Electric vehicle operating system

Abstract

The present invention relates to an electric vehicle, that is, a battery-powered electric vehicle, and more particularly to an electric vehicle operating system. The electric vehicle operating system 100 comprises an electric machine 10 having a stator 11 and a rotor 12, a drive unit 15, an accelerator device 20 having a stroke between a maximum power position PM and a released position PU for a motor mode and a deceleration mode of the electric vehicle, a power source, an excitation system 30, and a control unit 25. The drive unit 15 is driven by the electric machine 10, which, in turn, drives the drive wheel (not shown) for the propulsion of the electric vehicle.The control unit 25 operates in motor mode or in free-rolling mode or in regenerative mode by controlling the excitation system 30 based on the position of the accelerator device 20 using the signals from the sensing unit 21. Figure for the abbreviation: Figure 1.

Description

Title of the invention: Electric vehicle operating system

[0001] The present invention relates to an electric vehicle, that is to say an electric vehicle operating on a battery, and more particularly concerns an electric vehicle operating system.

[0002] The electric vehicle uses an electric motor to propel itself, and a battery is used to power the electric motor. Conventional electric vehicles have two operating modes: a motor mode and a braking mode with regenerative braking. The motor mode propels the electric vehicle, and the braking mode with regenerative braking decelerates the electric vehicle. The motor mode is operated by an accelerator pedal, and the regenerative braking mode is operated by a brake pedal. This is known as the two-pedal operating mode, in which two individual pedals have their own acceleration and braking functions.

[0003] In certain electric vehicles, the same accelerator pedal is configured to produce both motor mode when the accelerator pedal is moved to the maximum power position and regenerative braking or deceleration mode when the accelerator pedal is moved to the released position, which moderately slows the electric vehicle by converting kinetic energy into electrical energy. In addition, the electric vehicle has a separate brake pedal for bringing the vehicle to a stop. In regenerative braking mode, the kinetic energy of the moving electric vehicle is converted into electrical energy. This electrical energy is sent to the battery and stored there via an excitation system. The stored electrical energy is then used.In the present application, the regenerative braking mode is executed both during deceleration, i.e. during the movement of the accelerator pedal towards the released position of the pedal, and during braking in the two-pedal operating mode.

[0004] In this known manner, the energy recovery and restitution circuit produced by the regenerative braking mode appears at first glance to be very efficient. However, for small amounts of energy, for example when slowing down at the entrance to a village, etc., or when slowing down slightly on a motorway to let a vehicle overtake by releasing the accelerator pedal or applying the brake, very significant switching losses occur in the The excitation system experiences a back-and-forth energy transfer from the excitation system to the battery, and then back again to the excitation system and the electric machine, due to the continuous switching between motor and regenerative modes. Therefore, it is necessary to resolve the technical problem related to the assembly described above.

[0005] The present invention therefore aims to provide an electric vehicle operating system and a method of operating an electric vehicle system comprising a freewheeling zone for electric vehicles, in order to remedy the aforementioned disadvantages and other disadvantages of known devices.

[0006] The present invention relates to an electric vehicle operating system comprising: an electric machine having a stator and a rotor; a drive unit which is driven by the electric machine to drive the electric vehicle; an accelerator device having a stroke between a motor mode and a deceleration mode of the electric vehicle; a power source for supplying electricity; a control unit; at least one excitation system for exciting the electric machine; a detection unit comprising a position sensor for detecting a position of the accelerator device; wherein, during the deceleration stroke of the accelerator device relative to a position of maximum motor power, a first predetermined position is located after the position of maximum motor power.A second predetermined position is located after the first predetermined position, and a released position is located after the second predetermined position. The first predetermined position is distinct from the second predetermined position, and the control unit performs the following operation by controlling the excitation system based on the position of the throttle device using signals from the sensing unit: (i) the throttle device travel between the maximum power position and the first predetermined position corresponds to a motor mode, (ii) the throttle device travel between the first predetermined position and the second predetermined position corresponds to a freewheeling mode, (iii) the throttle device travel between the second predetermined position and the released position corresponds to a regenerative mode. Therefore,Thanks to the integration of coasting mode between motor and regenerative modes, the electric vehicle will coast or move due to its own inertia, without the back-and-forth energy transfer between the electric motor and the battery, via the control unit, that occurs during frequent switching between motor and regenerative modes. As a result, the efficiency of the electric motor is improved compared to the energy transfer that occurs during the frequent conversion between motor and regenerative modes. The motor mode and the regenerative mode are eliminated, thus improving the efficiency of the electric vehicle when driving is carried out at virtually zero torque.

[0007] According to one aspect of the invention, the accelerator device is configured to rotate at least partially around an axis.

[0008] According to one aspect of the invention, the released position is at 0% of the accelerator device's travel, the maximum motor power position is at 100% of the accelerator device's travel relative to the released position, the first predetermined position is between 5% and 50% of the accelerator device's travel relative to the released position, and the second predetermined position is between 1% and 45% of the accelerator device's travel relative to the released position. Consequently, when the accelerator device is between the first and second predetermined positions, the electric vehicle will be coasting, i.e., it will roll due to its own inertia, and will operate between motor and regenerative modes.Therefore, the energy efficiency of the electric vehicle is improved due to the elimination of losses occurring during the switchover between motor mode and regenerative mode.

