WO2013012380A1

WO2013012380A1 - Parallel hybrid system and method pertaining to a parallel hybrid system

Info

Publication number: WO2013012380A1
Application number: PCT/SE2012/050769
Authority: WO
Inventors: Johan LINDSTRÖM
Original assignee: Scania Cv Ab
Priority date: 2011-07-15
Filing date: 2012-07-03
Publication date: 2013-01-24
Also published as: EP2731842A4; SE1150685A1; EP2731842A1

Abstract

The invention relates to a method pertaining to a parallel hybrid system (299) for propulsion of a motor vehicle (100; 110) comprising a combustion engine (230) in combination with an electrical machine configuration (250, 253, 255) which includes an electrical machine (250). The method comprises the step, during an initial movement phase of the vehicle's propulsion, of running an extra electrical machine (257) by means of said engine (230) to supply power to the electrical machine (250) of the electrical machine configuration, which extra electrical machine (257) is also used during said initial movement phase to supply power to at least one consumer unit (290). The invention relates also to a computer programme product containing programme code (P) for a computer (210; 220) to implement a method according to the invention. The invention relates also to a parallel hybrid system and a motor vehicle which is equipped with the parallel hybrid system.

Description

Parallel hybrid system and method pertaining to a parallel hybrid system

TECHNICAL FIELD

The present invention relates to a method pertaining to a parallel hybrid system for propulsion of a motor vehicle comprising a combustion engine in combination with an electrical machine configuration which includes an electrical machine provided with power supply. The invention relates also to a computer programme product containing programme code for a method according to the invention. The invention relates also to a parallel hybrid system for propulsion of a motor vehicle comprising a combustion engine in combination with an electrical machine configuration which includes an electrical machine provided with power supply, and to a motor vehicle which is equipped with the parallel hybrid system.

BACKGROUND In today's vehicles it is becoming increasingly usual to use various types of hybrid techniques, e.g. so-called series hybrid systems and so-called parallel hybrid systems.

A parallel hybrid system comprises a combustion engine which has an output shaft connected to a mechanical clutch. The clutch is also connected to an input shaft of a gearbox. The gearbox has an output shaft connected to a torque distributor for conveying power to a number of powered wheels via respective driveshafts. The parallel hybrid system further comprises an electrical machine associated with the gearbox input shaft. The electrical machine is connected electrically to a battery. A control system of the vehicle may be adapted to running the parallel hybrid system in suitable ways, i.e. to distributing, when the vehicle is in operation, the torque

RECORD COPY-T ANSLAT'ON

(Rule 12,4) respectively provided by the combustion engine and the electrical machine which is supplied with power by the battery. The electrical machine can in a conventional way serve as a generator to charge the battery during braking of the vehicle.

Although there are now parallel hybrid systems which work well, vehicle manufacturers are constantly endeavouring to improve the performance of their vehicles while at the same time taking into account the costs which this involves. It is for example desirable for them to provide improved parallel hybrid systems which are not too complex and expensive to manufacture and maintain.

WO 2008/077345 describes a rather complicated parallel hybrid system for a motor vehicle comprising a combustion engine, a first motor, a second motor, a third motor, a battery, a first clutch, a second clutch and a third clutch. The first motor and the second motor are connected electrically to the battery and the third motor is connected electrically to the battery or another battery. The combustion engine is connected to the first motor via the first clutch and to the third motor via the third clutch. The first motor is connected to the second motor via the second clutch, and the second motor is connected to a driveshaft. A separate battery is provided to run the first motor and the second motor via a respective power converter.

WO 2008/092353 also describes a rather complicated parallel hybrid system for a motor vehicle comprising a combustion engine, a first motor, a second motor, a battery, a first clutch and a second clutch. The first motor and the second motor are connected electrically to the battery. The combustion engine is connected to the first motor via the first clutch. The first motor is connected to the second motor via the second clutch, and the second motor is connected to a driveshaft. A separate battery is provided to run the first motor and the second motor via a respective power converter. US20080156550 describes a hybrid vehicle comprising a combustion engine (100), a generator (200), a battery (400), a clutch (500), an electric driving motor (300), an automatic transmission system (600) and a control system (810). At low vehicle speeds the electric driving motor is used to propel the vehicle. If the battery's charge level goes below a certain level, the generator, which is driven by the combustion engine, is used to charge the battery.

