HYBRID POWER UNIT DEVELOPMENT
`
`FOR FIAT MULTIPLA VEHICLE
`
`981124
`
`A. Caraceni, G. Cipolla
`ELASIS ScPA - Motori
`
`R. Barbiero
`FIAT AUTO - VAMlA
`
`Copyright© 1998 Society of Automotive Engineers, Inc.
`
`ABSTRACT
`
`for
`concerns
`increasing
`of
`“scenario"
`the
`In
`environmental pollution, hybrid vehicles will play a
`significant role in the near future. Compared to electric
`vehicles, the hybrid ones have an unrestricted driving
`range, higher performance and transport capability,
`still
`fulfilling ZEV emission regulation.
`
`The hybrid vehicle features a power train that integrates
`a thermal engine with an electric motor. Among the
`several possible configurations for hybrid vehicle,
`the
`parallel hybrid one has been chosen for
`the FIAT
`MULTIPLA, for the following reasons:
`
`.
`
`.
`
`.
`
`lower weight and volume of the electric unit to obtain
`the same driving mission;
`
`higher global efficiency of the system, due to direct
`thermal to mechanical energy conversion;
`
`a better vehicle performance (acceleration and max
`speed), thanks to the contribution of both motors to
`traction.
`
`the
`in the development of a hybrid parallel concept,
`critical aspects to be overcome are related to the system
`mechanical complexity and the simultaneous control of
`the two motors.
`
`In this paper the Fiat Auto and Elasis approach to the
`hybrid vehicle is presented with particular reference to
`the powertrain unit and its control strategies.
`
`INTRODUCTION
`
`legislation and
`the European
`last years
`the
`In
`environmental
`issues have focused the attention to the
`
`inconvenience produced by traffic density in our most
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`Page 1 of 8
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`29
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`congested European urban centers. Electric vehicles, as
`reported by several
`studies performed in different
`European cities, could substitute less than 10 0/0 of the
`vehicles in circulation in the cities, provided that they can
`assure a real range of more than 80 km. On the contrary
`hybrid vehicle would allow a substitution of a bigger
`portion of the vehicle city park, thanks to their “range
`extension" and “peak performance" features.
`
`The hybrid vehicle seems to be a very promising answer
`to today’s different demands such as:
`
`0
`
`.
`
`0
`
`.
`
`.
`
`.
`
`.
`
`free driving in emission protected zones
`
`ability to match different condition in urban or extra
`urban driving
`
`unrestricted range and transport capabilities like
`thermal vehicles
`
`similar
`or
`same
`conventional vehicle
`
`driving
`
`characteristics
`
`as
`
`a
`
`reduced dependency on batteries
`
`use of existing infrastructure
`
`commercially interesting image.
`
`The mass production feasibility of the electric vehicle
`remains nowadays a big concern, primarily because of
`the battery problems.
`In case of
`the hybrid vehicle,
`battery dependency is reduced and so the hybrid vehicle
`is more acceptable to the public.
`
`Conventional vehicles, especially those equipped with
`gasoline engines, have lower fuel economy and higher
`emissions especially in short
`range distance driving
`during warm-up phases, but offer high performance. long
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`FORD 1203
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`FORD 1203
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`

`

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`distance and high transportation capability.
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`Although hybrid vehicles suffer from a higher weight if
`
`
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`
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`compared to conventional
`internal
`combustion driven
`
`
`
`
`
`
`
`
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`and pure electric vehicles, they may offer a possibility of
`
`
`
`
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`
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`satisfying personal and commercial needs with lower
`
`
`
`
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`emissions and higher global efficiency.
`
`
`
`
`
`
`
`On
`the other hand hybrid vehicles have higher
`
`
`
`
`complexity
`than
`their
`counterparts.
`The main
`
`
`
`
`
`disadvantages can be summarized as:
`
`
`0
`
`
`.
`
`
`
`
`
`higher number of components
`
`
`
`higherweight
`
`
`
`
`sophisticated
`o more
`
`strategies
`
`
`vehicle
`
`
`electronic
`
`control
`
`
`
`
`
`.
`higher costs.
`
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`The hybrid powertrain structure and power size must be
`
`
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`
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`carefully selected to minimize the above mentioned
`
`
`
`
`disadvantages. Hybrid propulsion systems
`can be
`
`
`
`
`arranged, in a variety of configurations,
`two basic
`in
`
`
`
`
`
`
`categories: series and parallel (Fig 1).