[0009] According to another aspect of the invention, i) for motor mode, the control unit is configured to perform motor mode operation by providing a motor mode input to the excitation system, ii) for freewheel mode, the control unit is configured to perform freewheel mode operation by providing a zero torque command to the excitation system, and iii) for regenerative mode, the control unit is configured to perform regenerative mode operation by providing regenerative power to the energy source.Thanks to zero-torque control, the control unit sends a corresponding signal to the electric motor, thus eliminating the back-and-forth energy flow from the electric vehicle to the electric motor via the battery, which occurs during frequent switching between motor and regenerative modes, and the associated energy conversion losses are eliminated. Consequently, the efficiency of the electric vehicle is improved when the drive operates at virtually zero torque.

[0010] According to another aspect of the invention, the electric machine is a synchronous machine.

[0011] According to one example of the invention, the synchronous machine is an electrically excited synchronous machine, and the excitation system is configured to excite the rotor and the stator. It is advantageous to use an electrically excited synchronous machine. Since the excitation and de-excitation of the rotor and stator windings of the electrically excited synchronous machine are simpler, torque is generated with a short response time.

[0012] According to an example of the invention, the synchronous machine is an electrically excited synchronous machine and the excitation system is configured to excite the stator.

[0013] According to one example of the invention, the accelerator device is a power pedal or an accelerator pedal or a lever.

[0014] According to yet another aspect, the present invention relates to a method for operating an electric vehicle system using an electric machine having a stator and a rotor, a drive unit which is driven by the electric machine to drive the electric vehicle, an accelerator device having a stroke between a motor mode and a deceleration mode of the electric vehicle, a power source for electrical supply, a control unit, a detection unit including a position sensor, the method for operating the electric vehicle system comprising: the excitation of the electric machine by the excitation system, the control of the excitation system by the control unit based on the position of the accelerator device using the signals from the detection unit, wherein,During the deceleration stroke of the accelerator device relative to a maximum power position, a first predetermined position is located after the maximum power position, a second predetermined position is located after the first predetermined position, and a released position is located after the second predetermined position, the first predetermined position being distinct from the second predetermined position; and (i) the execution, by the control unit, of motor mode operation when the stroke of the accelerator device is between the maximum power position and the first predetermined position, (ii) the execution, by the control unit, of coasting mode operation when the stroke of the accelerator device is between the first predetermined position and the second predetermined position, (iii) the execution, by the control unit,of regenerative operation when the accelerator device travel is between the second predetermined position and the released position.

[0015] According to another aspect of the present invention, the method of operating the electric vehicle system includes the execution, by the control unit, of motor mode operation by providing a motor mode input to the excitation system, of freewheel mode operation by providing a zero torque control to the excitation system and of regenerative mode operation by providing regenerative power to the energy source.

[0016] According to another example of the operating method of the electric vehicle system, the electric machine is an electrically excited synchronous machine and The operating process of the electric vehicle system includes the excitation of the rotor by the excitation system.

[0017] According to another example of the method of operation of the electric vehicle system, the electric machine is a permanent magnet synchronous machine and the method of operation of the electric vehicle system includes the excitation of the stator by the excitation system.

[0018] According to yet another aspect, the operating process of the electric vehicle system is implemented by a computer.

[0019] The features, aspects, and advantages of the present invention will become more apparent with reference to the following description and figures. The elements in the figures are not necessarily to scale, the emphasis being on illustrating the principles of the invention. Furthermore, in the figures, identical reference numbers designate corresponding parts. In the drawings:

[0020] Fig. 1 illustrates a structural functional diagram of an electric vehicle operating system with a freewheeling zone for an electric vehicle according to the present invention;

[0021] [Fig.2] illustrates a flowchart of a method of operation of an electric vehicle system with freewheeling zone for an electric vehicle according to the present invention;

[0022] Figures [Fig.3a], [Fig.3b] and [Fig.3c] illustrate the position of the accelerator device according to different driving conditions of the electric vehicle according to the present invention.

[0023] The figures are not necessarily to scale, and the size of certain parts may be exaggerated to more accurately illustrate the example shown. Furthermore, the drawings provide examples and / or examples that conform to the description; however, the description is not limited to the examples and / or examples illustrated in the drawings.

[0024] In the following description, reference is made to the accompanying drawings, which form part thereof, and in which specific embodiments in which the invention can be implemented are shown by way of illustration. These embodiments are described in sufficient detail to enable a person skilled in the art to implement the invention, and it will be understood that the embodiments can be combined, or that other embodiments can be used, and that structural and logical modifications can be made without departing from the scope of the present invention. The detailed description that follows should therefore not be interpreted in a restrictive manner, and the scope of the present invention is defined by the appended claims and their equivalents.

[0025] Identical, similar, or analogous elements retain the same reference from one figure to another. Ordinal numbers are used to differentiate features. They do not define the position of an element. Consequently, for example, a third feature of a product does not mean that the product possesses a first and / or a second feature.

