Vehicle electrical power supply system

Abstract

The invention relates to a method for controlling an electrical power supply system (1) for a motor vehicle, the vehicle comprising an electric machine (ME), the power supply system (1) comprising a first electrical energy storage device (10) and a second electrical energy storage device (20) capable of supplying electrical energy to power the electric machine (ME). The method is characterized in that it comprises the steps of: Determining an environmental impact criterion based on the environmental impact of the first and second storage devices (10, 20), Determining the value of the power demand (P10_opti) to be supplied by the first storage device (10) and the value of the power demand (P20_opti) to be supplied by the second storage device (20) so as to minimize the determined environmental impact criterion and so as to respect the total electrical power demand (Preq).Figure for the abridged version: Fig 1.

Description

Title of the invention: Electrical power supply system for vehicles. Technical field

[0001] The invention relates to the field of hybrid or electric vehicles, and more specifically a method of controlling an electrical system comprising in particular a battery and a fuel cell and a control unit capable of implementing this control method. Previous technique

[0002] As is known, an electric or hybrid vehicle includes an electric machine. In order to power the electric machine, the vehicle may include a battery and a fuel cell.

[0003] The vehicle also includes a control unit capable of controlling the power supplied by the battery and the power supplied by the fuel cell to power the vehicle's electric motor. The electric motor can be powered simultaneously by the battery and the fuel cell. The power supplied by the battery and the fuel cell is determined according to the torque demand expressed by the vehicle's driver.

[0004] The control strategy for defining the power supplied by the battery and the power supplied by the machine is also dependent on hydrogen consumption. In order to optimize hydrogen consumption, a single criterion, related to hydrogen consumption, can be used to determine the power command for the battery and the power command for the fuel cell so as to minimize hydrogen consumption. However, in this case, no criterion relates to the battery.

[0005] In another case, the strategy for controlling and optimizing the share of power supplied by the battery and that supplied by the fuel cell is carried out using a multi-criteria optimization that takes into account the consumption and durability of the components from the moment the components were integrated into the vehicle.

[0006] However, none of these control strategies considers the overall life of each component, even before it is integrated into the vehicle.

[0007] There is therefore a need for a solution to overcome, at least in part, the disadvantages described above. Description of the invention

[0008] To this end, the invention relates to a method for controlling an electrical power supply system for a motor vehicle, the vehicle comprising an electric machine, the electrical power supply system comprising: a. a first electrical energy storage device capable of supplying electrical energy to power the electrical machine, b. a second electrical energy storage device capable of supplying electrical energy to power the electrical machine, The process is remarkable in that it includes the steps of: - Determine the total electrical power demand to be supplied to the electrical machine, - Determine the environmental impact of the first storage device, referred to as the "first environmental impact", - Determine the environmental impact of the second storage device, referred to as the "second environmental impact", - Determine an environmental impact criterion based on all the identified environmental impacts, - Determine the value of the power demand to be supplied by the first storage device and the value of the power demand to be supplied by the second storage device so as to minimize the determined environmental impact criterion and so as to respect the total determined electrical power demand.

[0009] Thus, the power demand to be supplied by each storage device to the electric machine is determined by considering the environmental impact of each element of the power system in addition to considering the total power demand. This allows for optimal control of the power system, ensuring on the one hand that the electric machine is correctly supplied and minimizing the environmental impact of the first and second storage devices.

[0010] Preferably: a. The first storage device is a power supply battery, b. The second storage device is a fuel cell, configured to generate electrical energy from hydrogen. The process is remarkable in that: - It includes, simultaneously with the determination of the first environmental impact of the battery and the step of determining the second environmental impact of the fuel cell, a determination step of the environmental impact of hydrogen consumption, referred to as the "third environmental impact", - The environmental impact criterion sums the first environmental impact, the second environmental impact and the third environmental impact.

[0011] The method can therefore be applied to a power supply system frequently used in vehicles comprising at least one battery and at least one fuel cell.

[0012] Preferably, the battery being characterized by a predefined battery aging model and by a first environmental impact model specific to the battery, the step of determining the first environmental impact of the battery corresponds to: a. Determine the battery lifespan from the battery aging model, b. Determine the environmental impact from the determined lifespan and the first environmental impact model of the battery.

