component of the global irradiance. This paper also implements an improved variable step size maximum power point tracking (MPPT) algorithm that is suitable for multiple maximum power points occurring during PSC. Thereafter, the modeling of a complete PV/water pumping system is built using MATLAB. The performance deviation is analyzed with sunshine hours for a given day an...
Power transformers are the most expensive assets for power utilities. They are exposed to harmoni... more Power transformers are the most expensive assets for power utilities. They are exposed to harmonic distortion causes negative effects on their operation. Traditionally, harmonic mitigation filters were installed by large power users on the customer side of the power system and the utilities had no control over their operation. Utilities should invest in harmonic mitigation filters to grant them full controllability on the harmonic content coming from either side (utility/customer). This paper presents a proposed design of harmonic mitigation filters installed by the power utilities for power transformers. DIgSILENT software is used for the modelling, analysis, and implementation of the proposed filter design and the verification case studies. A comparative study shows the significant reduction of the total harmonic distortion (THD) for power transformers using the designed filters. With this THD reduction, the negative impacts are reduced and the designed life expectancy of the tran...
The share of renewable energy systems in modern smart grids have increased in many countries, and... more The share of renewable energy systems in modern smart grids have increased in many countries, and with that increase the quality of power becomes a major concern for power system operators, especially at the load side. Among the most important power quality challenges, the harmonics comes on top, as they affect the voltage and current quality at the point of common coupling (PCC), and negatively affects the loads. One of the most used renewable generators is the solar photovoltaic (PV) systems, where it is connected into the low voltage distribution grid using power electronics inverters, and with the increased penetration level, massive harmonic current is injected into the network. There is a need to analyse the resulting harmonics distortion and highlight its possible constraints. This paper presents a case study of a radial distribution network with a connected 5 MW Solar PV plant. The system is modelled and simulated using DigSilent software to assess the total harmonics distor...
To ensure optimum operation with the stochastic nature sources, it is essential to develop an eff... more To ensure optimum operation with the stochastic nature sources, it is essential to develop an efficient forecasting model for wind and solar power generation. A hybrid Markov chain is used to forecast solar radiation as it is suitable for modelling discrete process. While, auto regressive integrated moving average (ARIMA) model is used to predict wind speed as a continuous process. Renewable forecasting methods which built in this paper was compared with the other forecasting models and found that the recommended model in this research more accurate, simpler and faster than other models. Wind speed and solar radiation are forecasted at local sites in Egypt. Based on the forecasting outcomes, it would be possible to perform unit commitment to ensure optimal operation with the presence of renewable energy. Unit committed objective for the Eastern Portion of the Egyptian electrical grid is obtained. Also, to overcome the variation and error of renewable forecasting in unit commitment, ...
Powerline communication is gaining momentum with the rise of the smart grid, the Internet of Thin... more Powerline communication is gaining momentum with the rise of the smart grid, the Internet of Things as part of the 4th industrial revolution and associated applications such as transportation and energy efficiency. Coupling and channel characterization are essential parts of a power-line communication system. Therefore, understanding these components allows performance evaluation and prediction of the system. This paper presents an entire review of couplers and channel characterization modeling techniques used in narrow and broadband power-line communication systems. Types and applications of different couplers are presented; a review of different power-line communication channel modeling techniques and the fundamentals allows a clear understanding of factors influencing or affecting the signal propagation through the channel. The purpose of this review is to guide researchers and system designers looking for literature resources on couplers and channel characterization for power-li...
International Conference on Renewable Power Generation (RPG 2015), 2015
Nowadays, economic and environmental requirements are increased. Therefore, this paper presents a... more Nowadays, economic and environmental requirements are increased. Therefore, this paper presents a proposed solution of the unit commitment problem for a multi-area grid, which contains conventional and renewable energy sources and storage units. To ensure optimum and economic operation with the stochastic nature sources, it is essential to develop an efficient forecasting model for renewable power generation. Forecasting model was built by using a hybrid Markov to forecast solar power, while, auto regressive integrated moving average model is used to predict wind power. Unit commitment problem incorporate with forecasting model to develop probabilistic unit commitment. The proposed formulation is subject to multi-constraints. To overcome the variation and error of renewable power forecasting, the reserve coefficient is modified to develop two new reserves; up reserve and down reserve. The optimization algorithm used to solve probabilistic unit commitment is Dynamic programming based on Neural Network. The system under study in this paper is a standard IEEE 30, with wind speed and solar radiation data are based on the available data of the city of Florida in USA.
