Fuel supply device for a catalyst heating device and method for supplying fuel to a catalyst heating device

Abstract

The invention relates to a power supply device for a heating device (21) of a catalyst (20) for a motor vehicle (1) with an internal combustion engine (M), said vehicle (1) comprising an electrical network (10), a battery (30), a DC / DC voltage converter (80), a first switch (60), a second switch (70) and an electric machine (40), the battery (30) being adapted to operate in a charging mode in which it stores electrical energy, and in a discharging mode in which it supplies electrical energy, characterized in that the first switch (60) is coupled to the catalyst (20) and to the electric machine (40) and is adapted to be either in a closed-circuit position electrically coupling the catalyst (20) and the electric machine (40) to allow a temperature rise of the catalyst (20), or in an open-circuit position,allowing electrical isolation of the catalyst (20) from the electric machine (40), the second switch (70) is coupled on one side to the electric machine (40) and the first switch (60), and on the other side to the DC / DC voltage converter (80). The second switch (70) is adapted to be either in a closed-circuit position, allowing electrical coupling between the electric machine (40) and the battery (30) through the DC / DC voltage converter (80) to allow its recharging, or in an open-circuit position, electrically isolating the battery (30) from the electric machine (40). Figure for the abbreviation: Fig 2,

Description

Title of the invention: Device for supplying a heating device for a catalyst and method for supplying a heating device for a catalyst Technical field

[0001] The invention relates to the field of a motor vehicle comprising a heat engine and equipped with a pollution control device with a heating device. The invention also relates to a method for supplying the heating device of the pollution control device. Prior art

[0002] A thermal motor vehicle nowadays includes a catalyst, otherwise known as a "catalytic converter", which allows the exhaust gases emitted by the vehicle's thermal engine to be depolluted.

[0003] The catalyst may in particular be an electrically heated catalyst, commonly called "EHC" for "Electrical Heated Catalyst" in English. This type of catalyst comprises a heating device for rapidly increasing the temperature in the catalyst to control gas emissions even when the motor vehicle is cold, i.e. when starting. For heating, the heating device comprises in particular a resistor.

[0004] Such a vehicle generally comprises a battery and an electrical machine, more precisely a direct current machine. The direct current machine is capable of operating in two operating modes: a motor operating mode, in which the direct current machine converts electrical energy into mechanical energy in order to start the thermal engine, and a generator operating mode, in which the electrical machine converts the mechanical rotational energy of the engine into electrical energy to store it in the battery. The battery is for example a 12 Volt, 24 Volt or 48 Volt battery.

[0005] The heating device is coupled to an electrical network via a specific control device and is configured to connect or not connect the heating device to the electrical network and therefore heat or not heat the catalytic converter.

[0006] To achieve efficiency and responsiveness of the catalytic converter resistance, significant power is required almost instantly. To achieve this, it is common to use a 48-volt battery. This battery has sufficient available power to allow the resistance to be heated when necessary to allow the gases to be cleaned.

[0007] A major drawback of this solution is the need to have electronics of the vehicle compatible with such a voltage level, in this case 48 Volts. This solution requires the use of additional circuits which generates additional costs.

[0008] There is therefore a need for a solution to at least partially remedy these drawbacks. Statement of the invention

[0009] To this end, the invention relates to a device for supplying a device for heating a catalyst for a motor vehicle with a thermal engine, said vehicle comprising an electrical network, a battery, a DC / DC voltage converter, a first switch, a second switch and an electrical machine, the battery being adapted to operate in a recharge mode in which it stores electrical energy, and in a discharge mode in which it supplies electrical energy.The first switch is coupled to the catalyst and the electrical machine and is adapted to be either in a closed circuit position electrically coupling the catalyst and the electrical machine to allow a temperature rise of the catalyst, or in an open circuit position, allowing the electrical isolation of the catalyst from the electrical machine, the second switch is coupled on the one hand to the electrical machine and to the first switch, and on the other hand to the DC / DC voltage converter, the second switch is adapted to be either in a closed circuit position, allowing the electrical coupling between the electrical machine and the battery through the DC / DC voltage converter to allow its recharging, or in an open circuit position electrically isolating the battery from the electrical machine.