[0013] Thus, the first environmental impact is adapted according to the lifespan of the battery and corresponds to said battery mounted in the vehicle.

[0014] Advantageously, since the fuel cell is characterized by a second predefined fuel cell aging model and by a second fuel cell-specific environmental impact model, the step of determining the second environmental impact of the fuel cell corresponds to: a. Determine the lifespan of the fuel cell from the fuel cell aging model, b. Determine the environmental impact of the fuel cell from the determined lifespan and the second environmental impact model of the fuel cell.

[0015] Thus, the second environmental impact is adapted according to the lifespan of the fuel cell and corresponds to said fuel cell mounted in the vehicle.

[0016] Advantageously, since the fuel cell is characterized by a predefined consumption model for the quantity of hydrogen, and hydrogen is also characterized by a third environmental impact model for hydrogen production, the step of determining the third environmental impact of hydrogen consumption corresponds to: a. Determine the predicted hydrogen consumption based on the consumption model, b. Determine the environmental impact of hydrogen from the prediction of hydrogen consumed determined and the third environmental impact model of hydrogen production.

[0017] Thus, the third environmental impact is adapted according to the predicted hydrogen consumption in the vehicle.

[0018] Preferably, the first environmental impact model of the battery considers at least one of the following criteria: a. The impact of the raw materials used in the composition of battery cells, b. The impact of the raw materials used in the composition of the battery's control electronics and the energy cost of its assembly, c. The impact of the raw materials used in the composition of the battery casing, d. The energy cost of assembling the battery, e. The transport of raw materials from their production sites to the battery production site, f. The transport of the battery from its production site to the car manufacturer, g. At the end of the battery's life, the proportion of batteries that will be reused for other applications, and the proportion of battery materials that will be recycled. h. the environmental cost of processing non-reused and / or non-recycled items.

[0019] Thus, the first environmental impact model considers the environmental impact of the entire life of the battery, whether before integration, during, and after integration of the battery into the vehicle.

[0020] Preferably, the second model of the environmental impact of the fuel cell considers at least one of the following criteria: a. Raw materials for the construction of the cells of said fuel cell, b. The energy cost of assembling the cells into a fuel cell, c. The environmental impact of all the auxiliary equipment necessary for the proper functioning of the fuel cell, d. The transport of the fuel cell from its production site to the car manufacturer, e. the impact of fuel cell recycling and the environmental cost of processing non-recycled components, f. and / or the possible reuse of a fuel cell.

[0021] Thus, the second environmental impact model considers the environmental impact of the entire life of the fuel cell, whether before integration, during, and after integration of the fuel cell into the vehicle.

[0022] Advantageously, the third environmental impact model of hydrogen considers at least one of the following criteria: a. the method of hydrogen production, b. the transport of hydrogen from the production site to the vehicle refueling site(s), c. hydrogen conditioning, d. the use / reuse and / or storage of waste produced during the chemical reaction during use of the fuel cell.

[0023] Thus, the third environmental impact model considers the environmental impact of the entire life of hydrogen, whether before, during, and after use in the vehicle.

[0024] Preferably, the method includes a step of determining the minimum power that the battery must provide and the maximum power that the battery can provide.

[0025] Preferably, the method includes a step of determining the minimum power that the fuel cell must provide and the maximum power that the fuel cell can provide.

[0026] Preferably, the determination of the value of the power demand to be supplied by the battery and the value of the power demand to be supplied by the fuel cell is dependent on the maximum and minimum power values ​​for the battery and the fuel cell, determined previously.

[0027] The invention also relates to an electrical power supply system for a motor vehicle, the vehicle comprising an electrical machine, the electrical system comprising: a. a first electrical energy storage device capable of supplying electrical energy to power the electrical machine, b. a second electrical energy storage device capable of supplying electrical energy to power the electrical machine, c. a control unit, configured to control the electrical power supplied by the first storage device and the electrical power supplied by the second storage device, and to implement the process as previously described.

[0028] The invention relates to a vehicle comprising an electrical power supply system as previously described. Brief description of the drawings

[0029] Other features and advantages of the invention will become apparent from the following description. This description is purely illustrative and should be read in conjunction with the accompanying drawings, in which:

[0030] [Fig-1] The [Fig.1] is a diagram representing an electrical system for vehicle according to the invention,

[0031] [Fig.2] Fig.2 is a schematic representation of the control method according to the invention of the electrical system presented in Fig.1.

