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International Journal of Engineering Transactions C: Aspects (24237167) 38(3)pp. 528-538
Regeneration of electric energy during braking is an important issue in electric railway systems. Especially in older electric railway systems that have non-reversible DC traction substations, the goal is to modify the structure of the DC traction substations and replace them with reversible converters at the lowest cost. Accurate evaluation of the power flow and the energy distribution in an electric railway system needs a comprehensive study of the whole railway system with multiple moving trains. But, the modeling and simulation of an electric railway network are complicated due to its nonlinear, time-variant, and large-scale structure. This paper presents the electric energy distribution in the Isfahan Metro Line 1 with and without regenerative braking. For this purpose, a simulator is developed for the DC electric railway systems with multiple moving trains. Driving control strategies, including coasting control, have been applied. The understudy system consists of 7 DC traction substations and 10 trains traveling on the up track. Different scenarios have been simulated with various combinations of reversible and non-reversible DC traction substations. Results reveal that the electric energy consumption of the system with regenerating trains and reversible DC traction substations is 27.13% lower than the system without regenerative braking. To mitigate the energy consumption in the Isfahan Metro Line 1 using the regenerative braking system, it is not mandatory to upgrade the structure of all 7 DC traction substations. Results show that it is possible to reduce electric energy consumption by 26% through installing only 5 reversible traction substations. © 2025 The author(s).
Scientia Iranica (23453605) 32(1)
Indirect Field-Oriented Control (IFOC) of a Linear Induction Motor (LIM) drive is an important challenge because of the end effect and nonlinear behavior of the LIM drive. It becomes more complex in high-speed applications and Flux-Weakening (FW) regions when current and voltage constraints must be satisfied. Moreover, considering the primary resistance in voltage constraint inequality makes the calculations even more complicated. This work presents a new FW control algorithm for LIM drives, considering the end effect and the primary resistance. Consequently, the reference d-axis current and maximum q-axis current are modified considering the primary resistance and end effect. Accordingly, new control strategies for the partial and full FW regions are implemented in a LIM drive. Fuzzy Logic Controller (FLC) has been used to overcome the nonlinear behavior of LIM drive and achieve appropriate dynamic characteristics. Simulation results validate the effectiveness of the suggested LIM drive based on FLC in different speed regions. Moreover, results manifest that in a LIM drive with end effect consideration, the base and the critical speeds are not constant. As the LIM speed increases, the base frequency reduces, whereas the critical frequency increases. © 2025 Sharif University of Technology.
Hamedani, Pegah ,
Garcia, Cristian ,
Rodriguez, Jose ,
Hamedani, P. ,
Garcia, C. ,
Rodriguez, J. Energies (19961073) 16(9)
Conventionally, DC arc furnaces are fed by thyristor rectifiers to control the level of current or power transferred to the load. With the advancement of high-power transistors, other structures such as diode rectifiers and DC choppers have been introduced and developed for the feeding system of DC electric arc furnaces. In this paper, the effect of different power supply systems on power quality indexes is discussed. In this regard, two types of feeding systems are considered, including a power supply system based on thyristor rectifiers and a power supply system based on diode rectifiers and DC choppers. In addition, different control methods, including constant current control (CCC) and constant power control (CPC), on DC electric arc furnaces are applied. For evaluating the power quality indexes, voltage and current harmonic distortion, unbalance of voltage and current, and power factor on the AC side are investigated for different power supply systems. Simulation results were performed with PSCAD/EMTDC software. It is shown that the power supply systems with diode rectifiers and DC choppers have superiority in comparison to the types based on thyristor rectifiers. According to the results, the average current THD is reduced from 16.55% in the thyristor rectifier to 8.40% in the chopper rectifiers with the CCC method and from 19.27% in the thyristor rectifier to 7.38% in the chopper rectifiers with the CPC method. Moreover, the average voltage THD is reduced from 5.67% in the thyristor rectifier to 3.02% in the chopper rectifiers with the CCC method. The result is similar to the CPC method. Furthermore, for a specific power supply system, the harmonic distortion is lower in the case of the CPC method than in the CCC method.
IEEE Access (21693536) 10pp. 37330-37344
The main purpose of this paper is to analyze a five-phase Voltage Source Inverter (VSI) that is operated with the Pulse Width Modulation (PWM) switching technique. Double Fourier integral (DFI) analysis has been used to extract the harmonics of the line-to-line voltages. Moreover, the harmonic current ripple has been calculated for an effective inductive five-phase load with a regular pentagon connection. Correspondingly, a new closed-form solution for calculating the harmonic losses in five-phase VSIs has been derived. In addition, a new equation for the weighted total harmonic distortion (WTHD) index has been extracted for five-phase VSIs. To validate the suggested analytical solutions (i.e., harmonic losses and WTHD equations), the results are compared with the DFI calculation method and the method of applying the fast Fourier transform (FFT) to a simulated waveform. The results show that the proposed analytical method has high accuracy and requires less mathematical effort, especially at high-frequency ratio values. Finally, the study includes simulation results and the implementation of an experimental setup. © 2013 IEEE.