[0010] Advantageously, the electrical machine is adapted to deliver a voltage of 24 Volts, or 48 Volts.

[0011] In an exemplary embodiment, the DC / DC voltage converter is a step-down voltage converter.

[0012] For example, the DC / DC voltage converter is a bidirectional converter.

[0013] In another exemplary embodiment, the battery is a 12-Volt battery.

[0014] In a second aspect, the invention relates to a method of feeding a Heating device for a motor vehicle with a heat engine, said vehicle comprising an electrical network, a catalyst capable of depolluting the exhaust gases emitted by the heat engine and comprising an electric heating device, a battery, a DC / DC voltage converter, an electric machine, a first switch adapted to switch between a closed circuit state and an open circuit state, a second switch adapted to switch between a closed circuit state and an open circuit state. Said method comprises the following steps:

[0015] el) verification of an open circuit state of the first switch corresponding to a catalyst not electrically heated,

[0016] e2) detection of a need to activate the electric heating device of the ca talyser,

[0017] e3) determination of the electrical power required to reach a temperature threshold temperature (Tseuil) of the catalyst and determination of the electrical power of the battery, in the case where the power of the battery is below a charge level Nseuilcharg then passage to a fourth step e4); in the case where the power of the battery is above a charge level Nseuilcharg then passage to a fifth step e5);

[0018] e4) verification that the second switch is in an open circuit state then posi operating the first switch in the closed circuit state to couple the electrical machine to the heating device,

[0019] e6) control of the electric machine so as to generate electric power allowing the catalyst to rise in temperature,

[0020] e7) checking the catalyst temperature,

[0021] e8) stopping the heating device and positioning the second switch in an open circuit state when the catalyst temperature is at least equal to the threshold temperature,

[0022] e5) comparison of the amount of electrical power required to heat the ca catalyst to reach the threshold temperature at the electrical power deliverable by the battery and by the electric machine, in the case where the electrical power deliverable by the battery is sufficient then passage to a ninth step e9), in the case where the electrical power deliverable by the electric machine is sufficient then passage to a tenth step el0), in the case where the electrical power necessary for heating the catalyst to reach the threshold temperature is greater than the electrical power deliverable by the electric machine and by the electrical power deliverable by the battery then passage to an eleventh step el 1),

[0023] e9) switching into a closed state of the second switch and switching into a open state of the first switch,

[0024] el2) control of the DC / DC converter so as to generate electrical power necessary for the heating device to allow the temperature of the catalyst to rise,

[0025] elO) switching into an open state of the second switch and switching into a closed state of the first switch,

[0026] el5) control of the electrical machine so as to generate electrical power necessary for the heating device to allow the temperature of the catalyst to rise,

[0027] e 11) control in a closed state of the second switch and switching in a closed state of the first switch,

[0028] el8) control of the electric machine and the battery so as to generate electrical power necessary for the heating device to allow the temperature of the catalyst to rise. Brief description of the drawings

[0029] Other characteristics and advantages of the invention will become apparent from reading the description which follows. This is purely illustrative and must be read in conjunction with the appended drawings in which:

[0030] [Fig-1] [Fig.l] illustrates an embodiment of the vehicle according to the invention,

[0031] [Fig.2] [Fig.2] illustrates a more detailed embodiment of the invention,

[0032] [Fig.3] [Fig.3] illustrates an exemplary embodiment of the method of the invention, and

[0033] [Fig.4] [Fig.4] illustrates another example of embodiment of the method of the invention. Description of the embodiments

[0034] With reference to [Fig.l], an embodiment of the device according to the invention will now be presented. The invention is suitable for installation in a thermal vehicle 1 or a hybrid vehicle comprising a thermal engine M. The vehicle 1 also comprises an electrical network 10, a catalyst 20, a battery 30, an electrical machine 40 and an electronic control unit 50. The thermal engine M is for example controlled by an engine control computer (not shown in the figures) also mounted in the vehicle 1.

[0035] The electrical network 10 makes it possible to supply electrical energy to the equipment of the vehicle 1. For this, the electrical network 10 comprises at least one electrical line mounted in the vehicle 1 and electrically connected to the equipment to be supplied.