[0026] Figure 1 illustrates a structural functional diagram of an electric vehicle operating system with a freewheeling zone for an electric vehicle according to the present invention. Said electric vehicle operating system 100 for an electric vehicle comprises an electric machine 10, a drive unit 15, an accelerator device 20, a power source, an excitation system 30, and a control unit 25. The electric machine 10 comprises a stator 11 and a rotor 12. The rotor 12 comprises, for example, a permanent magnet or an electromagnet. The excitation system 30 comprises a first electronic power converter circuit for DC-to-AC and AC-to-DC conversion.

[0027] The electric machine 10, the drive unit 15, and at least one drive wheel (not shown) are mechanically linked, enabling the transmission of torque. The drive unit 15 is driven by the electric machine 10, which, in turn, drives the drive wheel (not shown) for the propulsion of the electric vehicle. The architecture described above corresponds to the electric vehicle. It is understood that the electric vehicle operating system 100 of the embodiments of this application is intended for an electric vehicle, i.e., a battery-powered electric vehicle, and that it implements a method for operating an electric vehicle system in the aforementioned electric vehicle, i.e., the battery-powered electric vehicle according to the present invention.

[0028] The accelerator device 20 moves between a maximum drive power position PM and a released position PU to provide motor mode and deceleration of the electric vehicle. A power source supplies electrical power to the electric machine 10 and to the excitation system 30 via the control unit 25. The electric machine 10 is excited by the excitation system 30. The control unit 25, the excitation system 30, and the detection unit 21 are electrically connected. The detection unit 21 includes a position sensor for detecting the position of the accelerator device 20. This position data is sent as an electrical signal to the control unit 25. In one embodiment, the detection unit 21 further includes a slope sensor for detecting the slope of the road surface. This gradient data is sent as an electrical signal to the control unit.

[0029] The accelerator device 20 is configured to rotate at least partially around an axis, between a released position PU and a maximum drive power position PM. In other words, the accelerator device 20 moves back and forth between the released position PU and the maximum drive power position PM. In a non-limiting example, during the deceleration stroke of the accelerator device 20 from the maximum drive power position PM to the released position PU, a first predetermined position PI is configured to be located after the maximum drive power position PM, and a second predetermined position P2 is configured between the first predetermined position PI and a released position PU. The first predetermined position PI is distinct from the second predetermined position P2.The position of the accelerator device 20 during its stroke is detected by the position sensor of the sensing unit 21. In some embodiments, the position of the accelerator device 20 is determined by a user based on the driving situation and road conditions. In some embodiments, the position of the accelerator device 20 corresponds to a torque demand sent to the electric machine 10 via the control unit 25. In a non-limiting example, the accelerator device 20 is an accelerator pedal, a power pedal, or a lever.

[0030] In simpler terms, the accelerator device 20 comprises three regions, namely a motor mode region, a freewheeling mode region, and a regenerative mode region. The freewheeling mode region is configured between the motor mode region and the regenerative mode region. In other words, the motor mode region is located between the maximum accelerator position PM and the first predetermined position PI, the freewheeling mode region is located between the first predetermined position PI and the second predetermined position P2, and the regenerative mode region is located between the second predetermined position P2 and the released position PU.

[0031] The torque demand for the electric machine 10 depends on a change in the position of the accelerator device 20 in the three aforementioned regions, namely the motor mode region, the coasting mode region, and the regenerative mode region. The torque demand corresponding to the motor mode is defined as a demand for driving power. The torque demand corresponding to the regenerative mode is defined as a demand for regeneration or a demand for deceleration. During coasting mode operation, the electric vehicle will roll due to its own inertia without any torque demand, so the torque demand for the electric machine 10 during coasting mode is zero, and consequently, there is no torque command. is provided by the control unit 25 based on the position of the accelerator device 20.

[0032] The control unit 25 performs the following operation by controlling the excitation system 30 based on the position of the accelerator device 20 using signals from the sensing unit 21; (i) the stroke of the accelerator device 20 in the motor mode region, i.e., between the maximum motor power position PM and the first predetermined position PI, corresponds to operation in motor mode. In this operating mode, the electrical power is supplied by the energy source to the electric machine 10; (ii) the stroke of the accelerator device 20 in the freewheel mode region, i.e., between the first predetermined position PI and the second predetermined position P2, corresponds to operation in freewheel mode.In this operating mode, the magnetic interaction between the stator 11 and the rotor 12 is practically negligible, (iii) the stroke of the accelerator device 20 in the regenerative mode region, i.e. between the second predetermined position P2 and the released position PU, corresponds to operation in regenerative mode. In this operating mode, electrical energy in the form of regenerative power is transmitted to the energy source from the electric machine 10.

[0033] During operation in motor mode, the electric machine 10 functions as a motor, so that the drive wheel of the electric vehicle is driven by the electric machine 10. During operation in regenerative mode, the electric machine 10 functions as a generator, so that the drive wheel of the electric vehicle drives the electric machine 10, thereby inducing regenerative power. Conversely, during operation in freewheeling mode, the electric machine 10 functions neither as a motor nor as a generator, so that the electric vehicle moves due to its own inertia, with zero torque demand.

