Emad Awada - Academia.edu (original) (raw)
Papers by Emad Awada
Bulletin of Electrical Engineering and Informatics
In today’s modern power devices and rapid growth power demands, the need for precise and accurate... more In today’s modern power devices and rapid growth power demands, the need for precise and accurate protection relays is a must for the power distribution system. That is, to segregate faulty sectors within fewer cycles, power relays should perform at the highest level of accuracy to detect abnormal conditions in power distribution. Therefore, this work will investigate the enhancement of the numerical relay testing in terms of harmonic distortions effect on the digitized output waveform as direct causes of relay failures. However, as it is an expensive process of testing the digitizing element of the numerical relay, this paper proposes a new algorithm of Wavelet transforms in power quality signal processing testing using MATLAB simulation. As this newly proposed method of advanced waveform analysis algorithm will enhance the testing process of digitizing elements, and reduce data compiling complexity, a comparison between conventional Fourier Transforms testing and Wavelet algorithm...
Bulletin of Electrical Engineering and Informatics
This paper presents a robust sliding mode controller of DC-DC buck converter for renewable energy... more This paper presents a robust sliding mode controller of DC-DC buck converter for renewable energy applications, such as photovoltaic systems in off-grid configurations. Photovoltaic systems in off-grid configuration are exposed to significant variations in input voltage and power loads. The proposed sliding mode controller presents a simple and efficient method of continuously updating the duty cycle of a pulse width modulation unit (PWM) of a buck converter. The PWM unit is operated at constant switching frequency of 10 kHz carrier signal and varying duty cycle. The differences in input voltage and power load are treated as two bounded uncertainties, thus eliminating the need for input voltage sensor and output current sensors leaving the system with a single sensor required to measure the converter output voltage. That is, measured output voltage is compared with the reference voltage to continuously update the average duty cycle value of PWM unit. Adjustment of PWM duty cycle is ...
Journal of Southwest Jiaotong University, 2021
In today’s advanced technology and fast past energy demands, dependency on electrical power syste... more In today’s advanced technology and fast past energy demands, dependency on electrical power systems have reached the peak for daily human function in all life aspects. From high-voltage to low-voltage, big machines to a very articulated chipset, voltage optimization plays an important role in work operation and energy saving of electrical devices. Therefore, the importance of voltage relay in power systems is very significant to ensure normal operation, power system efficiency, power elements protection, and load safety. However, power system failures occur all the time due to numerous reasons which may lead to voltage variation (over-voltage or under-voltage). Such a variation can disrupt the essential elements of the power system and harm consumer load. Therefore, as network distribution cannot assure the same exact voltage at all day times, the need to optimize voltage relay has been a major issue in power system reliability and protection enhancements over the past few years. Th...
Proceedings of the 2019 3rd International Conference on Information System and Data Mining, 2019
In today advanced digital signal processing, many parameters must be tested to evaluate the accur... more In today advanced digital signal processing, many parameters must be tested to evaluate the accuracy performance of system output. Therefore, focusing down into an essential part of signal converts (Analog to Digital Converts) is a must prior to any system evaluations. As a result, this work will emphasize on the testing enhancement of Analog to Digital Converts parameters, such as Effected Number of Bits, to determine the accuracy of waveform regeneration and device performance with a newly implemented algorithm. That is, a new algorithm based on structuring Discrete Wavelet transform decomposition on prior interleave Hilbert transform, of Analog to Digital Converts output waveform, to measure Converts ability to reproduce a waveform in their full capacity. With such arrangement, the new algorithm intends to improve previous work for the testing process, higher testing accuracy, fewer computation data samples, and provide a platform of modulation process for other parameters measur...
The high frequency of advanced digital signal processing and data analysis in wide range of every... more The high frequency of advanced digital signal processing and data analysis in wide range of everyday data computing applications has propagated the uses of Analog to Digital Converters. However, such a converter can be very crucial and critical for some applications. Especially with the use of sensitive equipment's, errors or deviations from original signal could lead to catastrophic results. Therefore, testing output signal for dynamic parameters can always define the performance of the converters. In this research, the dynamic range parameters of Spurious-Free Dynamic Range will be tested using FFT testing application process based on Wavelet decomposition algorithms. This new proposes testing technique will utilize Wavelet special characteristic of decomposition feature, reduce compiling sample data, and expedite testing process. The new propose testing technique will be compared with conventional method of FFT application in term of accuracy, variance, and number of collect ...