[0036] The catalyst 20 is for example positioned at the outlet of the heat engine M, and has the function of depolluting the exhaust gases emitted by the heat engine M, before the exhaust gases are emitted outside the vehicle 1. For example, in the case of a heat engine M operating on diesel, the catalyst 20 makes it possible to transform the carbon monoxide and hydrocarbons in the exhaust gases into carbon dioxide and water. In the case of a heat engine M operating on gasoline, the catalyst 20 transforms the carbon monoxide and nitrogen dioxide in the exhaust gases into carbon dioxide.

[0037] A high temperature in the catalyst 20 makes it possible to accelerate the chemical reactions which occur in the catalyst 20, in order to quickly and effectively depollute the exhaust gases of the heat engine M. For this, the catalyst 20 comprises an electric heating device 21 making it possible to heat the interior of the catalyst 20. This is why this type of catalyst 20 can also be called "electrically heated catalyst" in English, by a person skilled in the art.

[0038] The heating device 21 notably comprises a heating resistor.

[0039] The invention proposes, in order to avoid 24 Volt or 48 Volt electronics, the use of an electrical machine 40 capable of providing a voltage of 24 Volts, or 48 Volts.

[0040] To do this, as illustrated in [Fig.2], the electrical machine 40 is coupled on the one hand to a first switch 60 and on the other hand to a second switch 70. The first switch 60 is also coupled to the heating device 21, itself coupled to the catalyst 20 which is not shown in [Fig.2].

[0041] The first switch 60 is capable, depending on a determined strategy, of being either in a closed position, allowing the passage of electrical energy to the heating device 21 to heat the catalyst 20, or in an open position, allowing the electrical isolation of the heating device 21 from the rest of the electrical circuit 10.

[0042] The second switch 70 is also coupled to a DC / DC voltage converter 80. The second switch 70 is capable, depending on a determined strategy, of being either in a closed position, allowing the passage of electrical energy, or in an open position, allowing electrical isolation from the rest of the electrical circuit, i.e. from the heating device 21 as well as from the electrical machine 40.

[0043] In a first embodiment, the DC / DC converter 80 is capable of converting the voltage of a value of the order of 24 Volts or 48 Volts delivered by the electrical machine 40 into a voltage compatible with the voltage admissible by the battery 30, for example 12 Volts. In this example, the DC / DC converter 80 is a unidirectional voltage step-down converter.

[0044] In a second exemplary embodiment, the DC / DC converter 80 is adapted to, on the one hand, convert the voltage coming from the electric battery 30 into a voltage compatible with the heating device 21, i.e. 24 Volts or 48 Volts, and, on the other hand, is adapted to convert the voltage of a value of the order of 24 Volts or 48 Volts, delivered by the electric machine 40 into a voltage compatible with the voltage admissible by the battery 30, for example 12 Volts. In this exemplary embodiment, the DC / DC converter 80 is said to be bidirectional. As illustrated in [Fig. 2], the battery 30 is a 12 Volt battery and is adapted to be coupled to the on-board network of the vehicle 1.

[0045] Thus, thanks to the device of the invention, it is not necessary to have electronics of the vehicle 1 compatible with the voltage of the electric machine 40.

[0046] The method of the invention for controlling the heating device 21 will now be presented.

[0047] [Fig. 3] shows a first embodiment of the method of the invention corresponding to the use of a unidirectional DC / DC converter 80.

[0048] Said method comprises a first step e1, during which the heating device 21 is in a rest state, that is to say it is not activated to heat the catalyst 20; the first switch 60 is in an open state, that is to say the heating device 21 is electrically isolated from the rest of the electrical circuit 10 of the vehicle 1.

[0049] During a second step e2, the method of the invention detects the need to activate the heating resistor 21 of the catalyst 20 in order to raise the temperature of the catalyst 20. This step can be carried out using an electronic structure of the electronic calculator type adapted to record the temperature of the catalyst 20 and / or control the heating device 21 as well as the electrical machine 40.

[0050] In the case where a need to activate the catalyst 20 is detected, the method of the invention proposes moving to a third step e3. In the case where no need to heat the catalyst 20 is detected, the method loops to the second step e2.

