An Efficiency-Based Energy Management Strategy for Series Hybrid Electric Vehicles

Transcription

1 EVS28 KINTEX, Korea, May 3-6, 215 An Eiciency-Based Energy Management Strategy or Series Hybrid Electric Vehicles Soonkyu Jeong 1, Kyuhong Han, Seungtai Yeo, Yoonbok Lee 1 Acy or Deense Development, Yuseong P.O. Box 35-5, Daejeon 35-6, Republic o Korea, reingel@add.re.kr Abstract In this paper, an eiciency-based ine-erator set (GENSET) optimal control algorithm or series hybrid electric vehicles is proposed and its characteristics are compared to the conventional thermostat algorithm. The proposed algorithm controls the output power o the erator using eiciency maps o the GENSET and the high voltage tery pack. This proposed algorithm has the advantage o improving uel economy o the series hybrid electric vehicle. The vehicle is able to be operated as conventional vehicles because the ine operation synchronizes with the acceleration pedal position. The ine coolant temperature is maintained within a proper range. In addition to that, the tery SOC variation is reduced. These advantages o the proposed algorithm are veriied by the 5.5 tons real vehicle dynamometer test. Keywords: series hybrid electric vehicle, eiciency-based, energy management, ine-erator set (GENSET) 1 Introduction A wide range o research on hybrid electric driving systems (HEDSs) [1, 2] or commercial vehicles has been carried out to cope with the lack o ossil uel [3] and the environmental problems. In the ield o military vehicles, several advantages can be obtained by adopting HEDS. Special com strategy can be established by stealth (EV, electric vehicle) driving mode and operation range can be increased with improved uel economy. By utilizing high power and large capacity tery, mission equipment consuming large electric energy such as satellite communication systems can be applied to the military vehicles. The HEDS is typically composed o an internal combustion ine (ICE), one or more electric motors, and an energy storage system. Various conigurations o HEDS or commercial vehicles have been proposed such as series, parallel, and power-split [1, 2, 4]. Series hybrid electric driving system (SHEDS) with large capacity energy storage system is mainly used or military vehicles due to its advantages o the long distance stealth driving capability, the high power supply to mission equipment, and the lexibility o layout design [5, 6, 7]. The SHEDS is a system that one or more electric motors are mechanically connected to the driveline o the vehicle, and a high voltage tery and an ine-erator set (GENSET) supply the electric power. The most signiicant characteristic o the SHEDS is that the operating point o the GENSET can be controlled regardless o vehicle speed because the ine is mechanically separated to the driveline o the vehicle. With the characteristic, various kinds o energy and power management strategies such as thermostat strategy, equivalent consumption minimization strategy (ECMS) have been researched to maximize the system eiciency o the series hybrid electric vehicle [8]-[12]. Thermostat strategy basically controls the GENSET at the optimal operating point (OOP) and determines on/o o the GENSET depending on the state o charge (SOC) o the high voltage EVS28 International Electric Vehicle Symposium and Exhibition 1

