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Article
Publication date: 1 January 2013

Javier Pereda and Juan Dixon

The aim of this paper is to improve and adapt cascaded multilevel converters for electric vehicles (EVs) to have all the advantages of these converters and to eliminate…

Abstract

Purpose

The aim of this paper is to improve and adapt cascaded multilevel converters for electric vehicles (EVs) to have all the advantages of these converters and to eliminate its limitation in the use of EVs applications. Specifically, the purpose is to use only a single power source (battery pack, fuel cell, etc.) and to generate a higher power‐quality than regular multilevel converters.

Design/methodology/approach

This paper is based in a cascaded multilevel converter conformed by two 3‐level inverters connected in series. The voltage sources of the auxiliary inverter were replaced by floating capacitors which work as active filters, reducing the power sources to one. The floating capacitor voltages were controlled by a PI controller that adjusts the modulation index (m) to obtain a zero average power in the auxiliary inverters, and a predictive control selects the optimal redundant state to reduce the error and balance all the capacitor voltages. As the modulation index is determined by the PI controller, the output voltage magnitude must be controlled by a variable voltage source (e.g. buck‐boost chopper). Additionally, the converter works with new optimal voltage asymmetries to obtain higher power quality and capacitor control stability.

Findings

The proposed converter uses a topology that conventionally generates 9‐levels of voltage, but with the proposed asymmetry is as generate 11‐levels. Also, the auxiliary power sources were eliminated.

Research limitations/implications

The proposed solution has a limited dynamic response due to the variation rate of the capacitor voltage, which is limited by the load current and the capacitance. However, the dynamic response and control stability is satisfactory for EVs applications.

Originality/value

The paper presents a new control to manage the floating capacitor voltages and uses new voltage asymmetries in cascaded multilevel converters.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 32 no. 1
Type: Research Article
ISSN: 0332-1649

Keywords

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Article
Publication date: 30 March 2010

Chun‐Fei Hsu, Shuen‐Liang Wang, Ming‐Chia Li and Chih‐Min Lin

The DC‐DC converters which convert one level of electrical voltage to the desired level are widely used in many electrical peripherals. During the past two decade, many…

Abstract

Purpose

The DC‐DC converters which convert one level of electrical voltage to the desired level are widely used in many electrical peripherals. During the past two decade, many different control laws have been developed. The proportional‐integral (PI) control and sliding‐mode control have been carried out for the DC‐DC converters since they are simple to implement and easy to design. However, its performance using PI control and sliding‐mode control is obviously quite limited. The purpose of this paper is to a self‐tuning nonlinear function control (STNFC) propose for the DC‐DC converters. The adaptation laws of the proposed STNFC system are derived in the sense of Lyapunov function, thus not only the controller parameters can be online tuned itself, but also the system's stability can be guaranteed.

Design/methodology/approach

In general, the accurate mathematical models of the DC‐DC converters are difficult to derive. This paper proposes a model‐free STNFC design method. Since the proposed STNFC uses a simple fuzzy system with three fuzzy rules base to implement the control law, the computational loading of the fuzzy inference mechanism is slight. So the proposed STNFC system is suitable for the real‐time practical applications. The controller parameters of the proposed STNFC system can online tune in the Lyapunov sense, thus the stability of closed‐loop system can be guaranteed.

Findings

The proposed STNFC system is applied to a DC‐DC converter based on a field‐programmable gate array chip. The experimental results are provided to demonstrate the proposed STNFC system can cope with the input voltage and load resistance variations to ensure the stability while providing fast transient response.

Originality/value

The proposed STNFC approach is interesting for the design of an intelligent control scheme. The main contributions of this paper are: the successful development of STNFC system without heavy computational loading. The parameter‐learning algorithm is design based on the Lyapunov stability theorem to guarantee the system stability; the successful applications of the STNFC system to control the forward DC‐DC converter. And, the proposed STNFC methodology can be easily extended to other DC‐DC converters.