[0051] During the third step e3, the quantity of electrical power required to heat the catalyst 20 is studied, that is to say the electrical energy or electrical power required to raise the temperature of the catalyst 20 to a threshold temperature called Tthreshold making the catalysis effective for the depollution of the gases. The analyses of the measured parameters are easy for those skilled in the art and they will not be specified here. For example, the effective temperature of the catalyst 20, and / or the engine speed, and / or the gas flow rates, can be measured to estimate, based for example on manufacturer data stored in a memory (not shown here), the electrical power required to raise the temperature of the catalyst 20 as quickly as possible. In addition, during the same third step e3, the state of charge of the battery 30 is also analyzed by the electronic computer.

[0052] The method of the invention cleverly proposes to take into consideration the state of charge of the battery 30 to power or not the heating device 21. Thus, in the case where the state of charge of the battery 30 is low, that is to say that its charge level is lower than a charge level value Nseuilcharge, the method proposes to move on to the fourth step e4. In the case where the state of charge of the battery 30 is higher than the charge level Nseuilcharge, the method of the invention proposes to move on to a fifth step e5.

[0053] In the case where the state of charge of the battery 30 is low, the method according to the invention consists during the fourth step e4 in switching the second switch 70 to an open state in order to isolate the heating device 21 and the electrical machine 40 from the rest of the electrical circuit 10 of the vehicle 1. It is also, during this fourth step e4, switched into a closed state the first switch 60 to couple the heating device 21 and therefore the catalyst 20 to the electric machine 40. It is then proposed to move on to a sixth step e6.

[0054] During the sixth step e6, the electrical machine 40 is controlled so that it generates the electrical power necessary for the heating device 21 to allow the temperature of the catalyst 20 to rise. Cleverly, the electrical machine 40 can generate a variable electrical voltage allowing real-time control of the temperature of the catalyst 20. This control of the electrical voltage of the electrical machine 40 as a function of the electrical power necessary for the catalyst 20 can be carried out by the electronic computer.

[0055] Then, during a seventh step e7, the temperature of the catalyst 20 is recorded and analyzed and the electrical machine 40 is controlled to provide the necessary power until the catalyst 20 reaches its threshold temperature.

[0056] In the case where the threshold temperature of the catalyst 20 is reached, the method of the invention comprises an eighth step e8 consisting of deactivating the heating of the catalyst 20 by switching the first switch 60 to an open state.

[0057] Thus, thanks to the invention, it is possible to control the heating of the catalyst 20 without having complex electronics and especially compatible with an electrical voltage equal to 24 Volts or 48 Volts. It is also, thanks to the method of the invention, possible to heat the catalyst 20 using the electrical machine 40 without causing electrical or electromagnetic disturbances on the rest of the electrical network 10 thanks to the presence of the second switch 70 and its open state during the heating of the catalyst 20.

[0058] As mentioned previously, in the case where the state of charge of the battery 30 is higher than the charge level Nseuilcharge, the method of the invention proposes the transition to a fifth step e5. During this fifth step e5, cleverly the method proposes to switch the second switch 70 and the first switch 60 into a closed state so as to couple the heating device 21 to the DC / DC converter 80 and also to the direct current machine 40.

[0059] During the fifth step e5, the DC / DC converter 80 and the electrical machine 40 are also controlled so that they jointly generate the electrical power necessary for the heating device 21 to allow the temperature of the catalyst 20 to rise. This function is for example carried out by an electronic computer.

[0060] The temperature of the catalyst 20 is then recorded and analyzed during the ninth step e9, and the DC / DC converter 80 and the electrical machine 40 are controlled to provide the necessary power until the catalyst 20 reaches its threshold temperature.

[0061] In the case where the threshold temperature of the catalyst 20 is reached, the method of the invention comprises a tenth step el0 consisting of deactivating the heating of the catalyst 20 by switching the second switch 70 to an open state and alternatively by switching the first switch 60 to an open state. Of course, the electrical machine 40 as well as the DC / DC converter 80 are controlled so as to no longer supply electrical energy to the heating device 21.

[0062] [Fig.4] shows a second embodiment of the method of the invention corresponding to the use of a bidirectional DC / DC converter 80.

