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In this paper, a Switched Reluctance Motor (SRM) drive system is proposed to make a trade-off between torque profile and vibration amplitude. In the proposed drive system, the power factor correction and fast demagnetization are achieved using a single-phase Vienna rectifier as a front-end converter for SRMs with a nominal voltage equal to half DC-link voltage. The three-level Vienna rectifier provides doubled negative voltage in demagnetization, resulting in a shorter current tail and faster demagnetization. But, applying higher voltage in demagnetization has a negative impact on the vibration amplitude at the point of demagnetization. Therefore, a control algorithm is designed to apply a negative modulated voltage to the motor phase, with a minimum change rate at the beginning of demagnetization and a linear average during the demagnetization interval. Accordingly, the mitigation of the vibration occurring at the commutation point and prevention of negative torque are simultaneously achieved over a wide speed range. The simulation and experimental results demonstrate the proposed drive system’s positive effect on the vibration amplitude, grid side current quality, and SRM performance in a wide range of speed variations.
Zahra Sadeghi; Sayed Morteza Saghaian Nejad; Amir Rashidi; Mahdi Shahparasti. Fast Demagnetization and Vibration Reduction in Switched Reluctance Motor Drive System. IEEE Access 2021, 9, 110904 -110915.
AMA StyleZahra Sadeghi, Sayed Morteza Saghaian Nejad, Amir Rashidi, Mahdi Shahparasti. Fast Demagnetization and Vibration Reduction in Switched Reluctance Motor Drive System. IEEE Access. 2021; 9 ():110904-110915.
Chicago/Turabian StyleZahra Sadeghi; Sayed Morteza Saghaian Nejad; Amir Rashidi; Mahdi Shahparasti. 2021. "Fast Demagnetization and Vibration Reduction in Switched Reluctance Motor Drive System." IEEE Access 9, no. : 110904-110915.
This paper presents a proposal for potential bioelectrochemical power to gas stations. It consists of a two-level voltage source converter interfacing the electrical grid on the AC side and an electromethanogenesis based bioelectrochemical system (EMG-BES) working as a stacked module on the DC side. The proposed system converts CO2 and electrical energy into methane, using wastewater as the additional chemical energy input. This energy storage system can contribute to dampening the variability of renewables in the electrical network, provide even flexibility and grid services by controlling the active and reactive power exchanged and is an interesting alternative technology in the market of energy storage for big energy applications. The big challenge for controlling this system lays in the fact that the DC bus voltage of the converter has to be changed in order to regulate the exchanged active power with the grid. This paper presents a cascade approach to control such a system by means of combining external control loops with fast inner loops. The outer power loop, with a proportional-integral (PI) controller with special limitation values and anti-windup capability, is used to generate DC bus voltage reference. An intermediate loop is used for DC bus voltage regulation and current reference generation. A new proportional resonant controller is used to track the current reference. The proposed scheme has been validated through real-time simulation in OPAL OP4510.
Mahdi Shahparasti; Amirhossein Rajaei; Andres Tarraso; Jose Vidal Leon Romay; Alvaro Luna. Control and Validation of a Reinforced Power Conversion System for Upcoming Bioelectrochemical Power to Gas Stations. Electronics 2021, 10, 1470 .
AMA StyleMahdi Shahparasti, Amirhossein Rajaei, Andres Tarraso, Jose Vidal Leon Romay, Alvaro Luna. Control and Validation of a Reinforced Power Conversion System for Upcoming Bioelectrochemical Power to Gas Stations. Electronics. 2021; 10 (12):1470.
Chicago/Turabian StyleMahdi Shahparasti; Amirhossein Rajaei; Andres Tarraso; Jose Vidal Leon Romay; Alvaro Luna. 2021. "Control and Validation of a Reinforced Power Conversion System for Upcoming Bioelectrochemical Power to Gas Stations." Electronics 10, no. 12: 1470.
Employing both high bandwidth (HBW) controller and wide bandgap (WBG) devices in the structure of converters improve the system size, performance, and efficiency. In this paper, HBW model predictive controllers (MPCs) are proposed, with both fixed and unfixed switching frequencies, to control a single-phase five-level hybrid active neutral-point-clamped (ANPC) inverter. A hybrid modulation technique is considered in this paper, in which some of the switches are modulating with high frequency. Therefore, Silicon-Carbide (SiC) MOSFETs are employed in the converter structure to increase the switching frequency and consequently reduce the filter size and increase converter power density. To have the functionality of multilevel output voltage, some restrictions are defined in the adopted MPC with unfixed switching frequency. In the MPC with the constant switching frequency, predefined switching sequences are employed for all sectors. Moreover, to control the neutral point (NP) voltage, the applied times of both small voltage vectors are sets through a cost function. Finally, the simulation and experimental results prove the ability of both proposed methods to control the voltages of the load and NP.