[0032] [Fig.3] The [Fig.3] is a detailed representation of the process according to the [Fig.2]. Description of the implementation methods

[0033] Vehicle

[0034] With reference to [Fig.1], the hybrid or electric vehicle includes an electric machine MEnotably capable of rotating the wheels of the vehicle in order to make it move forward, and an electrical power supply system 1.

[0035] Power supply system 1

[0036] Battery 10 + Fuel cell 20

[0037] Still with reference to [Fig.1], the power supply system 1 comprises a battery 10, at least one fuel cell 20 and a control unit 30. In order to simplify the description below, it is considered that the power supply system 1 comprises only one fuel cell 20, but it is evident that the power supply system may comprise more than one fuel cell 20.

[0038] The battery 10 and the fuel cell 20 are electrically connected to the electric machine ME via an inverter 40.

[0039] The battery 10 is configured to store and supply electrical energy to power the electric machine ME. Similarly, at least one fuel cell 20 is configured to generate electrical energy from hydrogen to power the electric machine ME.

[0040] The power supplied by the battery 10 and the power supplied by the fuel cell 20 are not necessarily of equal value.

[0041] Thus, the battery 10 and the fuel cell 20 simultaneously supply electrical energy to the electric machine ME. Therefore, it is necessary to define the power distribution between the battery 10 and the fuel cell 20.

[0042] Control unit 30

[0043] The control unit 30 is configured to control the value of the power Pio supplied by the battery 10 and the value of the power P20 supplied by the fuel cell 20 to the electric machine ME.

[0044] In addition, the control unit 30 is configured to determine in an optimized manner the value of the power Pi0 and the power P20 according to the torque request emitted by the driver of the vehicle and according to the environmental impact of the different elements of the power system 10.

[0045] The environmental impact considers, for a given element of the power system 1, the impact of the manufacturing / transport / storage of the raw materials used to manufacture said element and the manufacturing / transport / storage of the finished product. The environmental impact also considers the element's life cycle after its use in the vehicle, particularly with regard to its potential for reconditioning or recycling. The environmental impact also considers the use of each element of the power system 1 itself. In other words, the environmental impact also considers the consumption of each element of the power system 1. For example, here, the environmental impact therefore considers the hydrogen consumption of each fuel cell 20. Thus, the environmental impact considers each element over its overall life cycle, before, during, and after its use in the vehicle.

[0046] With reference to [Fig.2], the control unit 30 is configured to: a. Receiving a torque request issued by the driver, particularly when the driver presses the accelerator pedal, the torque request is converted into a request for the total power Preq to be supplied by the power supply system 1; in other words, the total power Preq supplied by the power supply system 1 corresponds to the sum of the power Pi0 and the power P20, b. Determine the environmental impact Batimpact of battery 10, the environmental impact Batimpact representing a variable function depending on the power supplied by battery 10 and the operating conditions (temperature, state of charge, state of health) of said battery 10, c. Determine the environmental impact FCimpact of the fuel cell 20, the environmental impact FCimpact representing a variable function depending on the power supplied by the fuel cell 20 and the operating conditions (temperature, humidity, health status) of said fuel cell 20, d. Determine the environmental impact H2impact of hydrogen consumption, where H2impact is a variable function depending on the power supplied by the fuel cell. e. Determine an environmental impact criterion Cconso, which also represents a consumption criterion, based on all the Environmental impacts determined previously, more precisely, the environmental impact criterion Cconso is equal to the sum of the environmental impacts H2impact, FCimpact, Batimpact determined previously, f. Determine the value of the power request Pi0 _opti to be supplied by the battery 10 and the value of the power request P2o to be supplied by the fuel cell 20 so as to minimize the environmental impact criterion Cconso determined and so as to respect the electrical power request Preq emitted by the driver.

[0047] The process below will describe more precisely how the control unit 30 is configured to determine each environmental impact Batimpact> FCimpact, H2impact.

[0048] Process

[0049] With reference to [Fig.3], the detailed method of controlling a power supply system 1 as previously presented, comprising a battery 10 and a fuel cell 20, will be described. The method being implemented by the control unit 30.

