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The typical layout of power systems is experiencing significant change, due to the high penetration of renewable energy sources (RESs). The ongoing evaluation of power systems is expecting more detailed and accurate mathematical modeling approaches for RESs which are dominated by power electronics. Although modeling techniques based on state–space averaging (SSA) have traditionally been used to mathematically represent the dynamics of power systems, the performance of such a model-based system degrades under high switching frequency. The multi-frequency averaging (MFA)-based higher-index dynamic phasor modeling tool is proposed in this paper, which is entirely new and can provide better estimations of dynamics. Dynamic stability analysis is presented in this paper for the MFA-based higher-index dynamical model of single-stage single-phase (SSSP) grid-connected photovoltaic (PV) systems under different switching frequencies.
Rasel Mahmud; Ahmed F. Abdou; Hemanshu Pota. Stability Analysis of Grid-Connected Photovoltaic Systems with Dynamic Phasor Model. Electronics 2019, 8, 747 .
AMA StyleRasel Mahmud, Ahmed F. Abdou, Hemanshu Pota. Stability Analysis of Grid-Connected Photovoltaic Systems with Dynamic Phasor Model. Electronics. 2019; 8 (7):747.
Chicago/Turabian StyleRasel Mahmud; Ahmed F. Abdou; Hemanshu Pota. 2019. "Stability Analysis of Grid-Connected Photovoltaic Systems with Dynamic Phasor Model." Electronics 8, no. 7: 747.
Real-time energy management of a converter-based microgrid is difficult to determine optimal operating points of a storage system in order to save costs and minimise energy waste. This complexity arises due to time-varying electricity prices, stochastic energy sources and power demand. Many countries have imposed real-time electricity pricing to efficiently control demand side management. This paper presents a particle swarm optimisation (PSO) for the application of real-time energy management to find optimal battery controls of a community microgrid. The modification of the PSO consists in altering the cost function to better model the battery charging/discharging operations. As optimal control is performed by formulating a cost function, it is suitably analysed and then a dynamic penalty function in order to obtain the best cost function is proposed. Several case studies with different scenarios are conducted to determine the effectiveness of the proposed cost function. The proposed cost function can reduce operational cost by 12% as compared to the original cost function over a time horizon of 96 hours. Simulation results reveal the suitability of applying the regularised PSO algorithm with the proposed cost function, which can be adjusted according to the need of the community, for real-time energy management.
Alamgir Hossain; Hemanshu Roy Pota; Stefano Squartini; Ahmed Fathi Abdou. Modified PSO Algorithm for Real-Time Energy Management in Grid-Connected Microgrids. 2019, 1 .
AMA StyleAlamgir Hossain, Hemanshu Roy Pota, Stefano Squartini, Ahmed Fathi Abdou. Modified PSO Algorithm for Real-Time Energy Management in Grid-Connected Microgrids. . 2019; ():1.
Chicago/Turabian StyleAlamgir Hossain; Hemanshu Roy Pota; Stefano Squartini; Ahmed Fathi Abdou. 2019. "Modified PSO Algorithm for Real-Time Energy Management in Grid-Connected Microgrids." , no. : 1.
With the global trend to produce clean electrical energy, the penetration of renewable energy sources in existing electricity infrastructure is expected to increase significantly within the next few years. The solid state transformer (SST) is expected to play an essential role in future smart grid topologies. Unlike traditional magnetic transformer, SST is flexible enough to be of modular construction, enabling bi-directional power flow and can be employed for AC and DC grids. Moreover, SSTs can control the voltage level and modulate both active and reactive power at the point of common coupling without the need to external flexible AC transmission system device as per the current practice in conventional electricity grids. The rapid advancement in power semiconductors switching speed and power handling capacity will soon allow for the commercialisation of grid-rated SSTs. This paper is aimed at introducing a state-of-the-art review for SST proposed topologies, controllers, and applications. Additionally, strengths, weaknesses, opportunities, and threats (SWOT) analysis along with a brief review of market drivers for prospective commercialisation are elaborated.
Ahmed Abu-Siada; Jad Budiri; Ahmed F. Abdou. Solid State Transformers Topologies, Controllers, and Applications: State-of-the-Art Literature Review. Electronics 2018, 7, 298 .
AMA StyleAhmed Abu-Siada, Jad Budiri, Ahmed F. Abdou. Solid State Transformers Topologies, Controllers, and Applications: State-of-the-Art Literature Review. Electronics. 2018; 7 (11):298.