Mohammad Najjar; Mahdi Shahparasti; Rasool Heydari; Morten Nymand. Model Predictive Controllers With Capacitor Voltage Balancing for a Single-Phase Five-Level SiC/Si Based ANPC Inverter. IEEE Open Journal of Power Electronics 2021, 2, 202 -211.
AMA StyleMohammad Najjar, Mahdi Shahparasti, Rasool Heydari, Morten Nymand. Model Predictive Controllers With Capacitor Voltage Balancing for a Single-Phase Five-Level SiC/Si Based ANPC Inverter. IEEE Open Journal of Power Electronics. 2021; 2 (99):202-211.
Chicago/Turabian StyleMohammad Najjar; Mahdi Shahparasti; Rasool Heydari; Morten Nymand. 2021. "Model Predictive Controllers With Capacitor Voltage Balancing for a Single-Phase Five-Level SiC/Si Based ANPC Inverter." IEEE Open Journal of Power Electronics 2, no. 99: 202-211.
The increasing penetration of dc distributed energy resources (DERs) and dc loads has motivated the utilization of dc microgrids (MGs). In this paper, a new two-level control scheme is proposed for accurate power sharing and appropriate voltage regulation in dc MGs during islanded operation mode. In the primary control level, a P-V̇ droop method is proposed to eliminate the dependency of power sharing among DERs on line resistances. Since the P-V̇ droop deviates the voltage derivative to a nonzero value, a voltage derivative restoration mechanism is adopted in the secondary control level to provide voltage stability. The secondary control level also compensates the voltage deviations by cascading an outer voltage control loop with the inner voltage derivative restoration loop. The secondary control signal is broadcasted to each DER via a unidirectional low-bandwidth communication link. Small signal stability of the proposed scheme is analyzed by studying the locus of the system eigenvalues. To verify the efficacy of the proposed method and compare it with the conventional scheme, real-time simulations in OPAL-RT lab setup are provided.
Mehdi Baharizadeh; Mohammad S. Golsorkhi; Mahdi Shahparasti; Mehdi Savaghebi. A Two-Layer Control Scheme Based on P – V Droop Characteristic for Accurate Power Sharing and Voltage Regulation in DC Microgrids. IEEE Transactions on Smart Grid 2021, 12, 2776 -2787.
AMA StyleMehdi Baharizadeh, Mohammad S. Golsorkhi, Mahdi Shahparasti, Mehdi Savaghebi. A Two-Layer Control Scheme Based on P – V Droop Characteristic for Accurate Power Sharing and Voltage Regulation in DC Microgrids. IEEE Transactions on Smart Grid. 2021; 12 (4):2776-2787.
Chicago/Turabian StyleMehdi Baharizadeh; Mohammad S. Golsorkhi; Mahdi Shahparasti; Mehdi Savaghebi. 2021. "A Two-Layer Control Scheme Based on P – V Droop Characteristic for Accurate Power Sharing and Voltage Regulation in DC Microgrids." IEEE Transactions on Smart Grid 12, no. 4: 2776-2787.
Inertia requirement is the paramount challenge in future power systems with a significant share of renewable energy generators. A promising solution to this issue is applying Distributed Virtual Inertia (DVI) concept, i.e. releasing energy preserved in the dc-link capacitors of employed power converters in the grid following a frequency disturbance. Nonetheless, small-signal stability analyses affirm that a local mode associated with the control system is prone to become unstable when the grid-interactive converter augmented with the DVI operates in weak grids. To overcome this problem, an efficient compensator is proposed in this paper. This compensator introduces one degree-of-freedom to the direct axis current controller in synchronous reference frame, which eliminates the adverse impact of DVI function on converter stability. Finally, the efficacy of the proposed control framework is depicted by simulations in MATLAB. The results illustrate that the grid frequency rate of change following a disturbance is improved by 30% compared to the case in which the DVI loop is nullified.
Meysam Saeedian; Reza Sangrody; Mahdi Shahparasti; Shamsodin Taheri; Edris Pouresmaeil. Grid-Following DVI-Based Converter Operating in Weak Grids for Enhancing Frequency Stability. IEEE Transactions on Power Delivery 2021, PP, 1 -1.