[0034] Motor mode operation corresponds to a condition in which motor torque is supplied to the drive unit 15 by the electric machine 10 for the propulsion of the electric vehicle based on the motor power demand required by the user. This motor mode operation is performed by the control unit 25 when the user actuates the accelerator device 20 within the motor mode region, i.e., between the maximum motor power position PM and the first predetermined position PL. The position of the accelerator device 20 is detected by the detection unit 21 by means of a position sensor. This position data is sent as an electrical signal input to the control unit 25. The drive torque supplied by the electric machine 10 is based on an excitation level of the electric machine 10 by the system Excitation system 30. The excitation level depends on a motor mode input supplied to the excitation system 30 by the control unit 25. The excitation system 30 includes, for example, the first electronic power converter circuit for DC-to-AC conversion, which converts the DC power from the energy source into AC power to supply the stator 11. The excitation system 30 may also include a second electronic power converter circuit for converting the DC power from the energy source into either DC or AC power to supply the rotor 12, for example, of an electrically excited synchronous machine. The motor mode input is defined as an input supplied by the excitation system 30 to the electric machine 10 based on the position of the throttle device 20.During operation in motor mode, the electric machine 10 functions as an electric motor, converting electrical energy into mechanical energy and transferring it to the drive unit 15 to propel the electric vehicle. The demand for motor power increases progressively as a function of the position of the accelerator device 20 during its travel from the first predetermined position PI to the maximum motor power position PM. The demand for motor power decreases progressively as a function of the position of the accelerator device 20 during its travel from the maximum motor power position PM to the first predetermined position PL.

[0035] Regenerative operation corresponds to a condition in which the kinetic energy of the moving electric vehicle is converted into electrical energy in the form of regenerative power by the electric machine 10 based on the regeneration or deceleration demand requested by the user. This regenerative operation is performed by the control unit 25 when the user actuates the accelerator device 20 in the regenerative mode region, i.e., between the second predetermined position P2 and the released position PU. The control unit 25 commands the excitation system 30 to implement regenerative operation by interrupting the flow of electrical energy to the stator 11, and the rotation of the rotor 12 induces regenerative power in the stator 11. This regenerative power from the stator 11 is stored in the energy source.The first electronic power converter circuit of the excitation system 30 is used for AC to DC conversion, converting the AC power induced in the stator 11 into DC power to be stored in the power source. During regenerative operation, the electric machine 10 functions as a generator, so that mechanical energy is converted into electrical energy in the form of regenerative power and stored in the power source for later use.

[0036] Freewheeling operation corresponds to the condition in which a zero-torque command is supplied to the excitation system 30 by the control unit 25, in order to allow the electric vehicle to roll due to its own inertia without any torque demand. Without limitation, the electric vehicle will move with practically zero torque. Freewheeling operation occurs between the motor mode region and the regenerative mode region. This freewheeling operation is performed by the control unit 25 when the user actuates the accelerator device 20 in the freewheeling mode region, i.e., between the first predetermined position P1 and the second predetermined position P2. During freewheeling operation, the electric machine 10 generates neither motor torque, as is the case in motor mode, nor regenerative power, as is the case in regenerative mode.

[0037] The freewheeling operation can be implemented and controlled by the control unit 25, based on a decision by the user, i.e. when the user operates the accelerator pedal in the freewheeling region, i.e. between the first predetermined position PI and the second predetermined position P2, and the control unit 25 executes the freewheeling operation, so that the electric vehicle rolls due to its own inertia without any demand for motor power or deceleration.

[0038] In one embodiment, when the user does not prefer coasting mode due to driving conditions, the accelerator pedal travel in the coasting mode region, i.e., between the first predetermined position PI and the second predetermined position P2, is rapid. In other words, the time required for the accelerator device to travel between the first predetermined position PI and the second predetermined position P2 is negligible. Consequently, coasting mode is eliminated, allowing for an abrupt transition to engine or deceleration mode.

[0039] The released position PU is located at 0% of the stroke of the accelerator device 20, and the maximum drive power position PM is located at 100% of the stroke of the accelerator device 20 relative to the released position PU. The first predetermined position PI is between 2 and 80% of the stroke of the accelerator device 20 relative to the released position PU. The second predetermined position P2 is between 1 and 70% of the stroke of the accelerator device 20 relative to the released position PU. Preferably, in one embodiment, the first predetermined position PI is between 1% and 30% of the stroke of the accelerator device 20 relative to the released position PU, i.e., below 100% of the stroke of the accelerator device 20, and the freewheeling mode region corresponds to a stroke of the accelerator device 20 between the first position predetermined PI and the second predetermined position P2, that is to say that the range of the freewheeling mode region is between 1% and 30%.

[0040] The first predetermined position PI and the second predetermined position P2 of the accelerator device 20 in motor, freewheel and regenerative mode are based on said percentage range.

