Three static techniques (i.e., Power flow, Continuation Power Flow (CPF), and the Q-V curve) were... more Three static techniques (i.e., Power flow, Continuation Power Flow (CPF), and the Q-V curve) were used to assess the voltage stability of the power grid with a Solar Photovoltaic Generator (SPVG) and FACTS devices under nominal and heavy loading conditions. A static model is proposed for the power system that includes conventional power generation units and SPVGs with FACTS devices. Two models of SPVG were used (i.e., PV model and PQ model) to elucidate the effect of the SPVGs on the voltage stability under various operating conditions. The best location for FACTS devices was obtained under nominal and heavy load conditions using static techniques. The series and shunt FACTS devices under nominal and heavy loading conditions were compared using the abovementioned static techniques. The interaction between SPVGs and FACTS devices is detailed in this paper. The proposed approach was tested on the New England 39-bus standard test system, and the results confirmed the effectiveness of t...
2018 53rd International Universities Power Engineering Conference (UPEC), 2018
A PV-powered automatic irrigation system is designed and implemented in this paper. Dominant fact... more A PV-powered automatic irrigation system is designed and implemented in this paper. Dominant factors of the system such as the effect of solar radiation on motor power, current, and water discharge are considered in this study. The proposed system is implemented in the field to irrigate corn plant (maize) considering the optimum tilt angle for Duhok city. A new method for measuring the moisture content in the soil and sufficient level of moisture needed for normal growth of the crop is presented to design a timer for the system to reduce the amount of wasted water. Moisture sensors are used to check the availability of water in the soil and to enable the microcontroller to control the operation status of the pump. The results show that the proposed irrigation method is more accurate and efficient than the conventional irrigation methods in terms of the amount of the water used for irrigation, and the accuracy of irrigating times based on changing local climate. The results clearly d...
In this paper, Genetic Algorithms is applied to find out the number of PSSs and to optimize their... more In this paper, Genetic Algorithms is applied to find out the number of PSSs and to optimize their parameters and locations under different operating conditions for Iraqi power network. The problem is formulated as an optimization problem to maximize the minimum damping ratio of the electromechanical modes using different number of PSSs. The robustness and effectiveness of the proposed approach is approved in damping of electromechanical modes of oscillations using Eigenvalues analysis and nonlinear simulation results.
Solar Photovoltaic Generators (SPVGs) play a great and vital role in providing clean and enough e... more Solar Photovoltaic Generators (SPVGs) play a great and vital role in providing clean and enough energy to meet power loads. However, SPVGs integration on power systems increase power grid problems. It will lead to different problems including disturbance of the grid, instability of the voltage and swings of the power. The impact of SPVG on the voltage stability of the system is studied in this paper. The best location of SPVG is obtained using three static techniques. Power flow and the Q-V curve techniques are used to identify the weakest buses and test the stability of the system under nominal load condition respectively. On other hand, Continuation Power Flow (CPF) and the Q-V curve techniques are used to identify the weakest buses and test the stability of the system under heavy load condition respectively. The proposed techniques are apllied to the New England 39-bus standard system under various loading conditions. The results reveal that choosing a proper location for the SPV...
The work of this paper is a hopeful attempt to rectify poor damping issue of the Iraqi National S... more The work of this paper is a hopeful attempt to rectify poor damping issue of the Iraqi National Super Grid System (INSGS). Without proper damping control these oscillations drive the system toward instability following severe disturbances. In this paper, a Unified Power Flow Controller (UPFC)-based damping controller was proposed to improve the dynamic stability of the INSGS. The system with UPFC installed in different sectors was represented by the linearized Phillips-Heffron generator model. The excitation phase angle was used as input control signal to the UPFC. PI controller was applied to the design of the damping controller. The power system with the UPFC was tested in different sectors under different loading conditions and disturbances using the MATLAB Simulink program. Simulation results demonstrated that the UPFC can work successfully with INSGS in damping low-frequency oscillations and improving the dynamic stability and voltage profiles. In addition, the proposed approac...