AMA StyleMeysam Saeedian, Reza Sangrody, Mahdi Shahparasti, Shamsodin Taheri, Edris Pouresmaeil. Grid-Following DVI-Based Converter Operating in Weak Grids for Enhancing Frequency Stability. IEEE Transactions on Power Delivery. 2021; PP (99):1-1.
Chicago/Turabian StyleMeysam Saeedian; Reza Sangrody; Mahdi Shahparasti; Shamsodin Taheri; Edris Pouresmaeil. 2021. "Grid-Following DVI-Based Converter Operating in Weak Grids for Enhancing Frequency Stability." IEEE Transactions on Power Delivery PP, no. 99: 1-1.
In this paper, a new modified structure of a DC/DC T-source converter is proposed. Since the proposed converter provides high voltage gain, it is suitable for photovoltaic integration into uninterruptible power supply (UPS) systems. The proposed structure employs partial power processing technique to increase the output voltage as well as efficiency without requiring new hardware. Partial power converters (PPCs) process only a fraction of flowing power while the remaining power directly flows through output. This generally causes an improvement in efficiency and output voltage. A total of two structures are presented: conventional partial power T-source converters and improved partial power T-source converters. The key advantage of the improved partial power converter is a higher voltage gain. Furthermore, it reduces the voltage and the current stresses on switches and diodes. The steady-state operation principles are described for both converters and the governed rules and equations are derived. The PPCs and full power converter are compared in terms of efficiency, voltage gain, voltage stress, and current stress of converter elements. The converter performance is evaluated through experimental and simulation studies. The presented results show good consistency with the theoretical analysis.
Amirhossein Rajaei; Mahdi Shahparasti; Ali Nabinejad; Mehdi Savaghebi. A High Step-Up Partial Power Processing DC/DC T-Source Converter for UPS Application. Sustainability 2020, 12, 10464 .
AMA StyleAmirhossein Rajaei, Mahdi Shahparasti, Ali Nabinejad, Mehdi Savaghebi. A High Step-Up Partial Power Processing DC/DC T-Source Converter for UPS Application. Sustainability. 2020; 12 (24):10464.
Chicago/Turabian StyleAmirhossein Rajaei; Mahdi Shahparasti; Ali Nabinejad; Mehdi Savaghebi. 2020. "A High Step-Up Partial Power Processing DC/DC T-Source Converter for UPS Application." Sustainability 12, no. 24: 10464.
In high voltage applications, sensorless voltage control techniques can reduce the cost and increase the reliability of DC-DC converters. In this paper, a sensorless voltage observer for a current fed Cockcroft-Walton voltage multiplier is designed. The first step is to derive the converter model. Since any inaccuracy in the derived model can result in a discrepancy between the observed voltage and the actual output voltage, an accurate model is derived, which incorporates the influential elements. Then, two voltage observers based on the extended Kalman filter (EKF) are designed and used to estimate the output voltage, transformer magnetizing current and inductor current for two different configurations of the high step-up DC-DC converter. Experimental and simulation results of the system show the efficiency of the observers. The proposed observers represent good precision as the main parasitic parameters are considered in the converter model.
Karim Haadi; Amirhossein Rajaei; Mahdi Shahparasti; Akbar Rahideh. Sensorless Voltage Observer for a Current-Fed High Step-Up DC-DC Converter Using Extended Kalman Filter. Electronics 2020, 9, 2066 .
AMA StyleKarim Haadi, Amirhossein Rajaei, Mahdi Shahparasti, Akbar Rahideh. Sensorless Voltage Observer for a Current-Fed High Step-Up DC-DC Converter Using Extended Kalman Filter. Electronics. 2020; 9 (12):2066.
Chicago/Turabian StyleKarim Haadi; Amirhossein Rajaei; Mahdi Shahparasti; Akbar Rahideh. 2020. "Sensorless Voltage Observer for a Current-Fed High Step-Up DC-DC Converter Using Extended Kalman Filter." Electronics 9, no. 12: 2066.
This paper aims to present a new structure of the parallel Z-source inverters (ZSIs) for dual-input single-phase grid-connected photovoltaic (PV) systems. The ZSI is a single-stage buck-boost converter that uses an inductor-capacitor network between the inverter bridge and the PV string and follows the maximum power point by applying the shoot-through vector. Therefore, a DC/DC converter is no longer needed to track the maximum power point, and the cost and complexity of the power conditioning system (PCS) are reduced. For controlling the proposed PCS, a cascade control structure is employed in this paper. The inner current loop injects the maximum active power with unity power factor sinusoidal current to the grid. The outer capacitor voltage loop is applied to control capacitors voltages in the Z-source networks. Additionally, an enhanced dual-string maximum power point tracking (eDS-MPPT) method is proposed to find MPPs with minimum burden competitional. The eDS-MPPT does not need the PVs voltages measurements compared to other MPPT methods. The simulation results confirm the accuracy of the performance of the system.