Chicago/Turabian StyleAhmed Abu-Siada; Jad Budiri; Ahmed F. Abdou. 2018. "Solid State Transformers Topologies, Controllers, and Applications: State-of-the-Art Literature Review." Electronics 7, no. 11: 298.
The Microgrids (MGs) are an effective way to deal with the smart grid challenges, including service continuity in the event of a grid interruption, and renewable energy integration. The MGs are compounded by multiple distributed generators (DGs), and the main control goals are load demand sharing and voltage and frequency stability. Important research has been reported to cope with the implementation challenges of the MGs including the power sharing control problem, where the use of cybernetic components such as virtual components, and communication systems is a common characteristic. The use of these cybernetic components to control complex physical systems generates new modeling challenges in order to achieve an adequate balance between complexity and accuracy in the MG model. The standardization problem of the cyber-physical MG models is addressed in this work, using a cyber-physical energy systems (CPES) modeling methodology to build integrated modules, and define the communication architectures that each power sharing control strategy requires in an AC-MG. Based on these modules, the control designer can identify the signals and components that eventually require a time delay analysis, communication requirements evaluation, and cyber-attacks’ prevention strategies. Similarly, the modules of each strategy allow for analyzing the potential advantages and drawbacks of each power sharing control technique from a cyber physical perspective.
Carlos A. Macana; Ahmed F. Abdou; Hemanshu R. Pota; Josep M. Guerrero; Juan C. Vasquez. Cyber Physical Energy Systems Modules for Power Sharing Controllers in Inverter Based Microgrids. Inventions 2018, 3, 66 .
AMA StyleCarlos A. Macana, Ahmed F. Abdou, Hemanshu R. Pota, Josep M. Guerrero, Juan C. Vasquez. Cyber Physical Energy Systems Modules for Power Sharing Controllers in Inverter Based Microgrids. Inventions. 2018; 3 (3):66.
Chicago/Turabian StyleCarlos A. Macana; Ahmed F. Abdou; Hemanshu R. Pota; Josep M. Guerrero; Juan C. Vasquez. 2018. "Cyber Physical Energy Systems Modules for Power Sharing Controllers in Inverter Based Microgrids." Inventions 3, no. 3: 66.
The number of bridges, gate drive circuits and dc sources decrease by using asymmetrical is used to solve SHE equations to get the optimal switching angles. Genetic algorithm (GA) is also used to solve these equations to make comparison between Satin bowerbird optimisation (SBO) and GA algorithms. Matlab/Simulink software tool is used to carry out the simulation construction multilevel inverter. The selective harmonic elimination pulse width modulation (SHE-PWM) and sinusoidal pulse width modulation (SPWM) are carried out for a nine levels cascaded H-bridge (CHB) inverter with asymmetrical construction. Comparison between SHE and SPWM is done to get the benefit of SHE over SPWM. The elimination of some lower order harmonics and satisfy fundamental component in output voltage are the major purpose of SHE-PWM. The solving of the non-linear transcendental equations of SHE is the challenge to find out the switching angles, SBO technique.
M. Abdelateef Mostafa; Ahmed F. Abdou; Amal F. Abd El-Gawad; E. E. El-Kholy. SBO-based selective harmonic elimination for nine levels asymmetrical cascaded H-bridge multilevel inverter. Australian Journal of Electrical and Electronics Engineering 2018, 15, 131 -143.
AMA StyleM. Abdelateef Mostafa, Ahmed F. Abdou, Amal F. Abd El-Gawad, E. E. El-Kholy. SBO-based selective harmonic elimination for nine levels asymmetrical cascaded H-bridge multilevel inverter. Australian Journal of Electrical and Electronics Engineering. 2018; 15 (3):131-143.
Chicago/Turabian StyleM. Abdelateef Mostafa; Ahmed F. Abdou; Amal F. Abd El-Gawad; E. E. El-Kholy. 2018. "SBO-based selective harmonic elimination for nine levels asymmetrical cascaded H-bridge multilevel inverter." Australian Journal of Electrical and Electronics Engineering 15, no. 3: 131-143.