The tilt angle of solar panels is significant for capturing solar radiation that reaches the surf... more The tilt angle of solar panels is significant for capturing solar radiation that reaches the surface of the panel. Photovoltaic (PV) performance and efficiency are highly affected by its angle of tilt with respect to the horizontal plane. The amount of radiation reaching the surface of a PV panel changes with the changes in its tilt angle, hence adding a solar tracking system will maximize the amount of solar radiation reaching the surface of a PV panel at any time during the day, however, integrating solar tracking system will increase the total cost and maintenance of any PV system. Thus, using an optimized fixed tilt angle is the solution to element the initial, maintenance, and operation costs of a solar tracking system. Yet, the fixed angle is location-specific because it depends on the daily, monthly, and yearly location of the sun. In this study; daily, monthly and seasonally angles are calculated mathematically and the amount of incident radiation on the surface of the PV pa...
The agriculture sector nowadays relies mostly on conventional energy sources and traditional irri... more The agriculture sector nowadays relies mostly on conventional energy sources and traditional irrigation ways. Considering some factors such as high costs of fossil fuels and providing new power lines, especially to remote locations and where grid electricity is either inaccessible or expensive, a solar PV powered irrigation system can be a practical choice for irrigating crop fields. In this paper, a PV-powered dc water pump system design for irrigation is presented. A comprehensive comparison between Direct Current (DC) and an Alternative Current (AC) motors powered by PV is carried out in terms of power, current, water discharge and cost. Dominant factors of the system such as the effect of solar radiation on motor power, current, and water discharge are considered in this study. The optimum tilt angle for Duhok city is considered to perform this study. The specifications of PV, DC and AC motors are tested in Matlab Simulink to show the performance of the system components. The re...
Present endeavor is devoted to estimate the air-conditioning and heating energies or loads of mod... more Present endeavor is devoted to estimate the air-conditioning and heating energies or loads of modern buildings in Duhok City, Iraq using new mathematical models. Many parameters have been considered in current modeling, namely, area of building, number of storeys and types of the common materials of the building walls. Regression analysis is performed to formulate new mathematical linear and nonlinear models for the loads. In addition, Fuzzy logic is utilized in the third model employing Sugeno's regulation. The outcomes reveal that the reasonable matching is achieved between the proposed models and mechanical engineering analytical solutions of heating and air-conditioning standards. Consequently, high correlation coefficient as more than 85% is determined between the predicted values of the models and analytical results. The linear model shows perfect matching with the analytical outputs more than the other proposed mathematical formulations.
2016 IEEE Industry Applications Society Annual Meeting, 2016
A new methodology for the implementation of a power system model for damping low-frequency oscill... more A new methodology for the implementation of a power system model for damping low-frequency oscillations in field programmable gate array (FPGA)-based real-time simulator is proposed. The continuous form of the model is converted to discrete-time domain model, and then reduced to block diagrams involving the delay operators and gains for the implementation in the FPGA. The hardware implementation of a power system stabilizer (PSS) to control the system is also introduced using FPGA. The real-time implementation of the proposed approach in an FPGA is described. To verify the effectiveness of the proposed FPGA-based simulator, a single machine infinite bus system (SMIB) is tested with the stabilizer under different operating conditions. Results show the capability of implementing the power system with the stabilizer in an FPGA. Additionally, very short time and constant computation time per simulation time-step are established.
This paper presents the design a of Fuzzy-SMC-PI controller to improve the speed control of induc... more This paper presents the design a of Fuzzy-SMC-PI controller to improve the speed control of induction motors. By combining a sliding mode control and a PI controller through fuzzy logic, the resulting regulator solves the problems of overshoot and slow transient responses associated with fast response PI controllers in transient state and the chattering problem associated with robust sliding mode controllers in the steady state. In this strategy, Sliding Mode Control (SMC) is responsive during transient state while PI control becomes fully active in the steady state area. The combination of both control strategies through fuzzy logic provides a mean to create a hybrid control strategy that produce minimum overshoot, faster settling time and an almost chatter free system. Simulations of the proposed Fuzzy-SMC-PI strategy on the flux and speed controllers display diminished chatter, overshoot and significant reduction of settling time. One other significant result of applying Fuzzy-SM...
