Induction Motor Drives Fed by an NPC Inverter with Unbalanced DC-Link

Neutral Point Clamped (NPC) converters with n levels are traditionally controlled in such a way that the DC-link capacitors operate at 1/( n - 1) of the total DC-link voltage level. The voltage level across the DC-link capacitors has to be properly regulated by the capacitor unbalance control to contain the harmonic distortion of the converter output voltages. State-of-the-art modulation techniques address the problem of the DC-link voltage regulation for NPC inverters. However, they highly show reduced performance when unbalanced DC-link voltages are considered. In this paper, a novel Space Vector Modulation (SVM) is proposed for NPC converters with an unbalanced DC-link. At every modulation interval, the technique defines the optimal switching pattern by considering the actual unbalanced DC-link conditions. The proposed modulation allows improving the harmonic content of the NPC converter output voltage with respect to a traditional ML-SVM, when the same operating conditions are considered. As an extension, the proposed modulation technique will guarantee the same output voltage quality of a traditional ML-SVM with unbalanced DC-link, while improving the conversion efficiency thanks to a reduction of switching frequency.

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Dual-Mode Power Operation for Grid-Connected PV Systems with Adaptive DC-link Controller

Arabian Journal for Science and Engineering ◽

10.1007/s13369-021-05916-w ◽

2021 ◽

Author(s):

Mostafa Ahmed ◽

Ibrahim Harbi ◽

Ralph Kennel ◽

Mohamed Abdelrahem

Keyword(s):

Power Generation ◽

Voltage Regulation ◽

Operating Conditions ◽

Switching Frequency ◽

Atmospheric Conditions ◽

Voltage Profile ◽

Dual Mode ◽

Power Extraction ◽

Pv Systems ◽

Power Operation

AbstractPhotovoltaic (PV) power systems are integrated with high penetration levels into the grid. This in turn encourages several modifications for grid codes to sustain grid stability and resilience. Recently, constant power management and regulation is a very common approach, which is used to limit the PV power production. Thus, this article proposes dual-mode power generation algorithm for grid-connected PV systems. The developed system considers the two-stage PV configuration for implementation, where the dual-mode power generation technique is executed within the DC–DC conversion (boost) stage. Most of the techniques adopted for dual-mode power operation employ the conventional perturb and observe method, which is known with unsatisfactory performance at fast-changing atmospheric conditions. Considering this issue, this study suggests a modified maximum power point tracker for power extraction. Furthermore, a new adaptive DC-link controller is developed to improve the DC-link voltage profile at different operating conditions. The adaptive DC-link controller is compared with the traditional PI controller for voltage regulation. The inverter control is accomplished using finite-set model predictive control with two control objectives, namely reference current tracking and switching frequency minimization. The overall control methodology is evaluated at different atmospheric and operating conditions using MATLAB/Simulink software.

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Power quality of dual two-level inverter fed open end winding induction motor

Indonesian Journal of Electrical Engineering and Computer Science ◽

10.11591/ijeecs.v18.i2.pp688-697 ◽

2020 ◽

Vol 18 (2) ◽

pp. 688

Author(s):

Hayder Ali Mohamed ◽

Hanan Mikhael D. Habbi

Keyword(s):

Induction Motor ◽

Harmonic Distortion ◽

Voltage Source ◽

Current Signal ◽

Space Vector Pwm ◽

Dc Voltage ◽

Common Mode Voltage ◽

Voltage Quality ◽

Open End Winding

<p><span>This paper presents the minimization of the total harmonic distortion (THD) of the current signal for open-end winding induction motor by using dual two-level inverter. In order to obtain a good value of THD, the space vector PWM has been used for switching the dual two-level inverter to improve the output voltage quality, gets a low common mode voltage, reduce the execution time, and to save the memory capacity. The proposed scheme uses two different DC voltage source with two two level inverter in order of minimizing the number of components. As well as it is an important to utilize the energy which increases the application of dual inverter in microgrids. All simulation results are obtained using Matlab/Simulink. </span></p>

