Design of Planetary Plug-in Hybrid Powertrain and Its Control Strategy

Transcription

1 Page EVS5 Shenzhen, China, Nov 5-9, 010 Design of Planetary Plug-in Hybrid Powertrain and Its Control Strategy Antoni Szumanowsi 1, Zhiyin Liu 1, Yuhua Chang 1 1 The Faculty of Automotive and Construction Machinery Engineering, Warsaw University of Technology, ul. Narbutta 84, Warsaw, 0-54, Poland Antoni.Szumanowsi@simr.w.edu.l, zliu@simr.w.edu.l, yuhua.chang@simr.w.edu.l Abstract This aer resents the new comact hybrid lanetary transmission drive (CHPTD) as a solution of lug-in hybrid electric vehicle (PHEV). The resented CHPTD is more comact and lower costs than other seriesarallel hybrid drives equied with lanetary transmission and two motors. Proer architecture and elements were designed to achieve functions of PHEV. The owertrain and its comonents were otimized and determined by nonlinear dynamic modeling and simulations. Parameters of owertrain were adjusted and otimized by observation of simulation results. Two basic control strategies were analyzed to achieve minimum energy consumtion and suitable oeration range of battery state of charge. The very effective oeration of the wored out owertrain was roved by tests in different driving conditions regarding city traffic and suburb area. The advantages of lanetary transmission which is ower summing mechanical unit, was obtained by roer design and control of innovative high energy saving electromagnetic clutch/brae device based on classic dual-diahragm sring system. Keywords lug-in hybrid, lanetary transmission, design, simulation, energy consumtion minimizing 1 Configuration design of lug-in hybrid owertrain with lanetary transmission 1.1 Configuration design Different toologies of hybrid owertrain system have been develoed in the ast decades. Generally, lug-in hybrids are based on the same owertrain architectures as conventional electric hybrids. The Comact Hybrid Planetary Transmission Drive (CHPTD) is a comlex hybrid owertrain architecture which was original invented and develoed by Prof. Szumanowsi [1]. In this aer, CHPTD is alied as basic architecture in configuration design of lug-in hybrid owertrain. Figure 1 shows the new CHPTD with roer adjustment for lug-in hybrid. M 4Q ICE CHPTD with -ste gearbox and C/B system Brae I Clutch/Brae II Planetary gearbox -ste gearbox Clutch III Differential Fig. 1: Configuration of new CHPTD with roer adjustment for lug-in hybrid EVS5 World Battery, Hybrid and Fuel Cell Electric Vehicle Symosium 1

2 Page CHPTD uses only one electric motor for all oerating modes such as ure electric drive, hybrid drive and regenerative braing. A small internal combustion engine is emloyed as an alternative ower source. As a ower summing unit, the lanetary gearbox combines two ower sources. Clutch/brae system is equied in owertrain to achieve different oerating modes of lug-in hybrid owertrain. When either Brae I or Clutch/Brae II wors in braing status, the freedom degree of lanetary gearbox decreases from to 1. It gives more ossibility and flexibility for advanced control strategies of lugin hybrid owertrain. Additionally, a -ste gearbox is equied to obtain better erformance of energy consumtion in different woring conditions. It also extends the driving range of hybrid vehicle. 1. Clutch/brae system design The clutch/brae system emloyed in the lug-in hybrid owertrain influences the erformance of whole system. However, the existent electromagnetic clutch/brae system consumes electric ower continuously. To minimize the energy consumtion, the innovative zero steadystates electrical energy consumtion clutch/brae system is selected []. Figure resents the clutch/brae system for different alications, which consists of brae, clutch/brae and clutch for three shafts. Fig. : Construction of zero steady-states electrical energy consumtion clutch/brae systems 1- Electromagnetic actuator; - Clutch release late; 3 - Friction late; 4 - diahragm sring By rofiting from the nonlinear characteristic of dual-diahragm sring, the clutch/brae system can ee steady-states without consuming any electric energy. Modeling In order to evaluate the feasibility of designed lanetary lug-in hybrid owertrain and to otimize the arameters of system, dynamic model was built in MATLAB SIMULINK environment by using the original mathematical or digital models of each comonents. Fig. 3: The simulation flow of lanetary lug-in hybrid owertrain dynamic model.1 Vehicle model The mathematical equations used for vehicle model are as following. The gradient resistance Fg was ignored to simlify the model. M wheel ( Ff Faero Facc Fg ) rdyn (1) Ff mgcos f () ca x Faero v (3) dv Js j m J Facc m b ( b 1 ) 3.6 dt mr dyn (4). Planetary transmission model Planetary gearbox combines ower, torque and angular velocities of ICE, electric motor and outut shaft. In this alication, the ICE, electric motor and outut shaft connect to sun wheel, crown and yoe of lanetary gear searately. The following equations describe the relation of torque and angular velocity. In these equations, is basic ratio of lanetary gear which maes big influence on ower summing and differencing of hybrid owertrain. 1 ( 1 ) 3 0 (5) 1 J 1 1 1M1 M (6) 1 J 3 3 M3 3M (7).3 ICE model ICE model is based on engine ma (Figure 4). By inutting torque and rotary seed of engine, fuel EVS5 World Battery, Hybrid and Fuel Cell Electric Vehicle Symosium