`
`
`
`
`
`
`SERIES
`
`
`
`Thermal
`engine
`
`
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`
`
`
`
`
`
`Motor
`
`Generator
`
`
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`
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`The global objectives of Fiat MULTIPLA hybrid vehicle
`
`
`
`
`and its
`powertrain subsystems
`characteristics
`are
`
`
`
`
`discussed in the following paragraphs.
`
`MAIN VEHICLE OBJECTIVES
`
`
`
`
`
`
`
`
`
`
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`The goal of the present research activity is to design a
`
`
`
`
`
`
`hybrid vehicle, suitable for mass production, derived
`
`
`
`
`
`
`
`
`from the "MULTIPLA" equipped with a 1.6 litres gasoline
`
`
`
`
`
`
`
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`engine, with similar characteristics as far as it concerns
`
`
`
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`comfort, habitability and safety.
`
`
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`The daily vehicle mission could be summarized as 105
`
`
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`
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`km per day with 1/3 on urban driving in hybrid mode, 1/3
`
`
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`
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`in pure electric and 1/3 in hybrid mode on extraurban
`
`driving.
`
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`
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`The emission levels must be equivalent to ZEV in pure
`
`
`
`
`
`
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`electric and according to the European limits for year
`
`
`
`
`
`
`
`
`2005 (EEO phase IV) in hybrid or thermal mode. Tab 1
`
`
`
`
`
`
`shows the main vehicle performance requirements.
`
`Performance
`
`requirements
`
`
`Hybrid Thermal
`
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`Acceleration
`(8)
`
`
`0 — 100 km/h
`
`
`
`
`<18
`
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`
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`>30
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`Batteries
`
`
`
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`PARALLEL
`
`
`
`
`
`
`
`Motor
`
`
`
`*‘ '4 Generator
`
`
`7— 1:
`
`
`
`
`MT
`
`Thermal
`
`
`engine
`
`
`
`
`
`
`
`
`_
`
`Batteries
`
`¢~—>
`—‘<
`>
`
`
`
`
`L_> Regenerative power ‘H Engine power
`
`
`
`
`
`
`
`
`Figure 1
`
`
`
`
`
`
`
`In the series arrangement,
`all energy from thermal
`
`
`
`
`engine
`converted
`is
`electricity. The
`parallel
`into
`
`
`
`
`arrangement has
`addition a direct mechanical
`in
`connection to the transmission driveline which could
`
`
`
`
`
`
`
`
`
`
`
`
`include a conventional gearbox. The topology and the
`
`
`
`
`
`
`
`details of a hybrid propulsion system will depend heavily
`on the mission that the vehicle is intended to fulfill and on
`
`
`
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`
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`
`
`
`
`
`
`
`
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`
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`the constrains of today’s technology availability for mass
`
`production.
`
`30
`
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`3'‘1 gear (8)
`
`
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`Acceleration
`
`
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`4O—80km/h --
`
`
`
`
`
`Fuel consumption
`
`
`(ECE+EUDC) (l/100km)
`
`
`
`
`<10
`
`
`
`
`
`
`
`
`
`
`
`
`
`Table 1
`
`
`
`
`
`
`
`
`
`in this paper the impact of these requirements on the
`
`
`
`
`powertrain will be examined.
`
`
`
`POSSIBLE HYBRID CONFIGURATION
`
`
`
`
`
`
`
`
`Throughout
`investigation
`a
`preliminary
`with
`
`
`
`
`mathematical
`simulation models,
`the deployment of
`
`
`
`
`
`
`
`overall objectives has been performed into subsystems
`
`
`
`
`specification as a function of possibie powertrain
`
`
`
`
`configurations. For each of
`the possible solutions a
`
`
`
`
`
`
`
`weighted analysis of positive and negative aspects has
`been carried out.
`
`
`
`
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`
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`The results of this analysis can be summarized as
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`FORD 1203
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`follows:
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`Dual mode - The addition of an independent electric
`
`
`
`
`
`
`
`
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`power train on the thermal vehicle leads to the simplest
`
`
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`
`
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`hybrid configuration. The two power trains operate in
`
`
`
`
`
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`alternative, to meet the requirements of the circulation in
`
`
`
`
`
`
`
`typical urban areas (electric traction) or those of
`the
`
`
`
`
`extraurban missions (thermal engine).
`
`
`
`
`
`extraurban driving, with
`Typical mission:
`
`
`
`
`operation in ZEV urban area.