SUMMARY OF THE INVENTION

An object of the present invention is to propose a novel and advantageous method pertaining to a parallel hybrid system.

Another object of the invention is to propose a novel and advantageous parallel hybrid system and a novel and advantageous computer programme pertaining to a parallel hybrid system.

A further object of the invention is to propose a method, a parallel hybrid system and a computer programme for achieving an improved initial movement phase for a motor vehicle.

A further object of the invention is to propose a method, a parallel hybrid system and a computer programme for achieving a more environmentally friendly initial phase of movement for a motor vehicle.

A further object of the invention is to propose a method, a parallel hybrid system and a computer programme for achieving a more robust phase of initial movement for a motor vehicle whereby the number of undesired cessations of charging of the battery is reduced.

A further object of the invention is to propose a method, a parallel hybrid system and a computer programme for achieving an initial movement phase for a motor vehicle whereby necessary time for undesired cessations of charging of the battery is reduced.

These objects are achieved with a method pertaining to a parallel hybrid system for propulsion of a motor vehicle comprising a combustion engine in combination with an electrical machine configuration which includes an electrical machine provided with power supply, according to claim 1.

An aspect of the invention proposes a method pertaining to a parallel hybrid system for propulsion of a motor vehicle comprising a combustion engine in combination with an electrical machine configuration which includes an electrical machine provided with power supply. The method comprises the step, during an initial movement phase of the vehicle's propulsion, of running an extra electrical machine by means of said engine to supply power to the electrical machine of the electrical machine configuration.

Said power supply to the electrical machine of the electrical machine configuration may be direct or indirect. Indirect power supply means using electricity generated by the extra electrical machine to charge an energy store, e.g. a battery, of the electrical machine configuration or to run at least one consumer unit. In this case the extra electrical machine may be regarded as a supporting element for the energy store of the electrical machine configuration, which may thus use stored energy to supply power to the electrical machine of the electrical machine configuration instead of running said consumer unit. Using the extra electrical machine to charge the energy store of the electrical machine configuration provides assurance of a higher level of charge than previously, thereby reducing the number of undesired cessations of charging or reducing the time required for charging the energy store during an initial movement phase for propulsion of the vehicle. The result is a robust power train for vehicles equipped with the parallel hybrid system, since undesired standstills to charge an energy store of the electrical machine configuration are avoided or reduced during said initial movement phase.

Improved performance of the vehicle equipped with the parallel hybrid system is thus achieved, since wear on a clutch associated with an input shaft of the vehicle's gearbox is avoided or reduced during said initial movement phase.

An aspect of the invention proposes a method pertaining to a parallel hybrid system or propulsion of a motor vehicle comprising a combustion engine in combination with an electrical machine configuration which includes an electrical machine provided with power supply. The method comprises the step, during an initial movement phase of the vehicle's propulsion, of running an extra electrical machine by means of said engine to supply power to at least one consumer unit, e.g. an AC unit or a DC/DC converter.

An aspect of the invention proposes a method pertaining to a parallel hybrid system for propulsion of a motor vehicle comprising a combustion engine in combination with an electrical machine configuration which includes an electrical machine provided with power supply. The method comprises the step, during an initial movement phase of the vehicle's propulsion, of running an extra electrical machine by means of said engine to charge an energy store of said electrical machine configuration .

One version proposes a method pertaining to a parallel hybrid system for propulsion of a motor vehicle comprising a combustion engine in combination with an electrical machine configuration which includes an electrical machine provided with power supply. The method comprises the step, during an initial movement phase of the vehicle's propulsion, of running an extra electrical machine by means of said engine to supply power to the electrical machine of the electrical machine configuration and/or to supply power to at least one consumer unit and/or to charge an energy store of said electrical machine configuration. The power supply to the electrical machine of the electrical machine configuration may be provided by a generator of the extra electrical machine. This generator may be adapted to generating of the order of 10 kW. It may be adapted to producing during said initial movement phase an output within the range of 5-20 kW. In one version the extra electrical machine's generator is adapted to producing any suitable electrical output.