Details

International Journal of Intelligent Computing and Cybernetics, vol. 3 no. 1
Type: Research Article
ISSN: 1756-378X

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Article
Publication date: 11 February 2020

Vibha Kamaraj and Chellammal Nallaperumal

Growing concerns about the depletion of fossil fuels and global awareness about the environmental pollution motivate the automobile industries to search for an alternative…

Abstract

Purpose

Growing concerns about the depletion of fossil fuels and global awareness about the environmental pollution motivate the automobile industries to search for an alternative transportation system such as hybrid vehicular systems, plug-in hybrid vehicular systems and electric vehicular systems. To have carbon emission-free environment, these electric vehicles use renewable sources, such as solar and fuel cell, as primary source of supply. As these renewable sources are intermittent in nature, an energy buffer such as battery or super capacitor is required for the smooth supply and regulation of load power. The current electric vehicle systems use multistage power electronic converters for energy transfer. Therefore, this paper aims to propose a modified multiport converter based on Luo topology.

Design/methodology/approach

The suggested converter is developed based on Luo topology using voltage lift technique.

Findings

Most of the research presents buck boost converter as power electronic interface in electric vehicle applications. Whereas the converter proposed in this paper is based on Luo topology. It exhibits the features of single stage conversion between the input output ports, with less ripple, high efficiency, fewer components and centralized control for effective power management.

Originality/value

The presented converter can work in all possible modes such as buck and boost modes independently or simultaneously during various operating conditions of electric vehicles. During buck/boost mode, the primary source PV (Photovoltaic) in the converter provides the required power for the vehicle and charges the secondary source, i.e. battery, whereas during boost mode the battery supplies the sufficient power to load.

Details

Circuit World, vol. 46 no. 2
Type: Research Article
ISSN: 0305-6120

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Article
Publication date: 4 January 2011

Bingchang Ni and Constantinos Sourkounis

Wind energy plays a very important role in the future electrical power supply. With growing shares, the focus of the plant control will have to shift from maximum power…

Abstract

Purpose

Wind energy plays a very important role in the future electrical power supply. With growing shares, the focus of the plant control will have to shift from maximum power yield to grid friendly aspects, like stable power output despite fluctuating wind power. The purpose of this paper is to design a new operation management for wind energy converters that combines high‐energy yield, grid friendly power output characteristics and the ability to adapt to changing wind conditions.

Design/methodology/approach

An operation control based on stochastic dynamic optimization was developed for the special demands of variable speed wind energy converters. The task of the operation control is to set the appliance to the optimal operation point, following the above‐mentioned goals by adapting the control pattern to changing wind conditions.

Findings

It is shown that the novel control concept, the iterative self‐adapting system management with stochastic dynamic optimization, is able to control wind energy converters in such a way that the effect of the stochastic fluctuating wind energy supply on the output power fluctuation is smoothed while maintaining a high‐energy yield.

Originality/value

This non‐linear stochastic dynamic optimization structure has two special characteristics, first is the iterative self‐adaptation, and second is the optimization for an infinite process, while the optimization criteria are high‐power yield and low‐power output fluctuations. This will be of great value for further increase of wind energy converters in the electrical power supply.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 30 no. 1
Type: Research Article
ISSN: 0332-1649

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Article
Publication date: 1 January 2014

Hanen Mejbri, Kaiçar Ammous, Slim Abid, Hervé Morel and Anis Ammous

– This paper aims to focus on the trade-off between losses and converter cost.

Abstract

Purpose

This paper aims to focus on the trade-off between losses and converter cost.

Design/methodology/approach

The continual development of power electronic converters, for a wide range of applications such as renewable energy systems (interfacing photovoltaic panels via power converters), is characterized by the requirements for higher efficiency and lower production costs. To achieve such challenging objectives, a computer-aided design optimization based on genetic algorithms is developed in Matlab environment. The elitist non-dominated sorting genetic algorithm is used to perform search and optimization, whereas averaged models are used to estimate power losses in different semiconductors devices. The design problem requires minimizing the losses and cost of the boost converter under electrical constraints. The optimization variables are, as for them, the switching frequency, the boost inductor, the DC capacitor and the types of semiconductor devices (IGBT and MOSFET). It should be pointed out that boost topology is considered in this paper but the proposed methodology is easily applicable to other topologies.