`
`limited
`
`
`
`Advantages:
`
`
`
`.
`
`
`
`.
`
`simplicity
`
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`
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`no integration of the two powertrain possibility to
`
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`
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`have a two axles drive system in case of critical
`
`mobility
`
`Disadvantages:
`
`
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`
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`on the same shaft their respective torque to achieve the
`
`
`desired performance.
`
`
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`
`
`Typical mission: ZEV urban driving and full-performance
`
`
`extraurban driving
`
`
`
`Advantages:
`
`
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`
`.
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`
`.
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`.
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`.
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`low installed electric power,
`mission
`
`
`
`
`related to the urban
`
`
`
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`
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`thermal engine can be downsized without penalizing
`
`
`
`
`vehicle performance leading to a fuel economy
`benefit.
`
`
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`
`
`operating range in hybrid mode depending on
`
`
`
`
`vehicle fuel tank only
`
`
`
`
`
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`addition of electric power to the thermal for peak
`
`performance
`
`
`
`.
`
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`
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`flexibility in changing the vehicle mission.
`
`
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`.
`
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`
`
`critical
`layout due to the two traction axles, with
`considerable modification
`on
`structure
`and
`
`
`
`
`
`
`Disadvantages:
`
`
`
`mechanics;
`
`
`
`
`
`. mechanical complexity
`
`
`
`.
`
`
`
`
`not
`system in
`optimized
`terms
`of
`energy
`
`
`
`consumption and emissions
`
`
`
`-
`
`
`
`
`
`
`
`
`
`
`Series Hybrid - The thermal engine coupled to an electric
`
`
`
`
`
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`generator is used as a generating unit and motion is
`
`
`
`
`
`
`assured by an electric power train.
`
`
`
`
`
`
`
`Typical mission: driving in large ZEV urban area
`
`
`
`Advantages:
`
`
`
`
`
`.
`
`
`
`
`
`
`
`
`
`
`small size thermal engine and its utilization within the
`
`
`
`
`
`of
`favorable working conditions
`in
`terms
`most
`
`
`
`efficiency and emissions;
`
`.
`
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`
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`gearbox is not mandatory
`
`
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`
`
`.
`
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`
`
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`equal vehicle performance in electric and hybrid
`modes.
`
`
`
`
`Disadvantages:
`
`
`
`
`
`.
`
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`
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`number of installed components which have impact
`
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`
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`on the vehicle in terms of weight, volume and cost
`
`
`
`0
`
`
`
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`constant
`speed
`as
`a
`low efficiency
`over
`
`
`
`
`consequence of the energy conversions
`
`.
`
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`
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`
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`performance and operating range limited by battery
`
`
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`high installed electric power
`
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`Parallel Hybrid - Thermal engine and electric motor add
`
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`gearbox and specific coupling interface needed
`
`
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`-
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`system control complexity due to the management
`
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`necessity of the two propulsion systems.
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`The vehicle mission and performance, the uncertainties
`the evolution of
`the market, and cost constrain,
`of
`
`
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`
`
`requiring
`strong
`attention
`to
`the
`“carry
`over”
`a
`
`
`
`
`
`opportunities among the various production vehicles,
`
`
`
`
`
`have led to the choice of
`the parallel
`configuration
`
`(fig.2).
`
`TRASMISSION
`
`
`
`BATTERIES
`
`— '- THERMAL
`ENGINE
`
`ELECTRIC
`
`
`Figure 2
`
`POWERTRAlN DESCRIPTION
`
`
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`
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`Fig. 3 shows the powertrain where the thermal engine,
`
`
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`the electric motor, the interface and gearbox are visible.
`
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`Page 3 of 8
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`Page 3 of 8
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`FORD 1203
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`Torque(Nm)
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`F
`2000
`
`
`
`
`—-l-
`
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`Power(kW)
`
`i
`6000
`
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`.
`3000
`
`
`
`y
`4000
`
`
`5000
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`Speed (rprn)
`
`Figure 5
`
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`Thermal engine
`
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`The thermal engine chosen for this application is the new
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`FIRE 1242 16 valves, just in production on the Lancia Y
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`and on the Fiat PUNTO. An engine section is visible in
`
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`fig. 4 and fig. 5 shows the engine torque and power
`characteristics.
