Modeling and Simulation of Vehicular Power Systems - webfiles its ...

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When the power requirement varies, so does the operating point. Since the map is adescription of the combustion engine performance in stationary operation, the transientbehavior of the engine is not considered but with a kind of acceptable approximation thetransient change in operating point could be modeled by a first order low pass filter in thecontrol system with the time constant of 1.5 seconds. These transient behaviors arecaused by:• Acceleration and deceleration of gas and exhaust flow plugs• Wall-wetting phenomenonThere are some other dynamic modelings of the engine which can be used for transientsimulations [3].6.3 Control systemOne of the most important parts in the simulation of hybrid vehicles is the control system.In hybrid vehicles as there are at least two energy sources, so the power needed fortraction, recharging of batteries and ultra capacitors auxiliary loads must be provided byenergy sources. The way that this needed power is shared between sources called energymanagement which has some effects on the performance of the vehicle. Using differentcontrol strategies, the fuel consumption and performance of the hybrid drive train couldbe changed [14].40
7 Modeling in Simulink/MatlabOnce the analytical approaches have finished regarding each component used in a typicalhybrid drive train it is required to make a model for any of the components in asimulation area. All the components including battery, engine, electric motor andgenerator, vehicle dynamics, tyre, automatic driver, driving cycles and control system aremodeled in Matlab/Simulink. In the following, the modeling process in Matlab for eachpart is explained.7.1 BatteryOnce all the parameters including charging and discharging resistances, open circuitvoltage of the battery versus state of charge and temperature were measured byexperiments, those values are used as look up tables. The model consists of three parts:SOC calculation block, voltage calculation and thermal modeling block shown in figure7-1. The input of the model is the requested power out of the battery. According to therequested power using analytical solutions the current and terminal voltage of the batteryis calculated. As mentioned in chapter 4 during modeling in respect to the direction of thepower, charging and discharge resistances are selected. As current is drawn out of thebattery the total charge drawn out of the battery is calculated. Based on the internaltemperature coming from the thermal model and current, the maximum capacity of thebattery (A.h) is corrected by look-up tables. The charge drawn out of the battery isdivided by the maximum capacity of battery in a certain current and temperature givesthe state of charge of the battery.In each time step the parameters are updated according to temperature and state ofcharge. The maximum charging and discharging power, terminal voltage and current islimited in the model.41
Page 1:
AhaModeling and Simulation of Vehic
Page 4: To my parents, brother and my love
Page 7 and 8: Table of ContentsAcknowledgment....
Page 9 and 10: List of FiguresFigure 2-1: Oil cons
Page 11: List of TablesTable 3-1 List of som
Page 14 and 15: xii
Page 16 and 17: Chapter 4 discusses the dynamics of
Page 18 and 19: The Other environmental effects of
Page 20 and 21: So a modeling tool being able to de
Page 22 and 23: electric motor to provide the tract
Page 24 and 25: Figure 2-8: Configuration of a para
Page 26 and 27: Vehicle system modeling can be done
Page 28 and 29: Figure 3-2: EMTS solution flow-char
Page 30 and 31: Figure 4-2: The deflection of tyre
Page 32: V −Vwheel actualλa=( 4-9)VwheelV
Page 35 and 36: Figure 4-5 Friction coefficient cha
Page 37 and 38: The gear box consists of different
Page 39 and 40: Where• I = discharge current [amp
Page 41 and 42: decreases very rapidly. In electric
Page 43 and 44: Thus, this simulation model is capa
Page 45 and 46: VOCRchargeRdischargeSOCTempSOCQmaxT
Page 47 and 48: Figure 5-8 Battery open circuit vol
Page 49 and 50: Figure 5-11 Charging resistance ver
Page 51 and 52: 6 Engine, electric machine and cont
Page 53: 4 Idle speed 840 rpm5 Peak power 15
Page 57 and 58: Figure 7-3 Vehicle dynamics block i
Page 59 and 60: 7.3 EngineAs described in Chapter 5
Page 61 and 62: Figure 7-7 Automatic driver model b
Page 63 and 64: 8 Simulation ResultsIn this chapter
Page 65 and 66: Peak generator torque1074 N.mPeak g
Page 67 and 68: Figure 8-5 Wheel speed and translat
Page 69 and 70: Figure 8-7 Engine and generator pow
Page 71 and 72: Figure 8-9 Battery state of charge
Page 73 and 74: 9 ConclusionRegarding the significa
Page 75 and 76: References[1] Shuo Tian, Guijun Cao
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