3 Page consumtion rate is obtained as outut of engine ma. Table 1 shows the factors in equation (8) and (9) for 30Ah/43V Li-ion module from SAFT comany which is used in simulation. The aroximated equation and factors are based on battery discharging characteristics obtained by exeriments. Fig. 6: The battery model in MATLAB SIMULINK Fig. 4: Engine ma.4 Electric motor model The electric motor model is based on efficiency ma of electric motor and inverter (Figure 5). Power efficiency is obtained by inutting the torque and motor rotary seed. Fig. 5: Efficiency ma of electric motor with inverter Table 1: Factors of equation (8) and (9) for 30Ah Liion battery module from SAFT: Factors Internal resistance during discharging R() Electromotive force E() A B C D E F G Simulation results 3.1 Simulation arameters In order to analyze the influence of different control strategies and arameters, several comarison simulations were done under NEDC (New Euroean Driving Cycle). An ultra-light baset-tube frame vehicle is considered as the vehicle model (Figure 7). The dimension of the car is 3m in length and 1.5m in width. Table shows the arameters of lanetary lug-in hybrid owertrain..5 Battery model A nonlinear dynamic battery model is used in battery modeling [4]. In this method, the electromotive force E and internal resistance r are resolved in 6-order algebraic exression of battery SOC E() A e B e C e D e E e F e Ge (8) R() A r B r C r D r E r F r Gr (9) EVS5 World Battery, Hybrid and Fuel Cell Electric Vehicle Symosium 3

4 Page Fig. 7: The ultra-light baset-tube frame vehicle designed and rototyed by Prof. Szumanowsi grou Table : Parameters of lanetary lug-in hybrid owertrain and its comonents Vehicle Vehicle mass [g] 750 Rolling resistance coefficient Aerodynamic drag coefficient 0.33 Front surface square [ m ] 1.6 Dynamic radius of wheel [m] 0.57 Basic ratio of lanetary gear 1.99 Driving cycle NEDC Main reducer ratio 3.6 Reducer ratio between motor and lanetary transmission 1.35 Battery Battery tye Li-ion Battery ac number 3 Nominal voltage [V] 43*3 Nominal caacity [Ah] 30 PM motor Pea ower [W] 75 Continuous ower [W] 30 Maximal rotary seed [rm] 5000 Nominal torque [Nm] 60 Maximal torque [Nm] 40 Thermal engine (Gasoline) 3 Volume [ cm ] 100 Maximal ower [W] 35 Maximal torque [Nm] 78 Rotary seed rang [rm] 1000~ Basic control strategy The control of whole owertrain is connected with clutch/brae oerations. Table 3 shows the relation between control signal of clutch/brae system and oerating modes of owertrain. In control strategy, vehicle seed, torque on transmission shaft and battery SOC are used as feedbac signals for changing the oerating mode of owertrain. The basic control method is listed as below. For starting, ure electric mode is enabled to reduce emission. For low seed and middle seed, control system determines the oeration mode according to torque on transmission shaft and battery SOC. When torque is too low, ure electric mode is selected to avoid ICE woring in a oor condition. For high seed mode, hybrid mode is selected when SOC is over threshold. If SOC is lower than threshold, ure engine mode is enabled to rotect battery. Table 3: Control signal of clutch/brae systems for different oerating modes of lug-in hybrid owertrain Oeration mode of lug-in hybrid owertrain Pure electric drive and regenerative brae Control signal of clutch/brae systems Clutch/Brae Brae I* II** Pure engine drive on on Hybrid drive on Engine charge battery (when vehicle sto) * on indicates brae engaged; ** on indicates clutch engaged and brae disengaged. 3.3 Comarison simulation for different control strategies To investigate the influence of different control strategies, this aer sets u two control strategies for demonstration which are Strategy I and Strategy II. In Strategy I, it uses vehicle seed cooerated with torque on transmission shaft as feedbac signal for changing oeration mode. In Strategy II, it uses torque on transmission shaft cooerated with demand ower as feedbac signal for changing oeration mode. EVS5 World Battery, Hybrid and Fuel Cell Electric Vehicle Symosium 4