In today’s modern technology and fast growth in electrical power supply, the need for precise pro... more In today’s modern technology and fast growth in electrical power supply, the need for precise protection relays has become a major issue in the power distribution system. That is, to ensure a safe operation at all levels of generation, distribution, and consumer load, the power relay should perform at the highest level of accuracy. Therefore, this work will investigate the enhancement of the Overcurrent Numerical Relay in terms of the quality of digitized incoming analog current waveform prior to numerical relay decision. However, as it is an expensive process of testing the digitizing element of numerical overcurrent relay, Analog to Digital Converter, this newly proposed method of combing test automation by LabView and advanced waveform analysis algorithms by Wavelet transform will be applied to enhance the testing process, reduce data compiling complexity, and decrease cost. In addition, the testing simulation will be presented using Matlab software to verify the testing result. ...
International Journal of Electrical and Computer Engineering (IJECE), 2018
In testing Mixed Signal Devices such as Analog to Digital and Digital to Analog Converters, some ... more In testing Mixed Signal Devices such as Analog to Digital and Digital to Analog Converters, some dynamic parameters, such as Differential Non-Linearity and Integral Non-linearity, are very critical to evaluating devises performance. However, such analysis has been notorious for complexity and massive compiling process. Therefore, this research will focus on testing dynamic parameters such as Differential Non-Linearity by simulating numerous numbers of bits Analog to Digital Converters and test the output signals base on new testing algorithms of Wavelet transform based on Hilbert process. Such a new testing algorithm should enhance the testing process by using less compiling data samples and prompt testing results. In addition, new testing results will be compared with the conventional testing process of Histogram algorithms for accuracy and enactment.
International Journal of Power Electronics and Drive Systems (IJPEDS), 2022
The use of induction machines has gained fast popularity in many aspects of today’s energy applic... more The use of induction machines has gained fast popularity in many aspects of today’s energy applications and industrial productions. However, just as with any other machine, failure is expected due to a variety of faults in component and system levels. Therefore, it is necessary to improve machine reliability by performing preventive maintenance and exploring faulty indications in advance to avoid future failures. In normal operation, a distinct machine sound signature can be identify. Therefore, at any faulty operation, diagnosis of potential error can be defined based on output signature sound data analysis. Yet, this process of monitoring induction machine sounds and vibration can be hectic and extensive in terms of collecting data and compiling analysis. That is, a huge number of data samples need to be collected and stored in order to define abnormality operation. Therefore, in this work, wavelet-based algorithms were developed as an analysis process to analyze collected data an...
Energies, 2022
This paper presents a two-stage grid-connected PV system with reactive power management capabilit... more This paper presents a two-stage grid-connected PV system with reactive power management capability. The proposed model can send phase-shifted current to the grid during a low-voltage ride through (LVRT) to recover the voltage levels of the grid’s feeders. The novelty of the proposed algorithm, unlike the common methods, is that it does not need to disable the maximum power point tracking (MPPT) state while managing active and reactive power injection simultaneously. Moreover, the new method promotes a safety factor by offering overcurrent protection to the PV inverter. The phase-locked loop based on the synchronous reference frame (SRF-PLL) is optimized using a genetic algorithm (GA). The settling time of SRF-PLL’s step response is minimized, and the frequency dynamics are improved to enhance synchronization during LVRT. The system’s performance is tested and verified using MATLAB/Simulink simulations. The obtained results prove the effectiveness of the proposed control algorithm in...
