Method for powering a heating device for a catalytic converter

Abstract

The invention relates to a device for powering a heating device (21) that heats a catalytic converter (20) for a motor vehicle (1) having 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 electrical machine (40), the battery (30) being suitable for operating in a recharging 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 catalytic converter (20) and to the electrical machine (40) and is suitable for being either in a closed-circuit position electrically coupling the catalytic converter (20) and the electrical machine (40) to allow the catalytic converter (20) to increase in temperature, or in an open-circuit position, allowing the electrical isolation of the catalytic converter (20) from the electrical machine (40); and the second switch (70) is coupled on the one hand to the electrical machine (40) and to the first switch (60), and on the other hand to the DC / DC voltage converter (80), the second switch (70) being suitable for being either in a closed-circuit position, allowing electrical coupling between the electrical machine (40) and the battery (30) through the DC / DC voltage converter (80) to allow battery recharging, or in an open-circuit position electrically isolating the battery (30) from the electrical machine (40).

Description

[0001] METHOD FOR POWERING A HEATING DEVICE FOR A CATALYST

[0002] DESCRIPTION

[0003] [Technical field]

[0004] 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 power to the heating device of the pollution control device.

[0005] [State of the prior art]

[0006] A thermal motor vehicle today includes a catalyst, otherwise known as a "catalytic converter", which helps to depollute the exhaust gases emitted by the vehicle's thermal engine.

[0007] The catalyst may in particular be an electrically heated catalyst, commonly referred to as an "EHC" for "Electrical Heated Catalyst" in English. This type of catalyst includes a heating device for rapidly increasing the temperature in the catalyst to control gas emissions even when the motor vehicle is cold, i.e. at startup. To heat, the heating device includes, in particular, a resistor.

[0008] 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.

[0009] 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 the catalytic converter.

[0010] To achieve efficiency and responsiveness from the catalytic converter resistor, 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 resistor to heat up when necessary to allow for gas depollution.

[0011] A major drawback of this solution is the need for vehicle electronics compatible with such a voltage level, in this case 48 Volts. This solution requires the use of additional circuits which generates additional costs.

[0012] There is therefore a need for a solution that can at least partially overcome these drawbacks.

[0013] [Statement of the invention]

[0014] To this end, the invention relates to a device for supplying a device for heating a catalyst for a motor vehicle with a heat engine, said vehicle comprising an electrical network, a battery, a direct / direct 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 the temperature of the catalyst to rise, 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.

[0015] Advantageously, the electrical machine is adapted to deliver a voltage of 24 Volts, or 48 Volts.

[0016] In an exemplary embodiment, the DC / DC voltage converter is a step-down voltage converter.

[0017] For example, the DC / DC voltage converter is a bidirectional converter.

[0018] In another exemplary embodiment, the battery is a 12-Volt battery. In a second aspect, the invention relates to a method for powering 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: e1) checking an open circuit state of the first switch corresponding to a catalyst not electrically heated, e2) detecting a need to activate the electric heating device of the catalyst,e3) determination of the electrical power required to reach a 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); e4) verification that the second switch is in an open circuit state then positioning the first switch in the closed circuit state to couple the electrical machine to the heating device, e6) control of the electrical machine so as to generate electrical power allowing the temperature of the catalyst to rise, e7) verification of the temperature of the catalyst,e8) stopping the heating device and positioning the second switch in an open circuit state when the temperature of the catalyst is at least equal to the threshold temperature, e5) comparing the amount of electrical power required to heat the catalyst to reach the threshold temperature with the electrical power delivered by the battery and by the electric machine, in the case where the electrical power delivered by the battery is sufficient then moving to a ninth step e9), in the case where the electrical power delivered by the electric machine is sufficient then moving to a tenth step e10), in the case where the electrical power required to heat the catalyst to reach the threshold temperature is greater than the electrical power delivered by the electric machine and by the electrical power delivered by the battery then moving to an eleventh step e11),e9) switching the second switch to a closed state and switching the first switch to an open state, e12) controlling the DC / DC converter so as to generate electrical power necessary for the heating device to allow the catalyst to rise in temperature, e10) switching the second switch to an open state and switching the first switch to a closed state, e15) controlling the electrical machine so as to generate electrical power necessary for the heating device to allow the catalyst to rise in temperature, e11) controlling the second switch to a closed state and switching the first switch to a closed state, e18) controlling the electrical machine and the battery so as to generate electrical power necessary for the heating device to allow the catalyst to rise in temperature.,

[0019] [Description of the drawings]

[0020] Other characteristics and advantages of the invention will become apparent from reading the description which follows. This description is purely illustrative and must be read in conjunction with the appended drawings in which:

[0021] [Fig. 1] Figure 1 illustrates an embodiment of the vehicle according to the invention,

[0022] [Fig. 2] Figure 2 illustrates a more detailed embodiment of the invention,

[0023] [Fig. 3] Figure 3 illustrates an exemplary embodiment of the method of the invention, and

[0024] [Fig. 4] Figure 4 illustrates another example of embodiment of the method of the invention.

[0025] [Description of embodiments]

[0026] With reference to Figure 1, 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. 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.

[0027] 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.

[0028] 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 those skilled in the art.

[0029] The heating device 21 notably comprises a heating resistor.

[0030] 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.

[0031] To do this, as illustrated in Figure 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 Figure 2.

[0032] 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.

[0033] 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. the heating device 21 as well as the electrical machine 40.