Said initial movement phase may refer to a state before full propulsion takes place with chosen gear in the vehicle's power train. In other words, said initial movement phase may comprise a state when a clutch in the power train is sliding together.

Said initial movement phase may comprise a state from when the vehicle moves off from stationary to when the clutch has slid together. Said initial movement phase may comprise a state in which the vehicle travels at a speed within a predetermined range, e.g. 0-5 km/h, 0.0-3.0 km/h or 1-3 km/h. Said initial movement phase may comprise a state when the vehicle travels at a speed not exceeding a predetermined threshold value, e.g. 2 km/h. Said initial movement phase may comprise the vehicle being stationary.

After said initial movement phase the vehicle may be run according to ordinary running routines, i.e. by torque from the combustion engine, torque from the electrical machine configuration or torque from both of these power sources, but without using the extra electrical machine herein described. The electrical machine of the electrical machine configuration may act upon an input shaft of a gearbox in the vehicle's power train, and vice versa. This means that the electrical machine can serve both as a motor to impart torque to an input shaft of a gearbox in the vehicle's transmission and as a generator to charge an energy store of the electrical machine configuration.

The method is easy to implement in existing motor vehicles. Software pertaining to a parallel hybrid system for propulsion of a motor vehicle comprising a combustion engine in combination with an electrical machine configuration which includes an electrical machine provided with power supply and the extra electrical machine may be installed in a control unit of the vehicle during the manufacture of the vehicle. A purchaser of the vehicle may thus have the possibility of selecting the function of the method as an option. Alternatively, software containing programme code for applying the innovative method pertaining to a parallel hybrid system for propulsion of a motor vehicle comprising a combustion engine in combination with an electrical machine configuration which includes an electrical machine provided with power supply may be installed in a control unit of the vehicle on the occasion of upgrading at a service station, in which case the software may be loaded into a memory in the control unit. The engine on board the vehicle can relatively easily be retrofitted with the extra electrical machine.

Software containing programme code for the method pertaining to a parallel hybrid system for propulsion of a motor vehicle comprising a combustion engine in combination with an electrical machine configuration which includes an electrical machine provided with power supply is easy to update or replace. Different parts of the software containing said programme code may also be replaced independently of one another. This modular configuration is advantageous from a maintenance perspective.

An aspect of the invention proposes a parallel hybrid system for propulsion of a motor vehicle comprising a combustion engine in combination with an electrical machine configuration which includes an electrical machine provided with power supply. The parallel hybrid system comprises an extra electrical machine adapted to being powered by said engine to supply power to the electrical machine of the electrical machine configuration during an initial movement phase of the vehicle's propulsion.

The extra electrical machine may comprise a generator adapted to supplying power to the electrical machine of the electrical machine configuration. Said generator may be adapted to running at least one consumer unit. Said generator may be adapted to charging an energy store of said electrical machine configuration.

The extra electrical machine may comprise a generator adapted to supplying power to the electrical machine of the electrical machine configuration, to running at least one consumer unit and to charging an energy store of said electrical machine configuration.

The electrical machine of the electrical machine configuration may be adapted to acting upon an input shaft of a gearbox in the vehicle's power train, and vice versa.

The above objects are also achieved with a motor vehicle provided with the innovative parallel hybrid system. The vehicle may be a truck, bus or car. An aspect of the invention is a proposed computer programme for a method pertaining to a parallel hybrid system for propulsion of a motor vehicle comprising a combustion engine in combination with an electrical machine configuration which includes an electrical machine provided with power supply, which programme contains programme code stored on a computer- readable medium for causing an electronic control unit or another computer connected to the electronic control unit to perform steps according to any one of claims 1-5. An aspect of the invention is a proposed computer programme for a method pertaining to a parallel hybrid system for propulsion of a motor vehicle comprising a combustion engine in combination with an electrical machine configuration which includes an electrical machine provided with power supply, which programme contains programme code for causing an electronic control unit or another computer connected to the electronic control unit to perform steps according to any one of claims 1-5. An aspect of the invention is a proposed computer programme product containing a programme code stored on a computer-readable medium for performing method steps according to any one of claims 1-5 when said programme is run on an electronic control unit or another computer connected to the electronic control unit.