Mahdi Shahparasti; Mehdi Savaghebi; M. Ebrahim Adabi; Thomas Ebel. Dual-Input Photovoltaic System Based on Parallel Z-Source Inverters. Designs 2020, 4, 51 .
AMA StyleMahdi Shahparasti, Mehdi Savaghebi, M. Ebrahim Adabi, Thomas Ebel. Dual-Input Photovoltaic System Based on Parallel Z-Source Inverters. Designs. 2020; 4 (4):51.
Chicago/Turabian StyleMahdi Shahparasti; Mehdi Savaghebi; M. Ebrahim Adabi; Thomas Ebel. 2020. "Dual-Input Photovoltaic System Based on Parallel Z-Source Inverters." Designs 4, no. 4: 51.
Conventional model predictive control (MPC) of power converter has been widely applied to power inverters achieving high performance, fast dynamic response, and accurate transient control of power converter. However, the MPC strategy is highly reliant on the accuracy of the inverter model used for the controlled system. Consequently, a parameter or model mismatch between the plant and the controller leads to a sub-optimal performance of MPC. In this paper, a new strategy called model-free predictive control (MF-PC) is proposed to improve such problems. The presented approach is based on a recursive least squares algorithm to identify the parameters of an auto-regressive with exogenous input (ARX) model. The proposed method provides an accurate prediction of the controlled variables without requiring detailed knowledge of the physical system. This new approach and is realized by employing a novel state space identification algorithm into the predictive control structure. The performance of the proposed model-free predictive control method is compared with conventional MPC. The simulation and experimental results show that the proposed method is totally robust against parameters and model changes compared with the conventional model based solutions.
Jose Rodriguez; Rasool Heydari; Zahra Rafiee; Hector A. Young; Freddy Flores-Bahamonde; Mahdi Shahparasti. Model-Free Predictive Current Control of a Voltage Source Inverter. IEEE Access 2020, 8, 211104 -211114.
AMA StyleJose Rodriguez, Rasool Heydari, Zahra Rafiee, Hector A. Young, Freddy Flores-Bahamonde, Mahdi Shahparasti. Model-Free Predictive Current Control of a Voltage Source Inverter. IEEE Access. 2020; 8 (99):211104-211114.
Chicago/Turabian StyleJose Rodriguez; Rasool Heydari; Zahra Rafiee; Hector A. Young; Freddy Flores-Bahamonde; Mahdi Shahparasti. 2020. "Model-Free Predictive Current Control of a Voltage Source Inverter." IEEE Access 8, no. 99: 211104-211114.
In this paper, a current sharing method based on the circular chain control (3C) method is proposed for controlling parallel inverters of unequal ratings in uninterruptible power supply (UPS) applications. Due to its circular structure, 3C is one of the most convenient methods which can be used in UPS as well as microgrid systems. However, the conventional 3C control strategy is only applicable to inverters of equal power ratings. The proposed method not only retains the circular structure of the 3C method, but also provides adaptability for the parallel operation of inverters with different power ratings. Moreover, this method adds hot-swap capability to the parallel inverter. A two-loop control structure is used to control the inverters. For proper current sharing, currents of inverters are conveyed in a circular structure with appropriate gains through control links. Simulation and experimental results for linear and nonlinear loads verify the effectiveness of the proposed strategy.
Mahdi Shahparasti; Mehdi Savaghebi; Majid Hosseinpour; Navid Rasekh. Enhanced Circular Chain Control for Parallel Operation of Inverters in UPS Systems. Sustainability 2020, 12, 8062 .
AMA StyleMahdi Shahparasti, Mehdi Savaghebi, Majid Hosseinpour, Navid Rasekh. Enhanced Circular Chain Control for Parallel Operation of Inverters in UPS Systems. Sustainability. 2020; 12 (19):8062.
Chicago/Turabian StyleMahdi Shahparasti; Mehdi Savaghebi; Majid Hosseinpour; Navid Rasekh. 2020. "Enhanced Circular Chain Control for Parallel Operation of Inverters in UPS Systems." Sustainability 12, no. 19: 8062.