[0034] 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.

[0035] 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 it is adapted to be coupled to the on-board network of the vehicle 1.

[0036] 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.

[0037] The method of the invention for controlling the heating device 21 will now be presented.

[0038] Figure 3 shows a first embodiment of the method of the invention corresponding to the use of a unidirectional DC / DC converter 80.

[0039] 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.

[0040] 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. 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.

[0041] During the third step e3, the amount of electrical power required to heat the catalyst 20 is studied, i.e. 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 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.

[0042] 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.

[0043] 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 the first switch 60 to a closed state 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.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] Thus, thanks to the invention, it is possible to control the heating of the catalyst 20 without having complex electronics and above all 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.

[0048] 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, the method cleverly proposes switching 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.

[0049] 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.

[0050] 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.

[0051] In the case where the threshold temperature of the catalyst 20 is reached, the method of the invention comprises a tenth step e10 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. Figure 4 shows a second embodiment of the method of the invention corresponding to the use of a bidirectional DC / DC converter 80.

[0052] 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.

[0053] 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.

[0054] 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.

[0055] During the third step e3, the amount of electrical power required to heat the catalyst 20 is studied, i.e. 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 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.

[0056] 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 to move on to a fifth step e5.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.

[0057] 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 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.

[0058] 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.

[0059] 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.

[0060] 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.

[0061] 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. The thirty-first step e31 consists of switching the second switch 70 and the first switch 60 to a closed state 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 thirty-second step e32.

[0062] During the thirty-second step e32, the electric machine 40 is commanded to generate the electrical power necessary both for the heating device 21 to allow the catalyst 20 to rise in temperature and for the battery 30 to allow it to be recharged.

[0063] 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.

[0064] 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.

[0065] 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 on to a thirty-sixth step e36. Otherwise the method proposes continuing to charge the battery 30 using the electric machine 40.

[0066] 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 electric machine 40 and also for example to position the second switch 70 in an open state.

[0067] 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.

[0068] As mentioned previously, in the case where the state of charge of the battery 30 is higher than the charge level Nthresholdcharge, 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 to heat 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 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, as well as the state of charge of the battery 30 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.

[0069] 20 as quickly as possible. These calculations can be performed by the electronic calculator.

[0070] 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.

[0071] In the case where the electrical power required by the heating device 21 to allow the temperature of the catalyst 20 to rise can only be generated by the electrical machine 40, the method proposes moving to a tenth step e10.

[0072] 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 e11.

[0073] In the ninth step e9, the method proposes to switch the second switch 70 to a closed state and to switch the first switch 60 to 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.

[0074] 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 e12.

[0075] During the twelfth step e12, the DC / DC converter 80 is commanded to generate the electrical power necessary for the heating device 21 to allow the temperature of the catalyst 20 to rise. This command can be carried out by the electronic computer 50.

[0076] Then, during a thirteenth step e13, 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 e14 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.

[0077] Thus, thanks to the invention, it is possible to control the heating of the catalyst 20 without using the electrical machine 40.

[0078] During the tenth step e10, the method proposes switching the second switch 70 into 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 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 e15.

[0079] During the fifteenth step e15, 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.

[0080] Then, during a sixteenth step e16, 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.

[0081] In the case where the threshold temperature of the catalyst 20 is reached, the method of the invention comprises a seventeenth step e17 consisting of deactivating the heating of the catalyst 20 by switching the first switch 60 to an open state.

[0082] Thus, thanks to the invention, it is possible to control the heating of the catalyst 20 without having complex electronics and above all 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.

[0083] In the eleventh step e11, the method proposes to switch the second switch 70 and the first switch 60 into a closed state so that the electric 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 e18. During the eighteenth step e18, both the electric machine 40 and the DC / DC converter 80 are controlled so that they generate the necessary electrical power to the heating device 21 to allow the temperature of the catalyst 20 to rise. Cleverly, the electric 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 required by the catalyst 20 can be carried out by the electronic computer.

[0084] Then, during a nineteenth step e19, the temperature of the catalyst 20 is recorded and analyzed 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.

[0085] 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.

[0086] 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 the battery 30 to be charged and the catalyst 20 to be heated simultaneously by the electrical machine 40. In such a case, the DC / DC converter 80 is bidirectional.

[0087] 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. Method for supplying 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: e1) 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 electrical machine (40), in the case where the electrical power deliverable by the battery (30) is sufficient then moving to a ninth step e9), in the case where the electrical power deliverable by the electrical machine (40) is sufficient then moving to a tenth step e10), in the case where the power, electrical power required to heat the catalyst (20) to reach the threshold temperature (Tseuil) is greater than the electrical power deliverable by the electric machine (40) and by the electrical power deliverable by the battery (30) then moving to an eleventh step e11), e9) switching the second switch (70) into a closed state and switching the first switch (60) into an open state, e12) controlling the DC / DC converter (80) so as to generate electrical power required by the heating device (21) to allow the catalyst (20) to rise in temperature, e10) switching the second switch (70) into an open state and switching the first switch (60) into a closed state, e15) controlling the electric machine (40) so as to generate electrical power required by the heating device (21) to allow the catalyst (20) to rise in temperature,e11) control in a closed state of the second switch (70) and switching in a closed state of the first switch (60), e18) control of the electric machine (40) and of the battery (30) so as to generate an electric power necessary for the heating device (21) to allow the temperature of the catalyst (20) to rise.,

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