International Journal of Power Electronics and Drive Systems (IJPEDS), 2021
This paper presents a single-phase grid-connected photovoltaic system with direct control of acti... more This paper presents a single-phase grid-connected photovoltaic system with direct control of active and reactive power through a power management system of a Photovoltaic inverter. The proposed control algorithm is designed to allow maximum utilization of the inverter’s available KVA capacity while maintaining grid power factor and current total harmonic distortion (THD) requirements within the grid standards. To reduce the complexity and improve the efficiency of the system, two independent PI controllers are implemented to control single-phase unipolar PWM voltage source inverter. One controller is used to control the power angle, and hence the active power flow, while the other controller is used to control the reactive power, and consequently the power factor by adjusting the voltage modulation index of the inverter. The proposed system is modelled and simulated using MATLAB/Simulink. The PV inverter has been examined while being simultaneously connected to grid and local load. ...
In evaluating the quality of waveform energy, Total Harmonic Distortion can be one of the unique ... more In evaluating the quality of waveform energy, Total Harmonic Distortion can be one of the unique testing parameters showing the disturbance effect on pure waveform or regenerated waveform. As harmonics may added to distort the fundamental waveform, the analysis of signal dynamic characteristic and the measurement of harmonics effect on the integrity of the waveform will be study to explore and enhance the testing process. In previous work, Fourier Transform and Wavelet Transform algorithms were employed to analyze characteristics of a waveform. In this work, Hilbert Transform in pairs with Wavelet Transform algorithms, that draw a lot of researchers attention, will be investigated as new propose testing technique to identify signal distortion with the effect on the waveform energy and fundamental frequency. This new proposed testing technique will be validated with conventional methods in terms of accuracy, number of collected data samples, and complexity of data compiling.
International Journal of Energy Economics and Policy, 2021
As an ingenious efficient environment, smart buildings can be considered as essential constituent... more As an ingenious efficient environment, smart buildings can be considered as essential constituents for energy conservation. That is, in today's energy demands upsurges and energy sources degradation, the idea of the smart home building has a major implication on improving the living environment along with cutting down on energy consumptions. Therefore, this study investigates the energy conservation theme in Amman, Jordan in terms of opportunities and challenges vs. renewable energy technology. This study was based on interviews with the expert (academics, professionals architects, and electrical engineers, in addition to employees in Electrical companies) aiming to identify the problematic gap in designing theoretical analysis of a smart automated building based on collaboration work between Electrical and Architectural Engineering. From an Electrical Engineering point of view, automated control building systems can provide efficient means of comfort, sustainable habitat environment, and energy conservation as a building advantage. Such a scheme can be accomplished through automated control software (LabView), sensors, network infrastructure, logic design, and mechanical actuators. Meanwhile, from an architecture point of view, passive design strategies can reduce energy consumption along with public awareness for building users. This was implemented through simulation for base case building showing the integration between architectural and electrical systems through using a hybrid system. As a result, this new building automation design will help reducing energy consumption by controlling light fixtures, air-condition, water pumps, and many more appliances. The design guidelines, once formulated and enacted, will guarantee energy conservation qualitatively which will serve as a proposed guideline for enhancing buildings' regulation and codes.
Energies, 2019
This paper presents a control scheme for a photovoltaic (PV) system that uses a single-phase grid... more This paper presents a control scheme for a photovoltaic (PV) system that uses a single-phase grid-connected inverter with low-voltage ride-through (LVRT) capability. In this scheme, two PI regulators are used to adjust the power angle and voltage modulation index of the inverter; therefore, controlling the inverter’s active and reactive output power, respectively. A fuzzy logic controller (FLC) is also implemented to manage the inverter’s operation during the LVRT operation. The FLC adjusts (or de-rates) the inverter’s reference active and reactive power commands based on the grid voltage sag and the power available from the PV system. Therefore, the inverter operation has been divided into two modes: (i) Maximum power point tracking (MPPT) during the normal operating conditions of the grid, and (ii) LVRT support when the grid is operating under faulty conditions. In the LVRT mode, the de-rating of the inverter active output power allows for injection of some reactive power, hence p...