In small–scale power systems, distributed virtual inertia (DVI)–based converters can effectively participate in primary frequency regulation. In this method, the synthetic inertia provision is fulfilled by discharging the preserved energy of dc–side capacitors employed in grid–interactive converters. Nevertheless, the eigenvalue analyses provided by small–signal state–space model of the converter reveal that the DVI function induces instability to the converter operating in weak grid connection. To address this issue aimed at improving grid frequency stability during frequency events, a new compensator is presented in this work. The compensator is designed so as eliminates the negative effect of DVI regulator on system stability. The effectiveness of proposed approach is illustrated by the time–domain simulations in MATLAB. The results show that the frequency rate of change following a frequency perturbation is enhanced by 40.38% compared with the scenario in which the synthetic inertia functionality is nullified.
Meysam Saeedian; Bahram Pournazarian; Bahman Eskandari; Mahdi Shahparasti; Edris Pouresmaeil. Enhancing Frequency Stability of Weak Grids with Modified Distributed Virtual Inertia Method. 2020 IEEE 11th International Symposium on Power Electronics for Distributed Generation Systems (PEDG) 2020, 187 -192.
AMA StyleMeysam Saeedian, Bahram Pournazarian, Bahman Eskandari, Mahdi Shahparasti, Edris Pouresmaeil. Enhancing Frequency Stability of Weak Grids with Modified Distributed Virtual Inertia Method. 2020 IEEE 11th International Symposium on Power Electronics for Distributed Generation Systems (PEDG). 2020; ():187-192.
Chicago/Turabian StyleMeysam Saeedian; Bahram Pournazarian; Bahman Eskandari; Mahdi Shahparasti; Edris Pouresmaeil. 2020. "Enhancing Frequency Stability of Weak Grids with Modified Distributed Virtual Inertia Method." 2020 IEEE 11th International Symposium on Power Electronics for Distributed Generation Systems (PEDG) , no. : 187-192.
This study proposes a control scheme for high power grid-connected wind power converters, which is oriented to enhance their performance when connected to weak grids with low short circuit ratio. The proposed controller consists of an outer current reference generation loop and an inner current loop, working in stationary reference frame. In the outer loop, the current reference is calculated to comply simultaneously with the grid code requirements, the control of the DC link, and the operational safety margins of the converter during faulty conditions. On the other hand, the proposed inner current loop consists of a proportional resonant controller, a capacitor voltage feedforward and a phase shifter. Moreover, simulation results considering different weak grid conditions, as well as experimental results of a full-scale 4 MW converter test-bench are presented to validate the good performance of the proposed method.
Mahdi Shahparasti; Pedro Catalan; Ignacio Garcia; J. Ignacio Candela; Andres Tarraso; Alvaro Luna. Enhanced performance controller for high power wind converters connected to weak grids. IET Renewable Power Generation 2020, 14, 2058 -2067.
AMA StyleMahdi Shahparasti, Pedro Catalan, Ignacio Garcia, J. Ignacio Candela, Andres Tarraso, Alvaro Luna. Enhanced performance controller for high power wind converters connected to weak grids. IET Renewable Power Generation. 2020; 14 (12):2058-2067.
Chicago/Turabian StyleMahdi Shahparasti; Pedro Catalan; Ignacio Garcia; J. Ignacio Candela; Andres Tarraso; Alvaro Luna. 2020. "Enhanced performance controller for high power wind converters connected to weak grids." IET Renewable Power Generation 14, no. 12: 2058-2067.
Bioelectrochemical systems performing electromethanogenesis (EMG-BES) represent an emerging technology for Power-to-gas as well as wastewater treatment. Moreover, EMG-BES can be used as a high-capacity energy storage system to absorb surplus energy in the electrical grid. This paper presents a modelling approach, which is based on building an equivalent electric circuit of the EMG-BES, which can be used to emulate static and dynamic non-linear behaviour of EMG-BES for different input voltages, which is advantageous if compared to other existing models. This model is a suitable choice for future studies in the development of the electric converters for EMG-BES plants connected to the electrical grid. The proposed model consists of practical and commercial elements, including capacitors, resistors, voltage sources, and a diode. The modelling of non-linear behaviour is achieved by adding a diode to the model. Four simple tests were performed to determine the equivalent circuit parameters in a medium-scale EMG-BES prototype. This prototype was built by stacking 45 cells together and connecting them in parallel, and it was long-term operated and tested under different electric inputs to determine the model parameters. A comparative study was finally conducted as reported in this paper in order to validate the proposed model against experimental results and values collected with other models.
