Reduction of CO 2 Emissions and Fuel Consumption in Vehicles Comprising Start-Stop Technology

Transcription

1 Reduction of CO 2 Emissions and Fuel Consumption in Vehicles Comprising Start-Stop Technology Eberhard Meissner, Joern Albers, Sepehr Shirazi Johnson Controls Power Solutions EMEA

2 Content Company Introduction Targets of Automotive Industry to reduce CO 2 Emissions and Fuel Consumption Legal Requirements for CO 2 Emissions and Standard Test Cycles for Vehicle Operation Start-Stop Technology and Battery Duty Quantification of Benefit of Start-Stop Operation in Synthetic Vehicle Test Cycles Quantification of Benefit of Start-Stop Operation in Real-Life Operation on the Road Conclusions and Implications for Battery Industry 2 Johnson Controls PowerPoint Guidelines February 8, 2008

3 Johnson Controls Power Solutions: Global leader in automotive batteries Supplying more than one-third of the world s lead-acid batteries to major automakers and aftermarket retailers. More than 50 manufacturing, recycling and distribution centers worldwide World-class customer base in stable aftermarket Original Equipment (OE) batteries sold to every major automaker in the world Through our innovations, we are building the advanced battery industry for hybrid and electric vehicles We were the first company in the world to produce lithium-ion batteries for mass-production hybrid vehicles Johnson Controls Power Solutions: Regional Distribution of 2013 sales US$ 6.5 billion Americas Asia 58% 9% Americas 57% EMEA 34% 3

4 Targets of Automotive Industry to reduce CO 2 emissions and fuel consumption Automotive Industry: need for action Legal Regulations End User wishes environment, economy of country cost for fuel, environmental awareness Regional differences worldwide Legal Regulations, incl. local traffic bans in cities => the force to take action Social environment, fuel cost, vehicle ownership, public transport alternatives Habits, environmental awareness (public, individual) Automotive Industry: type of action Various alternative technical concepts and improvements Many can be combined 4

5 Targets of Automotive Industry to reduce CO 2 emissions and fuel consumption Technical means to be combined a) mechanical / electrical efficiency of ICE, auxiliary aggregates, comfort components: e.g. downsizing of ICE, turbo-charging, electrification of water pump, oil pump, power steering and power braking, LED lights, controlled A/C b) intelligent operating strategies for components, operated only when needed; key strategy is Start-Stop operation of the ICE c) recuperation, harvesting free electrical energy from braking d) hybrid, using electrical energy for propulsion when ICE is not efficient Automotive Industry: type of action Nearly all vehicles already follow a) Significant added cost for HEV to follow d): Micro-Hybrid < Mild Hybrid < Full Hybrid Economically attractive compromise: combine a) with Start-Stop b) and/or with c) 5

6 Legal Requirements for CO 2 Emissions and Standard Test Cycles for Vehicle Operation Regulations on CO 2 emissions comprise emission target [g CO 2 /100 km], e.g. for overall fleet of manufacturer standardized driving scheme, e.g. v = f(t), gear shift scheme, vehicle pre-condition, Different regional regulations: dynamics, stop periods, driving distance ~8-23 km, duration ~20-30 min CO 2 emission targets N.B.: values depend on various parameters, e.g. curb weight, max speed, etc Test Cycle: WLTP, class 3, for passenger cars with >34 kw/t and v_max >135 km/h 6

7 Legal Requirements for CO 2 Emissions and Standard Test Cycles for Vehicle Operation Comparison of Driving Schemes, some artificial, others derived from real-world vehicle speed (max, average), time portion of stops, acceleration, deceleration, cruise FTP75 and esp. WLTP patterns much more dynamic than NEDC and JC08 Different driving patterns evoke different technical strategies to cope with successfully Test Name Region Dist. [km] Time [sec] Speed max [km/h] Speed ave [km/h] Stop periods (v=0) Accel. periods Decel. periods Cruise periods (v=const) NEDC EU % 23% 16% 36% WLTP Global % 44% 41% 2% FTP75 USA % 42% 37% 12% JC08 Japan % 26% 21% 20% 7

8 Start-Stop Technology Strategy: ICE-off when not needed for propulsion Conventional Stop at idling: only at vehicle standstill (v=0) delay period (~1sec) to consider change of mind Advanced Stop at idling: already when decelerating at low speed (e.g. <8km/h) => increases opportunities & duration Stop-in-motion ( sailing, cruising ): engine-off whenever propulsion is not needed, upon deceleration and cruising at any speed => further increase in opportunities & duration for engine-off Start-Stop works perfect with automatic gear (Start-Stop control via brake pedal) limitations with manual gear (Start-Stop control via clutch pedal), as clutch needs to be released (with gear in neutral) for engine disengagement => today s Start-Stop on the road is more effective with automatic gear => an electrical controlled clutch with manual gear may automate Start-Stop, providing even some semi-automatic features (announced for 2016) 8