International Journal of Electrical and Computer Engineering (IJECE), 2019
Connecting a single-phase or three-phase inverter to the grid in distributed generation applicati... more Connecting a single-phase or three-phase inverter to the grid in distributed generation applications requires synchronization with the grid. Synchronization of an inverter-connected distributed generation units in its basic form necessitates accurate information about the frequency and phase angle of the utility grid. Phase Locked Loop (PLL) circuit is usually used for the purpose of synchronization. However, deviation in the grid frequency from nominal value will cause errors in the PLL estimated outputs, and that’s a major drawback. Moreover, if the grid is heavily distorted with low order harmonics the estimation of the grid phase angle deteriorates resulting in higher oscillations (errors) appearing in the synchronization voltage signals. This paper proposes a modified time delay PLL (MTDPLL) technique that continuously updates a variable time delay unit to keep track of the variation in the grid frequency. The MTDPLL is implemented along a Multi-Harmonic Decoupling Cell (MHDC) ...
European Journal of Electrical Engineering and Computer Science, Dec 28, 2019
Proceedings 2007 IEEE SoutheastCon, 2007
This paper discusses the work done in the testing and measurement of differential nonlinearity (D... more This paper discusses the work done in the testing and measurement of differential nonlinearity (DNL) of analog- to-digital converters (ADCs) by applying a novel testing technique of wavelet transform. The results of the new method are compared with conventional testing methods. The wavelet transform technique shows significant advantage over the conventional techniques.
International Journal of Computer Science and Information Technology, 2013
In evaluating Analog to Digital Convertors, many parameters are checked for performance and error... more In evaluating Analog to Digital Convertors, many parameters are checked for performance and error rate. One of these parameters is the device Effective Number of Bits. In classical testing of Effective Number of Bits, testing is based on signal to noise components ratio (SNR), whose coefficients are driven via frequency domain (Fourier Transform) of ADC's output signal. Such a technique is extremely sensitive to noise and require large number of data samples. That is, longer and more complex testing process as the device under test increases in resolutions. Meanwhile, a new time-frequency domain approach (known as Wavelet transform) is proposed to measure and analyze Analog-to-Digital Converters parameter of Effective Number of Bits with less complexity and fewer data samples. In this work, the algorithm of Wavelet transform was used to estimate worst case Effective Number of Bits and compare the new testing results with classical testing methods. Such an algorithm, Wavelet transform, have shown DSP testing process improvement in terms of time and computations complexity based on its special properties of multi-resolutions.
European Journal of Scientific Research, Feb 28, 2014
Bulletin of Electrical Engineering and Informatics
In today’s modern power devices and rapid growth power demands, the need for precise and accurate... more In today’s modern power devices and rapid growth power demands, the need for precise and accurate protection relays is a must for the power distribution system. That is, to segregate faulty sectors within fewer cycles, power relays should perform at the highest level of accuracy to detect abnormal conditions in power distribution. Therefore, this work will investigate the enhancement of the numerical relay testing in terms of harmonic distortions effect on the digitized output waveform as direct causes of relay failures. However, as it is an expensive process of testing the digitizing element of the numerical relay, this paper proposes a new algorithm of Wavelet transforms in power quality signal processing testing using MATLAB simulation. As this newly proposed method of advanced waveform analysis algorithm will enhance the testing process of digitizing elements, and reduce data compiling complexity, a comparison between conventional Fourier Transforms testing and Wavelet algorithm...
Bulletin of Electrical Engineering and Informatics
This paper presents a robust sliding mode controller of DC-DC buck converter for renewable energy... more This paper presents a robust sliding mode controller of DC-DC buck converter for renewable energy applications, such as photovoltaic systems in off-grid configurations. Photovoltaic systems in off-grid configuration are exposed to significant variations in input voltage and power loads. The proposed sliding mode controller presents a simple and efficient method of continuously updating the duty cycle of a pulse width modulation unit (PWM) of a buck converter. The PWM unit is operated at constant switching frequency of 10 kHz carrier signal and varying duty cycle. The differences in input voltage and power load are treated as two bounded uncertainties, thus eliminating the need for input voltage sensor and output current sensors leaving the system with a single sensor required to measure the converter output voltage. That is, measured output voltage is compared with the reference voltage to continuously update the average duty cycle value of PWM unit. Adjustment of PWM duty cycle is ...