2 tery. The ine is turned o when SOC is higher than a high level and is turned on when SOC is lower than a low level. Thermostat strategy can increase the eiciency o the GENSET but decrease the system eiciency o the vehicle due to large charge/discharge current o the tery. Excessive charge and discharge current o the tery can deteriorate the lie o the tery. Meanwhile, the driver may eel discomort because the acceleration pedal position and the ine operating point do not match. The ine is operated at a high torque and speed because OOP is typically at a high power point. Thus, it is hard to maintain the ine coolant temperature within a proper range. Last but not least, the ine can be damaged i the driver key o the vehicle while the ine is operating at OOP, especially the diesel ine with turbo charger. In this research, the optimal control algorithm which can increase the system eiciency considering the eiciencies o the GENSET and the tery at the same time is proposed. Using this algorithm, the uel economy is increased and the tery SOC luctuation is decreased. The driver eeling is improved by coupling the acceleration pedal position and the ine power. The ine cooling system operates similar to that o the conventional ine powered vehicle. The driver can saely key o the vehicle because the ine is stopped or is idling while the vehicle is stopped. In this research, a 5.5 tons our wheel drive (4WD) series hybrid electric military vehicle is tested on the 4WD transmission dynamometer to verity the advantage o the proposed control strategy. FTP-72 driving cycle and a newly developed military driving cycle [13] are used to perorm the test. Ater testing the vehicle with the thermostat strategy and the proposed optimal control strategy, the results could be obtained that the uel economy is increased, the tery SOC variation is reduced, and the ine coolant temperature is properly maintained. 2 Vehicle under Consideration The vehicle considered in this research is a 5.5 tons 4WD military vehicle and its system coniguration is shown in Figure 1. A ront and rear electric motors drive the ront and rear axles o the vehicle via motor reduction gears, dierentials, and hub reduction gears, respectively. The ront and rear electric motors are controlled by a ront and rear electric motor controllers, respectively. A diesel ine is mechanically connected to a erator which is controlled by a erator controller. A large capacity high voltage tery is used to supply and store electric power and energy. When the vehicle is driven, electric power is supplied to the electric motors rom the erator and/or the high voltage tery. When the vehicle is braking, the tery is charged by electric power erated by the electric motors. Speciications o the vehicle and major components are listed in Table 1. Figure 1: System coniguration o the vehicle under consideration EVS28 International Electric Vehicle Symposium and Exhibition 2

3 Table 1: Speciications o vehicle and major components Component Parameter Value Vehicle Mass 55 kg Engine Battery Front/Rear Motor Generator Type Rated power Type Rated voltage Rated capacity Peak power Rated power Peak power Rated power 3 Control Algorithm Diesel 171 kw Li-ion Polymer 68 V 31 Ah 12 kw 65 kw 12 kw 85 kw 3.1 Thermostat Algorithm Thermostat algorithm is a traditional GENSET control algorithm or SHEDSs. Thermostat algorithm basically controls the GENSET at OOP and determines on/o o the GENSET depending on SOC o the tery. The ine is turned on when SOC is lower than a low limit SOC and the output power o the erator low is controlled at OOP o the GENSET. The ine is turned o when SOC is higher than a high limit SOC and the output power o the erator high is reduced to zero. The ine ignition status and the output power o the erator is maintained the same as the previous states when SOC is between the high limit and the low limit. Thermostat algorithm can be described as ì poop ( SOC < SOClow) i ï i-1 p = p ( SOClow SOC < SOChigh) (1) í ï î ( SOC ³ SOChigh) where p is the current erator power i i 1 command; p - is the previous erator power command; p is the optimal operating point oop power o the GENSET; and SOC is the current SOC o the tery. 3.2 Eiciency-Based Optimal Control Algorithm A block diagram o the eiciency-based optimal control algorithm proposed in this research is shown in Figure 2. This algorithm is composed o two parts; Engine On/O Control and Generator Power Control. Engine On/O Control part determines the ine ignition on/o and Generator Power Control part calculates the erator power command. Figure 2: Block diagram o an eiciency-based optimal control algorithm EVS28 International Electric Vehicle Symposium and Exhibition 3