ABSTRACT Normally, to study the behavior of any power system when subjected to small disturbances... more ABSTRACT Normally, to study the behavior of any power system when subjected to small disturbances, such as a gradual load changes, the Eigenvalue analysis method is used. This analysis is considered as a complementary tool to the usual transient stability analysis. In this paper, the eigenvalue analysis is used to determine the small signal stability of the Iraqi National Super Grid System (400 Kv). In the last decade, this system’s electrical load went through a rapid growth that some of the transmission lines came to their thermal limits. Therefore, the weak areas of the system prone to voltage collapse need to be identified and protected against these collapses. The connection between the stability of the machine and voltage collapse phenomena are also discussed in this paper. First, the mathematical model of the power system is formed after establishing the initial conditions. Then, the high order nonlinear differential equations are linearized by using the perturbation method. In here, the machine speed equations of the system are derived and the eigenvalues are obtained from the state matrix. The contribution of a particular machine in a particular mode is examined for the small signal stability studies. Based on the system’s condition, the magnitude of the eigenvalues varied from negative infinity to a maximum value of zero when the machine speed is said to be instable. To verify the proposed method, the results are compared with an established stability index method.
ABSTRACT This paper proposes a new Fuzzy Gain Scheduled Integral and Derivative (FGID) controller... more ABSTRACT This paper proposes a new Fuzzy Gain Scheduled Integral and Derivative (FGID) controller for load frequency control in a two area hydro system. This approach is applied to control systems comprising two area hydro turbines connected together through tie line. Simulation results demonstrate the ability of the proposed control modal in damping frequency oscillations and tie line power deviations due to area load changes. To demonstrate the ability of the proposed controller, the approach is compared against a PID based Genetic Algorithm (GA) controller. In this study, settling times, overshoots, and undershoots of the frequency responses are used as comparison criteria. The results show that the proposed controller can provide better performance than the PID-GA method. Maintaining frequency of each area and the net tie-line power at scheduled values are the two considered objectives when designing the proposed controller. In addition, each area should be able to regulate its own load fluctuations.
ABSTRACT This paper focuses on the contingency monitoring and voltage collapse prediction of the ... more ABSTRACT This paper focuses on the contingency monitoring and voltage collapse prediction of the Iraqi National Super Grid System. The system consists of 22 buses and 35 400 kV overhead transmission lines. In the last decade, this system’s electrical load went through a rapid growth that some of the transmission lines came to their thermal limits. It is absolutely difficult to construct a new overhead transmission lines due to the high cost, political and environment constraints. In this paper, the most effective way applied for online system status monitoring and thus voltage collapse prediction is described. The work presents the stability index that is based on the concept of maximum possible power transfer through a line permissible loading condition. The proposed method is applied to calculate the stability indicator that varies from 0 to 1 utilizing normal power flow calculations. In addition, the stressed conditions of the lines are detected and the weak areas prone to the voltage collapse are revealed.
ABSTRACT For over two decades Neural Network (NN) has been applied to power system monitoring and... more ABSTRACT For over two decades Neural Network (NN) has been applied to power system monitoring and control. Conventional controllers suffer from certain limitations which NN as an Artificial Intelligence (AI) technique is able to overcome. Therefore, many researchers prefer to use NN technique in the monitoring and control of power systems. This paper reviews published recently schemes for control and monitoring based on NN. The performance of various NN controllers is compared with one another as well as to the performance of other types of controllers. This review further reveals that the design of a proper NN control can maintain first-swing stability, damp oscillation, ensure voltage stability and the reliable supply of electric power.