Direct power control (DPC) has gained much attention for medium-voltage applications due to its fast power control capability. However, a conventional static switching table based DPC can lead to unsatisfactory response when the converter is connected to an electric grid because it is commonly designed assuming ideal and constant voltages of the grid and the dc link. Therefore, the actual grid voltage and the actual converter dc-link voltage should be considered while designing the switching table. This paper proposes a novel dynamic switching table for the DPC, considering actual grid and dc-link voltages variation. The proposed dynamic switching table incorporates a new definition of power influence crossover angles of each converter space vector. The proposed scheme dynamically adapts the switching table by feeding forward the actual grid and dc-link voltages, and hence the converter's power is precisely controlled. The proposed technique is verified for the three-level neutral point clamped converters connected to a standard IEEE 9-bus test system. Moreover, the real-time simulations are performed in a real-time digital simulator, OPAL-RT. The obtained results verified the effectiveness of the proposed DPC strategy under different grid fault scenarios.
Hany A. Hamed; Ahmed F. Abdou; Samrat Acharya; Mohamed Shawky El Moursi; E. E. El-Kholy. A Novel Dynamic Switching Table Based Direct Power Control Strategy for Grid Connected Converters. IEEE Transactions on Energy Conversion 2018, 33, 1086 -1097.
AMA StyleHany A. Hamed, Ahmed F. Abdou, Samrat Acharya, Mohamed Shawky El Moursi, E. E. El-Kholy. A Novel Dynamic Switching Table Based Direct Power Control Strategy for Grid Connected Converters. IEEE Transactions on Energy Conversion. 2018; 33 (3):1086-1097.
Chicago/Turabian StyleHany A. Hamed; Ahmed F. Abdou; Samrat Acharya; Mohamed Shawky El Moursi; E. E. El-Kholy. 2018. "A Novel Dynamic Switching Table Based Direct Power Control Strategy for Grid Connected Converters." IEEE Transactions on Energy Conversion 33, no. 3: 1086-1097.
Repeated faults in an industrial grid have affected a steel manufacturing plant and resulted in frequent tripping of all medium voltage converters. The reason for the trips was a synchronization fault due to a severe short duration voltage dip. Converters need a relatively long time to resume its normal operation after dip recovery due to the capacitors precharging process. If the capacitor's discharging is prevented, the converter can resume its normal operation after being synchronized. The synchronization process is performed by a phase locked loop type SRF-PLL with a very low bandwidth and low-pass in-loop filter, which delays the recovery process. In this paper, a solution for the aforementioned trip is presented by proposing two different synchronization hybrid schemes. The first scheme is assuming the converter already lost the synchronization, and a ride-through sequence is implemented to prevent the capacitor from discharging. The second scheme is proposed to prevent the synchronization fault and to recover the converter quickly after dip ends. Both schemes are implemented using a single-input fuzzy logic controller to obtain a very fast response. The performance of the proposed schemes is validated through simulation and a prototype experimental setup.
Hany A. Hamed; Ahmed F. Abdou; Ehab H. E. Bayoumi; E. E. El-Kholy. A Fast Recovery Technique for Grid-Connected Converters After Short Dips Using a Hybrid Structure PLL. IEEE Transactions on Industrial Electronics 2017, 65, 3056 -3068.
AMA StyleHany A. Hamed, Ahmed F. Abdou, Ehab H. E. Bayoumi, E. E. El-Kholy. A Fast Recovery Technique for Grid-Connected Converters After Short Dips Using a Hybrid Structure PLL. IEEE Transactions on Industrial Electronics. 2017; 65 (4):3056-3068.
Chicago/Turabian StyleHany A. Hamed; Ahmed F. Abdou; Ehab H. E. Bayoumi; E. E. El-Kholy. 2017. "A Fast Recovery Technique for Grid-Connected Converters After Short Dips Using a Hybrid Structure PLL." IEEE Transactions on Industrial Electronics 65, no. 4: 3056-3068.
This letter presents a modified switching technique for a three-level neutral-point-clamped converters controlled by direct power control (DPC). The proposed switching technique avoids the hard state transition of each phase module as well as reduces the overall switching frequency. For any phase module, it inserts sequence of vectors to avoid the direct transition from positive to negative state and vice versa. The proposed vector sequence is called optimal transition route (OTR). The OTR technique optimizes the route between the present and the next requested vector to avoid the hard transition of any module. The proposed technique not only avoids the risk of damaging the semiconductor switches, but also minimizes the switching frequency resulted in reducing the switching losses. As a result, the reliability and the overall efficiency of the converter is increased. The obtained results confirm its applicability for medium- and high-power grid-connected converters controlled by the DPC method.
Hany A. Hamed; Ahmed F. Abdou; Mohamed Shawky El Moursi; E. E. El-Kholy. A Modified DPC Switching Technique Based on Optimal Transition Route for of 3L-NPC Converters. IEEE Transactions on Power Electronics 2017, 33, 1902 -1906.