4 3.2.1 Engine On/O Control Engine On/O Control part requires three input signals and is composed o our sub-blocks and two logic operators. Engine On/O By Global SOC block has the tery SOC, HvSoc, as input signal and ine on/o control command, Engine_OnO_Cmd, as output signal. I the ine on/o control command is, it means ine o and 1 means ine on. This block sends out i HvSoc is greater than the high limit and 1 i less than the low limit. The high limit is set to 9 % and the low limit is slightly lower than the high limit. Engine On/O By Global SOC block is expressed as glb ì glb ( SOC > SOChigh) IG = í (2) glb î1 ( SOC < SOClow ) where IG is the ine ignition on/o glb glb command by global SOC; SOC is the high high glb limit o global SOC; and SOC is the low limit low o global SOC. Engine On/O By Idle Stop block is the implementation o idle stop and go (ISG) unction which turns o ine when the vehicle is stopped and turns on while the vehicle is running. Engine On/O By Idle Stop block has the vehicle speed, VehSpd, and the brake pedal position, BrkPedl, as input signals. I VehSpd is less than a very low value and BrkPedl is greater than a certain limit, the block sends out. I VehSpd is greater than a predeined value and BrkPedl is less than a low limit, it sends out 1. I the previous conditions are not met, it sends out the same as the previous command. Engine On/O By Idle Stop block can be expressed as ì ( _ AND _ ) isg ï v < v o b > b o IG = í (3) ïî 1 ( v > v _ on AND b < b _ on) isg where IG is the ine ignition on/o command by idle stop and go; v is the vehicle speed; b is the brake pedal position; v and _ o _ o b is vehicle speed and brake pedal position at which the ine is turned o, respectively; v and _ on b is vehicle speed _ on and brake pedal position at which the ine is turned on, respectively. Engine On/O By Power Req block improves the uel economy by turning o the ine when the GENSET is operated ar away rom OOP. Engine On/O By Power Req block receives the erator power command, Gen_Power_Cmd, which is the output o Generator Power Control part. I Gen_Power_Cmd is less than a low limit, the block sends out and i it is greater than a high limit, it sends out 1. Engine On/O By Power Req block is expressed as low ì ( ) pwr ï p < p IG = í (4) high ïî 1 ( p > p ) pwr where IG is the ine ignition on/o command by power request; p is the erator low power command; p is the low limit o the erator power command; and is the high high p limit o the erator power command. The purpose o Engine On/O By SOC block is to erate ine on/o control command depending on SOC o the tery. I SOC is greater than a high limit, it sends out and i it is less than a low limit, it sends out 1. The output o Engine On/O By SOC block is combined with the output o Engine On/O By Idle Stop by OR logic operator. It makes the ine charge the tery i SOC is low even though the idle stop condition is met. In addition to that unction, the output o Engine On/O By SOC block operates a switch block and switches between two modes o erator power control. I the output o Engine On/O By SOC is, the erator power control mode is switched to CHARGE HOLD mode and i it is 1, the mode is switched to CHARGE mode. CHARGE mode is to charge the tery eiciently by the erator power and CHARGE HOLD mode is to maintain SOC within a predeine range eiciently. I SOC is low, CHARGE mode is activated and i SOC is high enough, CHARGE HOLD mode is activated. The concept o CHARGE mode and CHARGE HOLD mode is shown is Figure 3. Figure 3: CHARGE mode and CHARGE HOLD mode Engine On/O By SOC block is expressed as ì soc ( SOC > SOChigh) IG = í (5) î1 ( SOC < SOClow) EVS28 International Electric Vehicle Symposium and Exhibition 4