Further objects, advantages and novel features of the present invention will become apparent to one skilled in the art from the following details, and also by applying the invention. Although the invention is described below, it should be noted that it is not limited to the specific details described. One skilled in the art who has access to the teachings herein will recognise further applications, modifications and incorporations within other fields, which are within the scope of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

Fuller understanding of the present invention and further objects and advantages of it may be gained by reading the following detailed description in conjunction with the accompanying drawings, in which the same reference notations pertain to similar items in the various diagrams, and in which:

Figure 1 illustrates schematically a vehicle according to an embodiment of the invention; Figure 2 illustrates schematically a parallel hybrid system for the vehicle depicted in Figure 1 , according to an embodiment of the invention;

Figure 3 is a schematic diagram illustrating an aspect of the invention;

Figure 4a is a schematic flowchart of a method according to an embodiment of the invention;

Figure 4b is a more detailed schematic flowchart of a method according to an embodiment of the invention; and

Figure 5 illustrates schematically a computer according to an embodiment of the invention.

DETAILED DESCRIPTION OF THE DRAWINGS

Figure 1 depicts a side view of a vehicle 100. The vehicle exemplified comprises a tractor unit 110 and a semitrailer 112. It may be a heavy vehicle, e.g. a truck or a bus. It may alternatively be a car.

The term "link" refers herein to a communication link which may be a physical line such as an opto-electronic communication line, or a non-physical line such as a wireless connection, e.g. a radio link or microwave link.

Figure 2 depicts a parallel hybrid system 299 of the vehicle 100. The parallel hybrid system is situated in the tractor unit 110.

The parallel hybrid system 299 comprises a combustion engine 230 which has an output shaft 235 connected to a clutch 240. The clutch may be any suitable clutch. It may be a sliding clutch with pressure discs and plates. It may in one alternative be implemented as a so-called lock-up function in a torque converter in cases where the vehicle's transmission has an automatic gearbox. The clutch 240 is connected to an input shaft 245 of a gearbox 260. The gearbox has an output shaft 265 connected to a torque distributor 270 for conveying power to a number of powered wheels 280 via respective driveshafts 275. The parallel hybrid system 299 further comprises an electrical machine configuration comprising an electrical machine 250 associated with the gearbox input shaft 245. The electrical machine 250 is connected electrically to an energy store 255. The electrical machine may in one example be suited to an operating power of 60-120 kW. The energy store 255 may be of any suitable kind. It may in one example be a battery of any suitable kind, e.g. a lithium ion battery. The battery may alternatively be for example an NiMH battery. In another example the energy store 255 may be an electrochemical energy store, e.g. an electrochemical capacitor known as SuperCap. Said energy store is herein exemplified with a battery of conventional kind for parallel hybrid systems.

In one version, the electrical machine 250 is adapted to being supplied with power by said energy store 255 and thereby serving as a motor in the vehicle's power train to impart driving torque to the gearbox input shaft 245. In one version the electrical machine 250 is adapted to serving as a generator of the electrical machine configuration and thereby charging the energy store 255 during braking of the vehicle 100. Said electrical machine 250 may typically run alternately as motor and generator.

In the version of this example the battery 255 is connected electrically to an electrical rectifier 253 by a cable L255. The rectifier 253 is adapted to converting DC voltage supplied from the battery via the cable L255 to a desired suitable three-phase voltage. The rectifier 253 is adapted to supplying said three-phase voltage to the electrical machine 250 via a cable L253 to power and run the electrical machine. Said DC voltage may amount to several hundred volts, e.g. 400 volts or 600 volts. Said electrical machine configuration comprises said electrical machine 250, electrical rectifier 253, battery 255 and necessary connections between them. The rectifier 253 is arranged accordingly so that during braking of the vehicle it converts to DC voltage a three-phase voltage generated from the electrical machine 250 and supplied to the rectifier. The rectifier 253 is arranged to supply said DC voltage to the battery 255 via the cable L255 to charge the battery.

A component configuration comprising the electrical machine 250, the cable L253, the rectifier 253, the cable L255 and the energy store 255 is herein called the electrical machine configuration. It should be noted that different versions of said electrical machine configuration are feasible. In one version the energy store 255 and the rectifier 253 may be manufactured as an integrated unit which is connected electrically to the electrical machine 250. In another version the rectifier 253 and the electrical machine 250 may be manufactured as an integrated unit which is connected electrically to the energy store 255. In a third version the energy store 255, the rectifier 253 and the electrical machine 250 may be manufactured as an integrated unit.