Three static techniques (i.e., Power flow, Continuation Power Flow (CPF), and the Q-V curve) were... more Three static techniques (i.e., Power flow, Continuation Power Flow (CPF), and the Q-V curve) were used to assess the voltage stability of the power grid with a Solar Photovoltaic Generator (SPVG) and FACTS devices under nominal and heavy loading conditions. A static model is proposed for the power system that includes conventional power generation units and SPVGs with FACTS devices. Two models of SPVG were used (i.e., PV model and PQ model) to elucidate the effect of the SPVGs on the voltage stability under various operating conditions. The best location for FACTS devices was obtained under nominal and heavy load conditions using static techniques. The series and shunt FACTS devices under nominal and heavy loading conditions were compared using the abovementioned static techniques. The interaction between SPVGs and FACTS devices is detailed in this paper. The proposed approach was tested on the New England 39-bus standard test system, and the results confirmed the effectiveness of t...
2018 53rd International Universities Power Engineering Conference (UPEC), 2018
A PV-powered automatic irrigation system is designed and implemented in this paper. Dominant fact... more A PV-powered automatic irrigation system is designed and implemented in this paper. Dominant factors of the system such as the effect of solar radiation on motor power, current, and water discharge are considered in this study. The proposed system is implemented in the field to irrigate corn plant (maize) considering the optimum tilt angle for Duhok city. A new method for measuring the moisture content in the soil and sufficient level of moisture needed for normal growth of the crop is presented to design a timer for the system to reduce the amount of wasted water. Moisture sensors are used to check the availability of water in the soil and to enable the microcontroller to control the operation status of the pump. The results show that the proposed irrigation method is more accurate and efficient than the conventional irrigation methods in terms of the amount of the water used for irrigation, and the accuracy of irrigating times based on changing local climate. The results clearly d...
In this paper, Genetic Algorithms is applied to find out the number of PSSs and to optimize their... more In this paper, Genetic Algorithms is applied to find out the number of PSSs and to optimize their parameters and locations under different operating conditions for Iraqi power network. The problem is formulated as an optimization problem to maximize the minimum damping ratio of the electromechanical modes using different number of PSSs. The robustness and effectiveness of the proposed approach is approved in damping of electromechanical modes of oscillations using Eigenvalues analysis and nonlinear simulation results.
Solar Photovoltaic Generators (SPVGs) play a great and vital role in providing clean and enough e... more Solar Photovoltaic Generators (SPVGs) play a great and vital role in providing clean and enough energy to meet power loads. However, SPVGs integration on power systems increase power grid problems. It will lead to different problems including disturbance of the grid, instability of the voltage and swings of the power. The impact of SPVG on the voltage stability of the system is studied in this paper. The best location of SPVG is obtained using three static techniques. Power flow and the Q-V curve techniques are used to identify the weakest buses and test the stability of the system under nominal load condition respectively. On other hand, Continuation Power Flow (CPF) and the Q-V curve techniques are used to identify the weakest buses and test the stability of the system under heavy load condition respectively. The proposed techniques are apllied to the New England 39-bus standard system under various loading conditions. The results reveal that choosing a proper location for the SPV...
The work of this paper is a hopeful attempt to rectify poor damping issue of the Iraqi National S... more The work of this paper is a hopeful attempt to rectify poor damping issue of the Iraqi National Super Grid System (INSGS). Without proper damping control these oscillations drive the system toward instability following severe disturbances. In this paper, a Unified Power Flow Controller (UPFC)-based damping controller was proposed to improve the dynamic stability of the INSGS. The system with UPFC installed in different sectors was represented by the linearized Phillips-Heffron generator model. The excitation phase angle was used as input control signal to the UPFC. PI controller was applied to the design of the damping controller. The power system with the UPFC was tested in different sectors under different loading conditions and disturbances using the MATLAB Simulink program. Simulation results demonstrated that the UPFC can work successfully with INSGS in damping low-frequency oscillations and improving the dynamic stability and voltage profiles. In addition, the proposed approac...