5 soc where IG is the ine ignition on/o command by SOC; SOC is the high limit o high SOC; and SOC is the low limit o SOC. low Engine on/o control commands erated as above are combined with logic operators, thus, become an overall ine on/o control command IG : glb isg soc pwr IG = IG AND ( IG OR IG ) AND IG (6) Diesel ine which is mainly used in military vehicles should be idled or a certain amount o time beore it is turned o to prevent its component, especially, turbo charger, rom being damaged. Engine O Idle block makes the ine idle or a while beore the ine is turned o. I IG is changed rom to 1, it sends out 1 immediately but i it is changed back to, it sends out ater a predeined time delay Generator Power Control Gen Power (Charge) block calculates the erator power command or CHARGE mode. It receives vehicle power consumption, VehPwrCns, and the tery SOC, HvSoc, as input signals. The vehicle power consumption is obtained by 2 i i veh = motwmot + bdnet i= 1 p å T p (7) i where p veh is the vehicle power consumption; T mot i is the i -th motor torque; w is the i -th motor mot speed; and p is the boardnet power bdnet consumption which means vehicle power consumption except driving. i = 1 means the ront motor and i = 2 means the rear motor. Figure 4: Power low o CHARGE mode The power low o CHARGE mode can be depicted as Figure 4. The tery is mainly charged by the erator power when CHARGE mode is activated. I the eiciency o the GENSET rom uel to electric power is h set and the eiciency between the tery charging power and the stored power in the tery is h, the system eiciency h can be calculated by sys hsys = hset h (8) The eiciency o the GENSET can be obtained using a unction o the erator power as h = h ( p ) (9) set set i the GENSET is always operated along optimal operating line (OOL). The eiciency o the tery can be calculated using a unction o the tery SOC and the tery charge power p as h = h ( SOC, p ) (1) p can be obtained by p = pveh - p (11) * Given p and SOC, veh p which maximizes h sys * can be ound. p is used or the erator power command i CHARGE mode is activated : * hsys ( p ) = max é ëh sys ( pveh, SOC, p ) ù (12) û Min Charge Power block calculates minimum charge power or the tery that raises the erator power command i the tery SOC and soc p is low. I IG is 1, the erator power * command becomes the maximum value between the output o Min Charge Power block p * and p : p = p p (13) * max(, min _ ch ) min _ ch min _ ch p is calculated by a predeined look-up table which is the unction o SOC as pmin _ ch = pmin _ ch ( SOC) (14) Ater CHARGE HOLD mode is activated, the electric motors are driven by the electric power supplied by the GENSET and the tery as shown in Figure 5. h means the eiciency o the _ ch tery charge and h means the eiciency o _ dch the tery discharge. The system eiciency is the sum o h and set h because the electric _ dch power supplied to the electric motors is the sum o the erator power and the tery power. However, the energy discharged rom the tery should be charged in the near uture. So the eiciency o the tery discharge should be multiplied by the eiciency o the tery charge. The system eiciency or CHARGE HOLD mode can be obtained by h = h + h h (15) sys set _ dch _ ch EVS28 International Electric Vehicle Symposium and Exhibition 5

6 4 Perormance Evaluation and Result Analysis 4.1 Test Environment h Figure 5.Power low o CHARGE HOLD mode _ dch is calculated as a unction o SOC and tery discharge power h _ dch _ dch _ dch p _ dch p as _ dch = h ( SOC, p ) (16) can be obtained by p = p - p (17) _ dch veh The eiciency o the tery charge is calculated with a unction o SOC and the tery charge power p : h _ ch = h ( SOC, p ) (18) _ ch _ ch _ ch SOC and p in (18) should be estimated _ ch because the tery charge happens in the uture. The current tery SOC can be used instead assuming that the tery charge happens in the very near uture. p can be assumed to be equal to than Given _ ch p because min _ ch _ ch p. min _ ch p, SOC, and veh min _ ch p is equal or greater ** p, p which ** maximizes h can be ound. sys p is used or the erator power command i CHARGE HOLD mode is activated : ** hsys ( p ) = max é ëh sys ( pveh, SOC, p ) ù (19) û Using the method suggested in this research, the erator power rises when the driver presses the acceleration pedal to supply electric power consumed by the motors. So the driver eeling is improved because the acceleration pedal and the ine-erator power synchronize. The tery charge and discharge power is minimized because the vehicle power consumption and the erator power synchronize. Thus, the lie o tery is increased and the tery SOC is stabilized. In addition to that, it makes easy to control the ine coolant temperature Test Equipment In this research, a transmission (TM) dynamometer is used to emulate longitudinal vehicle resistance; rolling resistance, aerodynamic drag, and grading resistance. Figure 6 shows a military vehicle with SHEDS installed in the dynamometer. The dynamometer which is supplied by AVL Company has our load motors and a control and monitoring system called PUMA. Figure 6: Transmission dynamometer with the target hybrid vehicle A rapid control prototype (RCP) is used or controlling the SHEDS, gathering and monitoring test data. RCP is a commercial o-the-shel (COTS) controller used to accelerate the development process o electronic control units (ECUs). RCP is mainly used to substitute the ECU in the early development stage. MicroAutoBox and ControlDesk supplied by dspace Company are used as an RCP and a monitoring sotware, respectively Test Scenario In this research, two driving cycles are used to evaluate the perormance o the proposed control algorithm. The irst one is FTP-72 which is requently used to evaluate the uel economy o the commercial vehicles and its proile is shown in Figure 7. The other one show in Figure 8 is TWVC (tactical wheeled vehicle or communication) which is developed by ADD (Acy or Deense Development)[13]. EVS28 International Electric Vehicle Symposium and Exhibition 6