An aspect of the invention proposes an extra electrical machine 257 which in a preferred version is an electrical generator. During an initial movement phase, the combustion engine 230 is adapted to driving the extra electrical machine 257, e.g. via a gearwheel configuration or a drivebelt configuration (not depicted). When the vehicle is in operation, the electrical machine 257 is adapted to supplying a three-phase voltage to an electrical rectifier 259 via a cable L257. The rectifier 259 is adapted to converting the three-phase voltage to DC voltage and to supplying the DC voltage to the cable L255. In an alternative version of the invention, electrical machines herein described may be run with any desired number of phases, e.g. one phase or two phases. According to an aspect of the invention, the DC voltage supplied may, during a moving-off procedure for propulsion of the vehicle, be used to

1 ) run the electrical machine 250 and/or

2) charge the battery 255 and/or 3) run at least one consumer unit 290.

It should be noted that different versions of the present invention are feasible. In one version the extra electrical machine 257 and the rectifier 259 may be manufactured as an integrated unit which is connected electrically to an output side of the battery 255 (corresponding to an input side of the rectifier 253). In a second version the extra electrical machine may be connected electrically directly to the electrical machine 250.

In a third version, the extra electrical machine 257, the rectifier 259 and the engine 230 may be manufactured as an integrated unit.

In a fourth version, the extra electrical machine 257, the rectifier 259 and the battery 255 may be manufactured as an integrated unit.

In a fifth version, the extra electrical machine 257, the rectifier 259, the battery 255 and/or the rectifier 253 may be manufactured as an integrated unit.

In a sixth version, the extra electrical machine may be mounted directly on the engine 230.

In a seventh version, the extra electrical machine may be situated close to the engine 230.

In an eighth version, the extra electrical machine may be fitted as a separate unit. In a ninth version, the extra electrical machine may be detachably associated with the engine 230.

In a tenth version one or more of versions 1-9 above may be suitably combined where compatibility so allows.

During an initial movement phase of the vehicle's propulsion, the extra electrical machine 257 is adapted to generating electrical energy when it is driven by the engine 230, to supply power to the electrical machine 250 of the electrical machine configuration. During an initial movement phase of the vehicle's propulsion, the extra electrical machine 257 is adapted to generating electrical energy when it is driven by the engine 230, to supply power to at least one consumer unit 290. During an initial movement phase of the vehicle's propulsion, the extra electrical machine 257 is adapted to generating electrical energy when it is driven by the engine 230, to charge the battery 255.

In one version, at least one consumer unit 290 is connected electrically to an output side of the battery 255. Said at least one consumer unit may for example be an AC (air conditioning) unit or a cab fan. The battery is adapted to running said at least one consumer unit. In another version, said parallel hybrid system lacks said consumer unit. Alternatively, said consumer unit is adapted to being run by some other power source than said battery 255, e.g. the engine 230. It should however be noted than the present invention is particularly suitable for parallel hybrid systems in which said battery 255 is adapted to running at least one consumer unit 290, since the extra electrical machine 255 can provide at least part of the energy required to run said consumer unit, mainly when the vehicle is stationary. A first control unit 210 is arranged for communication with the rectifier 259 via a link 210. The first control unit is adapted to controlling the operation of the electrical machine 257 by means of the rectifier 259 according to stored running routines. The first control unit is adapted to determining whether the vehicle is in an initial movement phase or not. In one version of the present invention the first control unit is adapted to activating operation of the extra electrical machine 257 when it is determined that an initial movement phase for propulsion of the vehicle is beginning. In one version, the first control unit is adapted to continuously allowing and controlling the operation of the extra electrical machine during said initial movement phase for propulsion of the vehicle. In one version, the first control unit is adapted to deactivating operation of the extra electrical machine when it is determined that the vehicle is no longer in an initial movement phase for its propulsion. In one version, the first control unit is adapted to activating stored running routines for the parallel hybrid system when it is determined that the vehicle is no longer in an initial movement phase for its propulsion, and consequently to running the vehicle in a conventional way.