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Novel Step-Down DC–DC Converters Based on the Inductor–Diode and Inductor–Capacitor–Diode Structures in a Two-Stage Buck Converter

Energies ◽

10.3390/en12061131 ◽

2019 ◽

Vol 12 (6) ◽

pp. 1131 ◽

Cited By ~ 2

Author(s):

Mauricio Dalla Vecchia ◽

Giel Van den Broeck ◽

Simon Ravyts ◽

Johan Driesen

Keyword(s):

Output Voltage ◽

Buck Converter ◽

Switching Frequency ◽

Two Stage ◽

Voltage Level ◽

Multiple Strategies ◽

Power Electronics Converters ◽

Load Demand ◽

Duty Cycles ◽

Step Down

This paper explores and presents the application of the Inductor–Diode and Inductor-Capacitor-Diode structures in a DC–DC step-down configuration for systems that require voltage adjustments. DC micro/picogrids are becoming more popular nowadays and the study of power electronics converters to supply the load demand in different voltage levels is required. Multiple strategies to step-down voltages are proposed based on different approaches, e.g., high-frequency transformer and voltage multiplier/divider cells. The key question that motivates the research is the investigation of the aforementioned Inductor–Diode and Inductor–Capacitor–Diode, current multiplier/divider cells, in a step-down application. The two-stage buck converter is used as a study case to achieve the output voltage required. To extend the intermediate voltage level flexibility in the two-stage buck converter, a second switch was implemented replacing a diode, which gives an extra degree-of-freedom for the topology. Based on this modification, three regions of operation are theoretically defined, depending on the operational duty cycles δ2 and δ1 of switches S2 and S1. The intermediate and output voltage levels are defined based on the choice of the region of operation and are mapped herein, summarizing the possible voltage levels achieved by each configuration. The paper presents the theoretical analysis, simulation, implementation and experimental validation of a converter with the following specifications; 48 V/12 V input-to-output voltage, different intermediate voltage levels, 100 W power rating, and switching frequency of 300 kHz. Comparisons between mathematical, simulation, and experimental results are made with the objective of validating the statements herein introduced.

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Optimization of PFC SEPIC Converter Parameters Design for Minimization of THD and Voltage Ripple

International Journal of Engineering & Technology ◽

10.14419/ijet.v7i4.30.22274 ◽

2018 ◽

Vol 7 (4.30) ◽

pp. 240 ◽

Cited By ~ 1

Author(s):

M. K. R. Noor ◽

A. Ponniran ◽

M. A. Z. A. Rashid ◽

A. A. Bakar ◽

J. N. Jumadril ◽

...

Keyword(s):

Design Optimization ◽

Output Voltage ◽

Harmonic Distortion ◽

Input Voltage ◽

Switching Frequency ◽

Unity Power Factor ◽

Voltage Ripple ◽

Voltage Variation ◽

Balancing Energy ◽

Energy Compensation

This paper discusses the current total harmonic distortion (THDi) and voltage ripple minimization of SEPIC converter based on parameters design optimization. This conventional PFC SEPIC converter is designed to operate in discontinuous conduction mode in order to achieve almost unity power factor. The passive components, i.e., inductor and capacitor are designed based on switching frequency and resonant frequency. Meanwhile, the ranges of duty cycle for buck and boost operations are between 0<D<0.5 and 0.5<D<1, respectively, for the output voltage variation of the converter. The principle of the parameters design optimization is based on the balancing energy compensation between the input capacitor and output inductor. The experimental results show that, the current THD is reduced to 2.66% from 70.9% after optimization process is conducted. Furthermore, it is confirmed that the output voltage ripple frequency is always double from the input line frequency, fL = 2foutand the output voltage ripple is always lower than the maximum input voltage ripple. Therefore, the designed parameters of the experimental converter is confirmed with approximately 65 W of the converter output power.