`'
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`THERMAL ENGINE TORQUE AND POWER
`
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`For the hybrid application some modifications of
`the
`
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`
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`series production thermal engine are required, mainly in
`
`
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`
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`the electronic control package which features a drive-by-
`
`
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`wire system. Engine ECU re-calibration is of course
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`necessary to optimize fuel economy, emission and
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`driveability for the hybrid application. Table 2 reports the
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`
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`main engine characteristics.
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`ENGINE CHARACTERISTICS
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`365.5kW@6250r-m
`
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`.lnisg “System
`
`
`
`
`.Mszstgrgys.............................. i.1l§l§lm@fi7..§9f9m..............
`Max
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`The choice of a gasoline engine versus a diesel engine
`
`
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`
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`has been done mainly because the handicap of
`the
`
`
`
`
`
`
`
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`diesel engine is the relatively high NOX emission, which
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`with today's technology cannot be reduced to the same
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`
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`
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`extent as a gasoline engine equipped with a three-way
`
`catalyst.
`
`Electric motor and inverter
`
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`The electric drive system is based on an induction motor
`with vector control inverter.
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`Table 3 and table 4 reports the main motor and inverters
`
`
`
`
`
`
`
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`characteristics.
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`ELECTRIC MOTOR CHARACTERISTICS
`
`
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`Table 3
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`Page 4 of 8
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`FORD 1203
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`32
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`Page 4 of 8
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`FORD 1203
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`INVERTER CHARACTERISTICS
`
`
`
`
`Transmission
`
`
`Table 4
`
`............................................................................................................................
`
`Control algorithm
`
`
`
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`
`
`Switching frequency
`
`
`
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`
`
`Power section input voltage
`Rated
`
`
`Allowed
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`i160-260V
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`3140-280v
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`Fig 6 shows the motor torque and power characteristics.
`
`ELECTRIC MOTOR TORQUE AND
`
`
`
`
`
`.
`no _________
`W
`
`35
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`
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`To minimize modifications and to make the solution
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`compatible with the industrial needs, the integration of
`
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`the two engines has been implemented through a
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`parallel axle transmission (fig. 8).
`
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`120
`100
`
`
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`
`30
`* 25
`
`
`
`
`‘r—Fifl
`'—“Rated power
`“—"Penk power
`
`
`T0
`‘ Ruled Torqut
`
`
`
`
`“Q
`
`UE “0
`‘Peaktor u:
`
`‘l
`(N
`rn) 50
`40
`
`
`
`
`p0
`w
`20
`
`ER
`
`(k
`15 W)
`
`10
`
`
`
`s
`
`
`
`Power switches
`
`
`
`lgure
`
`
`
`
`
`
`
`
`the inverter and the battery management
`The motor,
`
`
`
`
`
`
`
`
`
`have been designed for the application to the Fiat 600
`
`
`
`
`
`
`
`electric vehicle, under development at Fiat Auto and
`Elasis.
`
`
`Page 5 of 8
`
`FORD 1203
`
`33
`
`
`
`Table 5
`
`
`VEHICLE OPERATING MODES
`
`
`
`
`
`
`
`
`
`
`The driver can select between the following four
`
`
`operating modes:
`
`
`
`
`
`
`The mechanical coupling between the two axles is
`
`
`
`
`
`
`performed throughout a toothed belt. An electromagnetic
`
`
`
`
`
`clutch has been designed and manufactured to the
`
`
`
`
`
`connection and disconnection of
`the thermal engine.
`
`
`
`
`
`
`
`This alloWs for an automatic switching from electric to
`
`
`
`
`
`
`
`
`
`hybrid mode during vehicle operation, based on the drive
`
`
`
`
`
`
`
`train control strategies. The transmission to the vehicle
`
`
`
`
`
`wheels is performed by a normal production manually
`
`
`
`shifted 5 speed gearbox.
`
`
`
`
`
`
`
`The main results of a simulation activity on vehicle
`
`
`
`
`performance with
`the
`above described powertrain
`
`
`
`
`components is shown in table 5.
`
`PERFORMANCE
`
`HYBRID THERMAL ELECTRIC
`
`
`
`s
`=
`
`REFER.
`
`
`;
`CONV.
`VEHICLE
`
`
`
`
`
`
`
`
`
`
`
`Top speed (km/h)
`
`0 — 100
`
`
`
`
`
`
`
`
`
`
`
`
`km/h
`
`
`'...............‘...... ......................................,...........................................
`Acceleration
`0 —- 80
`
`
`km/h
`
`
`
`.r,.....................