In one version, activation and deactivation of operation of the extra electrical machine 257 may for example act upon a gearwheel configuration or drivebelt configuration (not depicted) for conveying power between the engine and the extra electrical machine.

The electrical machine 250 may herein be called a first electrical machine. The extra electrical machine 257 may herein be called a second electrical machine. The first control unit 210 is arranged for communication with the engine 230 via a link L230. The first control unit is adapted to controlling the operation of the engine according to stored running routines. It is for example adapted to guiding an engine's prevailing speed (or output shaft torque) towards a demanded speed (or demanded output shaft torque).

The first control unit 210 is arranged for communication with the clutch 240 via a link L240. The first control unit is adapted to controlling the operation of the clutch according to stored running routines. It is for example adapted to opening the clutch, sliding the clutch together and closing the clutch according to said stored routines. The first control unit 210 is arranged for communication with the electrical machine 250 via a link L250. The first control unit is adapted to controlling the operation of the electrical machine 250 according to stored running routines. Although in Figure 2 the link L250 is connected to the electrical machine 250, it is in practice connected to the rectifier 253. In practice the first control unit is adapted to controlling the electrical machine 250 by means of the rectifier 253. For example, the first control unit is adapted to choosing the running direction for the electrical machine 250 according to said stored routines. This means that the first control unit is adapted to using the rectifier 253 to cause the electrical machine 250 to serve as a motor to impart driving torque to the gearbox input shaft 245. This also means that where appropriate the first control unit is adapted to causing the electrical machine 250 to serve as a generator to charge the battery 255.

The first control unit 210 is arranged for communication with the gearbox 260 via a link L260. The first control unit is adapted to controlling the operation of the gearbox according to stored running routines. It is for example adapted to causing different gear steps in the gearbox, including neutral position, according to said stored routines. The gearbox may be a so-called manual gearbox, e.g. a robotised/automated manual gearbox, or an automatic gearbox.

A second control unit 220 is arranged for communication with the first control unit 210 via a link L220. The second control unit 220 may be detachably connected to the first control unit 210. The second control unit 220 may be a control unit external to the vehicle 100. The second control unit may be adapted to effecting the innovative method steps according to the invention. It may be used to cross-load software to the first control unit, particularly software for applying the innovative method. It may alternatively be arranged for communication with the first control unit via an internal network on board the vehicle. The second control unit may for example be adapted to performing substantially similar functions to the first control unit, e.g. controlling the operation of the engine 230, the clutch 240, the electrical machine configuration comprising the electrical machine 250, the rectifier 253 and the battery 255, and the gearbox 260. The second control unit may be adapted to performing substantially similar functions to those of the first control unit, e.g. controlling, during a phase of initial movement of the vehicle, the operation of the extra electrical machine 257 by means of said engine 230 to supply power to the electrical machine 250 of the electrical machine configuration.

It should be noted that certain of the above functions may be performed by the first control unit 210 and certain of them by the second control unit 220.

Figure 3 is a schematic diagram in general terms of a version of the present invention. It schematically illustrates regulating states of the vehicle's transmission, the clutch 240 and the extra electrical machine (generator) 257. It makes it clear that only when the clutch is open during an initial movement phase for propulsion of the vehicle does the electrical machine 257 serve actively as a generator (see graph for vehicle speed v [km/hour] as a function of time t [seconds]).

Figure 4a is a schematic flowchart of a method pertaining to a parallel hybrid system for propulsion of a motor vehicle comprising a combustion engine in combination with an electrical machine configuration which includes an electrical machine provided with power supply, according to an embodiment of the invention. The method comprises a first step s401 comprising, during an initial movement phase of the vehicle's propulsion, the step of running an extra electrical machine by means of said engine to supply power to the electrical machine of the electrical machine configuration. The method ends after step s401. Figure 4b is a schematic flowchart of a method pertaining to a parallel hybrid system 299 for propulsion of a motor vehicle 100 comprising a combustion engine 230 in combination with an electrical machine configuration which includes an electrical machine 250 provided with power supply, according to an embodiment of the invention.