The tilt angle of solar panels is significant for capturing solar radiation that reaches the surf... more The tilt angle of solar panels is significant for capturing solar radiation that reaches the surface of the panel. Photovoltaic (PV) performance and efficiency are highly affected by its angle of tilt with respect to the horizontal plane. The amount of radiation reaching the surface of a PV panel changes with the changes in its tilt angle, hence adding a solar tracking system will maximize the amount of solar radiation reaching the surface of a PV panel at any time during the day, however, integrating solar tracking system will increase the total cost and maintenance of any PV system. Thus, using an optimized fixed tilt angle is the solution to element the initial, maintenance, and operation costs of a solar tracking system. Yet, the fixed angle is location-specific because it depends on the daily, monthly, and yearly location of the sun. In this study; daily, monthly and seasonally angles are calculated mathematically and the amount of incident radiation on the surface of the PV pa...
The agriculture sector nowadays relies mostly on conventional energy sources and traditional irri... more The agriculture sector nowadays relies mostly on conventional energy sources and traditional irrigation ways. Considering some factors such as high costs of fossil fuels and providing new power lines, especially to remote locations and where grid electricity is either inaccessible or expensive, a solar PV powered irrigation system can be a practical choice for irrigating crop fields. In this paper, a PV-powered dc water pump system design for irrigation is presented. A comprehensive comparison between Direct Current (DC) and an Alternative Current (AC) motors powered by PV is carried out in terms of power, current, water discharge and cost. Dominant factors of the system such as the effect of solar radiation on motor power, current, and water discharge are considered in this study. The optimum tilt angle for Duhok city is considered to perform this study. The specifications of PV, DC and AC motors are tested in Matlab Simulink to show the performance of the system components. The re...
Present endeavor is devoted to estimate the air-conditioning and heating energies or loads of mod... more Present endeavor is devoted to estimate the air-conditioning and heating energies or loads of modern buildings in Duhok City, Iraq using new mathematical models. Many parameters have been considered in current modeling, namely, area of building, number of storeys and types of the common materials of the building walls. Regression analysis is performed to formulate new mathematical linear and nonlinear models for the loads. In addition, Fuzzy logic is utilized in the third model employing Sugeno's regulation. The outcomes reveal that the reasonable matching is achieved between the proposed models and mechanical engineering analytical solutions of heating and air-conditioning standards. Consequently, high correlation coefficient as more than 85% is determined between the predicted values of the models and analytical results. The linear model shows perfect matching with the analytical outputs more than the other proposed mathematical formulations.
2016 IEEE Industry Applications Society Annual Meeting, 2016
A new methodology for the implementation of a power system model for damping low-frequency oscill... more A new methodology for the implementation of a power system model for damping low-frequency oscillations in field programmable gate array (FPGA)-based real-time simulator is proposed. The continuous form of the model is converted to discrete-time domain model, and then reduced to block diagrams involving the delay operators and gains for the implementation in the FPGA. The hardware implementation of a power system stabilizer (PSS) to control the system is also introduced using FPGA. The real-time implementation of the proposed approach in an FPGA is described. To verify the effectiveness of the proposed FPGA-based simulator, a single machine infinite bus system (SMIB) is tested with the stabilizer under different operating conditions. Results show the capability of implementing the power system with the stabilizer in an FPGA. Additionally, very short time and constant computation time per simulation time-step are established.
This paper presents the design a of Fuzzy-SMC-PI controller to improve the speed control of induc... more This paper presents the design a of Fuzzy-SMC-PI controller to improve the speed control of induction motors. By combining a sliding mode control and a PI controller through fuzzy logic, the resulting regulator solves the problems of overshoot and slow transient responses associated with fast response PI controllers in transient state and the chattering problem associated with robust sliding mode controllers in the steady state. In this strategy, Sliding Mode Control (SMC) is responsive during transient state while PI control becomes fully active in the steady state area. The combination of both control strategies through fuzzy logic provides a mean to create a hybrid control strategy that produce minimum overshoot, faster settling time and an almost chatter free system. Simulations of the proposed Fuzzy-SMC-PI strategy on the flux and speed controllers display diminished chatter, overshoot and significant reduction of settling time. One other significant result of applying Fuzzy-SM...
