Cost functions for degradation control of electric motors in electric vehicles

This paper introduces a novel set of electric motor degradation cost functions based on energy usage, energy loss and work output, against their continuous operation rated values recommended by the manufacturer. Unlike conventional electric motor degradation indicators such as the bearing life and insulation life based service factors, these cost functions account for the quantified time in the degradation process. The cost functions are evaluated throughout the operational life of the motor using real-time measurements. Hence, they give a very accurate indication, which may be adapted for online controller tuning. This solid establishment of a degradation cost function also enables the system designer to give the user a choice between performance and degradation minimization. The proposed cost function scheme has experimentally been verified using a hardware-in-the-loop electric powertrain test-rig where standard drive cycles are used to conduct the experiments. The experimental results reveal that the degradation cost functions Cumulative Input Energy Ratio (CIER), Cumulative Loss Ratio (CLR) and Cumulative Work Ratio (CWR) accurately represent the electric motor degradation both qualitatively and quantitatively

OCCIDENT & ORIENT: Newsletter of the German Protestant Institute of Archaeology in Amman (Volume 1, No. 2, December 1996)

A Commitment to Strengthening German-Jordanian Cooperation, Promoting Protection of Sites By: Hans-Dieter Bienert, German Protestant Institute of Archaeology (Amman) A New Project on the Nabataean Settlement of Wadi Rum By: Laurent Tholbecq, Institut Francais d’Archéologie du Proche-Orient, Amman (Jordan) Documenting Tools of Old Stone Age Hunters in the Azraq Oasis. By: R. Low, D. Schnurrenberger, R. Watson, G. Rollefson, L. Quintero ‘Ain Ghazal Excavations (1996) unearth Neolithic “Temples” By: Gary Rollefson, ‘Ain Ghazal Research Institute (AGRI), Ober-Ramstadt (Germany) Zeidan Kafafi, Institute of Archaeology and Anthropology, Yarmouk University (Jordan) Petra proper and Greater Petra: The Archaeological Activities of Naturhistorische Gesellschaft Nürnberg (Germany) By: Manfred Lindner, Naturhistorische Gesellschaft Nürnberg (Germany) The Gods of the Nabataeans: A New Research Project By: Helmut Merklein, University of Bonn (Germany), Robert Wenning, University of Bonn (Germany) Is it Possible to Manage Future Agriculture in the Jordan Valley by Utilizing SalineWater? By: Brigitta Meier, Frankfurt/Main (Germany) Tell Johifiyeh: An Iron Age Site in Northern Jordan – Preparation of An archaeological Investigation. By: Roland Lamprichs, University of Freiburg (Germany) The ACOR Madaba Project. By: Timothy Harrison, ACOR (Jordan), Patricia Bikai, ACOR (Jordan) Twenty Years in Umm Qais (ancient Gadara) By: Ute Wagner-Lux, Basel (Switzerland), Karel J. H. Vriezen, Utrecht University (Netherlands) Breaking Ground For Professional Conservation. By: Friedrich Zink, Expert Conservator CIM Integrated Expert Program, Institute of Archaeology and Anthropology (IAA), Yarmouk University, Irbid (Jordan) CARCIP: The Second Phase By: Helge H. Fischer, Project Director CARCIP

Electric vehicle battery management algorithm development using a HIL simulator incorporating three-phase machines and power electronics

This paper describes a hardware-in-the-loop (HIL) test rig for the test and development of electric vehicle battery management and state-estimation algorithms in the presence of realistic real-world duty cycles. The rig includes two back-to-back connected brushless DC motors, the respective power electronic controllers, a target battery pack, a dSPACE real-time simulator, a thermal chamber and a PC for human-machine interface. The traction motor is commanded to track a reference velocity based on a drive cycle and the target battery pack provides the required power. Except the battery pack and the electric machine which are real, other parts of a vehicle powertrain system are modelled and used in the real-time simulator. A generic framework has been developed for real-time battery measurement, model identification and state estimation. Measurements of current and battery terminal voltage are used by an identification unit to extract parameters of an equivalent circuit network (ECN) model in real-time. Outputs of the identification unit are then used by an estimation unit which uses an artificial intelligent model trained to find the relationship between the battery parameters and state-of-charge (SOC). The results demonstrate that even with a high noise level in measured data, the proposed identification and estimation algorithms are able to work well in real-time

Degradation control for electric vehicle machines using nonlinear model predictive control

Electric machines (motors and generators) are over actuated systems. In this paper, we show how to exploit this actuation redundancy in order to mitigate machine degradation while simultaneously ensuring that the desired closed loop performance is maintained. We formulate a multiobjective optimization problem with a cost function having terms representing closed loop performance and component degradation for an inverter-fed permanent magnet synchronous motor. Such machines are important as they are widely used as the prime mover of commercial electric vehicles. The resulting optimal control problem is implemented online via a nonlinear model predictive control (NMPC) scheme. The control framework is validated for standard vehicle drive cycles. Results show that the NMPC scheme allows for better closed loop performance and lower degradation than standard industrial controllers, such as the field-oriented control method. Hence, this paper demonstrates how the remaining useful life of a machine can be increased by appropriate controller design without compromising performance