`
`
`0—50
`
`
`Continuous speed (km/h)
`
`
`
`
`Acceleratio
`
`
`in 3'‘1 (s)
`
`
`
`.,v.....................
`
`Acceleration
`
`
`
`
`
`
`
`
`
`
`(s)
`in 4‘"
`
`
`
`
`,,.,.....................
`
`Acceleration
`
`
`
`
`
`ln 5‘h (5)
`
`
`
`
`
`
`
`20
`
`
`
`0
`
`
`
`
`
`
`
`
`
`o
`'
`l
`l
`.
`l
`l
`
`no
`ma
`you
`son
`100
`600
`n
`100
`zoo
`300
`400
`500
`on
`on
`0
`l)
`o
`o
`0
`0
`l)
`o
`a
`
`
`SPEED (rpm)
`
`
`
`
`
`
`
`
`
`Figure 6
`
`
`
`
`
`
`
`
`
`
`
`
`The motor features a low weight, reduced dimensions,
`
`
`
`
`
`
`
`
`and high utilization range with good efficiency (fig. 7).
`
`
`
`Electric motor and inverter mesured efficiency
`
`
`
`
`
`lst quadrant @ voltage 240 [V]
`
`
`
`
`
`
`
`
`
`
`
`
`35 o
`1250175022502750
`Speed [rpm]
`
`
`0 '500 55006500
`
`
`
`30
`
`
`
`a
`
`
`
`
`
`
`
`
`
`
`50 Torque [Nm]
`
`
`
`
`
`F‘
`
`7
`
`
`Page 5 of 8
`
`FORD 1203
`
`

`

`
`
`
`
`
`
`
`economical point of view, to recharge battery from the
`
`
`
`
`
`
`
`electric distribution through the on-board electric battery
`
`
`
`
`
`
`charger. In this operation mode optimization of recharge
`
`
`
`
`
`
`
`strategies is necessary as a function of the battery state
`
`
`
`
`
`
`
`of charge and/or fuel economy and emissions. Fig 9
`
`
`
`
`shows a typical torque management.
`
`
`
`
`HYBRID MODE
`
`
`1,2.3.2.4.S.
`:
`:
`:-- --:
`:
`
`
`
`RECHARGE MODE
`
`
`6.7.6‘2'4'5'
`z
`:
`:--:--:
`‘
`
`
`THERMAL MODE
`
`
`
`
`
`
`
`
`
`Electric
`Titer-"rut
`_ _ _ nrtm tnrque
`‘ teeque
`‘_ turque
`request
`
`
`
`
`
`
`
`
`
`The electric motor provides all the required torque where engine has high speclfic ruel consumption
`The engine tieliveres torque with limited torque gmdienl; the electric motor deliveres complementary torque
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`The engine delivers the total requested torque
`
`
`
`
`
`
`
`
`
`
`
`
`
`Electric meter torque is nddcd when ttte requested torque is higher than the maximum engine torque
`
`
`
`
`
`
`
`Braking torque is provided by the electric motor to recharge the batteries
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`The electric motor recharges the batteries: the thermal engine delivers torque for both traction and recharge
`The electric motor does not deliver any positive torque for traction (limited vehicle performance)
`
`
`
`
`
`
`
`
`
`T’P‘?’.‘P‘!":‘
`
`
`
`
`
`
`
`
`
`Figure 9
`
`
`
`CONTROL SYSTEM AND MANAGEMENT
`
`
`
`STRATEGIES
`
`
`
`
`
`
`
`
`
`The
`by
`a Vehicle
`system is managed
`hybrid
`
`
`
`
`
`
`
`Management Unit (VMU) which implements the working
`
`
`
`
`
`
`
`strategies of the vehicle and activates the two drive
`
`
`
`
`
`
`
`
`
`
`trains through the inverter for the electric motor and the
`
`
`
`
`
`engine electronic control
`unit
`respectively. System
`
`
`
`
`
`
`diagnosis, driver’s controls, dashboard warning lights‘
`
`
`
`
`
`management and battery state of charge are also
`
`
`
`
`
`
`
`accomplished by the VMU. Fig. 10 shows the control
`
`
`
`system scheme.
