design and simulation of a series hybrid electric vehicle (hev) powertrain

Project Name: Shaunak ChandwadkarStudent ID: 0003590164 Hybrid Electric Transportation

Indiana University – Purdue University Indianapolis

Purdue School of Engineering and Technology

Department of Mechanical Engineering

Hybrid Electric Transportation ME-50105

ProjectDesign and Simulation of a series Hybrid Electric

Vehicle (HEV) Powertrain

MAY 1st, 2016

Presented by:

Shaunak Chandwadkar

Contribution:

Shaunak Chandwadkar – 100%


Agenda

1. Abstract....................................................................................................................................3

2. Introduction..............................................................................................................................4

3. Project overview.......................................................................................................................5

4. Component Sizing and Optimization........................................................................................6

5. Simulation Results....................................................................................................................8

6. Comparison............................................................................................................................17

7. Conclusion..............................................................................................................................19

8. References..............................................................................................................................19

List of Figures2.1

Series Hybrid Electric powertrain.........................................................................................................4

4.1 Component Selection for the vehicle..............................................................................................6

4.2 Setup parameters for simulations...................................................................................................6

4.3 Setting up process ...........................................................................................................................7

5.1 Acceleration Performance simulation results..................................................................................8

5.2 Engine Fuel rate...............................................................................................................................8

5.3 State of Charge................................................................................................................................8

5.4 Energy Balance................................................................................................................................9

5.5 Vehicle Forward Energy losses

5.6 Energy Balance better configuration

5.7 Forward Energy Losses better configuration

5.8 HWFET cycle details

5.9 HWFET energy balance

5.10 Forward energy losses

5.11 Reverse energy losses

5.12 HWFET energy balance

............................................................................................................................................................14

15.13 UDDS cycle values for the vehicle..............................................................................................15

5.14 UDDS energy balance..................................................................................................................15

5.15 UDDS forward energy losses .......................................................................................................16


5.16 UDDS energy balance .................................................................................................................16

6.1 UDDS and HWFET comparison ......................................................................................................17

6.2 Driver acceleration deman............................................................................................................18

6.3 Motor efficiency............................................................................................................................18

6.4 Motor power input........................................................................................................................18

6.5 Motor power output .....................................................................................................................18

6.6 Engine efficiency ...........................................................................................................................18

6.7: Engine fuel consumption..............................................................................................................18

1. AbstractThis project focusses on the design and simulation of a Series Hybrid Vehicle. The scope of this project is the find optimal design and component sizing for a hybrid electric vehicle. Different configurations were considered and tested on Autonomie software, with a view to find an optimal design. The reduction of cost, engine size and increase of efficiency was achieved in the process by testing different component sizing for fixed vehicle body.

By reducing the engine size, the power output was reduced to 70kW from 80kW and increasing the motor power to 75 from 65 kW and increase in mileage was found to increase by around 4.5 miles/gallon. While keeping the cost of vehicle well close to the initial cost. This result proves to support the claim that there is a huge scope for hybridization of vehicles. The cost saving by getting the extra mileage and saving fuel seem to be very promising. The increased efficiency means lesser pollution due to burning of less fuel. Although the reduction in engine size results in more pollutants released as compared to the initial configuration, but the gross


2. IntroductionHybrid Electric Vehicles have gained increasing importance in the recent decade due to the advancement in the field of Electronics and battery technology. Hybrid Vehicles constitute of two power sources, generally a IC engine and a Battery power or Fuel cell. The Engine works on fuels obtained from crude oil, viz. Gasoline or Diesel, while the battery or fuel cell power is provided to electric motor which in turn drives the vehicle. These two power sources work in different configuration like parallel, series, combined or complex. The vehicle also generated power as brakes are applied through regenerative braking. This regenerated energy is supplied back to the batteries for storing. The outcome of this combination is improved efficiency and reduced emissions. The controlling of this advanced Hybrid vehicle required advanced controllers and simulations to design and simulate the optimum configurations for a vehicle. The software AUTONOMIE is used in this project to design and simulate a Series Hybrid Electric Vehicle such as the Chevrolet Volt which is available in market. AUTONOMIE is a powerful tool which uses MATLAB to simulate the outcomes of different configurations. The vehicle Chevrolet Volt is selected for this purpose and optimization is done by trial and error method to optimize the components. The design is tested for different standard driving cycles like the Urban and Highway FET. These cycles provide us with insights about the vehicle behaviour during different driving conditions.