AMA StyleHany A. Hamed, Ahmed F. Abdou, Mohamed Shawky El Moursi, E. E. El-Kholy. A Modified DPC Switching Technique Based on Optimal Transition Route for of 3L-NPC Converters. IEEE Transactions on Power Electronics. 2017; 33 (3):1902-1906.
Chicago/Turabian StyleHany A. Hamed; Ahmed F. Abdou; Mohamed Shawky El Moursi; E. E. El-Kholy. 2017. "A Modified DPC Switching Technique Based on Optimal Transition Route for of 3L-NPC Converters." IEEE Transactions on Power Electronics 33, no. 3: 1902-1906.
This paper presents a new technique to adapt the cascaded delayed signal cancellation phase-locked loop (CDSC-PLL) using a proposed axis drift control (ADC). When grid frequency changes, the estimated grid angle by PLL drifts with a residual error proportional to the frequency change value thus, the accuracy and performance of the conventional CDSC-PLL is deteriorated which can lead to malfunction of the connected applications. Accordingly, CDSC-PLL type has to be adaptable to frequency changes with high immunity to grid disturbances. Designing frequency adapted CDSC-PLL is complex and needs a dedicated design due to the high nonlinearity introduced by adaptive loops. The ADC is proposed as an online adaptive technique that contains a self-tuned DSC operator to mitigate the grid disturbances and a PI controller to perform the adaptation task. The proposed technique is mathematically analyzed and systematic tuning methods are presented. A new analysis for CDSC under off-nominal sample parameter is presented and verified. The robustness of proposed adaptive controller is investigated under parameters uncertainty and various grid disturbances. The proposed technique is numerically and experimentally verified.
Hany A. Hamed; Ahmed F. Abdou; Ehab H. E. Bayoumi; E. E. El-Kholy. Frequency Adaptive CDSC-PLL Using Axis Drift Control Under Adverse Grid Condition. IEEE Transactions on Industrial Electronics 2016, 64, 2671 -2682.
AMA StyleHany A. Hamed, Ahmed F. Abdou, Ehab H. E. Bayoumi, E. E. El-Kholy. Frequency Adaptive CDSC-PLL Using Axis Drift Control Under Adverse Grid Condition. IEEE Transactions on Industrial Electronics. 2016; 64 (4):2671-2682.
Chicago/Turabian StyleHany A. Hamed; Ahmed F. Abdou; Ehab H. E. Bayoumi; E. E. El-Kholy. 2016. "Frequency Adaptive CDSC-PLL Using Axis Drift Control Under Adverse Grid Condition." IEEE Transactions on Industrial Electronics 64, no. 4: 2671-2682.
The doubly fed induction generator (DFIG) is interfaced to the AC network through voltage source converters (VSCs) which are considered to be the core of the DFIG system. This paper investigates the impact of different intermittent VSC faults on the overall performance of a DFIG-based wind energy conversion system (WECS). The fault ride through capability of the DFIG under various VSC faults is also investigated. Faults such as open circuit and short circuit across the switches, when they occur within the grid side converter (GSC) and rotor side converter (RSC), are considered and compared in this paper. Short circuit and open circuit across the DC-link capacitor are also considered in this study as common VSC problems. Simulation results indicate that the short circuit faults have a severe impact on the overall performance of the DFIG, especially when they occur within the GSC. This is attributed to the fact that the GSC directly regulates the point of common coupling voltage. The open circuit faults have less impact on the performance of the DFIG-based WECS. A proper controller along with flexible AC transmission device should be available to compensate the required active and reactive power during these faults. A protection technique is necessary to detect these faults in advance to protect the VSC switches and the machine winding from any catastrophic failure.
A. F. Abdou; A. Abu-Siada; H. R. Pota. Effect of intermittent voltage source converter faults on the overall performance of wind energy conversion system. International Journal of Sustainable Energy 2012, 33, 606 -618.
AMA StyleA. F. Abdou, A. Abu-Siada, H. R. Pota. Effect of intermittent voltage source converter faults on the overall performance of wind energy conversion system. International Journal of Sustainable Energy. 2012; 33 (3):606-618.
Chicago/Turabian StyleA. F. Abdou; A. Abu-Siada; H. R. Pota. 2012. "Effect of intermittent voltage source converter faults on the overall performance of wind energy conversion system." International Journal of Sustainable Energy 33, no. 3: 606-618.