Journal of Southwest Jiaotong University, 2021
In today’s advanced technology and fast past energy demands, dependency on electrical power syste... more In today’s advanced technology and fast past energy demands, dependency on electrical power systems have reached the peak for daily human function in all life aspects. From high-voltage to low-voltage, big machines to a very articulated chipset, voltage optimization plays an important role in work operation and energy saving of electrical devices. Therefore, the importance of voltage relay in power systems is very significant to ensure normal operation, power system efficiency, power elements protection, and load safety. However, power system failures occur all the time due to numerous reasons which may lead to voltage variation (over-voltage or under-voltage). Such a variation can disrupt the essential elements of the power system and harm consumer load. Therefore, as network distribution cannot assure the same exact voltage at all day times, the need to optimize voltage relay has been a major issue in power system reliability and protection enhancements over the past few years. Th...
Proceedings of the 2019 3rd International Conference on Information System and Data Mining, 2019
In today advanced digital signal processing, many parameters must be tested to evaluate the accur... more In today advanced digital signal processing, many parameters must be tested to evaluate the accuracy performance of system output. Therefore, focusing down into an essential part of signal converts (Analog to Digital Converts) is a must prior to any system evaluations. As a result, this work will emphasize on the testing enhancement of Analog to Digital Converts parameters, such as Effected Number of Bits, to determine the accuracy of waveform regeneration and device performance with a newly implemented algorithm. That is, a new algorithm based on structuring Discrete Wavelet transform decomposition on prior interleave Hilbert transform, of Analog to Digital Converts output waveform, to measure Converts ability to reproduce a waveform in their full capacity. With such arrangement, the new algorithm intends to improve previous work for the testing process, higher testing accuracy, fewer computation data samples, and provide a platform of modulation process for other parameters measur...
The high frequency of advanced digital signal processing and data analysis in wide range of every... more The high frequency of advanced digital signal processing and data analysis in wide range of everyday data computing applications has propagated the uses of Analog to Digital Converters. However, such a converter can be very crucial and critical for some applications. Especially with the use of sensitive equipment's, errors or deviations from original signal could lead to catastrophic results. Therefore, testing output signal for dynamic parameters can always define the performance of the converters. In this research, the dynamic range parameters of Spurious-Free Dynamic Range will be tested using FFT testing application process based on Wavelet decomposition algorithms. This new proposes testing technique will utilize Wavelet special characteristic of decomposition feature, reduce compiling sample data, and expedite testing process. The new propose testing technique will be compared with conventional method of FFT application in term of accuracy, variance, and number of collect ...
In today’s modern technology and fast growth in electrical power supply, the need for precise pro... more In today’s modern technology and fast growth in electrical power supply, the need for precise protection relays has become a major issue in the power distribution system. That is, to ensure a safe operation at all levels of generation, distribution, and consumer load, the power relay should perform at the highest level of accuracy. Therefore, this work will investigate the enhancement of the Overcurrent Numerical Relay in terms of the quality of digitized incoming analog current waveform prior to numerical relay decision. However, as it is an expensive process of testing the digitizing element of numerical overcurrent relay, Analog to Digital Converter, this newly proposed method of combing test automation by LabView and advanced waveform analysis algorithms by Wavelet transform will be applied to enhance the testing process, reduce data compiling complexity, and decrease cost. In addition, the testing simulation will be presented using Matlab software to verify the testing result. ...
International Journal of Electrical and Computer Engineering (IJECE), 2018
In testing Mixed Signal Devices such as Analog to Digital and Digital to Analog Converters, some ... more In testing Mixed Signal Devices such as Analog to Digital and Digital to Analog Converters, some dynamic parameters, such as Differential Non-Linearity and Integral Non-linearity, are very critical to evaluating devises performance. However, such analysis has been notorious for complexity and massive compiling process. Therefore, this research will focus on testing dynamic parameters such as Differential Non-Linearity by simulating numerous numbers of bits Analog to Digital Converters and test the output signals base on new testing algorithms of Wavelet transform based on Hilbert process. Such a new testing algorithm should enhance the testing process by using less compiling data samples and prompt testing results. In addition, new testing results will be compared with the conventional testing process of Histogram algorithms for accuracy and enactment.