[0050] The method first includes a first PI phase of determining the total power demand Preq to be supplied by the power supply system 1.

[0051] First PI phase

[0052] This first phase of PI determination is implemented in particular when the driver requests acceleration of the vehicle, for example by pressing the accelerator pedal. A torque request Creq is then determined as a function of the vehicle speed V and the acceleration request issued by the driver.

[0053] The control unit 30 receives the torque request Creq and determines the total power request Preq from the value of the torque request Creq. The control unit 30 can also directly receive the predefined total power request Preq.

[0054] Second phase P2

[0055] The method also includes a second phase of determining P2 the operating interval of the battery 10 and the operating interval of the fuel cell 20.

[0056] More specifically, for the battery 10, the control unit 30 determines the minimum power Pi0_min that the battery 10 must provide and the maximum power Pi0_max that the battery 10 can provide, according to parameters relating to the battery 10, such as the type of battery 10, the technical limits due to the model of battery 10 used in the power supply system 1, the state of charge of the battery 10, the temperature of the battery 10 and the "health status" of the battery 10.

[0057] The health status of the battery 10 corresponds to a value that combines various phenomena of battery 10 degradation; said value is quantified in such a way usual, for a battery 10, through an increase in the internal resistance of the battery 10 and a loss of capacity.

[0058] In an analogous way, the control unit 30 determines the minimum power P2o_min that the fuel cell 20 must provide and the maximum power P2o_max that the fuel cell 20 can provide, according to parameters relating to the fuel cell 20, such as the temperature of the fuel cell 20, the air pressure in the fuel cell 20, the hydrogen pressure, the humidity or the state of health of the fuel cell.

[0059] The health status of the fuel cell 20 is quantified through a value defining a voltage loss.

[0060] This second phase P2 can be carried out simultaneously, before or after the first phase PI.

[0061] Third phase P3

[0062] Following the first phase PI and the second phase P2, the process also includes a phase for determining the environmental impact P3 of each element of the power system 1. According to the example presented here, the third phase P3 makes it possible to determine the environmental impact of the battery 10, the fuel cell 20 and the hydrogen.

[0063] Environmental impact of Battery 10

[0064] The third phase P3 includes a step El of determining the second environmental impact Batimpact of the battery 10.

[0065] The battery 10 is characterized by a predefined battery aging model mvi0 of battery 10 and by a first environmental impact model ml, specific to battery 10.

[0066] The first environmental impact model ml of battery 10 is defined according to the following parameters: a. The impact of the raw materials used in the composition of the battery control electronics 10 and the energy cost of its assembly, b. The impact of the raw materials used in the composition of the battery casing 10, c. The impact of the raw materials used in the composition of battery cells 10; for example, for an NMC Li-ion battery, this will be nickel, manganese and cobalt for the electrodes, lithium for the reactant and graphite for the separator, d. The energy cost of assembling battery 10, e. The transport of raw materials from their production sites to the battery production site 10, f. The transport of battery 10 from its production site to the car manufacturer, g. At the end of the life of battery 10, the proportion of batteries 10 that will be reused for other applications (stationary energy storage for example), the proportion of materials from battery 10 that will be recycled, h. the environmental cost of processing non-reused / non-recycled items.

[0067] In the present case, the first step El comprises the steps of: a. Determine the lifespan di0 of battery 10 from the aging model mvio of battery 10, b. Determine the environmental impact batimpact from the determined lifetime di0 and the first environmental impact model ml of battery 10.

[0068] Fuel cell

[0069] In the present case, the third phase P3 also includes a step E2 for determining the second environmental impact FCimpact of fuel cell 20, the second step E2 being carried out in parallel with the first step El.

[0070] The fuel cell 20 is characterized by a predefined fuel cell 20 aging model mv20 and by a second environmental impact model m2, specific to the fuel cell 20.