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A 7-Level Single DC Source Cascaded H-Bridge Multilevel Inverter with a Modified DTC Scheme for Induction Motor-Based Electric Vehicle Propulsion

International Journal of Vehicular Technology ◽

10.1155/2013/718920 ◽

2013 ◽

Vol 2013 ◽

pp. 1-9 ◽

Cited By ~ 2

Author(s):

Farid Khoucha ◽

Khoudir Marouani ◽

Mohamed Benbouzid ◽

Abdelaziz Kheloui ◽

Abdeslam Mamoune

Keyword(s):

Induction Motor ◽

Electric Vehicle ◽

Output Voltage ◽

Motor Drives ◽

Multilevel Inverter ◽

Induction Motor Drives ◽

Voltage Level ◽

Vehicle Propulsion ◽

Control Scheme ◽

And Control

This paper presents a new hybrid cascaded H-bridge multilevel inverter motor drive DTC scheme for electric vehicles where each phase of the inverter can be implemented using a single DC source. Traditionally, each phase of the inverter requires DC source for output voltage levels. In this paper, a scheme is proposed that allows the use of a single DC source as the first DC source which would be available from batteries or fuel cells, with the remaining () DC sources being capacitors. This scheme can simultaneously maintain the capacitors of DC voltage level and produce a nearly sinusoidal output voltage due to its high number of output levels. In this context, high performances and efficient torque and flux control are obtained, enabling a DTC solution for hybrid multilevel inverter powered induction motor drives intended for electric vehicle propulsion. Simulations and experiments show that the proposed multilevel inverter and control scheme are effective and very attractive for embedded systems such as automotive applications.

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Comparison of Switching Angle Arrangement Techniques in Single-Phase Boost Multilevel Inverter for Low-THD Operation

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.793.167 ◽

2015 ◽

Vol 793 ◽

pp. 167-171

Author(s):

Mohd Aizuddin Yusof ◽

Yee Chyan Tan ◽

M. Othman ◽

S.S. Lee ◽

M.A. Roslan ◽

...

Keyword(s):

Output Voltage ◽

Single Phase ◽

Harmonic Distortion ◽

Multilevel Inverter ◽

Solar Photovoltaic ◽

Voltage Waveform ◽

Voltage Level ◽

Software Simulation ◽

Multilevel Inverters ◽

Simulation Results

Multilevel inverters are one of the preferred inverter choices for solar photovoltaic (PV) applications. While these inverters are capable of producing AC staircase output voltage waveform, the total harmonic distortion (THD) of the output voltage waveform can become worse if the switching angle of each voltage level is not carefully chosen. In this paper, four switching angle arrangement techniques are presented and the switching angles generated by these techniques are applied to a new single-phase boost multilevel (SPBM) inverter. The performance of 3-, 5-, 7-, 9-and 11-level SPBM inverter having four different sets of switching angles derived using the aforementioned techniques have been evaluated and compared using PSIM software. Simulation results show that one of the techniques is able to produce an output voltage waveform with the lowest THD, whilst the other generates an output voltage waveform with the highest fundamental voltage component.

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Research on the High Frequency Realization of High-Power Inverter

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.383-390.1077 ◽

2011 ◽

Vol 383-390 ◽

pp. 1077-1083

Author(s):

Run Hua Liu ◽

Gang Wang

Keyword(s):

High Power ◽

High Frequency ◽

Output Voltage ◽

Harmonic Distortion ◽

Soft Switching ◽

Multilevel Inverter ◽

Switching Frequency ◽

Switching Losses ◽

Simulation And Experiment

The paper presents the inverter method which based on cascade multilevel inverter and MOSFET-assisted soft-switching of IGBT and modulation strategy against the double requirement of high-power inverter and high frequency. The method can effectively improve the output voltage, reduce harmonic distortion and switching losses, improve the switching frequency and meet the double requirement of the high-power inverter and high frequency. The method proved to be feasible by simulation and experiment.