Findings

The results show that such design methodology for DC-DC converters presents several advantages. In particular, it proposes to the designer a set of solutions – as an alternative of a single one – so that the authors can choose a posteriori the adequate solution for the application under consideration. This then allows the possibility of finding the best design among all the available choices. Furthermore, the design values for the selected solution were obtainable components.

Originality/value

The authors focus on the general aspect of the discrete optimization approach proposed here. It can also be used by power electronics designers with the help of additional constraints in accordance with their specific applications. Furthermore, the use of such non-ideal average models with the multi-objective optimization is the original contribution of the paper and it has not been suggested so far.

Details

COMPEL: The International Journal for Computation and Mathematics in Electrical and Electronic Engineering, vol. 33 no. 1/2
Type: Research Article
ISSN: 0332-1649

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Article
Publication date: 3 December 2018

Mohsen Karimi, Mohammad Pichan, Adib Abrishamifar and Mehdi Fazeli

This paper aims to propose a novel integrated control method (ICM) for high-power-density non-inverting interleaved buck-boost DC-DC converter. To achieve high power…

Abstract

Purpose

This paper aims to propose a novel integrated control method (ICM) for high-power-density non-inverting interleaved buck-boost DC-DC converter. To achieve high power conversion by conventional single phase DC-DC converter, inductor value must be increased. This converter is not suitable for industrial and high-power applications as large inductor value will increase the inductor current ripple. Thus, two-phase non-inverting interleaved buck-boost DC-DC converter is proposed.

Design/methodology/approach

The proposed ICM approach is based on the theory of integrated dynamic modeling of continuous conduction mode (CCM), discontinuous conduction mode and synchronizing parallel operation mode. In addition, it involves the output voltage controller with inner current loop (inductor current controller) to make a fair balancing between two stages. To ensure fast transient performance, proposed digital ICM is implemented based on a TMS320F28335 digital signal microprocessor.

Findings

The results verify the effectiveness of the proposed ICM algorithm to achieve high voltage regulating (under 0.01 per cent), very low inductor current ripple (for boost is 1.96 per cent, for buck is 1.1) and fair input current balance between two stages (unbalancing current less than 0.5A).

Originality/value

The proposed new ICM design procedure is developed satisfactorily to ensure fast transient response even under high load variation and the solving R right-half-plane HP zeros of the CCM. In addition, the proposed method can equally divide the input current of stages and stable different parallel operation modes with large input voltage variations.

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Article
Publication date: 11 May 2010

Kaiçar Ammous, Elyes Haouas and Slim Abid

The purpose of this paper is to develop a simulation tool which permits reducing the cost of long time‐range simulation of complex converters and running at high frequency.

Abstract

Purpose

The purpose of this paper is to develop a simulation tool which permits reducing the cost of long time‐range simulation of complex converters and running at high frequency.

Design/methodology/approach

A different method is used to represent a simplified converter but the adopted technique uses the average representation of the cell converter.

Findings

The paper shows that the use of averaged representation of the pulse width modulation switch in multilevel converters is staying applied. The main advantage of the proposed averaged model is its simplified representation when only electrical behaviour is considered.

Research limitations/implications

The analytical algorithm of the averaged model can be introduced in different simulator as it has a description language, enabling study of the Compatibilité Electromagnétique and electrothermal phenomena.