The method comprises a first step s410 of determining whether a first state prevails. Said first state refers to an initial movement phase for propulsion of the vehicle. Said initial movement phase may for example refer to a state before full propulsion takes place with chosen gear in the vehicle's power train. The moving-off phase may comprise the vehicle being stationary. It may refer to a state when a clutch 240 in the vehicle's transmission is sliding together. The moving-off phase may comprises a state when the vehicle moves by so-called inching. The moving-off phase may refer to a state from when the vehicle is stationary to when a first chosen gear is fully engaged.

If said first state prevails, the next step s420 is performed. If said state does not prevail, step s410 is performed again.

Method step s420 comprises the step of running the extra electrical machine 257. Activating and running the extra electrical machine by means of the engine 230 in a desirable way during said initial movement phase may result in a number of advantages, e.g. undesired cessations of charging in the parallel hybrid system may be avoided. The electricity generated by the electrical machine 257 during the moving-off phase may be used in various ways. Step s420 may during an initial movement phase of the vehicle's propulsion comprise the step of running the extra electrical machine 257 by means of the engine 230 to supply power to the electrical machine 250 of the electrical machine configuration and/or to supply power to at least one consumer unit 290 and/or to charge the battery 255 of said electrical machine configuration. Step s420 is followed by a step s430. Method step s430 comprises the step of determining whether a second state prevails. Said second state may refer to a driving phase for propulsion of the vehicle 100 which follows said initial movement phase. Said driving phase may for example refer to a state after full propulsion takes place with chosen gear in the vehicle's power train. This driving phase may comprise the vehicle travelling at a speed which exceeds a predetermined value, e.g. 5 km/h or 2 km/h. It may refer to a state in which a clutch 240 in the vehicle's transmission has slid together. It may comprise a state in which the vehicle travels in some other way than by so-called inching. The second state may comprise a first chosen gear being fully engaged after the vehicle has been set in motion from stationary. The first state and the second state are different states which may be defined by any suitable limit, e.g. a predetermined value which represents a prevailing speed of the vehicle or a degree of sliding in of the clutch 240 (e.g. within a range of 95-100%, the clutch being closed at 100%).

If said second state prevails, a subsequent step s440 is performed. If said second state does not prevail, step s420 is performed again.

Method step s440 comprises the step of altering active running routines of the parallel hybrid system 299. This entails cessation of operation of the extra electrical machine 257. In one embodiment, operation of the extra electrical machine proceeds during said initial movement phase only.

Thereafter the parallel hybrid system 299 is run in the ordinary way, i.e. in a way which with advantage uses both the engine 230 and the electrical machine configuration which includes the electrical machine 250, separately or simultaneously, for propulsion of the vehicle. The method ends after step s440. Figure 5 is a diagram of a version of a device 500. The control units 210 and 220 described with reference to Figure 2 may in one version comprise the device 500. The device 500 comprises a non-volatile memory 520, a data processing unit 510 and a read/write memory 550. The non-volatile memory 520 has a first memory element 530 in which a computer programme, e.g. an operating system, is stored for controlling the function of the device 500. The device 500 further comprises a bus controller, a serial communication port, I/O means, an A/D converter, a time and date input and transfer unit, an event counter and an interruption controller (not depicted). The non-volatile memory 520 has also a second memory element 540.

A proposed computer programme P contains routines for running, during an initial movement phase of the vehicle's propulsion, the extra electrical machine 257 by means of the engine 230 to supply power to the electrical machine 250 of the electrical machine configuration according to the innovative method. The programme P contains routines for determining whether the first state described above prevails. The programme P contains routines for determining whether the first state continues to prevail or whether the second state described above prevails. The programme P may be stored in an executable form or in compressed form in a memory 560 and/or in a read/write memory 550.

Where it is stated that the data processing unit 510 performs a certain function, it means that the data processing unit effects a certain part of the programme stored in the memory 560 or a certain part of the programme stored in the read/write memory 550.

The data processing device 510 can communicate with a data port 599 via a data bus 515. The non-volatile memory 520 is intended for communication with the data processing unit via a data bus 512. The separate memory 560 is intended to communicate with the data processing unit via a data bus 511. The read/write memory 550 is intended to communicate with the data processing unit via a data bus 514. The data port may for example be connected to the links L210, L220, L230, L240, L250 and L260 (see Figure 2).