`
`BATTERY
`RECHARGE
`
`RECHARGE
`PLUG
`
`CATALYSTIC
`CONVERTER
`
`
`TRACTION
`
`ELECTRIC
`
`PARALLEL
`
`INTERFACE
`
`EAR
`BOX
`
`
`
`
`
`
`THERMAL
`ENGINE
`ENGINE
`STARTER
`
`
`'ZNSttlLs/At'rtMTtlks
`
`ENGINE SET
`ENGWE
`REQUIREMENTS
`CONTROL
`ENGINE
`
`use
`
`
`
`
`
`
`
`
`
`
`
`
`0
`
`-
`
`
`
`
`
`-
`
`
`0
`
`
`hybrid mode
`
`
`
`electric mode
`
`
`
`
`
`economy mode
`
`
`
`recharge mode
`
`
`
`
`
`
`
`
`
`
`In hybrid mode both the thermal engine and the electric
`motor are connected to the driveline to assure vehicle
`
`
`
`
`
`
`
`
`
`
`
`nominal performance and to minimize fuel consumption
`and emissions.
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`The vehicle operation can be divided into two basic
`
`
`
`
`
`
`modes: constant speed (cruising) and acceleration or
`deceleration.
`
`
`
`
`
`
`
`
`
`
`ln cruising mode, relatively low power is required from
`
`
`
`
`
`
`
`the drive train. However, a large amount of energy is
`
`
`
`
`
`
`consumed in a long trip.
`In acceleration mode, a high
`
`
`
`
`
`peak of power
`required but not much energy is
`is
`consumed due to its brief and transient occurrence.
`
`
`
`
`
`
`
`
`
`
`
`
`When maximum vehicle performance is not required, a
`
`
`
`
`
`proper combination
`of
`thermal engine operation for
`
`
`
`
`
`
`
`
`
`cruising, and electric motor for acceleration can be used
`
`
`
`
`to minimize
`consumption
`emissions.
`fuel
`and
`
`
`
`
`
`
`
`
`Furthermore when the vehicle operates with light loads it
`
`
`
`
`
`
`
`is convenient to use electric power instead of
`thermal
`
`
`
`
`
`
`
`
`
`
`one because of the high specific fuel consumption of the
`
`
`gasoline engine.
`
`
`
`
`
`
`
`
`
`The electric motor acts as a generator to recover energy
`
`
`
`
`during deceleration and braking.
`
`
`
`
`
`
`
`
`conventional way,
`The driver operates the vehicle in
`
`
`
`
`
`
`
`using accelerator, brake, clutch and gear shift.
`
`
`
`
`
`
`
`
`The powertrain management controls takes care of not
`
`
`
`
`
`
`
`discharging the battery below a certain threshold; if the
`
`
`
`
`
`
`
`
`
`threshold is reached the system does not allow the use
`
`
`
`
`
`
`of electric motor automatically switching in economy
`mode.
`
`
`
`
`
`
`
`
`
`
`
`in electric mode the thermal engine is shut down and
`
`
`
`
`
`mechanically disconnected through the electromagnetic
`
`
`
`
`
`
`
`
`
`clutch. In this mode, driving could be done without use of
`
`
`
`
`
`the manual gearbox, and the battery can be fully
`
`discharged.
`
`
`
`
`
`
`
`
`Thermal engine starts only if cabin cooling or heating is
`
`required.
`
`
`
`
`
`
`
`
`
`in economy mode all the torque necessary for vehicle
`
`
`
`
`
`
`operation is provided by the thermal engine. Braking
`
`
`
`energy is always recovered.
`
`
`
`
`
`
`
`
`
`In recharge mode the thermal engine delivers power
`
`
`
`
`
`
`
`
`
`both for traction and for battery recharge. As a general
`
`
`
`consideration
`it
`is
`always
`convenient,
`from an
`
`BATTERY - “VERTER '-
`
`
`ELEtTKlCMm‘nRSPEED
`
`ED.u
`
`
`asz’énot
`
`2473EL?
`
`PARKING
`VEHICLE
`MANAGMENT
`UNIT
`
`BATTERY PARAMETERS
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`Figure 10
`
`
`
`
`
`vehicle ECU,
`are
`and
`from engine
`Parameters
`
`
`
`
`
`
`
`exchanged through CAN protocol. The driver, through
`
`
`
`
`
`
`
`
`the accelerator pedal position, sets the required traction
`
`
`
`
`
`
`
`
`
`torque; this is then splitted (in hybrid mode) between the
`
`
`
`
`
`
`
`
`engine and the motor as a function of vehicle operating
`
`
`
`
`
`
`
`condition and battery state of charge to optimize fuel
`
`
`
`
`
`
`
`economy, emission and driveability. The electric torque
`
`
`
`
`
`request
`is
`then actuated through the inverter. The
`
`
`
`
`
`
`
`thermal engine torque request is supplied to the engine
`
`Page 6 of 8
`
`FORD 1203
`
`34
`
`
`
`Page 6 of 8
`
`FORD 1203
`
`

`

`
`
`
`
`
`
`
`control unit that set the throttle angle accordingly.