International Journal of Power Electronics and Drive Systems (IJPEDS), 2022
The use of induction machines has gained fast popularity in many aspects of today’s energy applic... more The use of induction machines has gained fast popularity in many aspects of today’s energy applications and industrial productions. However, just as with any other machine, failure is expected due to a variety of faults in component and system levels. Therefore, it is necessary to improve machine reliability by performing preventive maintenance and exploring faulty indications in advance to avoid future failures. In normal operation, a distinct machine sound signature can be identify. Therefore, at any faulty operation, diagnosis of potential error can be defined based on output signature sound data analysis. Yet, this process of monitoring induction machine sounds and vibration can be hectic and extensive in terms of collecting data and compiling analysis. That is, a huge number of data samples need to be collected and stored in order to define abnormality operation. Therefore, in this work, wavelet-based algorithms were developed as an analysis process to analyze collected data an...
Energies, 2022
This paper presents a two-stage grid-connected PV system with reactive power management capabilit... more This paper presents a two-stage grid-connected PV system with reactive power management capability. The proposed model can send phase-shifted current to the grid during a low-voltage ride through (LVRT) to recover the voltage levels of the grid’s feeders. The novelty of the proposed algorithm, unlike the common methods, is that it does not need to disable the maximum power point tracking (MPPT) state while managing active and reactive power injection simultaneously. Moreover, the new method promotes a safety factor by offering overcurrent protection to the PV inverter. The phase-locked loop based on the synchronous reference frame (SRF-PLL) is optimized using a genetic algorithm (GA). The settling time of SRF-PLL’s step response is minimized, and the frequency dynamics are improved to enhance synchronization during LVRT. The system’s performance is tested and verified using MATLAB/Simulink simulations. The obtained results prove the effectiveness of the proposed control algorithm in...
International Journal of Power Electronics and Drive Systems (IJPEDS), 2021
This paper presents a single-phase grid-connected photovoltaic system with direct control of acti... more This paper presents a single-phase grid-connected photovoltaic system with direct control of active and reactive power through a power management system of a Photovoltaic inverter. The proposed control algorithm is designed to allow maximum utilization of the inverter’s available KVA capacity while maintaining grid power factor and current total harmonic distortion (THD) requirements within the grid standards. To reduce the complexity and improve the efficiency of the system, two independent PI controllers are implemented to control single-phase unipolar PWM voltage source inverter. One controller is used to control the power angle, and hence the active power flow, while the other controller is used to control the reactive power, and consequently the power factor by adjusting the voltage modulation index of the inverter. The proposed system is modelled and simulated using MATLAB/Simulink. The PV inverter has been examined while being simultaneously connected to grid and local load. ...
In evaluating the quality of waveform energy, Total Harmonic Distortion can be one of the unique ... more In evaluating the quality of waveform energy, Total Harmonic Distortion can be one of the unique testing parameters showing the disturbance effect on pure waveform or regenerated waveform. As harmonics may added to distort the fundamental waveform, the analysis of signal dynamic characteristic and the measurement of harmonics effect on the integrity of the waveform will be study to explore and enhance the testing process. In previous work, Fourier Transform and Wavelet Transform algorithms were employed to analyze characteristics of a waveform. In this work, Hilbert Transform in pairs with Wavelet Transform algorithms, that draw a lot of researchers attention, will be investigated as new propose testing technique to identify signal distortion with the effect on the waveform energy and fundamental frequency. This new proposed testing technique will be validated with conventional methods in terms of accuracy, number of collected data samples, and complexity of data compiling.
International Journal of Energy Economics and Policy, 2021
As an ingenious efficient environment, smart buildings can be considered as essential constituent... more As an ingenious efficient environment, smart buildings can be considered as essential constituents for energy conservation. That is, in today's energy demands upsurges and energy sources degradation, the idea of the smart home building has a major implication on improving the living environment along with cutting down on energy consumptions. Therefore, this study investigates the energy conservation theme in Amman, Jordan in terms of opportunities and challenges vs. renewable energy technology. This study was based on interviews with the expert (academics, professionals architects, and electrical engineers, in addition to employees in Electrical companies) aiming to identify the problematic gap in designing theoretical analysis of a smart automated building based on collaboration work between Electrical and Architectural Engineering. From an Electrical Engineering point of view, automated control building systems can provide efficient means of comfort, sustainable habitat environment, and energy conservation as a building advantage. Such a scheme can be accomplished through automated control software (LabView), sensors, network infrastructure, logic design, and mechanical actuators. Meanwhile, from an architecture point of view, passive design strategies can reduce energy consumption along with public awareness for building users. This was implemented through simulation for base case building showing the integration between architectural and electrical systems through using a hybrid system. As a result, this new building automation design will help reducing energy consumption by controlling light fixtures, air-condition, water pumps, and many more appliances. The design guidelines, once formulated and enacted, will guarantee energy conservation qualitatively which will serve as a proposed guideline for enhancing buildings' regulation and codes.
