A Sensorless Direct Torque Control Scheme Suitable for Electric Vehicles

International audienceIn this paper a sensorless control is proposed to increase the efficiency of a Direct Torque Control (DTC) of an induction motor propelling an Electric Vehicle (EV). The proposed scheme uses an adaptive flux and speed observer that is based on a full order model of the induction motor. Moreover, it is evaluated on an EV global model taking into account the vehicle dynamics. Simulations were first carried out on a test vehicle propelled by a 37-kW induction motor to evaluate the consistency and the performance of the proposed control approach. The commonly used European drive cycle ECE-15 is adopted for simulation. The obtained results seem to be very promising. Then, the proposed control approach was experimentally implemented, on a TMS320F240 DSP-based development board, and tested on 1-kW induction motor. Experimental results show that the proposed control scheme is effective in terms of speed and torque performances. Indeed, it allows speed and torque ripple minimization. Moreover, the obtained results show that the proposed sensorless DTC scheme for induction motors is a good candidate for EVs propulsion

A Comparison of Symmetrical and Asymmetrical Three-Phase H-Bridge Multilevel Inverter for DTC Induction Motor Drives

International audienceEarlier studies have pointed out the limitations of conventional inverters, especially in high-voltage and high-power applications. In recent years, multilevel inverters are becoming increasingly popular for high-power applications due to their improved harmonic profile and increased power ratings. Several studies have been reported in the literature on multilevel inverters topologies, control techniques, and applications. However, there are few studies that actually discuss or evaluate the performance of induction motor drives associated with three-phase multilevel inverter. This paper presents then a comparison study for a cascaded H-bridge multilevel direct torque control (DTC) induction motor drive. In this case, symmetrical and asymmetrical arrangements of five- and seven-level H-bridge inverters are compared in order to find an optimum arrangement with lower switching losses and optimized output voltage quality. The carried out experiments show that an asymmetrical configuration provides nearly sinusoidal voltages with very low distortion, using less switching devices. Moreover, torque ripples are greatly reduced

Commande DTC d'une propulsion moteur asynchrone / onduleur multiniveaux asymétrique pour un véhicule électrique

International audienceCet article présente une technique de commande d'un moteur asynchrone alimenté par un onduleur asymétrique en cascade, destinée à des systèmes d'entraînements électriques de type véhicule urbain. Cette technique de contrôle est basée sur le principe de la commande directe du couple. La référence du vecteur de tension de l'onduleur est calculée à partir de l'erreur de flux imposée par le contrôleur de couple. Cette référence de tension est alors produite par l'utilisation d'un onduleur multiniveaux asymétrique en H, dont les cellules du convertisseur sont alimentées par des sources de tensions de nature différentes qui peuvent être dans le cas du véhicule électrique : des piles à combustibles, des batteries ou des supercondensateurs. Cette structure d'onduleur fournie des tensions presque sinusoïdales avec un taux d'harmonique très faible. En raison du faible gradient de la tension, les ondulations de couple sont considérablement réduites. Un autre avantage de la structure asymétrique est l'utilisation de différents types de composants qui peuvent commuter à des fréquences élevées avec des pertes réduites. Par conséquent, de bonnes performances dynamiques en terme de vitesse et de couple sont obtenues, permettant ainsi à la commande directe du couple associée à des convertisseurs asymétriques d'être un excellent candidat pour des applications de type véhicule électrique urbain

Integrated Energy Management of a Plug-in Electric Vehicle in Residential Distribution Systems with Renewables

International audienceAccording to innovation in grid connected transportation industry and with ever increasing concerns on environmental issues and clean energy, electric vehicles (EVs) and hybrid electric vehicles (HEVs) with low noise, zero emission, and high efficiency have attracted more and more attention of researchers, governments and industries, they are becoming the most likely fleets to replace gasoline vehicles in future power systems. In addition to the approved advantages for transportation, EVs have the potential to provide other benefits within the connected residential distribution to micro-grids and smart grids as part of a vehicle-to-grid (V2G) system, knowing that in future systems residential distribution can be seen as an energy resource with decentralized and autonomous decisions in the energy management called smart house or prosumer. They can participate effectively in helping to balance supply and demand by valley filling and peak shaving. The EV battery can be charged during low demand and the stored power can be fed power back into the micro-grid during high-demand periods, providing a spinning reserve to dump short power demand changes. V2G may also be used to buffer renewable energy sources, such as photovoltaic generators, by storing excess energy produced during illumination periods, and feeding it back into the grid during high-load periods, thus effectively stabilizing the intermittency of solar power. In this context, this paper describes an energy management system for a smart house based on hybrid PV-battery and V2G. Keywords—Vehicle-to-grid (V2G), vehicle-to-home (V2H), residential distribution, smart house, balance supply and demand