[0071] The second environmental impact model m2 of the fuel cell 20 is defined according to the following parameters: a. Raw materials for the construction of the cells (Nafion for the proton exchange membrane), graphite or aluminum for the bipolar plates, platinum for the catalyst, b. The energy cost of assembling the cells into a fuel cell 20, c. The environmental impact of all the auxiliary equipment necessary for the proper functioning of the fuel cell 20 (compressor, humidifier, H2 injector, valves, DCDC voltage converter...), d. The transport of the fuel cell 20 from its production site to the car manufacturer, e. the impact of fuel cell recycling 20 and the environmental cost of processing non-recycled components, f. and / or the possible reuse of a fuel cell 20, in particular the reuse of the still valid fuel cell 20 cells.

[0072] In the present case, the second step E2 comprises the steps of: a. Determine the lifetime d20 of the fuel cell 20 from the aging model mv2o of the fuel cell 20, b. Determine the environmental impact of the fuel cell 20 from the determined lifetime d20 and the second environmental impact model m2 of the fuel cell 20.

[0073] H2 consumption

[0074] The third phase P3 also includes a step E3 of determining the third environmental impact H2 impact of hydrogen consumption, the third step E3 being carried out in parallel with the first step E1 and the second step E2.

[0075] The fuel cell 20 is also characterized by a predefined consumption model mH2 of the quantity of hydrogen, the hydrogen also being characterized by a third environmental impact model m3 of the production of hydrogen.

[0076] The third environmental impact model m3 of hydrogen consumption is defined according to the following parameters: a. the method of hydrogen production (e.g., hydrolysis of water using green or non-green electricity, or hydrocarbon reforming...), b. the transport of hydrogen from the production site to the vehicle refueling site(s) (service stations), c. hydrogen conditioning (pressurizing the gas and storing it in tanks or other containers), d. the impact of its use, and therefore use / reuse and / or storage of waste produced during the chemical reaction during use of the fuel cell 20 (and therefore water).

[0077] The third step E3 comprises the steps of: a. Determine the predicted hydrogen consumed ph2 based on the mH2 consumption model. b. Determine the environmental impact H2impact of hydrogen from the prediction of hydrogen consumed ph2 determined and the third environmental impact model m3 of hydrogen production.

[0078] Determination of criterion P4

[0079] Following the third phase P3, the process includes a calculation step P4 of the consumption criterion Cconso as a function of all the environmental impacts determined previously. More precisely, the consumption criterion Cconso is equal to the sum of the environmental impacts Batimpact > FCimpact, H2impact determined previously.

[0080] Determine queries in power P5

[0081] Finally, after the calculation step P4, the process includes a step E5 of determining the value of the power request Pi0_opti to be supplied by the battery 10 and the value of the power request P2o_opti to be supplied by the fuel cell 20 so as to minimize the environmental impact criterion Cconso determined and so as to comply with the electrical power request Preq.

[0082] The power supply system 1 is controlled from the power request Pio_opti to be supplied by the battery 10 and the power request P2o_opti to be supplied by the fuel cell 20 determined previously.

[0083] The power distribution between the power supplied by the fuel cell 20 and the power supplied by the battery 10 to power the electric machine ME is determined by considering the entire life of each element of the power system 1, whether before integration and after integration of this element into the vehicle.

[0084] This advantageously reduces the environmental impact of using a power supply system 1 as described above, particularly for long-life vehicles (e.g., freight trucks) for which replacement of all or part of the electrical power supply system 1 is conceivable.

Claims

Demands

1. A method for controlling an electrical power supply system (1) for a motor vehicle, the vehicle comprising an electrical machine (EM), the electrical power supply system (1) comprising: a. a first electrical energy storage device (10) capable of supplying electrical energy to power the electrical machine (ME), the first storage device (10) corresponds to an electrical power supply battery (10), b. a second electrical energy storage device (20) capable of supplying electrical energy to power the electrical machine (ME), the second storage device (20) being a fuel cell (20) configured to generate electrical energy from hydrogen, the fuel cell (20) being characterized by a predefined consumption model (mH2) of the quantity of hydrogen, the hydrogen also being characterized by a third environmental impact model (m3) of hydrogen production, the third environmental impact model (m3) of hydrogen considering at least one of the following criteria: • the method of hydrogen production, • the transport of hydrogen from the production site to the vehicle refueling site(s), • hydrogen conditioning, • the use / reuse and / or storage of waste products during the chemical reaction during use of the fuel cell (20), the process being characterized in that it comprises the steps of:

2. - Determine (PI) the total demand (Preq) for electrical power to be supplied to the electrical machine (ME), - Determine (El) the environmental impact of the first storage device (10), called the "first environmental impact" (Batimpact), - Determine (E2) the environmental impact of the second storage device (20), called the "second environmental impact" (FCimpact), - determine (E3) the environmental impact (H2impact) of hydrogen consumption, referred to as the "third environmental impact", this step including the sub-steps aimed at: • Determine the predicted amount of hydrogen (ph2) consumed based on the consumption model (mH2), • Determine the environmental impact (H2impact) of hydrogen from the predicted hydrogen consumption (ph2) and the third environmental impact model (m3) of hydrogen production, - the third step E3 being carried out in parallel with the first step E1 and the second step E2, - Determine (P4) an environmental impact criterion (Cconso) based on all the environmental impacts determined (Batimpact, FCimpact H2impact), - Determine (P5) the value of the power request (Pio_opti) to be provided by the first storage device (10) and the value of the power request (P2o_opti) to be provided by the second storage device (20) so as to minimize the environmental impact criterion (Cconso) determined and so as to respect the total electrical power request (Preq) determined. Control method according to the preceding claim, characterized in that the environmental impact criterion (Cconso) sums the first environmental impact (Batimpact), the second environmental impact (FCimpact) and the third environmental impact (H2impact).

3. A method according to the preceding claim, the battery (10) being characterized by a predefined battery (10) aging model (mvi0) and by a first environmental impact model (ml) specific to the battery (10), a method in which determining (El) the first environmental impact (Batimpact) of the battery (10) corresponds to: a. Determine the lifespan (di0) of the battery (10) from the aging model (mvio) of the battery (10), b. Determine the environmental impact (Batimpact) from the determined lifetime (di0) and the first environmental impact model (ml) of the battery (10).

4. A method according to any one of claims 2 and 3, the fuel cell (20) being characterized by a predefined second aging model (mv20) of the fuel cell (20) and by a second environmental impact model (m2) specific to the fuel cell (20), a method in which determining (E2) the second environmental impact (FCimpact) of the fuel cell (20) corresponds to: a. Determine the lifetime (d20) of the fuel cell (20) from the aging model (mv20) of the fuel cell (20), b. Determine the environmental impact (FCimpact) of the fuel cell (20) from the determined lifetime (d20) and the second environmental impact model (m2) of the fuel cell (20).

5. A method according to any one of claims 3 to 5, wherein the first environmental impact model (ml) of the battery (10) considers at least one of the following criteria: a. The impact of the raw materials used in the composition of battery cells (10), b. The impact of the raw materials used in the composition of the battery control electronics (10) and the energy cost of its assembly, c. The impact of the raw materials used in the composition of the battery casing (10), d. The energy cost of battery assembly (10), e. The transport of raw materials from their production sites to the battery production site (10), f. The transport of the battery (10) from its production site to the car manufacturer, g. At the end of the battery's life (10), the proportion of the batteries (10) that will be reused for other applications, the proportion of the battery materials (10) that will be recycled, h. the environmental cost of processing non-reused and / or non-recycled items.

6. A method according to any one of claims 4 to 6, wherein the second model of the environmental impact (m2) of the fuel cell (20) considers at least one of the following criteria: a. Raw materials for the construction of the cells of said fuel cell (20), b. The energy cost of assembling the cells into a fuel cell (20), c. The environmental impact of all the auxiliary equipment necessary for the proper functioning of the fuel cell (20), d. The transport of the fuel cell (20) from its production site to the car manufacturer, e. the impact of fuel cell recycling (20) and the environmental cost of processing non-recycled components, f. and / or the possible reuse of a fuel cell (20).

7. Electrical power supply system (1) for a motor vehicle, the vehicle comprising an electrical machine (EM), the electrical system (1) comprising: a. a first electrical energy storage device (10) capable of supplying electrical energy to power the electrical machine (ME), b. a second electrical energy storage device (10) capable of supplying electrical energy to power the electrical machine (ME), c. a control unit (30), configured to control the electrical power supplied by the first storage device (10) and the electrical power supplied by the second storage device (20), and to implement the method according to any one of the preceding claims.

8. Vehicle comprising an electrical power supply system (1) according to the preceding claim.

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