[0063] Said method comprises a first step e1, during which the heating device 21 is in a rest state, that is to say it is not activated to heat the catalyst 20; the first switch 60 is in an open state, that is to say the heating device 21 is electrically isolated from the rest of the electrical circuit 10 of the vehicle 1.

[0064] During a second step e2, the method of the invention detects the need to activate the heating resistor 21 of the catalyst 20 in order to raise the temperature of the catalyst 20. This step can be carried out using an electronic structure of the electronic calculator type adapted to record the temperature of the catalyst 20 and / or control the heating device 21 as well as the electrical machine 40.

[0065] In the case where a need to activate the catalyst 20 is detected, the method of the invention proposes moving to a third step e3. In the case where no need to heat the catalyst 20 is detected, the method loops to the second step e2.

[0066] During the third step e3, the quantity of electrical power required to heat the catalyst 20 is studied, that is to say the electrical energy or electrical power required to raise the temperature of the catalyst 20 to a threshold temperature called Tthreshold making the catalysis effective for the depollution of the gases. The analyses of the measured parameters are easy for those skilled in the art and they will not be specified here. For example, the effective temperature of the catalyst 20, and / or the engine speed, and / or the gas flow rates, can be measured to estimate, based for example on manufacturer data stored in a memory (not shown here), the electrical power required to raise the temperature of the catalyst 20 as quickly as possible. In addition, during the same third step e3, the state of charge of the battery 30 is also analyzed by the electronic computer.

[0067] The method of the invention cleverly proposes to take into consideration the state of charge of the battery 30 to power or not the heating device 21. Thus, in the case where the state of charge of the battery 30 is low, that is to say that its charge level is lower than a charge level value Nseuilcharge, the method proposes to move on to the thirtieth step e30. In the case where the state of charge of the battery 30 is higher than the charge level Nseuilcharge, the method of the invention proposes the transition to a fifth step e5.

[0068] In the case where the state of charge of the battery 30 is low, the method according to the invention consists during the thirtieth step e30 of choosing either heating the heating device 21 using the electric machine 40 only symbolized by the transition to a fourth step e4, or of using the electrical energy of the electric machine 40 to provide both electrical energy to heat the heating device 21 and to recharge the battery 30 symbolized by the transition to a thirty-first step e31. In such a latter case, the DC / DC converter will be actuated to ensure that the electrical energy is delivered to the battery 30.

[0069] The fourth step e4 consists of switching the second switch 70 to an open state in order to isolate the heating device 21 and the electrical machine 40 from the rest of the electrical circuit 10 of the vehicle 1. During this fourth step e4, the first switch 60 is also switched to a closed state in order to couple the heating device 21 and therefore the catalyst 20 to the electrical machine 40. It is then proposed to move on to a sixth step e6.

[0070] During the sixth step e6, the electrical machine 40 is controlled so that it generates the electrical power necessary for the heating device 21 to allow the temperature of the catalyst 20 to rise. Cleverly, the electrical machine 40 can generate a variable electrical voltage allowing real-time control of the temperature of the catalyst 20. This control of the electrical voltage of the electrical machine 40 as a function of the electrical power necessary for the catalyst 20 can be carried out by the electronic computer.

[0071] Then, during a seventh step e7, the temperature of the catalyst 20 is recorded and analyzed and the electrical machine 40 is controlled to provide the necessary power until the catalyst 20 reaches its threshold temperature.

[0072] In the case where the threshold temperature of the catalyst 20 is reached, the method of the invention comprises an eighth step e8 consisting of deactivating the heating of the catalyst 20 by switching the first switch 60 to an open state.

[0073] Thus, thanks to the invention, it is possible to control the heating of the catalyst 20 without having complex electronics and especially compatible with an electrical voltage equal to 24 Volts or 48 Volts. It is also, thanks to the method of the invention, possible to heat the catalyst 20 using the electrical machine 40 without causing electrical or electromagnetic disturbances on the rest of the electrical network 10 thanks to the presence of the second switch 70 and its open state during the heating of the catalyst 20.

[0074] The thirty-first step e31 consists of switching the second switch 70 and the first switch 60 into a closed state to couple the heating device 21 and therefore the catalyst 20 to the electric machine 40. It is then proposed to move on to a thirty-second step e32.