5 Page Fig. 8: Comarison of average fuel consumtion in different control strategy Fig. 9: Comarison of battery SOC in different control strategy Figure 8 and 9 show the simulation results for Strategy I and Strategy II. For the same driving range (540m), fuel consumtion of Strategy I is less than that of Strategy II by %. By the end of simulation, battery SOC is limited to the roer set value in Strategy II. While in Strategy I, battery SOC is out of control and decreases to It means that the owertrain could wor in hybrid mode for long distance driving to achieve better fuel economy without damaging the battery. Considering requirements of lug-in hybrid and similar fuel economy erformance, Strategy II is better than Strategy I. 3.4 Simulation for ure electric drive Battery caacity influences driving range for ure electric drive of lug-in hybrid owertrain. To fulfill the functionality of lug-in hybrid, battery caacity is adjusted to 3.9Wh. According to simulation results, the hybrid owertrain could drive over 50m for ure electric drive with full charged battery. 3.5 Otimization of -ste gearbox The -ste gearbox is an imortant element for the lug-in hybrid owertrain. With roer adjusted gear ratio and gear changing strategy, it could increase the energy efficiency for different driving conditions regarding to city traffic and suburban area. Table 4 shows simulation results for different gear ratios. In these simulation exeriments, driving range and battery conditions are the same. According to simulation results, smaller ed-gear ratio could achieve better fuel efficiency for high seed drive. However, by changing gear ratio, it also changes the oerating oints of ICE on engine ma. With limitation of oerating range, the adjustment of gear ratio should cooerate with observing the oerating oints to ee ICE woring in efficient area. Table 4: Comarison of simulation results for different gear ratios 1 st - gear edgear Seed threshold for changing gear (m/h) Average fuel consumtion (L/100m) The simulation results in Table 5 rove that the seed threshold for changing gear also has influence on fuel consumtion. Furthermore, the main reducer ratio and additional gear ratio between engine and lanetary transmission are roer adjusted to cooerate with -ste gearbox for minimizing fuel consumtion. Table 5: Comarison of simulation results for different seed threshold with the same gear ratio 1/0.8 Seed threshold for changing gear (m/h) Average fuel consumtion (L/100m) Conclusions This aer resents the method of designing lugin hybrid owertrain with lanetary transmission based on CHPTD. CHPTD is more comact and lower costs than other series-arallel hybrid drives equied with lanetary transmission and two motors. Dynamic model of the owertrain has been established in MATLAB SIMULINK environment. The simulation results show: EVS5 World Battery, Hybrid and Fuel Cell Electric Vehicle Symosium 5

6 Page CHPTD is a suitable configuration for lug-in hybrid alication. The advantage of lanetary transmission is obtained by roer design and control of new electromagnetic clutch/brae device based on classic dual-diahragm sring system. Control strategy influences the erformance of hybrid owertrain a lot. With roer designed control strategy, the lug-in hybrid owertrain could achieve good erformance on fuel consumtion and battery SOC management. With otimized gear ratio and control strategy, the imlementation of -ste gearbox increases the fuel efficiency in different driving conditions. According to comarison simulation results, the fuel consumtion of hybrid owertrain with -ste gearbox is decreased by 9% than that without - ste gearbox. References [1] Antoni Szumanowsi, Yuhua Chang and Piotr Piórowsi, Analysis of Different Control Strategies and Oerating Modes of Comact Hybrid Planetary Transmission Drive, Vehicle Power and Proulsion, 005 IEEE Conference, Se [] Antoni Szumanowsi, Zhiyin Liu and Hajduga Aradiusz, Zero Steady-states Electrical Energy Consumtion Clutch System, High Technology Letters, Vol.16 No.1, Mar. 010, : [3] Keyu Chen, Alain Bouscayrol, Alain Berthon, Philie Delarue, Daniel Hissel and Rochdi Trigui, Global Modeling of Different Vehicles, Vehicular Technology Magazine, IEEE, Volume 4 Issue, Jun. 009, : [4] Antoni Szumanowsi, Yuhua Chang, Battery Management System Based on Battery Nonlinear Dynamics Modeling, IEEE Transactions on Vehicular Technology, Volume 57 Issue 3, May 008, : [5] T. Hofman, D. Hoestra, R.M. van Druten and M. Steinbuch, Otimal Design of Energy Storage Systems for Hybrid Vehicle Drivetrains, Vehicle Power and Proulsion, 005 IEEE Conference, Se [6] Mar S. Duvall, Battery Evaluation for Plug-in Hybrid Electric Vehicles, Vehicle Power and Proulsion, 005 IEEE Conference, Se [7] A. Kleimaier, D. Schroder, An Aroach for the Online Otimized Control of a Hybrid Powertrain, 7 th International Worsho on Advanced Motion Control Proceedings, 00, : Authors Prof. Antoni Szumanowsi Antoni Szumanowsi is the rofessor of Warsaw University of Technology. He has been involved in hybrid electric vehicles research since He earned both Ph.D. and D.Sc. degrees from Warsaw University of Technology, where he is the leader of the Scientific Division which activity is suorted by government and university grants. He is the member of AVERE. Msc. Zhiyin Liu Zhiyin Liu obtained Msc degree from the Automobiles and Construction Machinery Engineering Faculty of Warsaw University of Technology (WUT) in 008. He has been the research assistant of Prof. A. Szumanowsi since 009 in the field of HEVs roulsion system simulation and comonents design. Dr. Yuhua Chang Yuhua Chang received the M.Sc. and Ph.D. degrees from Warsaw University of Technology (WUT), Warsaw, Poland, in 005 and 007, resectively. Since 003, she has been a Research Assistant of Prof. A. Szumanowsi in the field of battery modeling and management in HEVs and the configuration design of a roulsion system for HEVs by simulation. EVS5 World Battery, Hybrid and Fuel Cell Electric Vehicle Symosium 6