Energies, 2019
This paper presents a control scheme for a photovoltaic (PV) system that uses a single-phase grid... more This paper presents a control scheme for a photovoltaic (PV) system that uses a single-phase grid-connected inverter with low-voltage ride-through (LVRT) capability. In this scheme, two PI regulators are used to adjust the power angle and voltage modulation index of the inverter; therefore, controlling the inverter’s active and reactive output power, respectively. A fuzzy logic controller (FLC) is also implemented to manage the inverter’s operation during the LVRT operation. The FLC adjusts (or de-rates) the inverter’s reference active and reactive power commands based on the grid voltage sag and the power available from the PV system. Therefore, the inverter operation has been divided into two modes: (i) Maximum power point tracking (MPPT) during the normal operating conditions of the grid, and (ii) LVRT support when the grid is operating under faulty conditions. In the LVRT mode, the de-rating of the inverter active output power allows for injection of some reactive power, hence p...
International Journal of Electrical and Computer Engineering (IJECE), 2019
Connecting a single-phase or three-phase inverter to the grid in distributed generation applicati... more Connecting a single-phase or three-phase inverter to the grid in distributed generation applications requires synchronization with the grid. Synchronization of an inverter-connected distributed generation units in its basic form necessitates accurate information about the frequency and phase angle of the utility grid. Phase Locked Loop (PLL) circuit is usually used for the purpose of synchronization. However, deviation in the grid frequency from nominal value will cause errors in the PLL estimated outputs, and that’s a major drawback. Moreover, if the grid is heavily distorted with low order harmonics the estimation of the grid phase angle deteriorates resulting in higher oscillations (errors) appearing in the synchronization voltage signals. This paper proposes a modified time delay PLL (MTDPLL) technique that continuously updates a variable time delay unit to keep track of the variation in the grid frequency. The MTDPLL is implemented along a Multi-Harmonic Decoupling Cell (MHDC) ...
European Journal of Electrical Engineering and Computer Science, Dec 28, 2019
Proceedings 2007 IEEE SoutheastCon, 2007
This paper discusses the work done in the testing and measurement of differential nonlinearity (D... more This paper discusses the work done in the testing and measurement of differential nonlinearity (DNL) of analog- to-digital converters (ADCs) by applying a novel testing technique of wavelet transform. The results of the new method are compared with conventional testing methods. The wavelet transform technique shows significant advantage over the conventional techniques.
International Journal of Computer Science and Information Technology, 2013
In evaluating Analog to Digital Convertors, many parameters are checked for performance and error... more In evaluating Analog to Digital Convertors, many parameters are checked for performance and error rate. One of these parameters is the device Effective Number of Bits. In classical testing of Effective Number of Bits, testing is based on signal to noise components ratio (SNR), whose coefficients are driven via frequency domain (Fourier Transform) of ADC's output signal. Such a technique is extremely sensitive to noise and require large number of data samples. That is, longer and more complex testing process as the device under test increases in resolutions. Meanwhile, a new time-frequency domain approach (known as Wavelet transform) is proposed to measure and analyze Analog-to-Digital Converters parameter of Effective Number of Bits with less complexity and fewer data samples. In this work, the algorithm of Wavelet transform was used to estimate worst case Effective Number of Bits and compare the new testing results with classical testing methods. Such an algorithm, Wavelet transform, have shown DSP testing process improvement in terms of time and computations complexity based on its special properties of multi-resolutions.
European Journal of Scientific Research, Feb 28, 2014