[0041] In a non-limiting example, with reference to [Fig.3a],

[0042] i) the second predetermined position P2 is located at a minimum value within the range between 1% and 70% of the stroke of the accelerator device 20 relative to the released position, namely

[0043] P2=l % of the stroke of the accelerator device 20 relative to the released position PU and

[0044] ii) the first predetermined position PI is located at a minimum value within the range between 2% and 80% of the stroke of the accelerator device 20 relative to the released position PU, namely

[0045] Pl=2% of the stroke of the accelerator device 20 relative to the released position PU,

[0046] and consequently,

[0047] With regard to the at least partial clockwise rotation of the accelerator device 20, according to the example above, each time the accelerator device 20 moves from the released position PU to 1% of the stroke, i.e. the second predetermined position P2, the electric vehicle will operate in regenerative mode; each time the position of the accelerator device 20 crosses 1% of the stroke, i.e. the second predetermined position P2, but less than 2% of the stroke, i.e. the first predetermined position PI, the electric vehicle will operate in freewheel mode; each time the position of the accelerator device 20 crosses 2% of the stroke, i.e. the first predetermined position PI, and up to the maximum position of the accelerator PM, the electric vehicle will operate in motor mode.

[0048] Based on the road conditions and the electrical signals provided by the slope sensor, the control unit 25 determines the values ​​of the first predetermined position PI and the second predetermined position P2 of the accelerator device 20 during operation in motor, coasting, and regenerative modes. Since motor mode operation is initiated after 5% of the accelerator device 20's travel relative to the released position PU, the above condition corresponds to an uphill driving condition.

[0049] In a non-limiting example, with reference to [Fig.3b],

[0050] i) the second predetermined position P2 is located at a maximum value within the range between 1% and 70% of the stroke of the accelerator device 20 relative to the released position PU, namely

[0051] P2 = 70% of the stroke of the accelerator device 20 relative to the position released PU and

[0052] ii) the first predetermined position PI is located at a maximum value within the range between 5% and 80% of the stroke of the accelerator device 20 relative to the released position PU, namely

[0053] Pl=80% of the stroke of the accelerator device 20 relative to the position released PU,

[0054] and consequently,

[0055] With regard to the at least partial clockwise rotation of the accelerator device 20, according to the example above, each time the accelerator device 20 moves from the released position PU to 70% of the stroke, i.e. the second predetermined position P2, the electric vehicle will operate in regenerative mode, each time the position of the accelerator device 20 passes 70% of the stroke, i.e. the second predetermined position P2, but less than 80% of the stroke, i.e. the first predetermined position PI, the electric vehicle will operate in freewheel mode, and each time the position of the accelerator device 20 passes 80% of the stroke, i.e. the first predetermined position PI, and up to the maximum position of the accelerator PM, the electric vehicle will operate in motor mode.

[0056] Based on the road conditions and the electrical signals provided by the slope sensor, the control unit 25 determines the values ​​of the first predetermined position PI and the second predetermined position P2 of the throttle device 20 during operation in motor, coasting, and regenerative modes. Since regenerative mode operation is performed up to 70% of the throttle device 20's travel relative to the released position PU, the above condition corresponds to a downhill driving condition.

[0057] In a non-limiting example, with reference to [Fig.3c],

[0058] i) the second predetermined position P2 is located at

[0059] P2 = 25% of the stroke of the accelerator device 20 relative to the position released PU and

[0060] ii) the first predetermined position PI is located at

[0061] Pl=55% of the stroke of the accelerator device 20 relative to the position released PU,

[0062] and consequently,

[0063] With regard to the at least partial clockwise rotation of the accelerator device 20, according to the example above, each time the accelerator device 20 moves from the released position PU to 25% of the stroke, i.e. the second predetermined position P2, the electric vehicle will operate in regenerative mode, each time the position of the accelerator device 20 passes 25% of the stroke, i.e. the second predetermined position P2, but less than 55% of the stroke, i.e. the first predetermined position PI, the electric vehicle will operate in freewheel mode, and each time the position of the accelerator device 20 passes 55% of the stroke, i.e. the first predetermined position PI, and up to the maximum position of the accelerator PM, the electric vehicle will operate in motor mode.

[0064] Based on the road conditions and the electrical signals provided by the slope sensor, the control unit 25 determines the values ​​of the first predetermined position PI and the second predetermined position P2 of the accelerator device 20 during operation in motor, coasting, and regenerative modes. Since motor mode operation is only initiated after 55% of the travel of the accelerator device 20 relative to the released position PU, and coasting mode operation is only initiated after 25% of the travel of the accelerator device 20 relative to the released position PU, the above condition corresponds to the highway driving condition. In other words, the electric vehicle will operate in coasting mode between 25% and 55% of the travel of the accelerator device 20 relative to the released position PU.