7 1 Vehicle Target Speed [km/h] Figure 7: FTP-72 driving cycle 6 Vehicle Target Speed [km/h] Figure 8: TWVC driving cycle 4.2 Test Results Analysis Fuel Economy Calculation Method The uel economy o the hybrid electric vehicles may not be properly calculated i the energy consumed or stored by the tery is not considered. In this research, the uel economy is calculated by the ollowing method. First, the test duration time D is deined by subtracting the start time t start rom the end time t end as D = tend - t (2) start The start time and the end time are the times when the vehicle starts to move and stops at the end, respectively. Vehicle travel distance d can be obtained by integrating the vehicle speed rom t t as to start end t end d = ò v( t) dt (21) tstart Next, total uel consumption m can be calculated by integrating instantaneous uel consumption m& using t end m = ò m& ( t) dt (22) tstart m& is measured by ine management system (EMS) and is transerred to the supervisory controller through the Vehicle CAN Line. In the meantime, total discharge energy o the tery E is calculated by integrating discharge power o the tery which can be obtained by multiplying the voltage V and the discharge current I o the tery as tend E = ò V I dt (23) tstart I is positive when the tery is discharged and is negative when charged. Assuming the consumed or stored energy o the tery is charged or discharged again at OOP, E can be converted to the equivalent uel consumption m by / EVS28 International Electric Vehicle Symposium and Exhibition 7

8 multiplying uel to tery energy ratio r ( g / kwh )as m = E r (24) / And r can be calculated as ò m& / oopdt r = - V I dt ò Where m& / oop / oop / oop (25) is instantaneous uel consumption at OOP; V and / oop I are the voltage and the / oop discharge current o the tery when the erator operates at OOP and the tery is only charged by the erator. When the tery is charged, the discharge current o the tery is negative. So the minus should be inserted to make r positive in (25). The compensated uel consumption m can be calculated by adding / c m and m as / m = m + m (26) / c / I the density o uel is s ( g / l ), the uel economy h ( km / l ) can be obtained by d h = m s (27) / c / FTP-72 Cycle Result To compare the perormance o two algorithms, real vehicle tests using FTP-72 driving cycle was perormed. Test results o ine on/o state, motor power, tery power, erator power, and tery SOC o thermostat algorithm and proposed algorithm are shown in Figure 9 and 1, respectively. The motor power is the sum o the ront and rear motor power. Engine On/O Command [,1] Motor Power [kw] Battery Power [kw] Generator Power [kw] Battery SOC [%] Vehicle Speed [km/h] Figure 9: Engine on/o, component power, tery SOC, and vehicle speed o thermostat algorithm (FTP-72 cycle) Engine On/O Command [,1] Motor Power [kw] Battery Power [kw] Generator Power [kw] Battery SOC [%] Vehicle Speed [km/h] Figure 1: Engine on/o, component power, tery SOC, and vehicle speed o proposed algorithm (FTP-72 cycle) EVS28 International Electric Vehicle Symposium and Exhibition 8