[0075] During the thirty-second step e32, the electrical machine 40 is controlled so that it generates the electrical power necessary both for the heating device 21 to allow the temperature of the catalyst 20 to rise and for the battery 30 to allow it to be recharged.

[0076] Then, during a thirty-third step e33, the temperature of the catalyst 20 is recorded and analyzed and the electrical machine 40 is controlled to provide the necessary power until the catalyst 20 reaches its threshold temperature.

[0077] In the case where the threshold temperature of the catalyst 20 is reached, the method of the invention comprises a thirty-fourth step e34 consisting of deactivating the heating of the catalyst 20 by switching the first switch 60 to an open state.

[0078] The method cleverly proposes a thirty-fifth step e35 consisting of raising the charge level of the battery 30. If the charge level is reached then the method of the invention proposes moving to a thirty-sixth step e36. Otherwise the method proposes continuing to charge the battery 30 using the electrical machine 40.

[0079] In the case where the state of charge of the battery 30 is reached, the method proposes during the thirty-sixth step e36 to deactivate the electrical machine 40 and also for example to position the second switch 70 in an open state.

[0080] Thus, thanks to the invention, it is possible to control the heating of the catalyst 20 without having complex electronics and especially compatible with an electrical voltage equal to 24 Volts or 48 Volts. It is also, thanks to the method of the invention, possible to heat the catalyst 20 using the electrical machine 40 without causing electrical or electromagnetic disturbances on the rest of the electrical network 10 thanks to the presence of the second switch 70 and its open state during the heating of the catalyst 20. It is furthermore possible to also charge the battery 30 while heating the catalyst 20.

[0081] As mentioned previously, in the case where the state of charge of the battery 30 is higher than the charge level Nseuilcharge, the method of the invention proposes moving to a fifth step e5. During this fifth step e5, the method of the invention proposes recording the quantity of electrical power required for heating the catalyst 20, i.e. the electrical energy or electrical power required by the heating device 21 to raise the temperature of the catalyst 20 to a threshold temperature called Tseuil making the catalysis effective for the depollution of the gases. The analyses of the measured parameters are easy for those skilled in the art and they will not be specified here. For example, the temperature can be measured effective temperature of the catalyst 20, and / or the engine speed, and / or the gas flow rates, as well as the state of charge of the battery 30 to estimate, based for example on manufacturer data stored in a memory (not shown here), the electrical power necessary to raise the temperature of the catalyst 20 as quickly as possible. These calculations can be carried out by the electronic computer.

[0082] In the case where the state of charge of the battery 30 is sufficient in itself to raise the temperature of the catalyst 20 to a threshold temperature, the method proposes moving to a ninth step e9.

[0083] In the case where the electrical power required by the heating device 21 to enable the temperature of the catalyst 20 to rise can be generated solely by the electrical machine 40, the method proposes moving to a tenth step el0.

[0084] In the case where the state of charge of the battery 30 is not sufficient on its own to raise the temperature of the catalyst 20 to a threshold temperature and it is necessary to add the electrical power that can be generated by the electrical machine 40, the method proposes moving to an eleventh step el 1.

[0085] During the ninth step e9, the method proposes to switch the second switch 70 into a closed state and to switch the first switch 60 into an open state in order to isolate the electrical machine 40. Thus, cleverly, only the battery 30 through the DC / DC converter 80 will be used to power the heating device 21 and thus raise the temperature of the catalyst 20 to the threshold temperature. The DC / DC converter 80 is for example used in “Buck” mode. The method then proposes the transition to a twelfth step el2.

[0086] During the twelfth step el2, the DC / DC converter 80 is controlled so that it generates the electrical power necessary for the heating device 21 to allow the temperature of the catalyst 20 to rise. This control can be carried out by the electronic computer 50.

[0087] Then, during a thirteenth step el3, the temperature of the catalyst 20 is recorded and analyzed and the DC / DC converter 80 is controlled to supply the necessary power to the heating device 21 so that the catalyst 20 reaches its threshold temperature. In the case where the threshold temperature of the catalyst 20 is reached, the method of the invention comprises a fourteenth step el4 consisting of deactivating the heating of the catalyst 20 by switching the second switch 70 to an open state and / or by stopping the control of the DC / DC converter 80.

