Omar Hegazy

Control and Analysis of an Integrated Bidirectional DC/AC and DC/DC Converters for Plug-In Hybrid Electric Vehicle Applications

The plug-in hybrid electric vehicles (PHEVs) are specialized hybrid electric vehicles that have the potential to obtain enough energy for average daily commuting from batteries. The PHEV battery would be recharged from the power grid at home or at work and would thus allow for a reduction in the overall fuel consumption. This paper proposes an integrated power electronics interface for PHEVs, which consists of a novel Eight-Switch Inverter (ESI) and an interleaved DC/DC converter, in order to reduce the cost, the mass and the size of the power electronics unit (PEU) with high performance at any operating mode. In the proposed configuration, a novel Eight-Switch Inverter (ESI) is able to function as a bidirectional single-phase AC/DC battery charger/ vehicle to grid (V2G) and to transfer electrical energy between the DC-link (connected to the battery) and the electric traction system as DC/AC inverter. In addition, a bidirectional-interleaved DC/DC converter with dual-loop controller is proposed for interfacing the ESI to a low-voltage battery pack in order to minimize the ripple of the battery current and to improve the efficiency of the DC system with lower inductor size. To validate the performance of the proposed configuration, the indirect field-oriented control (IFOC) based on particle swarm optimization (PSO) is proposed to optimize the efficiency of the AC drive system in PHEVs. The maximum efficiency of the motor is obtained by the evaluation of optimal rotor flux at any operating point, where the PSO is applied to evaluate the optimal flux. Moreover, an improved AC/DC controller based Proportional-Resonant Control (PRC) is proposed in order to reduce the THD of the input current in charger/V2G modes. The proposed configuration is analyzed and its performance is validated using simulated results obtained in MATLAB/ SIMULINK. Furthermore, it is experimentally validated with results obtained from the prototypes that have been developed and built in the laboratory based on TMS320F2808 DSP.

Particle Swarm Optimization for optimal powertrain component sizing and design of fuel cell hybrid electric vehicle

In this paper, an optimal design to minimize the cost, mass and volume of the fuel cell (FC) and supercapacitor (SC) in a fuel cell hybrid electric vehicle is presented. Because of the hybrid powertrain, component sizing significantly affects vehicle performance, cost and fuel economy. Hence, during sizing, various design and control constraints should also be satisfied simultaneously. In this research, there are two optimization techniques have tested to achieve optimal design of the powertrain. These are Genetic Algorithm (GA) and Particle Swarm Optimization (PSO). The proposed schemes have been simulated by MATLAB/ SIMULINK. Simulation results have demonstrated that the optimal sizing of the powertrain components has been improved when the PSO is applied, which means high-performance operation for FCHEV.

Optimal power management and powertrain components sizing of fuel cell/battery hybrid electric vehicles based on particle swarm optimisation

Combining a Fuel Cell (FC), as primary power source, with a Battery Energy System (BES), as an auxiliary source, for high power demands is a promising approach for future hybrid electric vehicles (HEV). The powertrain control strategy and the component sizing significantly affect the vehicle performance, cost, vehicle efficiency and fuel economy. This paper presents a developed control strategy for optimising the power sharing between sources and components sizing by using Particle Swarm Optimisation (PSO) algorithm. This control strategy implemented on FC/Battery hybrid electric vehicle in order to achieve the best performance with minimum fuel consumption and minimum powertrain components sizing for a given driving cycle with high efficiency. The powertrain and the proposed control strategy have been simulated by Matlab/Simulink. The simulation results have demonstrated that the optimal sizing of the powertrain of FC/battery components and the minimum fuel consumption have been improved by applying the PSO control strategy.

PSO algorithm‐based optimal power flow control of fuel cell/supercapacitor and fuel cell/battery hybrid electric vehicles

Purpose – The purpose of this paper is to optimize the design and power management control fuel cell/supercapacitor and fuel cell/battery hybrid electric vehicles and to provide a comparative study between the two configurations.Design/methodology/approach – In hybrid electric vehicles (HEVs), the power flow control and the powertrain component sizing are strongly related and their design will significantly influence the vehicle performance, cost, efficiency and fuel economy. Hence, it is necessary to assess the power flow management strategy at the powertrain design stage in order to minimize component sizing, cost, and the vehicle fuel consumption for a given driving cycle. In this paper, the PSO algorithm is implemented to optimize the design and the power management control of fuel cell/supercapacitor (FC/SC) and fuel cell/battery (FC/B) HEVs for a given driving cycle. The powertrain and the proposed control strategy are designed and simulated by using MATLAB/Simulink. In addition, a comparative study...