Hamedani, P. ,
Garcia, C. ,
Flores-Bahamonde F. ,
Sadr S. ,
Rodriguez, J. ,
Hamedani, P. ,
Garcia, C. ,
Flores-Bahamonde F. ,
Rodriguez, J. 2025 29th International Computer Conference, Computer Society of Iran, CSICC 2025 pp. 224-229
Recently, multilevel inverters have attracted the attention of different electric transportation industries due to the possibility of increasing the dc-link voltage. Flying Capacitor (FC) multilevel inverter is an efficient structure that does not need different dc sources and is therefore suitable for electric vehicle applications. Moreover, Model Predictive Control (MPC) is a well-known control strategy for different electric drive systems like induction machines. However, MPC of electrical machines supplied with a multilevel FC inverter has not been investigated yet.As a result, this paper concentrates on the predictive control of an IM drive with 4-level FC inverters. The application of this control strategy is simple and many objective functions can be simultaneously taken into account in the optimization of the cost function, such as the dynamic tracking behavior and the voltage balancing of the FCs. To compensate the delay time which emerges due to a large number of calculations in each sampling instant, delay compensation method has been utilized. According to the results, the proposed predictive control of the IM drive with a 4-level FC inverter offers fast dynamic behavior with no overshoot, low torque and current ripples, and perfect voltage balancing of the FCs. © 2022 IEEE.
2025 29th International Computer Conference, Computer Society of Iran, CSICC 2025
In the past two decades, multiphase electrical motor drives (with more than three phases) have attracted a lot of attention due to their superior advantages. Obviously, multiphase voltage source inverters (VSIs) play an important role in supplying the multiphase motor drives. Moreover, in the field of multiphase VSIs based Pulse Width Modulation (PWM) switching strategy and their harmonic evaluation, adequate research has not been reported yet. Therefore, this paper concentrates on analytical analysis of seven-phase VSIs with Pulse Width Modulation (PWM) switching strategy. Consequently, new equations have been calculated to determine exactly the harmonic contents of the phase to midpoint and line-to-line voltages in seven-phase VSIs using the double Fourier integral (DFI) analysis. Correspondingly, the related frequency spectrum and the dominant harmonic components with respect to the amplitude modulation index have been represented in this work for the first time. In order to investigate the accuracy of the proposed analytical solutions, the results obtained from double Fourier integral calculation method are compared with the results achieved by directly applying Fast Fourier Transform (FFT) to a simulated waveform. Furthermore, to achieve a more valuable verification of the theoretical and simulation results, experimental results of a seven-phase VSI have been also provided. The simulation and experimental results validate the accuracy of extracted equations. © 2020 IEEE.
Advances in Electrical and Computer Engineering (18447600) 16(3)pp. 15-24
Multicarrier based PWM switching patterns are commonly utilized to control Cascaded H-bridge (CHB) inverters. The main contribution of this paper is to comprehensively investigate the effect of various multicarrier based PWM techniques on harmonic content of the CHB multilevel inverter. In order to achieve this, both of the CHB output voltage and the input current at power grid side have been taken into account. In this work, various PWM modulations such as level shifted (LS), phase shifted (PS), hybrid, and rotative-LS (R-LS) have been studied through both simulation and implementation of an experimental setup. By extracting the frequency spectrum and calculation of THD and WTHD indices, a quantitative comparative study of various multicarrier PWM techniques has been carried out. According to the results, the R-LS-PWM methods (i.e. R-PD, and two new proposed R-POD and R-APOD) reduce the harmonic distortion of the input current while keeping the obvious advantage of LS-PWM modulation such as lower harmonic distortion of the output voltage. Specially, the proposed R-APOD-PWM modulation offers these preferable privileges at odd frequency ratio values. © 2016 AECE.