[0088] Thus, thanks to the invention, it is possible to control the heating of the catalyst 20 without using the electrical machine 40.

[0089] During the tenth step el0, the method proposes to switch the second switch 70 to an open state in order to isolate the heating device 21 and the electrical machine 40 from the rest of the electrical circuit 10 of the vehicle 1. It is also during this fourth step e4 switches the first switch 60 into a closed state to couple the catalyst 20 to the electrical machine 40. It is then proposed to move on to a fifteenth step el5.

[0090] During the fifteenth step e 15, the electric machine 40 is commanded to that it generates the electrical power necessary for the heating device 21 to allow the temperature of the catalyst 20 to rise. Cleverly, the electrical machine 40 can generate a variable electrical voltage allowing real-time control of the temperature of the catalyst 20. This control of the electrical voltage of the electrical machine 40 as a function of the electrical power necessary for the catalyst 20 can be carried out by the electronic computer.

[0091] Then, during a sixteenth step el6, the temperature of the catalyst 20 is recorded and analyzed and the electrical machine 40 is controlled to provide the necessary power until the catalyst 20 reaches its threshold temperature.

[0092] In the case where the threshold temperature of the catalyst 20 is reached, the method of the invention comprises a seventeenth step el7 consisting of deactivating the heating of the catalyst 20 by switching the first switch 60 to an open state.

[0093] Thus, thanks to the invention, it is possible to control the heating of the catalyst 20 without having complex electronics and especially compatible with an electrical voltage equal to 24 Volts or 48 Volts. It is also, thanks to the method of the invention, possible to heat the catalyst 20 using the electrical machine 40 without causing electrical or electromagnetic disturbances on the rest of the electrical network 10 thanks to the presence of the second switch 70 and its open state during the heating of the catalyst 20.

[0094] In the eleventh step el 1, the method proposes to switch the second switch 70 and the first switch 60 into a closed state so that the electrical machine 40 and the battery 30 via the DC / DC converter 80 provide the necessary electrical power to the heating device 21 so that the catalyst 20 reaches the desired temperature. It is then proposed to move on to an eighteenth step el8.

[0095] During the eighteenth step el8, both the electrical machine 40 and the DC / DC converter 80 are controlled so that they generate the electrical power necessary for the heating device 21 to allow the temperature of the catalyst 20 to rise. Cleverly, the electrical machine 40 can generate a variable electrical voltage allowing real-time control of the temperature of the catalyst 20. This control of the electrical voltage of the electrical machine 40 as a function of the electrical power necessary for the catalyst 20 can be carried out by the electronic computer.

[0096] Then, during a nineteenth step el9, the temperature of the catalyst 20 and the electrical machine 40 and / or the DC / DC converter 80 are controlled to provide the necessary power until the catalyst 20 reaches its threshold temperature.

[0097] In the case where the threshold temperature of the catalyst 20 is reached, the method of the invention comprises a twentieth step e20 consisting of deactivating the heating of the catalyst 20 by switching the first switch 60 and the second switch 70 to an open state.

[0098] Cleverly, in an alternative embodiment of the invention (not shown), the method can combine the steps relating to the heating of the catalyst 20 and steps relating to the charging of the battery 30 allowing simultaneously the charging of the battery 30 and the heating of the catalyst 20 by the electric machine 40. In such a case the DC / DC converter 80 is bidirectional.

[0099] Thanks to the invention it is possible to achieve rapid heating of the catalyst without having vehicle electronics compatible with a voltage of 24 Volts or 48 Volts.