The figure 2.1 shows us the powertrain of a series hybrid electric vehicle

Figure 2.1 Series Hybrid Electric Vehicle Powertrain

The reservoir is the fuel tank of the vehicle. The engine takes fuel from the fuel tank and rotates the generator shaft to generate electric power. This electric power is fed to the batteries for charging. And the motor draws power from the battery using a power converter to drive the wheels. Different simultaneous modes of operation enable the engine to charge the battery as the motor discharges it, or engine can charge the battery while the


vehicle is stationery. The electric motor acts as a generator and charges the batteries during regenerative braking.

3. Project OverviewThe topic of research is Design and Simulation of a Series Hybrid Electric Vehicle (HEV) Powertrain. The main focus is on increasing the efficiency of the vehicle, decreasing the emissions. Various methods as discussed below were implemented to achieve this aim.

Vehicle Design:

The powerful tool of AUTONOMIE is used to recreate the model of the vehicle with the actual parameters of the actual Chevrolet Volt. The raw simulations without modifying the values of the vehicle were run and the results were confirmed with the actual as notified by Chevrolet website.

Testing for different cycles:

The simulations were run using stock configuration first on several pre-defined cycles like the Urban drive cycle and Highway Drive cycle. The output was then compared against the results obtained from updated configuration. This steps were repeated numerous times to determine the optimum configuration which would result in greater efficiency and lowered emissions.

Energy management:

The simulation ware run considering the Regenerative Braking in action and energy harvested through regenerative braking was studied.

The vehicle’s dependency on engine power was tried to me minimum. As the graphs suggest during idling the vehicle used battery power or no power at all from the engine. This resulted in increased efficiency or more mileage per gallon of gasoline.

The optimal component sizing was selected from the many combinations and it was found that the cost factor was reduced as well.


4. Component Sizing and optimizationThe sizing of the vehicle is selected as in figure 4.1. The sizing is complaint with the actual

sizing of Chevrolet Volt as found on Vehicle technical databases on the internet.

Figure 4.1 Component selection for the vehicle

This vehicle configuration was simulated for the Urban Dynamometer Driving Schedules (UDDS) and the Highway Fuel Economy Test (HWFET) along with performance simulations of Acceleration.The results were saved and component sizes were altered over subsequent simulation tests. Around 90 simulations were run and the optimal was selected comparing it to the original values of stock configuration simulation.


UDDS HWFET Gradeability Acceleration Performance (Normal)

Engine Type1.45L SI DOHC 1.45L SI DOHC 1.45L SI DOHC 1.45L SI DOHC

Engine Power Output (kW) 75 kW 75 kW 85 kW 75 kW

Total Motor Output (kW) 110 kW 110 kW 110 kW 110 kW

Initial SOC 60% 60% 60% 60%

Table 4.2 Setup parameters for simulations

Setting up the process:

The following processes were setup for the vehicle.

Figure 4.3 Setting up processes.


5. Simulation ResultsAfter running the simulation’s, the results are verified with the actual vehicle performance parameters available on Chevrolet website. The results were confirmed and modification in the vehicle configurations were started.

Acceleration performance

Figure 5.1 Acceleration Performance simulation results.

The figure shows the original vehicle configuration vs the best found configuration. The results are promising and the mil/gallon shows notable increase. The state of charge on the other hand SOC, remains almost unchanged, suggesting the modification to be better configuration then the original.

Figure 5.2: Engine Fuel Rate

Figure 5.3: State of Charge

The original losses for vehicle.


Figure 5.4: Energy Balance

Figure 5.5: Vehicle Forward Energy losses


The better configuration figures

Figure 5.6: Energy Balance better configuration

Figure 5.7: Forward Energy Losses better configuration

The results prove that the vehicle Chevrolet Volt has been optimized for better component sizing. The achievement is better SOC at the end of cycle, better Fuel economy.