9 Engine On/O Command [,1] Motor Power [kw] Battery Power [kw] Generator Power [kw] Battery SOC [%] Vehicle Speed [km/h] Figure 11: Engine on/o, component power, tery SOC, and vehicle speed o thermostat algorithm (TWVC cycle) Engine On/O Command [,1] Motor Power [kw] Battery Power [kw] Generator Power [kw] Battery SOC [%] Vehicle Speed [km/h] Figure 12: Engine on/o, component power, tery SOC, and vehicle speed o proposed algorithm (TWVC cycle) Table 2.Fuel economy result FTP-72 TWVC cycle Algorithm Eiciencybasebased Eiciency- Thermostat Thermostat Duration ( D ) ( sec ) ( sec ) 2114.( sec ) 2114.( sec ) Distance ( d ) ( km ) ( km ) ( km ) ( km ) Consumed Battery Energy ( E ) (Wh ) (Wh ) 269.2(Wh ) 17. (Wh ) Fuel Consumption o Engine ( m / s ) (l ) (l ) (l ) (l ) Equivalent Fuel Consumption o Battery ( m / / s ).2158 (l ) -.477( l ).834 (l ).5245 (l ) Compensated Total Fuel Consumption ( m / / s ) (l ) (l ) (l ) (l ) c Fuel Economy (h ) ( km / l ) ( km / l ) ( km / l ) ( km / l ) EVS28 International Electric Vehicle Symposium and Exhibition 9

10 8 7 Generator Power [kw] Acceleration Pedal [%] Figure 13: Generator power and acceleration pedal position o thermostat algorithm (TWVC cycle) 8 7 Generator Power [kw] Acceleration Pedal [%] Figure 14: Generator power and acceleration pedal position o proposed algorithm (TWVC cycle) Figure 15: Engine coolant temperature o TWVC cycle or (a) thermostat algorithm, (b) eiciency-based optimal control algorithm. EVS28 International Electric Vehicle Symposium and Exhibition 1

11 Figure 9 shows that the ine is turned on and o based on the tery SOC and the GENSET is operated at OOP while the ine is turned on. Idling time is inserted ater turning on the ine and beore turning it o to prevent the ine, especially turbo charger, rom being damaged. In Figure 1, ine on/o is mainly determined by the tery SOC. However, the ine is turned o i the motor power is small and the corresponding erator operating point exists at low eiciency area to increase the system eiciency. The erator power varies along with the motor power to maximize the eiciency o the GENSET and the tery. It is also shown that the motor power is the sum o the GENSET power and the tery power. The signiicant dierence between those two algorithms is shown when the ine is turned on and the tery is charged. In Figure 9, the tery is charged by the large power o the GENSET. However, in Figure 1, the tery charge power is relatively small because the erator power is directly transerred to the motor when the GENSET is operated near OOP TWVC Cycle Result Real vehicle tests using TWVC driving cycle is also perormed. Test results o ine on/o state, motor power, tery power, erator power, and tery SOC o thermostat algorithm and proposed algorithm are shown in Figure 11 and 12, respectively. The ine is turned on/o based on the tery SOC in Figure 11. In this case, the erator power is reduced to zero at the time o 5 sec and 135 sec because the ine coolant temperature is too high to operate. In Figure 12, the erator power is created to meet the requirement o the motor power. But, the erator power is increased to charge the tery at low SOC, even though the motor power is low in the test time o 4 sec ~ 6 sec and 16 sec ~ 17 sec. It can be also veriied that the motor power is the sum o the erator power and the tery power. In Figure 14, the ine is turned o due to the idle stop and go algorithm at the time o 6 sec Fuel Economy Result The uel economy results o the thermostat and proposed algorithm are shown in Table 2. The uel economy o the eiciency-based optimal control algorithm is better than that o the thermostat algorithm or both FTP-72 and TWVC cycles. These results show the advantage o the proposed algorithm in regards to the uel economy Additional Eect o the Proposed Algorithm Figure 13 and 14 show the erator power and the acceleration pedal position o the thermostat algorithm and the proposed algorithm when the vehicle is running along TWVC cycle. The erator power and the acceleration pedal position are synchronized when the proposed algorithm is used. It shows that the driver eeling is improved using the proposed algorithm. Figure 15 shows the ine coolant temperature when (a) the thermostat algorithm and (b) the eiciency-based optimal control algorithm are used. The ine is operated at high power and the coolant temperature is hard to be maintained within a stable range when the thermostat algorithm is used as shown in Figure 15 (a). Hence, the erator power should be reduced when the coolant temperature is excessively raised at the time o 5 sec and 135 sec. In the case o the proposed algorithm as shown in Figure 15 (b), the ine coolant temperature varies within a moderate range. 5 Conclusions In this paper, an eiciency-based ine-erator set optimal control algorithm or series hybrid electric vehicles was proposed and its advantages were veriied by a 5.5 tons real vehicle dynamometer test. The proposed algorithm is more eicient than the thermostat algorithm and increases the uel economy. The driver eeling was improved because the ine operated along with the acceleration pedal position. The ine coolant temperature was maintained with a proper range. Acknowledgments This research was supported by the Civil Military Technology Cooperation Center. Reerences [1] A. Kawahashi, A new-eration hybrid electric vehicle and its supporting power semiconductor devices, Proceedings o International Symposium on Power Semiconductor Devices and ICs, 24, Kitakyushu, Japan, May 24; pp [2] Y. Gao, et al., Hybrid Electric Vehicle: Overview and State o the Art, Proceedings o the IEEE International Symposium on Industrial Electronics (ISIE), Dubrovnik, Croatia, 2-23 June 25; pp EVS28 International Electric Vehicle Symposium and Exhibition 11