Claims

Claims

1. Device for supplying a heating device (21) of a catalyst (20) for a motor vehicle (1) with a heat engine (M), said vehicle (1) comprising an electrical network (10), a battery (30), a DC / DC voltage converter (80), a first switch (60), a second switch (70) and an electric machine (40), the battery (30) being adapted to operate in a recharge mode in which it stores electrical energy, and in a discharge mode in which it supplies electrical energy, characterized in that the first switch (60) is coupled to the catalyst (20) and to the electric machine (40) and is adapted to be either in a closed circuit position electrically coupling the catalyst (20) and the electric machine (40) to allow a rise in temperature of the catalyst (20), or in an open circuit position,allowing the electrical isolation of the catalyst (20) from the electric machine (40), the second switch (70) is coupled on the one hand to the electric machine (40) and to the first switch (60), and on the other hand to the DC / DC voltage converter (80), the second switch (70) is adapted to be either in a closed circuit position, allowing the electrical coupling between the electric machine (40) and the battery (30) through the DC / DC voltage converter (80) to allow its recharging, or in an open circuit position electrically isolating the battery (30) from the electric machine (40).,

2. Device for supplying a heating device (21) of a catalyst (20) for a motor vehicle (1) according to claim 1, in which the electrical machine (40) is adapted to deliver a voltage of 24 Volts, or 48 Volts.

3. Device for supplying a heating device (21) of a catalyst (20) for a motor vehicle (1) according to claim 1 or claim 2, in which the DC / DC voltage converter (80) is a voltage step-down converter.

4. Device for supplying a heating device (21) of a catalyst (20) for a motor vehicle (1) according to claim 1 or claim 2, in which the DC / DC voltage converter (80) is a bidirectional converter.

5. Device for supplying a heating device (21) of a catalyst (20) for a motor vehicle (1) according to any one of claims 1 to 4, in which the battery (30) is a 12 Volt battery.

6. Method for powering a heating device (21) for a motor vehicle (1) with a heat engine (M), said vehicle (1) comprising an electrical network (10), a catalyst (20) capable of depolluting the exhaust gases emitted by the heat engine (M) and comprising an electric heating device (21), a battery (30), a DC / DC voltage converter (80), an electric machine (40), a first switch (60) adapted to switch between a closed circuit state and an open circuit state, a second switch (70) adapted to switch between a closed circuit state and an open circuit state, said method comprising the following steps: el) checking an open circuit state of the first switch (60) corresponding to a catalyst (20) not electrically heated, e2) detecting a need to activate the electric heating device (21) of the catalyst (20),e3) determining the electrical power required to reach a threshold temperature (Tseuil) of the catalyst (20) and determining the electrical power of the battery (30), in the case where the power of the battery (30) is below a charge level Nseuilcharg then moving to a fourth step e4); in the case where the power of the battery (30) is above a charge level Nseuilcharg then moving to a fifth step e5); e4) verifying that the second switch (70) is in an open circuit state then positioning the first switch (60) in the closed circuit state to couple the electrical machine (40) to the heating device (21), e6) controlling the electrical machine (40) so as to generate electrical power allowing the temperature of the catalyst (20) to rise, e7) verifying the temperature of the catalyst (20),e8) stopping the heating device (21) and positioning the second switch (70) in an open circuit state when the temperature of the catalyst (20) is at least equal to the threshold temperature (Tseuil), e5) comparing the quantity of electrical power required to heat the catalyst (20) to reach the threshold temperature (Tseuil) with the electrical power deliverable by the battery (30) and by the machine, electric (40), in the case where the electric power deliverable by the battery (30) is sufficient then passage to a ninth step e9), in the case where the electric power deliverable by the electric machine (40) is sufficient then passage to a tenth step el0), in the case where the electric power necessary for heating the catalyst (20) to reach the threshold temperature (Tseuil) is greater than the electric power deliverable by the electric machine (40) and by the electric power deliverable by the battery (30) then passage to an eleventh step ell), e9) switching into a closed state of the second switch (70) and switching into an open state of the first switch (60), el2) control of the DC / DC converter (80) so as to generate an electric power necessary for the heating device (21) to allow the temperature of the catalyst (20) to rise,elO) switching the second switch (70) into an open state and switching the first switch (60) into a closed state, el5) controlling the electrical machine (40) so as to generate an electrical power necessary for the heating device (21) to allow the temperature of the catalyst (20) to rise, ell) controlling the second switch (70) into a closed state and switching the first switch (60) into a closed state, el8) controlling the electrical machine (40) and the battery (30) so as to generate an electrical power necessary for the heating device (21) to allow the temperature of the catalyst (20) to rise.,

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