Comparing results for UDDS and HWFET cycles

HWFET

The engine used for the initial and optimized configuration was the same, 1.45L SI DOHC gasoline engine. However, the size of engine was reduced in the optimized model of vehicle. The power rating of engine is ideally 75 kW which was reduced to 65 kW and was found to be optimum for the given motor and generator power. The generator was originally 54 kW which was increased to 60 kW while the motor was originally 110 kW which was upgraded to a 120 kW motor. The Chevrolet Volt used li-ion battery with 192 cells, which was upgraded to newer model of Volt which has 220 cells. The overall configuration was found to be cheaper by 200$ as the engine power was size reduced.

Figure 5.8: HWFET cycle details


Figure 5.9: HWFET energy balance

Figure 5.10: Forward energy losses


Figure 5.11: Reverse energy losses

The plot of energy losses is as follows.

Figure 5.12: HWFET energy balance


UDDS

The similar configuration was used for UDDS cycle which is as follows.

The engine used for the initial and optimized configuration was the same, 1.45L SI DOHC gasoline engine. However, the size of engine was reduced in the optimized model of vehicle. The power rating of engine is ideally 75 kW which was reduced to 65 kW and was found to be optimum for the given motor and generator power. The generator was originally 54 kW which was increased to 60 kW while the motor was originally 110 kW which was upgraded to a 120 kW motor. The Chevrolet Volt used li-ion battery with 192 cells, which was upgraded to newer model of Volt which has 220 cells. The overall configuration was found to be cheaper by 200$ as the engine power was size reduced.

Figure 5.13: UDDS cycle values


Figure 5.14: UDDS energy balance

Figure 5.15: UDDS forward energy losses


Figure 5.16: UDDS energy balance


6. Comparison

The comparison of both UDDS and HWFET cycles is as below.

Figure 6.1: UDDS and HWFET comparison

Figure 6.2: Driver acceleration demand

Motor comparison

Figure 6.3: Motor efficiency

Figure 6.4: Motor power input


Figure 6.5: Motor power output

Engine comparison

Figure 6.6: Engine efficiency

Figure 6.7: Engine fuel consumption


7. ConclusionThe altered values of Motor Power, Engine power, Generator capacity and battery capacity and number of cells has resulted in the improved vehicle performance. The graphs as attached above are a proof of the increased efficiency and lowered emissions of the vehicle. The vehicle is made more dependent on battery and motor power which has led to the increased efficiency.

The loss charts show that the losses in engine have increased as it has been downsized. But the overall efficiency of the vehicle has proved to be increasing.

8. References

1. http://media.chevrolet.com/media/us/en/chevrolet/vehicles/volt/2016.tab1.html2. http://gm-volt.com/full-specifications/3. Modern Electric, hybrid Electric and Fuel Cell Vehicles – Mehrdad Eshani , Yimin

Gao & Ali Emadi4. Class notes and lecture slides5. http://www.unep.org/transport/pcfv/PDF/HEV_Report.pdf6. https://www.princeton.edu/~ota/disk3/1982/8228/8228.PDF7. http://www.eesi.org/files/eesi_hybrid_bus_032007.pdf8. http://www.edisonfoundation.net/iei/Documents/

IEE_OnRoadElectricTransportationForecast_0413_FINAL.pdf9. http://www.hybridrive.com/

http://media.chevrolet.com/media/us/en/chevrolet/vehicles/volt/2016.tab1.html

http://gm-volt.com/full-specifications/

http://www.unep.org/transport/pcfv/PDF/HEV_Report.pdf

https://www.princeton.edu/~ota/disk3/1982/8228/8228.PDF

http://www.eesi.org/files/eesi_hybrid_bus_032007.pdf

http://www.edisonfoundation.net/iei/Documents/IEE_OnRoadElectricTransportationForecast_0413_FINAL.pdf

http://www.edisonfoundation.net/iei/Documents/IEE_OnRoadElectricTransportationForecast_0413_FINAL.pdf

http://www.hybridrive.com/

design and simulation of a series hybrid electric vehicle (hev) powertrain

Automotive