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Generation of Optimal Switching Angle for Nine Level Cascaded H Bridge MLI Using Most Valuable Player Algorithm

Turkish Journal of Computer and Mathematics Education (TURCOMAT) ◽

10.17762/turcomat.v12i6.4442 ◽

2021 ◽

Vol 12 (6) ◽

pp. 1919-1927

Author(s):

Vijaya Anand N, Hema Latha J, G Devadasu, Kumar C

Keyword(s):

Reactive Power ◽

Harmonic Distortion ◽

Voltage Level ◽

Computing Technique ◽

Power Exchange ◽

Point Of Common Coupling ◽

Terminal Voltage ◽

Common Coupling ◽

Micro Grids

Distributed generation (DG) sources often interfaced with grid by a Cascaded H-bridge multilevel inverter with a remote D.C source. The interface inverter has to adapt voltage on the either side of the grid and DG source while it has a control of active and reactive power exchange. The inverter terminal voltage is maintained based on frequency switching technique. However, in applications like micro grids are based on quality of output voltage at the point of common coupling. The present paper discusses an optimal frequency switching methodology that generates optimal fringing angle based on an evolutionary computing technique while maintaining the voltage level at PCC with a reduced harmonic distortion. Efficacy of the proposed method is illustrated by simulating a 9-level cascaded H bridge in MATLAB environment.

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Development of a Digitally Controlled Inductive Power Transfer System with Post-Regulation for Variable Load Demand

Electronics ◽

10.3390/electronics11010058 ◽

2021 ◽

Vol 11 (1) ◽

pp. 58

Author(s):

Kateryna Stoyka ◽

Antonio Vitale ◽

Massimo Costarella ◽

Alfonso Avella ◽

Mario Pucciarelli ◽

...

Keyword(s):

Phase Shift ◽

Output Power ◽

Output Voltage ◽

Voltage Regulation ◽

Control Technique ◽

Switching Frequency ◽

Variable Load ◽

Power Transfer ◽

Inductive Power Transfer ◽

Inductive Power

Inductive Power Transfer (IPT) is an emerging technology enabling a contactless charging process in manifold applications such as electric vehicles, wearable and portable devices, or biomedical applications. Such technology can be profitably used to develop enhanced electronic solutions in the framework of smart cities, homes and smart workplaces. This paper presents the development and realization of a series–series compensated IPT System (IPTS) followed by a post-regulator implemented by means of a DC–DC converter. Such a system is modeled through a first harmonic approximation method, and a sensitivity analysis of the IPTS performance is carried out with respect to the variations of the primary inverter switching frequency and phase-shift angle. As an element of novelty of this work, the bias points are determined which allow the efficiency maximization while ensuring system controllability. An enhanced dynamic modeling of the system is then performed by means of a coupled mode theory, including the inverter phase-shift modulation and extending its validity to whatever operating frequency. A digital control of the post-regulator is implemented by means of a commercial low-cost microcontroller enabling the output voltage regulation under both fixed and variable load conditions through a voltage mode control technique. An IPTS prototype is eventually realized, which is able to correctly perform the output voltage regulation at the desired nominal value of 12 V for static resistive loads in the range [5,24] Ω, yielding the output power in the range [6, 28.8] W and the experimental efficiencies going from 72.1% (for 24 Ω) to 91.7% (for 5 Ω). The developed system can also be effectively used to deliver up to 35 W output power to variable loads, as demonstrated during the battery charging test. Finally, an excellent output voltage regulation is ascertained for load transients between 5 Ω and 24 Ω, with limited over- and undershoot amplitudes (less than 3% of the nominal output voltage), thus enabling the use of the proposed system for both fixed and variable loads in the framework of smart homes and workplaces applications.

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