Drive cycles 4 Range extenders

Transcription

1 Drive cycles 4 Range extenders Jonas Sjöberg Drive cycles at s2: Jonas Fredriksson, Victor Judez, Mitra Pourabdollah, Viktor Larsson, Nikolce Murgovski, Anders Grauers, Bo Egardt, Lars Johannesson Signals & Systems, Chalmers University of Technology Jonas Sjöberg 1

2 What is a drive cycle? Speed Altitude Humidity Temperature Air pressure. The idea with a driving cycle is to describe a usual transportation task for a vehicle, i.e. it tries to describe an ordinary driving situation. Jonas Sjöberg 2

3 Test a vehicle in a controlled environment Expensive test Passenger cars are certified in this way many identical samples Heavy vehicles NOT, there are too many varieties Simulation is much cheaper and more flexible. Jonas Sjöberg 3

4 Describe the vehicle as a differential equation x(t) states y(t) output values u(t) input signals, typically the drive cycle Relevant parts of the vehicle propulsion system is modeled in the functions f and g, which can be quite complicated. Jonas Sjöberg 4

5 What are drive cycles used for? Design, optimize the design of the vehicle and its algorithms for the given use of it. Testing & certification, authorities test that vehicles fulfill legal requirements concerning pollution etc. Jonas Sjöberg 7

6 Range extender plug in hybrid with a large battery Electricity is cheap but batteries are expensive. Fuel cost Compromise: a large battery which is contains enough energy for most trips & a combustion engine which is used for the very long trips. How large should the battery distance be? Battery size Jonas Sjöberg 17

7 Battery electric vehicles may look very attractive. 80% of the days the average driver drives 75 km or less Does not mean that 80% of the cars can be Battery electric cars! Jonas Sjöberg 18

8 We must look at each individual vehicle! 20 km 70 km 150 km Very different vehicles required. Jonas Sjöberg 19

9 Available driving cycles Test Site Sweden (TSS) Access: limited, privately driven cars, for 2 months each. More than individual trips. GPS coordinates, speed and slope vs. time. Many types of measurements, GPS, CAN, video, eye tracking Jonas Sjöberg 20

10 Total driving distance relevant and trip lengths Total driving distance/year Rute length Jonas Sjöberg 21

11 Each trip can be done on electricity up to AER Total driving distance/year Fuel cost AER All Electric Range Rute length Battery size distance Jonas Sjöberg 22

12 Optimal battery size depends on prices, battery most significant Total driving distance/year Battery price Optimal battery size Rute length Jonas Sjöberg 23

13 Higher battery price gives smaller batteries as optimal choice Total driving distance/year AED f dist (x) dx =1 0 C batt T( f km e km ) Battery price Optimal battery size Rute length Jonas Sjöberg 24

14 One for all or all for one? What about when battery size can not be individually set? Lost ( ) N (Number of vehicle niches) Jonas Sjöberg 25

15 Current questions How should drivers be grouped for the same vehicle? Robustness issues, if something change, how far from optimum are we? Jonas Sjöberg 26

16 Department of Signals and Systems The end Thank you. Jonas Sjöberg 29