[0065] In one example, the electrical machine 10 is a synchronous machine whose stator 11 comprises wire coils and whose rotor 12 comprises permanent magnets, i.e., a permanent magnet synchronous machine. The wire coils of the stator 11 produce a rotating magnetic field required when they are energized or excited by the use of the energy source via the excitation system 30 by means of the control unit 25. The rotor 12, comprising the permanent magnet, produces a rotor flux or a magnetic field. The interaction between the rotor flux or the magnetic field of the rotor 12 and the rotating magnetic field of the stator 11 causes the rotation of the rotor 12, which corresponds to the torque generated by the synchronous machine. The rotating magnetic field of the stator 11 is controlled by the control unit 25 to perform the following operating modes within the scope of the invention:

[0066] To perform operation in motor mode, that is, when the position of the accelerator device 20 is in the motor mode region, i.e., between the maximum motor power position PM and the first predetermined position PI, the motor mode input is supplied to the excitation system 30 by the control unit 25. During this operation, based on the stroke of the accelerator device 20 from the first predetermined position PI to the maximum drive power position PM, the electrical power input from the energy source gradually increases to meet the drive power demand. Similarly, based on the stroke of the accelerator device 20 from the maximum accelerator position PM to the first predetermined position PI, the electrical power input from the energy source gradually decreases to meet the drive power demand.

[0067] To perform the freewheeling operation, i.e., when the position of the accelerator device 20 is in the freewheeling region, i.e., between the first predetermined position PI and the second predetermined position P2, the zero torque command is provided to the excitation system 30 by the control unit 25. The zero torque command for the synchronous machine as described above is defined as a power-up instruction aimed at modifying the rotating magnetic field of the wire coils of the stator 11 in order to cancel the rotor flux or the magnetic field of the rotor 12 to eliminate the drive torque and to simultaneously prevent the induction of regenerative power in the stator 11. Consequently, the electric vehicle will roll due to its own inertia without the input drive torque from the synchronous machine.

[0068] To operate in regenerative mode, that is, when the position of the accelerator device 20 is in the regenerative mode region, i.e., between the second predetermined position P2 and the released position PU, the excitation system 30 is configured accordingly to operate the synchronous machine as a generator. Consequently, the power supply from the energy source to the stator 11 of the electric machine 10 is interrupted. As a result, regenerative power is induced in the stator 11 and supplied to the energy source, and this regenerative power is stored in the energy source for later use. The flow of regenerative power is controlled by the control unit 25.Consequently, the kinetic energy of the moving electric vehicle is converted into electrical energy in the form of regenerative power by the synchronous machine which operates as a generator.

[0069] In another example, the electrical machine 10 is an electrically excited synchronous machine whose stator 11 comprises wire coils and whose rotor 12 comprises an excitation coil. Said rotor 12 comprising the excitation coils produces a necessary rotor flux or magnetic field when excited by use of the energy source via the excitation system 30 by means of the control unit 25. Similarly, said coils of The stator wires 11 produce a rotating magnetic field necessary when they are energized or excited by the power source via the excitation system 30 by means of the control unit 25. The interaction between the stator magnetic field 11 and the rotor flux or the rotor magnetic field 12 causes the rotor 12 to rotate, which corresponds to the torque output generated by the electrically excited synchronous machine. The rotor flux or the rotor magnetic field 12 and / or the rotating magnetic field of the stator 11 is controlled by the control unit 25 to perform the following operating modes within the scope of the invention:

[0070] To operate in motor mode, that is, when the position of the throttle device 20 is within the motor mode region, i.e., between the maximum motor power position PM and the first predetermined position PI, the motor mode input is supplied to the excitation system 30 by the control unit 25. The excitation system 30 is configured accordingly to excite the rotor 12 and / or to energize the stator 11 based on the supplied motor mode input. Based on the input from the excitation system 30, the rotor flux or the magnetic field of the rotor 12 is generated, in addition to the generation of the rotating magnetic field by the stator 11.During this operation, based on the stroke of the accelerator device 20 from the first predetermined position PI to the maximum drive power position PM, the electrical power input from the energy source to the electric machine 10 gradually increases to meet the drive power demand. Similarly, based on the stroke of the accelerator device 20 from the maximum accelerator position PM to the first predetermined position PI, the electrical power input from the energy source to the electric machine 10 gradually decreases to meet the drive power demand.

[0071] To operate in freewheel mode, i.e., when the position of the accelerator device 20 is in the freewheel mode region, i.e., between the first predetermined position P1 and the second predetermined position P2, zero torque is supplied to the excitation system 30 by the control unit 25. The zero torque command for the electrically excited synchronous machine is defined as follows: stopping the energizing of the stator 11 eliminates the rotating magnetic flux, and stopping the excitation of the rotor 12 eliminates the rotor flux or the magnetic field of the rotor 12 of the electrically excited synchronous machine. Consequently, the torque generated by the electrically excited synchronous machine is eliminated. As a result, the electric vehicle will roll due to its own inertia without the input drive torque from the electrically excited synchronous machine.

[0072] To operate in regenerative mode, that is, when the position of the accelerator device 20 is in the regenerative mode region, i.e., between the second predetermined position P2 and the released position PU, the excitation system 30 is configured accordingly to implement the electrically excited synchronous machine so that it operates as a generator. Consequently, the electrical supply from the power source to the stator 11 of the electric machine 10 is interrupted. The excitation of the rotor 12 is maintained, and the rotor is driven by the drive wheel. As a result, regenerative power is induced in the stator 11 and supplied to the power source, and the regenerative power is stored in the power source for later use. The flow of regenerative power is controlled by the control unit 25.Consequently, the kinetic energy of the moving electric vehicle is converted into electrical energy in the form of regenerative power by the electrically excited synchronous machine which operates as a generator.