ABSTRACT Normally, to study the behavior of any power system when subjected to small disturbances... more ABSTRACT Normally, to study the behavior of any power system when subjected to small disturbances, such as a gradual load changes, the Eigenvalue analysis method is used. This analysis is considered as a complementary tool to the usual transient stability analysis. In this paper, the eigenvalue analysis is used to determine the small signal stability of the Iraqi National Super Grid System (400 Kv). In the last decade, this system’s electrical load went through a rapid growth that some of the transmission lines came to their thermal limits. Therefore, the weak areas of the system prone to voltage collapse need to be identified and protected against these collapses. The connection between the stability of the machine and voltage collapse phenomena are also discussed in this paper. First, the mathematical model of the power system is formed after establishing the initial conditions. Then, the high order nonlinear differential equations are linearized by using the perturbation method. In here, the machine speed equations of the system are derived and the eigenvalues are obtained from the state matrix. The contribution of a particular machine in a particular mode is examined for the small signal stability studies. Based on the system’s condition, the magnitude of the eigenvalues varied from negative infinity to a maximum value of zero when the machine speed is said to be instable. To verify the proposed method, the results are compared with an established stability index method.
ABSTRACT This paper proposes a new Fuzzy Gain Scheduled Integral and Derivative (FGID) controller... more ABSTRACT This paper proposes a new Fuzzy Gain Scheduled Integral and Derivative (FGID) controller for load frequency control in a two area hydro system. This approach is applied to control systems comprising two area hydro turbines connected together through tie line. Simulation results demonstrate the ability of the proposed control modal in damping frequency oscillations and tie line power deviations due to area load changes. To demonstrate the ability of the proposed controller, the approach is compared against a PID based Genetic Algorithm (GA) controller. In this study, settling times, overshoots, and undershoots of the frequency responses are used as comparison criteria. The results show that the proposed controller can provide better performance than the PID-GA method. Maintaining frequency of each area and the net tie-line power at scheduled values are the two considered objectives when designing the proposed controller. In addition, each area should be able to regulate its own load fluctuations.
ABSTRACT This paper focuses on the contingency monitoring and voltage collapse prediction of the ... more ABSTRACT This paper focuses on the contingency monitoring and voltage collapse prediction of the Iraqi National Super Grid System. The system consists of 22 buses and 35 400 kV overhead transmission lines. In the last decade, this system’s electrical load went through a rapid growth that some of the transmission lines came to their thermal limits. It is absolutely difficult to construct a new overhead transmission lines due to the high cost, political and environment constraints. In this paper, the most effective way applied for online system status monitoring and thus voltage collapse prediction is described. The work presents the stability index that is based on the concept of maximum possible power transfer through a line permissible loading condition. The proposed method is applied to calculate the stability indicator that varies from 0 to 1 utilizing normal power flow calculations. In addition, the stressed conditions of the lines are detected and the weak areas prone to the voltage collapse are revealed.
ABSTRACT For over two decades Neural Network (NN) has been applied to power system monitoring and... more ABSTRACT For over two decades Neural Network (NN) has been applied to power system monitoring and control. Conventional controllers suffer from certain limitations which NN as an Artificial Intelligence (AI) technique is able to overcome. Therefore, many researchers prefer to use NN technique in the monitoring and control of power systems. This paper reviews published recently schemes for control and monitoring based on NN. The performance of various NN controllers is compared with one another as well as to the performance of other types of controllers. This review further reveals that the design of a proper NN control can maintain first-swing stability, damp oscillation, ensure voltage stability and the reliable supply of electric power.
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Papers by Lokman Hassan