Mahdi Shahparasti; Salim Bouchakour; Alvaro Luna; Daniele Molognoni; Pau Bosch-Jimenez; Eduard Borràs. Simplified modelling of nonlinear electromethanogenesis stack for power-to-gas applications. Journal of Energy Storage 2020, 31, 101633 .
AMA StyleMahdi Shahparasti, Salim Bouchakour, Alvaro Luna, Daniele Molognoni, Pau Bosch-Jimenez, Eduard Borràs. Simplified modelling of nonlinear electromethanogenesis stack for power-to-gas applications. Journal of Energy Storage. 2020; 31 ():101633.
Chicago/Turabian StyleMahdi Shahparasti; Salim Bouchakour; Alvaro Luna; Daniele Molognoni; Pau Bosch-Jimenez; Eduard Borràs. 2020. "Simplified modelling of nonlinear electromethanogenesis stack for power-to-gas applications." Journal of Energy Storage 31, no. : 101633.
Three-level converters have drawn extensive attention due to their ability to deliver high-quality power. High semiconductor count is the main drawback of three-level converters. As a solution to this, a 10-switch converter is presented, that has advantages over both two- and three-level converters, simultaneously, plus it is applicable to a variety of power ranges. However, the switching pattern of 10-switch converter is not as simple as standard three-level converter due to lack of medium vectors. This paper presents a novel space vector modulation (SVM) for a 10-switch converter to reduce total harmonic distortion (THD) and common mode voltage (CMV) of this converter in comparison to prior carrier-based modulation methods. A simplified, low-cost modulation algorithm for the converter is proposed. The designed switching sequence has aimed at a low output THD and enhancement of DC bus voltage utilization. The performance of the proposed SVM is then compared to upgraded sinusoidal PWM. AC power quality and CMV of a 10-switch converter based on two modulation methods are investigated via simulation models. It was validated via simulation and experimental models that the proposed SVM utilized DC bus voltage more efficiently, generated remarkably less THD compared to other methods, and had a lower peak and rms CMV.
Parviz Najafi; Abbas Houshmand Viki; Mahdi Shahparasti; S. Sajjad Seyedalipour; Edris Pouresmaeil. A Novel Space Vector Modulation Scheme for a 10-Switch Converter. Energies 2020, 13, 1855 .
AMA StyleParviz Najafi, Abbas Houshmand Viki, Mahdi Shahparasti, S. Sajjad Seyedalipour, Edris Pouresmaeil. A Novel Space Vector Modulation Scheme for a 10-Switch Converter. Energies. 2020; 13 (7):1855.
Chicago/Turabian StyleParviz Najafi; Abbas Houshmand Viki; Mahdi Shahparasti; S. Sajjad Seyedalipour; Edris Pouresmaeil. 2020. "A Novel Space Vector Modulation Scheme for a 10-Switch Converter." Energies 13, no. 7: 1855.
After about 80 years of introducing the Cockcroft–Walton (CW) circuit, it is still widely used because of its advantages, such as simplicity and high step-up gain. Several studies focused on the performance and design optimization of the circuit, but a dynamic model of the circuit remains to be established. This study analyzed the operation principles of an n-stage current-fed Cockcroft–Walton (CF-CWVM) during transient and steady-state operations. Then, an approach was derived to achieve a mathematical model for CF-CWVM with an arbitrary number of stages. A mathematical model for one- and two-stage CF-CWVM was developed, and its results were compared with simulation results. The theoretical model and simulations were validated by providing a prototype of CF-CWVM and comparing the results with the model outputs.
Amirhossein Rajaei; Iman Dehghanian; Mahdi Shahparasti; Edris Pouresmaeil. Behavioral switching model for current-fed Cockcroft–Walton voltage multiplier. Journal of Power Electronics 2020, 20, 365 -375.
AMA StyleAmirhossein Rajaei, Iman Dehghanian, Mahdi Shahparasti, Edris Pouresmaeil. Behavioral switching model for current-fed Cockcroft–Walton voltage multiplier. Journal of Power Electronics. 2020; 20 (2):365-375.
Chicago/Turabian StyleAmirhossein Rajaei; Iman Dehghanian; Mahdi Shahparasti; Edris Pouresmaeil. 2020. "Behavioral switching model for current-fed Cockcroft–Walton voltage multiplier." Journal of Power Electronics 20, no. 2: 365-375.