International Journal of Electrical Power & Energy Systems, 2016
Abstract In future electric grids it is expected that the share of power produced by renewable en... more Abstract In future electric grids it is expected that the share of power produced by renewable energy systems will increase to supply large deficits in power demand. Wind energy is one of the most important sources of renewable energy generation systems. With increased penetration level of wind energy conversion systems in modern electric grid, the quality of power will inevitably be affected. Power quality (PQ) indices are used to quantify the quality of the power. They serve as the basis for comparing negative impacts of different disturbances on power networks. Previous research of PQ indices with electric grids including wind energy sources was mainly based on fixed wind speed. Therefore, the PQ indices were calculated as instantaneous values that do not reflect the overall power quality impact of the grid connected wind energy systems. The main objective of this paper is to propose new probabilistic PQ indices for electric grids including wind energy systems. The proposed PQ indices combine both the probabilistic nature of wind speed using discrete Markov analysis and the electric grid behavior. The main PQ indices proposed are those concerning harmonics, flicker, and voltage sag. The developed indices are suitable for electric grids that include high penetration level of wind based power sources. The method used is general and can be applied to other power quality indices or power system performance indices.
The depletion of conventional energy sources, the global quest to reduce greenhouse emissions, an... more The depletion of conventional energy sources, the global quest to reduce greenhouse emissions, and the exponential increase in fossil fuel prices are a few reasons that there is more focus on renewable energy resources. Solar and Microhydropower (MHP) is a good solution for rural electrification to alleviate poverty by promoting socio-economic development. The challenge with one renewable resource is when operating independently does not guarantee continuous power flow due to its intermittent nature and the high initial cost. The effectiveness of the system requires more than one resource hence the development of hybrid systems. This paper presents a hybrid system to cater for the 180kW load in the rural area. The PV irradiance fluctuation is mimicked to test the robustness of the system with constant power from MHP. MHP uses a synchronous generator with the excitation system to maintain the required voltage, PV array control is done by the constant current controller and DC/DC/AC converters are employed to interface the PV system and MHP. Results show that when the irradiance is 1000w/m2 and flowrate is 0.27m3 /s the system meets the load demands, but the fluctuation of the irradiance leads to the load being shed to avoid a blackout.
Due to the latest advancements in innovative communication technologies, Energy Cyber-physical Sy... more Due to the latest advancements in innovative communication technologies, Energy Cyber-physical Systems (ECPS) have gradually transformed from a conventional simple type of system into a heterogeneous and more complex system incorporating computational and communication abilities that enables various embedded devices to monitor, communicate, sense and control the physical world. As a system with huge computational and storage needs, cloud computing seems to be a promising solution offering several possibilities and functionalities coupled with access to unlimited resources in a virtualized and scalable manner. Cloud computing has the ability to create an on-demand facility to gain admission into networks coupled with several integrated computational resources that can be promptly delivered with least managerial effort or little or no interaction from service providers. In this work, the role cloud computing plays in an energy cyber-physical system is explored with a view to analyzing...
Decentralized Generation (DG) is expected to play a vital role in the future of electric power sy... more Decentralized Generation (DG) is expected to play a vital role in the future of electric power system. The power electronics interfaced microturbine generation systems are currently attracting lot of attention to meet different needs both at end consumers and the distribution utility levels. Dynamic modelling of the microturbine is a challenging process because manufacturers do not readily provide model data, if any exist at all. In this paper a proposed microturbine DG dynamic model is developed in Matlab-Simulink and implemented using a test system built with SimpowerSystem block set. The proposed model is interfaced with the electrical system using a simplified Voltage Source Inverter (VSI) model. This model supports power system applications as long as harmonics are not the main concern. For many techno-economical reasons, the amount of DG systems is expected to increase rapidly, especially for rural electrification. Therefore, this paper investigates the autonomous operation of...
2016 International Conference on the Industrial and Commercial Use of Energy (ICUE), 2016
Variable Speed Wind Turbine (VSWT) employing Permanent Magnet Synchronous Generator (PMSG) uses f... more Variable Speed Wind Turbine (VSWT) employing Permanent Magnet Synchronous Generator (PMSG) uses full scale back- to-back converter that totally decouples the rotating parts of the wind turbine and the generator from the electrical network. Therefore, there is no inertial contribution from the PMSG VSWT for primary frequency regulation. The modern trend is to synthesize active power control (APC) capability which benefits from the fast response of the converter to change the active power production during a frequency disturbance. This paper introduces a proposed APC algorithm for PMSG VSWT in order to imitate the response of a conventional synchronous generator. The proposed APC method uses two auxiliary torque control loops; the first is the emulated inertia control loop based on the effective inertia constant which depends on the wind power produced, and the second is the droop control loop. Those two loops extract the instantaneous active power needed for primary frequency regulat...