Originality/value

This paper presents an averaged model of the multilevel converter which can be implemented in any simulator as it has a description language.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 29 no. 3
Type: Research Article
ISSN: 0332-1649

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Article
Publication date: 4 May 2012

Jean‐François Lange, Laurent Gerbaud, Hieu Nguyen‐Huu and James Roudet

An analytical approach is preferred to carry out the harmonic modelling of power electronics converters because it is generally faster than time simulation chained with…

Abstract

Purpose

An analytical approach is preferred to carry out the harmonic modelling of power electronics converters because it is generally faster than time simulation chained with FFT. However, the difficulty of such an approach is to build the model and to manage the uncontrolled commutations that occur in the studied static converter, and also to deal with large equations. The purpose of this paper is to propose an aid in the frequency modelling of the drive elements, in the frequency domain, including all key parameters for sizing aim i.e. a way to optimize the EMC filter using different algorithms.

Design/methodology/approach

The paper aims to propose an aid to create such models, and to assure its good solving, i.e. that the correct operating mode is represented. So, the solving problem is formulated as an optimization problem under constraints, to solve this difficulty.

Findings

The difficulty is to be sure to deal with the good operating mode of the static converter when soft or uncontrolled commutations occur. So, the model is formulated as a constrained optimization problem. The paper proposes a symbolic approach, that allows to build automatically the frequency model. It is translated to be solved in Matlab.

Research limitations/implications

The approach does not fit for static converters with a control implying numerous commutations per operating period. However, the approach deals with natural and soft commutations.

Originality/value

The modelling is based on the use of linear components and ideal switches.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 31 no. 3
Type: Research Article
ISSN: 0332-1649

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Article
Publication date: 1 January 2013

Luigi Alberti, Elisabetta Tedeschi, Nicola Bianchi, Maider Santos and Alessandro Fasolo

The purpose of this paper is to investigate the impact of control strategy selection on the power performance of wave energy converters for different ratings of the Power…

Abstract

Purpose

The purpose of this paper is to investigate the impact of control strategy selection on the power performance of wave energy converters for different ratings of the Power Take‐Off (PTO) system.

Design/methodology/approach

The case of a point absorber equipped with an all‐electric PTO is considered. The effect of control techniques and electrical generator design is analyzed from a theoretical standpoint and then verified through integrated hydrodynamic‐electric simulations.

Findings

It has been proved that control parameters that maximize the power extraction from the waves can be derived based on the power and torque constraints imposed by the electrical machine.

Originality/value

An optimized and integrated approach to the control strategy selection and generator design for point absorbers has been presented, which maximizes the electric power generation from sea waves under real conditions and represents a good trade‐off for the PTO from both the technical and the economic standpoint.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 32 no. 1
Type: Research Article
ISSN: 0332-1649

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Article
Publication date: 5 March 2018

Mohammad Maalandish, Seyed Hossein Hosseini, Mehran Sabahi and Pouyan Asgharian

The main purpose of this paper is to select appropriate voltage vectors in the switching techniques and, by selecting the proper voltage vectors, be able to achieve a DC…

Abstract

Purpose

The main purpose of this paper is to select appropriate voltage vectors in the switching techniques and, by selecting the proper voltage vectors, be able to achieve a DC link with the same outputs and a symmetric multi-level inverter.

Design/methodology/approach

The proposed structure, a two-stage DC–AC symmetric multi-level inverter with modified Model Predictive Control (MMPC) method, is presented for Photovoltaic (PV) applications. The voltage of DC-link capacitors of the boost converter is controlled by MMPC control method to select appropriate switching vectors for the multi-level inverter. The proposed structure is provided for single-phase power system, which increases 65 V input voltage to 220 V/50 Hz output voltage, with 400 V DC link. Simulation results of proposed structure with MMPC method are carried out by PSCAD/EMTDC software.

Findings

Based on the proposed structure and control method, total harmonic distortion (THD) reduces, which leads to lower power losses and higher circuit reliability. In addition, reducing the number of active switches in current path causes to lower voltage stress on the switches, lower PV leakage current and higher overall efficiency.

Originality/value

In the proposed structure, a new control method is presented that can make a symmetric five-level voltage with lower THD by selecting proper switching for PV applications.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 37 no. 2
Type: Research Article
ISSN: 0332-1649

Keywords

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