`
`
`
`
`
`
`
`
`
`When the accelerator pedal is released, a regenerative
`
`
`
`
`
`braking occurs while the electromagnetic clutch is
`
`disengaged.
`
`
`
`
`
`
`The braking effect, and the corresponding energy
`
`
`
`
`
`
`recovery is increased pushing the brake pedal.
`
`SIMULATION STUDIES
`
`
`
`
`
`
`
`
`
`A simulation package based on SIMULINKTM has been
`
`
`
`
`developed. SIMULINKTM is a program for simulating
`
`
`
`
`
`dynamic systems based on MATLABTM which is a
`
`
`
`
`powerful
`numerical
`math
`program.
`Individual
`
`
`
`components
`the
`drive
`train
`could
`be
`easily
`of
`
`
`
`by
`simulation
`blocks. They
`can be
`represented
`connected to constitute a mathematical model of the
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`entire power train. The model includes the possibility to
`
`
`
`
`implement different
`torque
`split
`strategies
`and to
`
`
`
`the
`effect on parameters
`such as
`fuel
`evaluate
`
`
`
`
`
`
`
`consumption, emission, battery state of charge etc.
`
`
`
`
`
`
`
`
`
`
`Fig 11 shows the top level block diagram of the hybrid
`
`powertrain.
`
`PARALLEL HYBRID PROPL LSION SYSTEM
`
`
`
`
`
`
`
`
`
`
`Driver cycl-
`
`
`
`
`
`canal
`
`
`
`Cunlrol slralzgles
`
`
`
`Elie”. Clutch
`
`
`
`Torque splitting on EUDC
`
`
`
`
`{9‘
`ThemIal engine torque gradient limited @1daNm/s
`
`
`
`
`
`
`
`
`é
`
`TarquetNm)
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`o‘a
`
`
`
`
`
`
`
`
`
`
`
`780
`820
`860
`900
`940
`980
`1020
`1060
`1100
`1140
`1180
`
`
`
`
`
`Time (s)
`
`
`
`
`
`
`
`
`Figure 13
`
`
`
`
`
`
`
`
`
`
`
`
`thermal engine
`Fig 14 shows the effect of different
`
`
`
`
`
`torque increase limitation on tailpipe emission,
`fuel
`
`
`
`
`
`consumption and electric energy consumption.
`
`ENGINE TRANSIENT TORQUE
`+00
`.5. H;
`
`
`
`
`
`LIMITATIONm +f‘bx
`~x— Bee. energy cars.
`
`ON ECEi—EUG)
`—<>— AVERAEBNEP
`—0— Fuel cons.
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`Percento!Varlatlon
`
`
`
`
`
`
`
`0,001
`
`
`
`0.01
`
`
`1
`0,1
`
`
`M17: them-n engine Inripe graient (Muis)
`figure 14
`
`
`
`
`
`
`
`
`
`
`
`
`10
`
`
`
`
`
`100
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`Eluculc m- or
`
`
`
`Figure 11
`
`
`
`
`
`
`
`
`
`
`
`
`
`Figure 12 and 13 show a typical torque split on ECE and
`
`
`
`
`
`
`on EUDC which is obtained by limiting the
`thermal
`
`
`
`
`engine torque increase at 1 daNm/s.
`
`Torque splitting on ECE
`
`
`
`
`Thermal engine torque gradient limited @1daMn/s
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`Torque(Nm)
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`—:‘ectg1r:n'otor
`__Speed
`
`
`
`
`
`
`
`
`Time(s)
`
`
`Figure 12
`
`
`
`Page 7 of 8
`
`FORD 1203
`
`35
`
`
`
`
`
`
`
`Figure
`of different constant
`15 shows
`the
`effect
`
`
`
`
`
`
`recharging thermal engine torque on tailpipe emission,
`
`
`
`
`
`
`
`fuel consumption and electric energy consumption, when
`
`
`
`
`
`
`
`the thermal engine torque gradient is limited at 2 Nm/s.