When data are received on the data port 599, they are stored temporarily in the second memory element 540. When input data received have been temporarily stored, the data processing unit 510 will be ready to effect code execution in a manner described above. In one version, signals received on the data port contain information about a prevailing speed of the engine 230. In one version, signals received on the data port contain information about a state of the clutch 240. This clutch state may comprise any of the states respectively representing the clutch fully open, the clutch to some extent slipping or the clutch fully closed. The signals received on the data port may be used by the device 500 to determine whether said first state prevails. The signals received on the data port may be used by the device 500 to determine whether said second state prevails. The signals received on the data port may be used by the device 500 for activating or deactivating operation of the extra electrical machine 257 on the basis of said signals containing information about, for example, clutch states.

Parts of the methods herein described may be applied by the device 500 by means of the data processing unit 510 which runs the programme stored in the memory 560 or the read/write memory 550. When the device 500 runs the programme, methods herein described are executed.

The foregoing description of the preferred embodiments of the present invention is provided for illustrative and descriptive purposes. It is not intended to be exhaustive, nor to limit the invention to the variants described. Many modifications and variations will obviously suggest themselves to one skilled in the art. The embodiments have been chosen and described in order best to explain the principles of the invention and its practical applications and hence to make it possible for one skilled in the art to understand the invention for various embodiments and with the various modifications appropriate to the intended use.

Claims

1. A method pertaining to a parallel hybrid system (299) for propulsion of a motor vehicle (100; 110) comprising a combustion engine (230) in combination with an electrical machine configuration (250, 253, 255) which includes an electrical machine (250) provided with power supply,

characterised by the step,

- during an initial movement phase of the vehicle's propulsion, of running an extra electrical machine (257) by means of said engine (230) to supply power to the electrical machine (250) of the electrical machine configuration, which extra electrical machine (257) is also used during said initial movement phase to supply power to at least one consumer unit (290).

2. A method according to claim 1 , in which the power supply to the electrical machine (250) of the electrical machine configuration is provided by a generator (257) of the extra electrical machine (257).

3. A method according to claim 1 or 2, in which said initial movement phase refers to a state before full propulsion takes place with chosen gear in the vehicle's power train.

4. A method according to any one of claims 1-3, in which said initial movement phase comprises the vehicle being stationary .

5. A method according to any one of claims 1-4, in which the electrical machine (250) of the electrical machine configuration acts upon an input shaft (245) of a gearbox (260) in the vehicle's power train, and vice versa.

6. A parallel hybrid system (299) for propulsion of a motor vehicle (100; 110) comprising a combustion engine (230) in combination with an electrical machine configuration (250, 253, 255) which includes an electrical machine (250) provided with power supply, characterised by

an extra electrical machine (257) adapted to being driven by said engine (230) to supply power to the electrical machine (250) of the electrical machine configuration during an initial movement phase of the vehicle's propulsion, which extra electrical machine (257) is adapted, during said initial movement phase, to supplying power to at least one consumer unit (290).

7. A parallel hybrid system according to claim 6, in which the extra electrical machine (257) comprises a generator (257) adapted to supplying power to the electrical machine (250) of the electrical machine configuration.

8. A parallel hybrid system according to either of claim 6 or claim 7, in which the electrical machine (250) of the electrical machine configuration is adapted to acting upon an input shaft (245) of a gearbox (260) in the vehicle's power train, and vice versa.

9. A motor vehicle (100; 110) provided with a parallel hybrid system (299) according to any one of claims 6-8.

10. A motor vehicle (100; 110) according to claim 9, which is any from among a truck, bus or car.

11. A computer programme (P) pertaining to a parallel hybrid system (299) for propulsion of a motor vehicle (100; 110) comprising a combustion engine (230) in combination with an electrical machine configuration (250, 253, 255) which includes an electrical machine (250), which computer programme (P) contains programme code for causing an electronic control unit (210; 500) or another computer (220; 500) connected to the electronic control unit (210; 500) to perform steps according to any one of claims 1-5. 2. A computer programme product containing a programme code stored on a computer-readable medium for performing method steps according to any one of claims 1-5 when said computer programme is run on an electronic control unit (210; 500) or another computer (220; 500) connected to the electronic control unit (210; 500).