[0073] Figure 2 illustrates a flowchart of a method for operating an electric vehicle system with a freewheeling zone for an electric vehicle according to the present invention. The method 101 for operating an electric vehicle as illustrated in Figure 2 comprises an electric machine 10, a drive unit 15, an accelerator device 20, a power source, an excitation system 30, and a control unit 25. The electric machine 10 comprises a stator 11 and a rotor 12. The electric machine 10, the drive unit 15, and at least one drive wheel (not shown) are mechanically connected, thereby enabling the transmission of torque. The drive unit 15 is driven by the electric machine 10, which, in turn, drives the drive wheel (not shown) for the propulsion of the electric vehicle.The accelerator device 20 moves between a maximum power position PM and a released position PU to provide motor mode and deceleration for the electric vehicle. A power source supplies electrical power to the electric machine 10 and the excitation system 30 via the control unit 25. The electric machine 10 is excited by the excitation system 30. The control unit 25, the excitation system 30, and the detection unit 21 are electrically connected. The detection unit 21 includes a position sensor for detecting the position of the accelerator device 20. This position data is sent as an electrical signal to the control unit 25.During the deceleration stroke of the accelerator device 20 from a maximum power position PM to the released position PU, a first predetermined position PI is configured to be located after the maximum power position PM, a second predetermined position P2 is configured to be located after the first predetermined position PI and a released position PU is configured. to be located after the second predetermined position P2. The first predetermined position PI is distinct from the second predetermined position P2.

[0074] With reference to [Fig. 2], in step 51, the stroke of the accelerator device 20 is between the maximum motor power position PM and the released position PU. In step 52, the position data is sent as an electrical signal to the control unit 25. The position of the accelerator device 20 is detected by the position sensor of the detection unit 21. In step 53, the excitation system 30 is controlled accordingly by the control unit 25 to excite the electric machine 10 to operate in one of the modes mentioned below, such as motor mode, freewheeling mode, or regenerative mode, based on the position data of the accelerator device 20.At step 54, if the position of the accelerator device 20 is between the maximum motor power position PM and the first predetermined position PI, motor mode operation is performed by the control unit 25 by providing a motor mode input to the excitation system 30. At step 55, if the position of the accelerator device 20 is between the first predetermined position PI and the second predetermined position P2, freewheeling mode operation is performed by the control unit 25 by providing a zero torque command to the excitation system 30. At step 56, if the position of the accelerator device 20 is between the second predetermined position P2 and the released position PU, regenerative mode operation is performed by the control unit 25 by providing regenerative power to the energy source.

[0075] In one example, according to one of the methods 101 of operating the electric vehicle system, the electric machine 10 is a synchronous machine whose stator 11 comprises wire coils and the rotor 12 comprises permanent magnets, i.e. a permanent magnet synchronous machine, and the freewheeling operation of step 55 is carried out by the control unit 25. The freewheeling operation method is carried out as follows: when the position of the accelerator device 20 is in the freewheeling region, i.e. between the first predetermined position PI and the second predetermined position P2, the zero torque command is supplied to the excitation system 30 by the control unit 25.The zero torque command for the synchronous machine as described above is defined as an energizing instruction aimed at modifying the rotating magnetic field of the wire coils of the stator 11 in order to cancel the rotor flux or the magnetic field of the rotor 12 to eliminate the drive torque and to simultaneously prevent the induction of regenerative power in the stator 11. Therefore, the electric vehicle will run due to this. of its own inertia without the input driving torque from the synchronous machine.

[0076] In one example, according to one of the methods 101 of operating the electric vehicle system, the electric machine 10 is an electrically excited synchronous machine whose stator 11 comprises wire coils and the rotor 12 comprises an excitation coil, and the freewheeling operation of step 55 is carried out by the control unit 25. The freewheeling operation method is carried out as follows: when the position of the accelerator device 20 is in the freewheeling region, i.e. between the first predetermined position PI and the second predetermined position P2, the zero torque command is supplied to the excitation system 30 by the control unit 25.The zero-torque control for the electrically excited synchronous machine is defined as follows: stopping the energizing of the stator 11 eliminates the rotating magnetic flux, and stopping the excitation of the rotor 12 eliminates the rotor flux or the magnetic field of the rotor 12 of the electrically excited synchronous machine. Consequently, the torque generated by the electrically excited synchronous machine is eliminated. As a result, the electric vehicle will move due to its own inertia without the input drive torque from the electrically excited synchronous machine.

[0077] In one embodiment, the method 101 of operating the electric vehicle system with freewheeling zone for an electric vehicle according to the present invention is implemented by a computer.