9 Start-Stop Technology Benefit on CO 2 emissions and fuel consumption Strong dependency - type of engine and drive train, vehicle size/weight, vehicle concept/manufacturer - on test stand: type of test standard used - on the road: driving conditions, driver habits Conventional Start-Stop at idling (@ v=0 only): savings - on test stand: some %; most with JC08 and NEDC - on the road: 0..5%; significant higher (>10%) in heavy traffic Advanced Start-Stop at idling (@ low v): savings some additional % (test cycles and on road) Stop-in-motion ( sailing, Start-Stop cruising ): savings total >15%..20% vs. reference w/o Start-Stop further benefit over conventional Start-Stop in WLTC by 5-7%, in FTP75 by 7-12% (depending on gear transmission), on the road by 10-12% *) *) data published by Robert Bosch in 2014 Press Release, and at 3. VDI Conference Automotive Board Net Development, Straubing, Feb 25-26,

10 Start-Stop Technology and Battery Duty Additional Duty from Start-Stop to the Battery Bridging stop (illumination, electronics, ventilation ) DCH low current ~25-70A for ~5-50sec (or more) stop phases => ~0,03.. 1Ah of discharge Restarting (warm) engine DCH high current many 100A for ~0,2-0,5 sec => <<0,1Ah of discharge voltage current inrush (>1000A) NOT to compromise electronics, unless powered via DC/DC or a buffer (second) battery Accepting charge quickly from engine-on RECHARGE to ensure charge balance Typical number of Start-Stop events on road (heavy traffic) average 2-3 Start-Stop / km; accumulated engine-off periods may >50% of time Typical Micro-Cycle per Start-Stop event is <1% DoD, but Deeper cycling (i) extended Stop periods (ii) drive periods between Stops not long enough to recharge / charge balanced 10

11 SoC SoC Start-Stop Technology and Battery Duty Ensuring Capability of Battery for sustainable Start-Stop operation Battery Management System (BMS) estimates actual battery status (SoC, SoH, temperature, internal resistance, ) predicts future load conditions --> secure cranking ability may recommend to disable Start-Stop temporarily, or to auto-restart during extended Stop Only provision BMS can do allow for more recharge / SoC up Strategy 1 Strategy 2 disable energy consumers (temporarily) Reasons to disable Start-Stop not related to battery engine / catalyst not yet reached operating temperature heating or air conditioning requires ICE operation vehicle operation safety time time 11

12 Quantification of benefit of Start-Stop operation in synthetic vehicle test cycles 130g CO 2 per km 95g CO 2 per km Implications from fuel consumption / emissions in synthetic vehicle test cycles Legal: manufacturer fleet average emission e.g. EU regulation require <130g CO 2 /100km by 2015, <95g CO 2 /100km by 2021 Higher fleet average emissions: fee of 95 / g of CO 2 / vehicle going to market Reputation (new vehicles) Fuel consumption is decision criterion Media and interest groups address fuel consumption Reputation (used vehicles) Fuel consumption is decision criterion High fuel consumption reducing value of used vehicles; aspect influencing also new vehicles sales Deviation of data from synthetic tests vs. real life May impair image of vehicle manufacturer or technology Putting public pressure to industry and legislation (=> implementation of WLTP) 12

13 speed speed Quantification of benefit of Start-Stop operation in synthetic vehicle test cycles Periods of vehicle standstill (idling stop): opportunity for engine-off Periods of engine-off shorter than periods of vehicle standstill Early clutch activation required by gear shifting regulation from standards (NEDC: 5 sec, WLTP: 1sec) Delay to initiate engine-off (typ. 1sec) NEDC WLTP Picture: Audi standard Start-Stop opportunity (automatic) opportunity (man.) ~1 5sec clutch reality (automatic) time ~1 opportunity (automatic) opportunity (manual) 1 reality (automatic) time ~1 reality (man.) 5sec clutch ~1 reality (manual) 1 advanced ~1 ~1 reality (automatic) reality (manual) 5sec clutch ~1 reality (automatic) reality (manual) ~1 1 13