Advances in Electrical and Computer Engineering (18447600) 15(3)pp. 3-12
Accurate vector control of a linear induction motor (LIM) drive is a complicated subject because of the end effect phenomenon especially in the field-weakening region. This paper concentrates on a novel field-weakening speed control strategy for LIM drive in which the end effect is taken into account. Considering the end effect, new voltage and current limits have been calculated using the Duncan's model. Accordingly, control strategies such as constant force region, partial field-weakening region, and full field-weakening region have been analytically calculated for the first time in this work. In order to improve the control characteristics of the LIM drive, Fuzzy Logic Controller (FLC) has been also implemented. Simulation results manifest the satisfactory resultants of the proposed FLC based LIM in the fieldweakening region including fast response, no overshoot, negligible steady-state error, and adaptability to load changes. In addition, a new constant force pattern is introduced in this paper by which the reductions of the LIM thrust due to the end effect will be compensated and thus, the current and voltage amplitudes in steady state will remarkably decrease.
Precise speed control of a Linear Induction Motor (LIM) drive becomes a complex issue due to the end effect phenomena which results in the weakening of the airgap flux and thrust. The end effect becomes severe when the LIM drive operates at higher speeds. The main purpose of this paper is to present an accurate qd dynamic model of linear induction motor suitable for vector control and drive applications considering the end effects. In this model not only the magnetizing inductance is modified but also the series resistance reflecting the eddy current is considered in the series with the magnetizing branch in both q and d axes. Moreover, a corresponding indirect field oriented control (IFOC) scheme is suggested. The effectiveness of the proposed IFOC scheme based LIM drive is verified by simulation results at different operating conditions. In addition, a five-level Cascaded H-bridge (CHB) inverter with multiband hysteresis modulation has been successfully applied for drive performance improvements. The results prove that the proposed LIM model and its related IFOC scheme show more accurate and comprehensive resultants and are therefore closer to the reality. Furthermore, utilization of the multilevel CHB inverter guarantees high drive performance and perfect control characteristics. ©2013 IEEE.
Unbalanced line currents cause unbalanced voltage drops on the three phases of the supply system. Consequently, the voltage system within the supply network will become unbalanced. Voltage unbalance has different detrimental effects in electrical power systems, such as the growth of losses in drive systems and adjustable speed drives, supplementary heating, line-current unbalance, derating, torque pulsation, mechanical stresses, etc. This paper makes an effort to have a comprehensive analysis of the effects of different connection types of three phase transformers on voltage unbalance propagation in distribution networks. The indices of voltage unbalance factor (VUF) and current unbalance factor (IUF) are used in this paper to evaluate the unbalance propagation. These indices are acquired utilizing symmetrical component theory on three phase voltages and currents earned through the system impedance matrix. © 2012 IEEE.
Expert Systems with Applications (09574174) 38(10)pp. 12643-12653
Precise speed control of an Interior Permanent Magnet Synchronous Motor (IPMSM) drive becomes a complex issue due to the nonlinear nature of its developed torque. The system nonlinearity becomes severe when the IPMSM drive operates in the field weakening region. In order to achieve perfect control characteristics, the main purpose of this paper is to present a detailed comparison of various intelligent based controllers for flux weakening speed control of an IPMSM drive. In this paper, the Brain Emotional Learning Based Intelligent Controller (BELBIC), Genetic-Fuzzy Logic Based Controller (GFLBC), as well as genetic-PI based controller, are considered. BELBIC is a computational model of emotional processing mechanism in the brain. The effectiveness of the proposed BELBIC controller-based IPMSM drive is verified by simulation results at different operating conditions. Moreover, control regimes such as Maximum Torque Per Ampere (MTPA) control and flux weakening (FW) control as well as voltage and current constraints have been successfully applied. The results prove BELBIC's perfect control characteristics, such as fast and smooth speed response, low maximum starting current, adaptability to speed and load changes and robustness to parameter variations, disturbance and sudden one-phase interruption. © 2010 Elsevier Ltd. All rights reserved.
Precise speed control of an Interior Permanent Magnet Synchronous Motor (IPMSM) drive becomes a complex issue due to complex coupling among its winding currents and the rotor speed as well as the nonlinear nature of the developed torque. The system nonlinearity becomes severe when the IPMSM drive operates in the field weakening region. The main purpose of this paper is to present the implementation of an emotional controller for flux weakening speed control of an IPMSM drive. The proposed controller is called Brain Emotional Learning Based Intelligent Controller (BELBIC) and is a computational model of emotional processing mechanism in the brain. The effectiveness of the proposed BELBIC controller-based IPMSM drive is verified by simulation results at different operating conditions. Moreover, control regimes such as Maximum Torque per Ampere (MTPA) control and Flux Weakening (FW) control as well as voltage and current constraints have been successfully applied. The results prove BELBIC's perfect control characteristics, fast response, simple implementation and adaptability to speed, load and parameter changes. © 2011 IEEE.