Claims

1. Demands Operating system of an electric vehicle (100) comprising: an electric machine (10) having a stator (11) and a rotor (12); a drive unit (15) which is driven by the electric machine (10) to drive an electric vehicle; an accelerator device (20) having a stroke between a motor mode and a deceleration mode of the electric vehicle; an energy source intended for an electrical power supply; a control unit (25); at least one excitation system (30) intended to excite the electrical machine (10), a detection unit (21) comprising a position sensor intended to detect a position of the accelerator device (20); in which, during the deceleration stroke of the accelerator device (20) relative to a maximum drive power position (PM), a first predetermined position (PI) is located after the maximum drive power position (PM), a second predetermined position (P2) is located after the first predetermined position (PI) and a released position (PU) is located after the second predetermined position (P2), the first predetermined position (PI) is distinct from the second predetermined position (P2) and the control unit (25) performs the following operation by controlling the excitation system (30) on the basis of the position of the accelerator device (20) using the signals from the detection unit (21); (i) the stroke of the accelerator device (20) between the maximum motor power position (PM) and the first predetermined position (PI) corresponds to a motor mode, (ii) the stroke of the accelerator device (20) between the first predetermined position (PI) and the second predetermined position (P2) corresponds to a freewheeling mode, (iii) the stroke of the accelerator device (20) between the second predetermined position (P2) and the released position (PU) corresponds to a regenerative mode.

2. Electric vehicle operating system (100) according to claim 1, wherein the accelerator device (20) is configured to rotate at least partially around an axis.

3. Electric vehicle operating system (100) according to claim 2, wherein the released position (PU) is at 0% of the stroke of the accelerator device (20), the maximum motor power position (PM) is at 100% of the stroke of the accelerator device (20) relative to the released position (PU), the first predetermined position (PI) is between 2% and 80% of the stroke of the accelerator device (20) relative to the released position (PU), the second predetermined position (P2) is between 1% and 70% of the stroke of the accelerator device (20) relative to the released position (PU).

4. Electric vehicle operating system (100) according to any one of claims 1 to 3, wherein i) for motor mode, the control unit (25) is configured to perform motor mode operation by providing a motor mode input to the excitation system (30), ii) for coasting mode, the control unit (25) is configured to perform coasting mode operation by providing a zero torque command to the excitation system (30), and iii) for regenerative mode, the control unit (25) is configured to perform regenerative mode operation by providing regenerative power to the energy source.

5. Electric vehicle operating system (100) according to any one of claims 1 to 4, wherein the electric machine (10) is a synchronous machine.

6. Electric vehicle operating system (100) according to claim 5, wherein the synchronous machine is an electrically excited synchronous machine and the excitation system (30) is configured to excite the rotor (12) and the stator (11).

7. Electric vehicle operating system (100) according to claim 5, wherein the synchronous machine is a permanent magnet synchronous machine and the excitation system (30) is configured to excite the stator (11).

8. Electric vehicle operating system (100) according to any one of claims 1 to 7, wherein the accelerator device (20) is a power pedal or an accelerator pedal or a lever.

9. A method (101) of operating an electric vehicle system using an electric machine (10) having a stator (11) and a rotor (12), a drive unit (15) driven by the electric machine (10) to drive an electric vehicle, a throttle device (20) having a stroke between a motor mode and a deceleration mode of the electric vehicle, a power source for supplying electricity, a control unit (25), a sensing unit (21) including a position sensor for sensing a position of the throttle device (20), the method (101) of operating the electric vehicle system comprising: excitation of the electric machine (10) by the excitation system (30), control of the excitation system (30) by the control unit (25) based on the position of the throttle device (20) using signals from the sensing unit (21), wherein,during the deceleration stroke of the accelerator device (20) relative to a maximum power position (PM), a first predetermined position (PI) is located after the maximum power position (PM), a second predetermined position (P2) is located after the first predetermined position (PI), and a released position (PU) is located after the second predetermined position (P2), the first predetermined position (PI) being distinct from the second predetermined position (P2); and (i) the execution, by the control unit (25), of motor mode operation when the stroke of the accelerator device (20) is between the maximum power position (PM) and the first predetermined position (PI), (ii) the execution, by the control unit (25),of a freewheeling operation when the stroke of the accelerator device (20) is between the first predetermined position (PI) and the second predetermined position (P2), (iii) the execution, by the control unit (25), of a regenerative mode operation when the stroke of the accelerator device (20) is between the second predetermined position (P2) and the released position (PU).

10. Method (101) of operating the electric vehicle system according to claim 9, wherein the method (101) of operating the electric vehicle system comprises the execution, by the control unit (25), of motor mode operation by providing a motor mode input to the excitation system (30), of freewheel mode operation by providing a zero torque command to the excitation system (30), and of regenerative mode operation by providing regenerative power to the energy source.

11. Method (101) of operating the electric vehicle system according to any one of claims 9 to 10, wherein the electric machine (10) is an electrically excited synchronous machine and the method (101) of operating the electric vehicle system comprises the excitation of the rotor (12) by the excitation system (30).

12. Method (101) of operating the electric vehicle system according to any one of claims 9 to 10, wherein the electric machine (10) is a permanent magnet synchronous machine and the method (101) of operating the electric vehicle system comprises the excitation of the stator (11) by the excitation system (30).

13. Method (101) of operating the electric vehicle system according to any one of claims 9 to 12, implemented by a computer.

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