12 [3] C.J. Campbell, et al. The End o Cheap Oil, Scientiic American, 1998, 273, [4] T. Hashimoto, et al, Development o new hybrid system or compact class vehicles, Trans. Soc. Automot. Eng. Jpn.21, 41, [5] G. Khalil, Challes o hybrid electric vehicles or military applications, Proceedings o IEEE Vehicle Power and Propulsion Conerence (VPPC), Dearborn, USA, 7-1 September 29; pp [6] D. Kramer, et al, Current state o military hybrid vehicle development, International Journal o Electric and Hybrid Vehicles, 211, 3, [7] P. Pisu, et al, Hybrid-Electric Powertrain Design Evaluation or Future Tactical Truck Vehicle Systems, In Proceeding o the ASME International Mechanical Engineering Congress and Exposition, Chicago, IL, USA, 5 1 November 26; pp [8] C. Hochgra, et al, Engine Control Strategy or a Series Hybrid Electric Vehicle Incorporating Load-Leveling and Computer Controlled Energy Management, SAE Technical Paper 9623, [9] N. Jalil, et al, A rule-based energy management strategy or a series hybrid vehicle, Proceedings o the American Control Conerence, Albuquerque, USA, 4-6 Jun 1997; pp [1] C. Musardo, et al, ECMS: An Adaptive Algorithm or Hybrid Electric Vehicle Energy Management, European Journal o Control, 25, 11, [11] H. Xie, et al, The Study o Plug-in Hybrid Electric Vehicle Power Management Strategy Simulation, In Proceedings o the 28 IEEE Vehicle Power and Propulsion Conerence (VPPC), Harbin, China, 3 5 September 28; pp [12] P.Z. Zhang, et al, Integral power management strategy or a complex hybrid electric vehicle Catering or the ailure o an individual component, Proc. Inst. Mech. Eng. D J. Automob. Eng.28, 222, [13] S. Jeong, et al, Development o Driving Cycle or Hybrid Electric Tactical Wheeled Vehicle, The 26th International Battery, Hybrid and Fuel Cell Electric Vehicle Symposium (EVS26), Los Angeles, USA, 6-9 May, 212; pp Authors Soonkyu Jeong Master Degree in 1998 at GIST, Korea. Recent research topics; Control algorithm and sotware development or hybrid electric military vehicle, hardware-in-the-loop simulation o hybrid electric vehicle. Kyuhong Han Master Degree in 21 at Hanyang University, Korea. Recent research topics; Control algorithm and sotware development or hybrid electric military vehicle, rapid control prototyping EVS28 International Electric Vehicle Symposium and Exhibition 12