Ming Cheng, Bo Chen, Michigan Technological University

THE MODEL INTEGRATION AND HARDWARE-IN-THE-LOOP (HIL) SIMULATION DESIGN FOR THE ANALYSIS OF A POWER-SPLIT HYBRID ELECTRIC VEHICLE WITH ELECTROCHEMICAL BATTERY MODEL Ming Cheng, Bo Chen, Michigan Technological University

The Outline Introduction Vehicle Model and Battery Electrochemical Model The Power-Split Hybrid Electric Vehicle Model The Simplified Average Single Particle Model The System Layout of the dspace Simulator and MicroAutoBoxII Controller The Simulation Results of the Complete HiL System Conclusions 2

Introduction: Background The need of further study on HEV and PHEV due to fuel economy and emission improvement demands The emphasis of battery control, especially battery aging study in the HEV and PHEV applications The broad application of Hardware-in-the-Loop in the development of automotive controllers The integration of high fidelity electrochemical Li-ion model with the model based design process 3

Introduction: The hardware-in-the-loop system for HEV application under development Real-time hybrid controller test system Real-time battery test system Temperature Control Discharge Current/Voltage Control Charge Current/Voltage Control Real-time Hybrid Controller 4

The Outline Introduction Vehicle Model and Battery Electrochemical Model The Power-Split Hybrid Electric Vehicle Model The Simplified Average Single Particle Model The System Layout of the dspace Simulator and MicroAutoBoxII Controller The Simulation Results of the Complete HiL System Conclusions 5

The Power-Split Hybrid Electric Vehicle Model Driver Controller: It mimics the behavior of driving s pushing gas and brake pedals with PID controller. Environment: It handles the environmental conditions of vehicle operations such as grade and wind drag. Vehicle model structure in Autonomie Driver Controller Vehicle Powertrain Controller Environment Vehicle Powertrain Controller: It deals with the power request for two motors, the IC engine and frictional brake. Vehicle Powertrain Model: The integration of components in vehicle powertrain and the interactive dynamics between each component. Vehicle Powertrain Architecture 6

The Power-Split Hybrid Electric Vehicle Model Toyota Prius E-CVT system parameters Max. engine power Max. engine torque Battery capacity Max. battery discharge power Max. battery charging power Curb weight Continuous power of ring gear motor (MG2) Peak power of MG2 Continuous power of sun gear motor (MG1) Peak power of MG1 values 57 kw 122.8 Nm 6.5 Ah 31 kw -23 kw 1449 kg 25 kw 50 kw 15 kw 30 kw Nominal voltage of the NiMH battery pack 201.6V *Picture source: http://www.twinkletoesengineering.info/hybrid_car.htm Cell capacity of the NiMH battery pack Nominal voltage of the Li-ion battery pack Cell capacity of the Li-ion battery pack 6.5Ah 399V 6.93Ah 7

The Simplified Average Single Particle Model Neg e - Sep Li + Pos Because current is averaged throughout the entire cell, kinetic overpotential at solid phase and electrolyte surface is directly determined by the current applied. Conservation of charge and mass for electrolyte across the entire cell is also simulated. r The lithium ion diffusion inside the electrode single particle is simulated using Fick s Law and solved by FDM. 8

The Outline Introduction Vehicle Model and Battery Electrochemical Model The Power-Split Hybrid Electric Vehicle Model The Simplified Average Single Particle Model The System Integration and Layout of the dspace Simulator and MicroAutoBoxII Controller The Simulation Results of the Complete HiL System Conclusions 9

The System Integration and Layout of the dspace Simulator and MicroAutoBoxII Controller Extra battery model outputs compared with the original battery model. The integration of the electrochemical lithium ion battery and the Prius MY04 model 10

The System Integration and Layout of the dspace Simulator and MicroAutoBoxII Controller The systematic layout of the complete hybrid electric vehicle model and controller in the dspace and MicroAutoBoxII 11

The ControlDesk Layout for the Real-Time Monitoring of the Hybrid Electric Vehicle HiL Setup Engine speed Vehicle speed Motor torque Battery current Request speed and actual vehicle speed profile Battery operational conditions 12

The Outline Introduction Vehicle Model and Battery Electrochemical Model The Power-Split Hybrid Electric Vehicle Model The Simplified Average Single Particle Model The System Integration and Layout of the dspace Simulator and MicroAutoBoxII Controller The Simulation Results of the Complete HiL System Conclusions 13

The Simulation Results of the Complete HiL System The complete HiL system is tested by simulation using US06 driving cycle The change of battery pack terminal voltage range due to the change of temperature: the lower temperature is, the higher the equivalent internal resistance. 14

The Simulation Results of the Complete HiL System The aging rate will slow down as the new cell starts to stabilize. The change of battery aging rate due to the change of temperature: the higher temperature is, the faster the battery ages. 15

The Outline Introduction Vehicle Model and Battery Electrochemical Model The Power-Split Hybrid Electric Vehicle Model The Simplified Average Single Particle Model The System Integration and Layout of the dspace Simulator and MicroAutoBoxII Controller The Simulation Results of the Complete HiL System Conclusions 16

Conclusions In this study, an electrochemical lithium ion battery model is integrated with the Autonomie Prius MY04 Power-Split vehicle model. The hardware-in-the-loop test system is set up with the complete vehicle model and individual controller models running in the dspace Ecoline Simulator and the hybrid controller running in the MicroAutoBox. The online simulation results demonstrate that the feasibility of an averaged single particle lithium ion battery model to be simulated in dspace simulator and to yield the battery aging performance with capacity loss and SEI thickness increase. In the future, the system could integrate the real-time battery testing system with the HEV model running in the Simulator and the battery being charged and discharged by equipment under certain temperature. 17

Thank you! 18

Backup slides 19

Backup slides The List of Signals Transmitting from Simulator to MicroAutoBoxII Signal Description Signal Range and Unit Actual speed of the vehicle [0,100] m/s Maximum propelling torque of MG2 [0,400] Nm Maximum regenerative torque of MG2 [-400,0] Nm Maximum propelling torque of MG1 [0,195.3] Nm Maximum regenerative torque of MG1 [-195.3,0] Nm Maximum positive power that battery pack can provide [0,61952] Watt Maximum negative power that battery pack can provide [-43560,0] Watt Maximum torque that engine can provide [0,121] Nm The real-time torque of MG2 [-400,400] Nm The real-time speed of MG2 [0,650] m/s The real-time torque of MG1 [-195.3,195.3] Nm The real-time speed of MG1 [-1047, 1047] m/s The battery SOC [0,1] The driver s speed demand [0,100] m/s The acceleration pedal position [0,1] The brake pedal position [-1,0] 20

Backup slides The List of Signals Transmitting from MicroAutoBoxII to Simulator Signal Description The torque request of MG1 The torque request of MG2 The torque request for the engine Signal Range and Unit [-400,400] Nm [-195.3,195.3] Nm [0,121] Nm The engine on/off request [0;1] The regenerative status [0;1;2;3;4;5] The frictional brake torque request [-2000,0] 21