Wind power plants with Permanent Magnet Synchronous Generators (PMSG) employ full scale back to b... more Wind power plants with Permanent Magnet Synchronous Generators (PMSG) employ full scale back to back converter that totally isolates the rotating system of the wind power plant from the electrical network. Therefore, there is no inertial contribution from wind power plant for primary frequency regulation. While the produced power of a WPGS is based on wind speed operating regimes, this power can be transiently increased with proper control action of the power electronics converter on the generator side. It is essential to design a centralized controller that manages the wind output power during normal operation mode, and that can be switched to the frequency contingency mode to support the network frequency. For normal operation mode, this paper proposes an adjustable controller with a dual objective of energy maximization and loading exertion minimization. For frequency contingency mode a transient active power control algorithm is proposed in order to imitate the response of a con...
In modern electric power systems, the dependence on solar power is increasing. The grid connected... more In modern electric power systems, the dependence on solar power is increasing. The grid connected applications are very important with deficit in conventional power stations due to fuel shortage. The design of the control strategy to connect photovoltaic (PV) systems to the electric distribution grid is a challenging issue. This paper focuses on a controller design and its implementation in grid connected PV systems for power factor correction in distribution power systems. The first step is modeling of the components of the PV system, mainly; the PV source, the DC-DC converter, and the grid interface inverter with the appropriate filter. PSCAD is used for simulating this study. The proposed controller is then designed. The proposed control strategy targets the design of the Maximum Power Point Tracking (MPPT) algorithm, and the control of injected active and reactive power. The control of the reactive power is addressed in this paper to equip the PV system with power factor correct...
2018 International Conference on the Industrial and Commercial Use of Energy (ICUE), 2018
Many remote communities in developing countries suffer from lack or weak grid connection. A relia... more Many remote communities in developing countries suffer from lack or weak grid connection. A reliable electric energy system is essential for the residential and small industrial applications. In modern smart grids, the concept of virtual utility is used to describe a cluster of hybrid Distributed Generation (DG) and storage systems. The optimum cluster of DG and storage systems within a virtual utility is essential for a reliable energy management system, to effectively supply the load demands. This requires the minimization of the Net Present Cost (NPC) of the cluster’s investment. Among various economic evaluation software tools, very effective software according to recent research and projects is the Hybrid Optimization Model for Electric Renewables (HOMER). In this paper, a remote load is used as a case study for economic evaluation of a cluster of DG resources. The available resources for the case study include PV arrays, small wind turbines, and a Hydrogen Fuel cell system alo...
The performance deviation of a PV/Water pumping system is inevitable due to the serious effect ca... more The performance deviation of a PV/Water pumping system is inevitable due to the serious effect caused by major ambient factors. Those factors are mainly the partial shading condition (PSC) of the PV array, the angle of incidence (AOI) of the solar beam, the air mass (AM), and the dust. This paper develops an aggregated irradiance model that incorporates the effects of all the major ambient factors. This model is developed by estimating the hourly global irradiance on the tilted surface, then dividing it into its main components. After that the effect of each ambient factor is modeled in association to a particular component of the global irradiance. This paper also implements an improved variable step size maximum power point tracking (MPPT) algorithm that is suitable for multiple maximum power points occurring during PSC. Thereafter, the modeling of a complete PV/water pumping system is built using MATLAB. The performance deviation is analyzed with sunshine hours for a given day an...
Power transformers are the most expensive assets for power utilities. They are exposed to harmoni... more Power transformers are the most expensive assets for power utilities. They are exposed to harmonic distortion causes negative effects on their operation. Traditionally, harmonic mitigation filters were installed by large power users on the customer side of the power system and the utilities had no control over their operation. Utilities should invest in harmonic mitigation filters to grant them full controllability on the harmonic content coming from either side (utility/customer). This paper presents a proposed design of harmonic mitigation filters installed by the power utilities for power transformers. DIgSILENT software is used for the modelling, analysis, and implementation of the proposed filter design and the verification case studies. A comparative study shows the significant reduction of the total harmonic distortion (THD) for power transformers using the designed filters. With this THD reduction, the negative impacts are reduced and the designed life expectancy of the tran...
The share of renewable energy systems in modern smart grids have increased in many countries, and... more The share of renewable energy systems in modern smart grids have increased in many countries, and with that increase the quality of power becomes a major concern for power system operators, especially at the load side. Among the most important power quality challenges, the harmonics comes on top, as they affect the voltage and current quality at the point of common coupling (PCC), and negatively affects the loads. One of the most used renewable generators is the solar photovoltaic (PV) systems, where it is connected into the low voltage distribution grid using power electronics inverters, and with the increased penetration level, massive harmonic current is injected into the network. There is a need to analyse the resulting harmonics distortion and highlight its possible constraints. This paper presents a case study of a radial distribution network with a connected 5 MW Solar PV plant. The system is modelled and simulated using DigSilent software to assess the total harmonics distor...
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Papers by Khaled Abo-Al-Ez