Dual loop digital control design and implementation of a DSP based high power boost converter in fuel cell electric vehicle

High power boost converter has become the essential part of the distributed power system that enables energy to be fully utilized in fuel cell powered electric vehicles. This paper presents a DSP based direct digital control (DDC) design and implementation for a high power boost converter. A single loop and dual loop voltage control are digitally implemented and compared. The real time workshop (RTW) is used for automatic real-time code generation. Experimental results of a 20 kW boost converter based on TMS320F2808 DSP during reference voltage changes, input voltage changes, and load disturbances are presented. The results show that dual loop control achieves better steady state and transient performance than single loop control. In addition, the experimental results validate the effectiveness of using the RTW for automatic code generation to speed up the system implementation.

Analysis and modeling of a bidirectional multiport DC/DC power converter for battery electric vehicle applications

Integration of multiple DC sources has received a growing interest to enhance the powertrain performance of the BEVs. To achieve this integration, multiport DC/DC power converters (MPCs) could play a significant role in the future powertrains and sustainable energy systems. This paper proposes a bidirectional multiport DC/DC power converter (BMPC) to integrate multiple-input DC sources (such as High Energy Battery (HEB), Supercapacitor (SC) or High Power Battery (HPB)) to common DC-link in the BEV powertrain. In this article, the proposed BMPC is responsible for the power flow control between the DC sources and DC-link. The proposed converter can provide a compact size, low EMI, centralized control system, high reliability and high efficiency for the BEV drivetrain system compared to other converter topologies. The proposed converter and its control system are investigated and designed by using Matlab/Simulink. Furthermore, the simulation results are provided to verify the dynamic performances of the proposed powertrain in different operating modes. The impact of the proposed topology on the energy consumption and driving range of the vehicle is presented.

Design approach and interoperability analysis of wireless power transfer systems for vehicular applications

This article gives an overview of the analysis and modelling for 22 kW wireless power transfer (WPT) for Light Duty (250V traction battery) and Heavy Duty (700V) electric vehicles (EV). The system under investigation is the series/series (SS) WPT compensation topology, for which an iterative design approach is considered to select the suitable final system parameters. A simulation study is performed for a selected WPT design for different power electronics topologies, differing in the converter type at secondary side and EV battery voltage. The study focusses on the design and system evaluation of two proposed WPT vehicle architectures and their control for the different secondary systems that are supplied by the same and identically controlled grid system, to achieve interoperable WPT systems. Stable control at high efficiency (>90%) is achieved for both studied topologies, one with a boost DC/DC converter at secondary side and charging a 700V battery, the other with buck DC/DC converter to 250V.

Modeling and control of interleaved multiple-input power converter for fuel cell hybrid electric vehicles

Interleaving techniques are widely used to reduce input/output ripples, to increase the efficiency and to increase the power capacity of the DC/DC converters. This paper proposes an interleaved multiple-input power converter (IMIPC) that interfaces the fuel cell and energy storage systems (e.g. Batteries or/and Supercapacitors) to the powertrain of the hybrid electric vehicles. The IMIPC is responsible for the power-flow management on-board vehicle for each operating mode. In this research, the IMIPC is proposed in order to reduce the input current ripples, to reduce the output voltage ripples and to reduce the size of passive components with high efficiency. In addition, low EMI and low stress in the switches are expected. Moreover, a generalized small-signal model of the IMIPC is derived in order to design the closed-loop control strategies. The proposed power electronics interface (PEI) and its controller are designed and analyzed by using Matlab/Simulink. The simulation results have demonstrated that the proposed power electronics interface achieves a high performance for high power converter and it can be applied in the FCHEVs.

Modeling and analysis of different control techniques of conductive battery chargers for electric vehicles applications

Purpose – The purpose of this paper is to analyze and simulate the control techniques that can be used to control the on-board conductive battery chargers (OCBCs) for electric vehicles applications. This paper also provides a comparative study of these control techniques. Design/methodology/approach – Battery chargers would play an important role in the development of new battery electric vehicles (BEVs). The control techniques of these OCBCs can significantly influence the BEV performance during the charging mode from the ac grid. In addition, the proper selection of control systems of the OCBCs has a great impact on the power quality of the AC grid during the charging period. Therefore, this paper presents the analysis of different control techniques that are commonly used to control the battery chargers. In addition, a comparative study of different control techniques of the OCBCs for BEVs is provided. Findings – The results have demonstrated that it is possible to significantly improve the efficiency,...

Influence of pulse variations on the parameters of first order empirical Li-ion battery model

Battery performance and safety constitute a bottleneck for electric vehicles to penetrate the car market. Online battery models are one of the engineering tools to enhance their performance. Empirical battery models form the subject of many scientific publications. In this paper a study, is performed of the usefulness of the first order impedance model through the consistency of the parameters under changes in the calibration signal, i.e. the current pulse. It can be concluded that simple first order models show little potential to really increase battery performance. Only the equivalent series resistance of the first order impedance model is insensitive to small variations of the calibration signal.