Fuzzy logic control for energy saving in autonomous electric vehicles

Limited battery capacity and excessive battery dimensions have been two major limiting factors in the rapid advancement of electric vehicles. An alternative to increasing battery capacities is to use better: intelligent control techniques which save energy on-board while preserving the performance that will extend the range with the same or even smaller battery capacity and dimensions. In this paper, we present a Type-2 Fuzzy Logic Controller (Type-2 FLC) as the speed controller, acting as the Driver Model Controller (DMC) in Autonomous Electric Vehicles (AEV). The DMC is implemented using realtime control hardware and tested on a scaled down version of a back to back connected brushless DC motor setup where the actual vehicle dynamics are modelled with a Hardware-In-the-Loop (HIL) system. Using the minimization of the Integral Absolute Error (IAE) has been the control design criteria and the performance is compared against Type-1 Fuzzy Logic and Proportional Integral Derivative DMCs. Particle swarm optimization is used in the control design. Comparisons on energy consumption and maximum power demand have been carried out using HIL system for NEDC and ARTEMIS drive cycles. Experimental results show that Type-2 FLC saves energy by a substantial amount while simultaneously achieving the best IAE of the control strategies tested

Novel Energy Management System for a DC MicroGrid

This paper presents a design and simulation of a rule based energy management system for a dc MicroGrid that considers a cost function to reflect the battery degradation and that relates to the actual battery parameters.The derivation of the battery cost function and the utilization of that to ensure an optimum utilization of the battery energy storage were presented. The detailed description of the algorithms used to implement the EMS was presented. Simulation on PSCAD/EMTDC software was used to demonstrate the operation of the EMS both under grid connected and islanded modes. Further, the inertia support provided by the super-capacitor to avoid the collapse of the dc link of the MicroGrid was demonstrated

A hardware-in-the-loop test rig for development of electric vehicle battery identification and state estimation algorithms

This paper describes a hardware-in-the-loop (HIL) test rig for the test and development of electric vehicle battery parameterisation and state-estimation algorithms in the presence of realistic real-world duty cycles. The rig includes two electric machines, a battery pack, a real-time simulator, a thermal chamber and a PC for human-machine interface. Other parts of a vehicle powertrain system are modelled and used in the real-time simulator. A generic framework has been developed for real-time battery measurement, model identification and state estimation. Measurements are used to extract parameters of an equivalent circuit network model. Outputs of the identification unit are then used by an estimation unit trained to find the relationship between the battery parameters and state-of-charge. The results demonstrate that even with a high noise level in measured data, the proposed identification and estimation algorithms are able to work well in real-time

Multi-terminal DC grid with wind power injection

With the development of offshore wind generation, the interest in cross-country connections is also increasing, which requires models to study their complex static and dynamic behaviors. This paper presents the mathematical modeling of an offshore wind farm integrated into a cross-country HVDC network forming a multi-terminal high-voltage DC (MTDC) network. The voltage source converter models were added with the control of active power, reactive power, frequency, and DC link voltages at appropriate nodes in the MTDC, resembling a typical cross-country multi-terminal type of HVDC scenario. The mathematical model for the network together with the controllers were simulated in MATLABTM and experimentally verified using a real-time digital simulator hardware setup. The resulting static and dynamic responses from the hardware setup agreed well with those from simulations of the developed models.peer-reviewe

Distributed control of electric drives via Ehernet

This report presents the work carried out aiming towardsdistributed control of electric drives through a networkcommunication medium with temporal constraints, i.e, Ethernet.A general analysis on time delayed systems is carried out,using state space representation of systems in the discretetime domain. The effect of input time delays is identified andis used in the preceding controller designs. The main hardwareapplication focused in this study is a Brushless DC servomotor, whose speed control loop is closed via a 10 MbpsSwitched Ethernet network. The speed control loop, which isapproximately a decade slower than the current control loop, isopened and interfaced to the network at the sensor/actuatornode. It is closed at the speed controller end at another nodein the same local area network (LAN) forming a distributedcontrol system (DCS). The Proportional Integral (PI) classical controller designtechnique with ample changes in parameter tuning suitable fortime delayed systems is used. Then the standard Smith Predictoris tested, modified with the algebraic design techniqueCoefficient Diagram Method (CDM), which increases the systemdegrees of freedom. Constant control delay is assumed in thelatter designs despite the slight stochastic nature in thetiming data observations. Hence the poor transient performanceof the system is the price for the robustness inherited to thespeed controllers at the design stage. The controllability andobservability of the DCS may be lost, depending on the range inwhich the control delay is varying. However a state feedbackcontroller deploying on-line delay data, obtained by means ofsynchronizing the sensor node and controller node systemclocks, results in an effective compensation scheme for thenetwork induced delays. Hence the full state feedbackcontroller makes he distributed system transient performanceacceptable for servo applications with the help of poleplacement controller design. Further, speed synchronizing controllers have been designedsuch that a speed fluctuation caused by a mechanical loadtorque disturbance on one motor is followed effectively by anyother specified motor in the distributed control network with aminimum tracking or synchronizing error. This type ofperformance is often demanded in many industrial applicationssuch as printing, paper, bagging, pick and place and materialcutting. Keywords:Brushless DC Motor, Control Delay, DistributedMotion Control Systems, Proportional Integral Controller, SmithPredictor, Speed Synchronization, State Feedback Controller,Stochastic Systems, Switched-Ethernet, Synchronizing Error,Time Delayed Systems, Tracking ErrorNR 2014080