`
`USEOFCONSTANI‘REU'IARGING
`TORQUE mmma)
`
`
`
`
`175)
`
`
`
`Emlu.,Fuol,EMEP('A 82%.IS
`
`Nm
`
`('n3»:1:
`
`('1:
`
`
`
`
`
`
`
`Elect.enrgycone.(7.)
`
`
`
` oDiEB
`
`Recharging Bigine Tong»: (daNm)
`Fgure IS
`
`
`
`
`
`
`
`
`Fig 16 shows the effect of different constant electric
`
`
`
`
`
`motor equivalent
`torque on tailpipe emission,
`fuel
`
`
`
`
`
`
`
`consumption and electric energy consumption, when the
`
`
`
`
`
`
`
`thermal engine torque gradient is limited at 9 Nm/s.
`
`Page 7 of 8
`
`FORD 1203
`
`

`

`
`
`Elrurt:
`
`
`
`Equhnlem Eleclrlc Torque (anrn)
`figure 16
`
`
`
`
`
`CONCLUSION
`
`
`
`
`
`
`
`
`The hybrid drive system presented in this paper is
`
`
`
`
`envisaged to use
`as much
`possible
`series
`as
`
`
`
`
`
`
`
`
`components to minimize development time and costs. At
`
`
`
`
`
`
`
`present time it
`is hard to predict which type of hybrid
`vehicle will be the best choice for the future traffic and
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`legislation
`scenario. Our studies showed that
`the
`
`
`
`
`
`
`
`parallel hybrid configuration could be the right choice.
`
`
`
`
`
`
`
`
`
`It is important to remark that the objective of the present
`
`
`
`
`research work is of
`identifying and prototyping a
`
`
`
`
`
`powertrain for a hybrid vehicle suitable for mass
`
`
`
`
`
`
`
`
`production. As a consequence, the focus of the research
`
`
`
`project has
`been the
`“system optimization”,
`i.e.
`
`
`
`
`identification
`of optimum configuration and control
`
`
`
`
`
`strategies using “conventional present technology”.
`
`
`
`
`
`
`
`
`
`
`At this stage the research and development activities of
`
`
`
`
`
`
`power
`train functions and control
`strategies, using
`
`
`
`
`
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`current level of technology on batteries, electric motor
`
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`
`
`
`
`
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`and combustion engine, have shown good results in fuel
`
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`
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`economy,
`emissions
`and
`performance.
`Further
`
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`improvements in this area are still possible and will be
`
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`
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`the main goals of the future activity.
`
`ACKNOWLEDGMENTS
`
`
`This work has been carried out in the frame of an Italian
`
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`Research project (Legge 64 peril Mezzogiorno d’ltalia)
`
`
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`
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`that economically supported the Elasis activities.
`I,
`
`
`
`
`CONSTANT ELECTRIC TORQUE EFFECT
`—-o-C0
`+HC
`+AVERAC£|IMEP
`ON ECE+EUCD
`+5“
`
`
`
`
`
`
`
`+Ekc|ri€
`energycuns.
`
`
`
`
`
`
`
`energymm(m
`
`
`
`Embasfud,RMEP(m)
`
`
`
`
`
`i
`
`
`.-
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`Figure 17 reports the kinetic energy breakdown during
`
`
`
`
`decelerations phases on ECE, EUDC, and at
`two
`deceleration rates.
`
`
`
`
`CALCULATED ENERGY BREAKDOW N
`
`
`
`Figure 17
`
`
`
`f/
`
`%
`
`20,6
`
`
`
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`
`
`
`y/
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`7/
`
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`
`100
`90
`
`807
`
`70
`
`60 >
`
`50
`
`4O
`
`30
`
`20
`
`10
`
`
`Energy
`
`(7.)
`
`
`
`EOE
`
`
`
`
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`
`
`
`
`
`DECELER.
`DECELER. 0.5
`ECE+EUDC
`EUDC
`
`W52 0.75 (rt/52
`
`
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`
`
`Energy saving
`
`
`
`I] Electric loss es
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`
`
`DAerodyn am ycs+rollyng+transm ission losses
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`Figure 18 shows the electric range autonomy on ECE,
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`and at two constat speed.
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`ELECT RIC RANGE
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`(km)
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`ECE
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`V250 (km/h) V=9O (km/h)
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`Figure 18
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`Page 8 of 8
`
`FORD 1203
`
`36
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`
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`Page 8 of 8
`
`FORD 1203
`
`