Khoudir Marouani

Hybrid Cascaded H-Bridge Multilevel-Inverter Induction-Motor-Drive Direct Torque Control for Automotive Applications

This paper presents a hybrid cascaded H-bridge multilevel motor drive direct torque control (DTC) scheme for electric vehicles (EVs) or hybrid EVs. The control method is based on DTC operating principles. The stator voltage vector reference is computed from the stator flux and torque errors imposed by the flux and torque controllers. This voltage reference is then generated using a hybrid cascaded H-bridge multilevel inverter, where each phase of the inverter can be implemented using a dc source, which would be available from fuel cells, batteries, or ultracapacitors. This inverter provides nearly sinusoidal voltages with very low distortion, even without filtering, using fewer switching devices. In addition, the multilevel inverter can generate a high and fixed switching frequency output voltage with fewer switching losses, since only the small power cells of the inverter operate at a high switching rate. Therefore, a high performance and also efficient torque and flux controllers are obtained, enabling a DTC solution for multilevel-inverter-powered motor drives.

Modelling and frequency separation energy management of fuel Cell-Battery Hybrid sources system for Hybrid Electric Vehicle

This paper presents a hybrid system of fuel cell-battery power sources for electric vehicle. Because fuel cell (FC) and battery have advantages and disadvantages of their own, it should be beneficial to have hybrid sources, in which FC supplies the base energy while battery supplies peak power for fast acceleration and captures the braking energy regeneration. In this paper a state space model for the Fuel Cell-Battery Hybrid Electric Vehicle (FCEV) power system is given and an energy management based on frequencies separation is discussed and validated by Matlab simulation.

Power factor correction of an electrical drive system based on multiphase machines

This paper deals with the energy efficiency improvement of an electrical drive which can be used both in wind energy conversion or motor drive applications. A power factor (PF) control scheme is presented allowing energy efficiency enhancement and optimization in high power variable-speed drives based on multiphase machines. Thus, the double-star induction machine is taken, as an example of multiphase machines, to introduce the principle of the study presented in this paper. In fact, the purpose of this paper is to maintain the PF of the power-winding, of the double star induction machine, in vicinity of unity whatever the drive operating point. Also, this control scheme can be generalized for several kinds of multiphase machines.

Experimental investigation of an emulator "Hardware In the Loop" for electric naval propulsion system

The purpose of this paper is the realization of an emulator for electric naval propulsion system. The main objective of an emulator is to reproduce the real system operation. The work consists of two principal parts: the first part concerns the modeling of the propeller and the different resistance forces opposed to the movement of the ship, allowing the estimation of the necessary propulsion power, and the second part presents the emulator of the ship propulsion system, based on the Hardware In the Loop (HIL) principle, using an electric machine operating as a generator to emulate the dynamic characteristic of the ship. The resulting model is validated by numerical simulations and then tested on an experimental test bench constituting the emulator. Different experiments are conducted taking into account the real operation of the ship.

Energy Management Based on Frequency Decoupling: Experimental Results with Fuel Cell-Electric Vehicle Emulator

Nowadays, there is tendency to develop vehicles that use clean and renewable energies. The Fuel cell (FC) electrical vehicles(EV) use hydrogen to generate electrical energy necessary to the traction. They present several advantages compared to other vehicles, but the use of the FC alone as energy source suffers of many problems in relation with her slow dynamic, where the interest in hybridization with a second source. This paper presents a control strategy scheme based on frequency separation for Fuel cell-Battery Hybrid Electric Vehicle (HEV), using a Fuel cell (FC) as a main energy source, and a battery as an auxiliary power source. In this strategy a frequency splitter is used to routing the low frequency content of power demand into the FC and its high frequencies into the battery, taking profit from the battery as a peak power unit. In order to validate this strategy, Simulation and experimental results are carried out, using an emulator of a multi sources traction assembly taking into consideration the vehicle dynamic and the effects of external environment.

Six-phase induction machine operating as a standalone self-excited induction generator

This paper deals with the use of multiphase induction machines in renewable energy applications such as wind and hydropower. Thus, some preliminary test results carried out on a six-phase induction machine operating as a stand-alone self-excited induction generator and supplying various loads under different conditions are presented. Firstly, the dynamic model of the power generation system is developed considering the magnetizing inductance saturation and excitation capacitors sizing to ensure the excitation task. Then, simulation and experimental results carried out on a 5.5 kW six-phase squirrel-cage induction generator are presented and discussed.

Energy management and optimal control strategies of fuel cell/supercapacitors hybrid vehicle

In this paper, an energy management strategy (EMS) based on optimal control theory is applied to a hybrid vehicle propelled by fuel cell and supercapacitors pack. In order to show the effectiveness of this strategy, another EMS based on thermostat method is proposed and compared with the first one. Firstly, the power sources used in this study are presented with the electrical model of each one, and the hybrid architecture is given. Then, the EMS based on optimal control is expressed, where the minimization of the hydrogen consumption is its objective as well as the supercapacitor state of charge control. Then, the thermostat method strategy, which is a simple control method based on rules imposed by the limits of the power sources is applied. These two EMSs have been simulated using Matlab/Simulink. The results indicate the effectiveness of the energy management based on optimal control, which leads to improving the fuel consumption and a good control of the auxiliary source.

Observation and measurement of magnetic flux in a dual star induction machine

This paper presents a comparative study of estimation and observation techniques of magnetic flux in a dual star induction motor (DSIM). The first estimation technique is open loop, based on the integration of the stator voltage equation. While the second method of estimation is closed loop, based on the Luenberger observer. The experimental results of these estimation techniques are confronted with experimental measurements performed using an extra winding mounted inside the machine and used as flux sensor. The results are conclusive and the study constitutes a very interesting basis and allows the development and validation of other methods of flux and speed observation and diagnosis.

A control strategy scheme for fuel cell-vehicle based on frequency separation

This paper presents a control strategy scheme based on frequency-separation for Fuel cell-Battery Hybrid Electric Vehicle (HEV), using a Fuel cell (FC) as a main energy source, and a battery as an auxiliary power source. First, an analysis of hybrid architecture using an FC and batteries for automotive applications is presented. Next, the model and the control strategy are described. In this strategy a frequency splitter is used for routing the low frequency content of power demand into the FC and its high frequencies into the battery, taking profit from the battery as a peak power unit. Simulation and experimental results validate the performance of this strategy.

Rotor flux control with copper losses reduction in a high power drive system

This paper presents a control strategy allowing energy efficiency improvement, in high power drive system based on a multiphase motor. In fact, the main objective of the control strategy is to minimize the magnetizing energy, by setting the magnetic state of the motor, according to the drive operating point. So, the current circulating through the motor windings can be reduced, and this leads to Joule losses reduction and therefore to machine efficiency improvement. The control strategy is validated by simulation, and experimental results carried out on a drive system based on a dual star induction motor (DSIM).