In this paper, two control strategies are proposed for distributed generation inverter (DGI) to control 1) active power exchange with the grid, 2) load voltage and 3) grid current. The main goal in these strategies is supplying of local load with a standard sinusoidal voltage in the presence of grid voltage distortions and load current nonlinearity. In conventional DGIs, the load is directly and without intermediate impedance connected to the grid, thus, the possibility of load feeding with appropriate voltage quality is hindered in the grid connected mode. In order to overcome this deficiency, DGI with a LC-L filter topology and two control strategies are presented in this paper to supply local load with standard voltage and exchanging power with the grid, simultaneously. In the first control strategy, local load is supplied with pure sinusoidal voltage and grid current quality is not important. In the second control strategy, load voltage waveform and grid current waveform are controlled with adding appropriate harmonics to load voltage. For the implementation of the mentioned controlling strategies a cascade power-voltage-current control structure has been proposed. A new controller has been introduced in the stationary reference frame for the voltage loop which gives the opportunity for compensation and tracking of harmonics without the need for complex and vast calculations. Test results under nonlinear load and non-ideal grid conditions validate that the proposed method can supply local load with standard voltage, inject power to grid and also control of grid current.
Mahdi Shahparasti. Distributed Generation Inverter: New control Strategies to Supply Local Load with Standard Voltage under Distorted Grid voltage.. 2019, 3, 1 -10.
AMA StyleMahdi Shahparasti. Distributed Generation Inverter: New control Strategies to Supply Local Load with Standard Voltage under Distorted Grid voltage.. . 2019; 3 (4):1-10.
Chicago/Turabian StyleMahdi Shahparasti. 2019. "Distributed Generation Inverter: New control Strategies to Supply Local Load with Standard Voltage under Distorted Grid voltage.." 3, no. 4: 1-10.
Bipolar hybrid microgrid application is enhancing in power systems since this type of microgrid owns a DC and AC bus simultaneously, feeds local loads with local resources, and presents two dc voltage levels to users and resources. Interlinking converter (ILC) is the most important part of the microgrid structure due to its essential responsibilities in various applications. In this paper, a 10 switch converter is presented as an ILC for bipolar hybrid microgrid that advantages from both two and three-level converters’ benefits simultaneously, plus it is applicable to a wide variety of power ranges. This paper presents a novel space vector modulation (SVM) for 10 switch converter in order to reduce total harmonic distortion (THD) and increase the dc-link voltage utilization in comparison to prior carrier-based modulation methods. Also, a simplified, full-scale dc-link voltage balancing strategy is proposed for this converter. The performance of existing dc-link voltage balancing strategies for carrier-based modulation method which are an extension to the general control structure of a grid-tied ILC is compared to the method presented in this paper that shows the superiority of the proposed robust full-scale balancing strategy and the proposed SVM method. Moreover, the structure of grid-tied ILCs is upgraded to eliminate low order harmonics.
Parviz Najafi; Abbas Hooshmand Viki; Mahdi Shahparasti. Novel space vector-based control scheme with dc-link voltage balancing capability for 10 switch converter in bipolar hybrid microgrid. Sustainable Energy, Grids and Networks 2019, 20, 100256 .
AMA StyleParviz Najafi, Abbas Hooshmand Viki, Mahdi Shahparasti. Novel space vector-based control scheme with dc-link voltage balancing capability for 10 switch converter in bipolar hybrid microgrid. Sustainable Energy, Grids and Networks. 2019; 20 ():100256.
Chicago/Turabian StyleParviz Najafi; Abbas Hooshmand Viki; Mahdi Shahparasti. 2019. "Novel space vector-based control scheme with dc-link voltage balancing capability for 10 switch converter in bipolar hybrid microgrid." Sustainable Energy, Grids and Networks 20, no. : 100256.
Employing partial power processing (PPP) technique for quasi Z-source converter (QZSC) a new structure of the converter is presented. Using PPP technique although eliminates electrical insolation, but permits reducing voltage and current stress at the semiconductors, if compared with full power proposals. In this work, two PPP structures are discussed: A first one, similar to the basic topology, where the output voltage of the power converter is in series with the input voltage; and a second one, where the output is in series with the capacitor of the QZSC. This minor modification, which requires no extra elements, improves the power rating, voltage gain, and requires a lower transformation ratio. An experimental prototype of the proposed converter has been tested and the results are compared with other implementations, permitting to validate the theoretical analysis as well as the advantages that this proposal provides.
Shahin Honarmand; Amirhossein Rajaei; Mahdi Shahparasti; Alvaro Luna; Edris Pouresmaeil. A Modified Partial Power structure for Quasi Z-Source Converter to Improve Voltage Gain and Power Rating. Energies 2019, 12, 2139 .