A Minimization of Speed Ripple of Sensorless DTC for controlled Induction Motors used in Electric Vehicles

International audienceThe main theme of this paper is to present different switching techniques in DTC induction motor drives for electric vehicle applications, witch insert zero-voltage vector and/or more non zero-voltage vectors to the conventional switching table associated to full adaptive flux and speed observer. Those techniques are quite effective in reducing the torque pulsation and the speed ripples of the motors, as demonstrated in experimental results

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

International audienceThis 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 n DC source for (2n + 1) 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 (n − 1) 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

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

International audienceThis 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

FC/Battery Power Management for Electric Vehicle Based Interleaved DC-DC Boost Converter Topology

International audienceDue to the fact that the environmental issues have become more serious recently, interest in renewable energy systems, such as, fuel-cells (FCs) has increased steadfastly. Among many types of FCs, proton exchange membrane FC (PEMFC) is one of the most promising power sources due to its advantages, such as, low operation temperature, high power density and low emission. However, using only PEMFC for electric vehicle may not be feasible to satisfy the peak demand changes especially during accelerations and braking. So, hybridizing PEMFC and an energy storage system (ESS) decreases the FC cost and improves its performance and life. Battery (B) appears to be the most powerful candidate to hybridize with PEMFC for vehicular applications. Therefore, the performance of PEMFC/B hybridization is limited considerably by the performance of the converter. Thus, a suitable dc-dc converter topology is required. Various isolated and nonisolated converter topologies for FC applications have been proposed in literature. The objective of this study is to design and simulate a fuel cell - interleaved boost dc-dc converter (FC-IBC) for hybrid power systems in electric vehicle application, in order to decrease the FC current ripple. Therefore Energetic efficiency can also be improved. A control strategy capable of determining the desired FC power and keeps the dc voltage around its nominal value by supplying propulsion power and recuperating braking energy is designed and tested with an urbane electric vehicle model

An Improved MPPT Interleaved Boost Converter for Solar Electric Vehicle Application

International audienceAn interleaved boost dc/dc converter is developed featuring smaller input/output filters, faster dynamic response and lower device stress than conventional designs, for solar electric vehicle (SEV) applications. The converter is connected between the photovoltaic power generation and dc bus in a multisource energy storage system of a SEV. Typically, interleaved converters require a current control loop to reduce the input current ripples, the output voltage ripples, and the size of passive components with high efficiency. A Maximum Power Point Tracking (MPPT) controller for a Photovoltaic (PV) solar system associated to backup source (Battery) guarantees an uninterrupted power supply and assist the propulsion of the vehicle during transients and recover energy during regenerative braking. The design, construction, and testing of an experimental hardware p rototype is presented, with the test results included

An optimal fuzzy logic power sharing strategy for Parallel Hybrid Electric Vehicles

International audienceVehicle emission reduction has been a research objective for many years, by improving fuel economy and energy efficiency. Therefore, this paper presents a fuzzy logic controller for a Parallel Hybrid Electric Vehicle (PHEV). The PHEV required driving torque is generated by a combined contribution from an Internal Combustion Engine (ICE) and an Induction Motor (IM). The proposed Fuzzy Logic Controller (FLC) is designed based on the desired driving torque and the batteries State of Charge (SoC) with the objective to minimize fuel consumption and emissions, while enhancing or maintaining the PHEV driving performance characteristics. The fuzzy controller output controls the ICE throttle angle degree to achieve operation in a high efficiency region. The induction motor is sized to supply peak power to meet the load power requirement of the PHEV. The proposed PHEV fuzzy controller is implemented and simulated via the advanced vehicle simulator ADVISOR using the European urban (ECE-15) and sub-urban (EUDC) driving cycles. Simulation results reveal that the proposed fuzzy torque distribution strategy is effective over the entire operating range of the vehicle in terms of performance, fuel economy, and emissions