14 Quantification of benefit of Start-Stop operation in synthetic vehicle test cycles Periods of vehicle cruising (stop-in-motion): more opportunity for engine-off High variation of stop periods between test patterns NEDC: 36% cruising (v=const.), requires engine operation only 16% of time deceleration: medium opportunity for stop-in-motion WLTP: only 2% cruising (v=const.), but 41% of time deceleration: much opportunity for stop-in-motion Potential from stop-in-motion much higher with WLTP than with NEDC! WLTP much more reflecting real world driving situations With stop-in-motion, battery reliability becomes critical for vehicle safety Bridge power steering & braking incl. ESP, ABS etc. during engine-off Fast engine re-cranking at sudden request for acceleration Dual-battery architectures to meet those requirements 14

15 Quantification of benefit of Start-Stop operation in real-life operation on the road Periods of vehicle standstill (idling stop): opportunity for engine off High variation of stop period pattern depending on vehicle operation: region, temperature, driver habits, --> deviation from test stand results In heavy traffic, standstill may >50%: fuel savings >>10% With steady long-distance driving: fuel savings = 0 At high & low ambient, idling stop is disabled for non-battery reasons: fuel savings = 0 Periods of engine-off shorter than periods of vehicle standstill Delay to initiate engine-off (typ. 1sec) Manual people always activating clutch: fuel savings = 0 people not activating clutch: fuel savings >> than with NEDC! Savings on the road from idling stop: published 3..8% from simple Start-Stop 15

16 speed Quantification of benefit of Start-Stop operation in real-life operation on the road Periods of vehicle cruising: more opportunity for engine-off (stop-in-motion) High portion of cruising (const. speed or slow deceleration) when driving on the road; depending on vehicle operation: region, temperature, driver habits, Potential vehicle operating strategy Have the ICE been dragged unfired: rapid vehicle deceleration, some for recuperation Have the vehicle rolling free with ICE off & de-coupled: modest vehicle deceleration drag ICE, unfired Coasting allows for extended vehicle rolling, with stop-in-motion; better use of kinetic energy than wasting to drag unfired ICE coasting time With stop-in-motion, battery reliability becomes critical for vehicle safety Bridge power steering & braking incl. ESP, ABS etc. during engine-off Fast engine re-cranking at sudden request for acceleration (change-of-mind) Dual-battery architectures to ensure such requirements 16

17 Quantification of benefit of Start-Stop operation in real-life operation on the road Differences between standardized tests and road condition complains that fuel consumption on road higher than values given in product data sheet Vehicles more and more optimized to cope with standard test (NEDC)? 100% = type approval test Discrepancy may be reduced by transition to WLTP after: icct The International Council on Clean Transportation; Working paper : Discrepancies between type approval and real-world fuel consumption and CO 2 values 17

18 Quantification of benefit of Start-Stop operation in real-life operation on the road Quality" of a Start-Stop System = system availability cranking capability secured number of "missed opportunities for Stop mode number of "premature auto-restart events => more engine idling => more fuel consumption Missed opportunities from reasons related to battery Management System estimates battery status not to cope with Start-Stop (SoC, SoH, ) valuation depends on correct estimation of battery state: precise measurement, reliable predictability of very battery design, correct algorithm implementation; influenced by target operating strategy Missed opportunities from reasons NOT related to battery Engine / catalyst not yet reached operating temperature Low or high ambient temperature to secure vehicle heating or A/C function Ensure operation of power braking and power steering 18

19 Conclusions and Implications for Battery Industry Motivation for Start-Stop technologies Legal regulations CO 2 emissions manufacturer cost standardized test cycles Customer wishes cost, comfort, environment real-world driving Different type of standardized test cycles, e.g. NEDC => WLTP May drive industry into different strategies to cope with CO 2 regulations, with giving different importance to improvement of electrical system NEDC -> WLTP: impact in scope of battery shorter stop periods idling stop less favorable extended decel. phase stop-in-motion more favorable higher average speed aerodynamics gain importance vs. electric higher average ICE power ICE characteristics gain importance vs. electric 19

20 Conclusions and Implications for Battery Industry Key for success of Start-Stop in the market system availability on the road: standard test cycles are not all! sustainable operation: not reflected by test cycles! It is not the battery only - but operating strategy making best use of battery capability provide electrical energy securely during stop periods recharge quickly in short driving periods between Stop phases allow for precise prediction of status and capability Predictability and Reliability of battery is key to convince OEs and system providers that they can make use of the battery, w/o compromising vehicle function and safety Traffic light by: Čeština: Semafór POZOR 20

21 Conclusions and Implications for Battery Industry Start-Stop is NOT a target by its own, but only one of several potential means to cope with targets and wishes of the players Customer: cost, comfort, real-world driving Car manufacturer: cost, standard test cycle compliance, image, system availability on the road (warranty) Authorities: macro-economics, environment Battery industry has an opportunity to contribute if we provide a reliable and sustainable solution Traffic light by: Čeština: Semafór POZOR 21