AMA StyleShahin Honarmand, Amirhossein Rajaei, Mahdi Shahparasti, Alvaro Luna, Edris Pouresmaeil. A Modified Partial Power structure for Quasi Z-Source Converter to Improve Voltage Gain and Power Rating. Energies. 2019; 12 (11):2139.
Chicago/Turabian StyleShahin Honarmand; Amirhossein Rajaei; Mahdi Shahparasti; Alvaro Luna; Edris Pouresmaeil. 2019. "A Modified Partial Power structure for Quasi Z-Source Converter to Improve Voltage Gain and Power Rating." Energies 12, no. 11: 2139.
Speed control of conventional low-voltage low-power induction motors (LV-LP-IMs) by two-level voltage source inverter (2LVSI) has some difficulties due to limitations of LV-LP-IMs especially insulation system. Besides, the use of multilevel inverters is not cost-effective either. In this paper, the new topology of reduced-switch-count three-level inverter with only eight switches is proposed for speed controlling of LV-LP IM. Eight-switch inverter is a newly three-level converter, which has the fewer number of switching devices, lower cost, smaller volume compared with the conventional three-level inverters, while it has sufficient switching vectors to speed control of IMs. In this paper, the structure and switching vectors of the eight-switch inverter are analyzed, and the direct torque control method based on the switching table and voltage balancing of the DC input voltage are presented for the LV-LP-IM speed control. Simulation results, considering different work conditions, are presented in order to validate finally the good performance of the proposed method. Moreover, the obtained results are compared with 2LVSI and conventional three-level inverters in different aspects.
Seyyedmohammadjavad Ghazi Ardakani; Majid Hosseinpour; Mahdi Shahparasti; Mehdi Siahi. Direct Torque Control of Low-Voltage Three-Phase Induction Motor Using a Three-Level Eight-Switch Inverter. Arabian Journal for Science and Engineering 2019, 44, 7121 -7131.
AMA StyleSeyyedmohammadjavad Ghazi Ardakani, Majid Hosseinpour, Mahdi Shahparasti, Mehdi Siahi. Direct Torque Control of Low-Voltage Three-Phase Induction Motor Using a Three-Level Eight-Switch Inverter. Arabian Journal for Science and Engineering. 2019; 44 (8):7121-7131.
Chicago/Turabian StyleSeyyedmohammadjavad Ghazi Ardakani; Majid Hosseinpour; Mahdi Shahparasti; Mehdi Siahi. 2019. "Direct Torque Control of Low-Voltage Three-Phase Induction Motor Using a Three-Level Eight-Switch Inverter." Arabian Journal for Science and Engineering 44, no. 8: 7121-7131.
In this paper, a new type of single-stage interlinking converters for Microbial Electrosynthesis (MES) energy storage applications connected to the three-phase grid is presented, in which impedance source network (ZSN) is employed to reduce cost and volume, and meanwhile improve the efficiency. Impedance source converter (ISC) with buck-boost characteristic is able to feed MES with a wide range of voltages in DC side, also, converter grid distortion in AC side is reduced because there is no need to dead time for switching. Different ZSNs are studied and discussed for MES energy application. The applicable ones are selected and a comprehensive comparison is presented. Also, the proposed efficient control for ISC consists of two parts, first ZSN capacitor control plus reactive power control are done by controlling modulation index, and second the objective of tracking active power reference can be achieved by means of controlling shoot-through duty cycle. Simulation results are presented to certify the comparison between ZSNs and to verify the merit of the proposed control scheme.
Mahdi Shahparasti; Joan Rocabert; Raul Santiago Munoz; Alvaro Luna; Pedro Rodriguez. Impedance Source Interlinking Converter for Microbial Electrosynthesis Energy Storage Applications. 2018 7th International Conference on Renewable Energy Research and Applications (ICRERA) 2018, 1340 -1345.
AMA StyleMahdi Shahparasti, Joan Rocabert, Raul Santiago Munoz, Alvaro Luna, Pedro Rodriguez. Impedance Source Interlinking Converter for Microbial Electrosynthesis Energy Storage Applications. 2018 7th International Conference on Renewable Energy Research and Applications (ICRERA). 2018; ():1340-1345.
Chicago/Turabian StyleMahdi Shahparasti; Joan Rocabert; Raul Santiago Munoz; Alvaro Luna; Pedro Rodriguez. 2018. "Impedance Source Interlinking Converter for Microbial Electrosynthesis Energy Storage Applications." 2018 7th International Conference on Renewable Energy Research and Applications (ICRERA) , no. : 1340-1345.