Abdesslem Djerdir

A Double Excited Synchronous Machine for Direct Drive Application—Design and Prototype Tests

This paper presents the analytical, numerical, and experimental results obtained with a double excited synchronous machine (DESM) prototype designed and constructed for an electric vehicle traction system. To obtain a wide speed range, the flux-weakening technique is implemented. Analytical design, 2-D finite element method (FEM) analysis, thermal analysis, and prototype construction of the DESM are discussed, and the performances are assessed with experimental data.

Modelling and simulation of stator winding inter‐turn faults in permanent magnet synchronous motors

Purpose – The purpose of this paper is to present a new model to study inter‐turn short circuit faults in a permanent magnet synchronous machine.Design/methodology/approach – The machine is modeled by using classical two‐axis theory, and the equations are modified to take into account the stator inter‐turn faults. A state space form of the system is presented for dynamic simulations.Findings – The machine model is global and can work in both normal and fault conditions due to a fictitious resistance in the winding circuit. Various simulation results have been presented indicating the fault instant and its corresponding effect. Validation is carried out by transient time finite element simulations.Originality/value – The model can serve as a step towards development of fault detection and diagnosis algorithms.

Energy efficiency and fault tolerance comparison of DC/DC converters topologies for fuel cell electric vehicles

Due to low DC voltage generated from fuel cell, a DC/DC converter must be used to interface fuel cell and DC bus in automotive applications such as fuel cell electric vehicles (FCEVs). Furthermore, the occurrence of power semiconductors failures in DC/DC converter has negative effects both for fuel cell and DC/DC converter and consequently on the whole powertrain. The purpose of this paper is to show and analyze the impacts of power semiconductors faults on energy efficiency and waveforms (e.g. FC and DC bus voltages, FC current) without modifying the topology and control. Besides, it has been chosen to focus this study on two topologies of interleaved DC/DC converters enabling to take into consideration the requirements of FCEV applications. These topologies have the capacity compared with the boost topology to operate even in case of faults, ensuring consequently a continuity of service.

Passivity-Based Control of Hybrid Power Sources using Fuel Cell, Supercapacitors, and Batteries on the DC link for Energy Traction System

The classic proper energy element in electric vehicle consists of batteries and fuel cell (FQ, which allow a relatively high autonomy, but they are with moderate power capability. On the other hand, the capacitors have high power capability they can only be considered for applications which require little energy. In term of specifics energy and power, supercapacitors are situated between accumulators and traditional capacitors. The hybridation of these sources with a power source as supercapacitor (SC) is proposed. A recent approach of passivity- based control (PBC) is the interconnection and damping assignment (IDA-PBC) which is a very useful technique to control systems assigning a desired port-controlled Hamiltonian (PCH) structure to the closed-loop.

Sliding Mode Control for Energy Management of DC Hybrid Power Sources Using Fuel Cell, Batteries and Supercapacitors

The use of fuel cells as embarked electrical energy needs a storage system with high dynamic performances [1]. This storage system allows a peak load shaving, and compensates the intrinsic limitations of the main source. The use of supercapacitors [2] for this storage system is quite suitable, because of appropriate characteristics (huge capacitance, weak serial resistance), of direct storage (energy ready for use), of easy control by power electronic conversion and high dynamic storage elements comparing with slow dynamic fuel cell device [3]. This paper deals with the conception of hybrid power sources using fuel cell as main source, batteries on the DC link and supercapacitors as transient power source. The proposed structure is presented with a sliding mode controller and simulation results.

FOC and DTC Techniques for Controlling a Double Excited Synchronous Machine

The double excited synchronous machine (DESM) which was designed, analyzed and constructed by the authors should offer an improved efficiency while speed is increased beyond the rated one, and the goal of this paper is to prove it. By using two control techniques, field oriented control (FOC) and direct torque control (DTC) the advantages of the studied prototype are revealed through numerical analysis (by using Matlab/Simulink and Flux2D software). Finally, the tests come to support the performances obtained by numerical calculation.

Fault detection in 3-phase Traction Motor using Artificial Neural Networks

Traction Motors Condition Monitoring is one of the important factors in increasing motor life time and prevention of any train sudden stop in track and thereupon avoiding interruptions in track traffic. In this paper, a neural network based method for detecting unbalanced voltage fault which is one of the various faults in 3-phase traction motors was surveyed. Proposed method is independent from load state and fault percentage; which means neural network is able to detect fault and load condition without any assumption about the state of the load and fault. In proposed method, two separate neural networks are used for each problem. Experimental acquired data is used to train neural networks. Based on first test results, the neural structure could detect unbalanced voltage fault percentage with 98.5% precision. Also, based on second test results, the neural network could detect load condition accurately in 97% of the cases. According to these results, neural network is a good choice for solving similar problems.

Electric Vehicle Control using the Simulator ELEVES

The new constraints in vehicle design for personal mobility are the development of a non-polluting and high safety vehicle. This is the consequence of increasing road traffic and climatic environmental problems. Like solution of these problems, the vehicle with electrical traction has been contemplated. The pollution is strongly decreased and the electric traction gives the possibility to achieve accurate and quick control of the distribution torque. This paper presents a traction control system of an electric vehicle (EV) based on the energetic macroscopic representation (EMR) and its maximum control structure (MCS). The simulator ELEVES has been used to simulate the studied system. Finally, in order to validate the simulation results, a comparison between the results obtained by ELEVES and those obtained by Matlab/Simulink software tool has been included.

Electrical Train Feeding By Association Of Supercapacitors, Photovoltaic And Wind Generators

Because of their appropriate characteristics (huge capacitance, weak serial resistance), of direct storage (energy ready for use) and of easy control through the power electronic conversion, the use of supercapacitors as a storage element is quite suitable to the embarked electrical energy management. This new supercapacitive device of storage having high dynamic performances offers the possibility of the peak load shaving but also the compensation of the intrinsic limitations especially when it is joined to a main sources as an auxiliary power unit as for example its combination with fuel cell devices. This paper deals with the conception of an embarked power source using supercapacitors which are charged by means of the combination of a photovoltaic source and an aerogenerator. These supercapacitors ensure the power supply of a miniature train of 150 W of power. The design of this device, its control strategy and the obtained simulation with some experimental results are presented.

SimRDH: A Modeling and Simulation Environment With Component Hybrid Dynamic Nets, Elevator Application

Component hybrid dynamic nets (CHDNs) are a graphic model for hybrid dynamic systems, which allow every component of the hybrid system to be individually represented. On the basis of this methodology, a software tool dedicated to electrical engineering simulations has been developed. Thus, the aim of this paper is to present a brief review of the model structure and to describe the developed software called SimRDH. In order to show the applications of this software tool, a hydraulic system, a mechanical system, and finally, an elevator system powered by supercapacitors have been studied.