Vehicle electrical power supply system

Abstract

The invention relates to a method for managing the use of an on-board battery charger for a motor vehicle. The vehicle comprises a supply battery. The on-board charger is connected to the battery and is intended to be connected to an external power supply network capable of providing three-phase voltage. Each phase of the network is characterized by a maximum overall power consumption. The on-board charger comprises a plurality of conversion modules (E1, E2, E3). Each conversion module (E1, E2, E3) comprises a plurality of independent power conversion elementary units (A, B, C, D, E, F, G, H, I). Each elementary unit (A, B, C, D, E, F, G, H, I) is characterized by a maximum power consumption threshold. Each conversion module (E1, E2, E3) is intended to be connected to one phase of the external power supply network. Figure 1 illustrates this in the abstract.

Description

Title of the invention: Electrical power supply system for a vehicle Technical field

[0001] The invention relates to the field of hybrid or electric vehicles, and more specifically to a method for managing the use of the different charging modules of an on-board charger for a motor vehicle. Prior art

[0002] As is known, an electric or hybrid vehicle comprises an on-board charger for recharging the battery(ies) of the vehicle. More specifically, the on-board charger comprises a power factor corrector, more commonly known as PFC, for "Power Factor Corrector" in English, for regulating the output voltage of the on-board charger.

[0003] The PFC power factor corrector comprises three power conversion modules. In addition, each conversion module comprises several elementary power conversion units, independent of each other. Each elementary unit is more commonly called a “bank” by those skilled in the art.

[0004] Each conversion module is intended to be connected to a phase of a power supply network external to the vehicle. For a given conversion module, the number of activated elementary power conversion units depends on the power required by the battery so that the latter can recharge. In this case, the order of activation of the elementary units is predefined. This has the consequence that the elementary units of each conversion module of the PFC power factor corrector are not used uniformly. In other words, by extension, each elementary unit ages differently and therefore all of the elementary conversion units do not wear out uniformly either.

[0005] There is therefore a need for a solution that can overcome, at least in part, the drawbacks described above. Statement of the invention

[0006] To this end, the invention relates to a method for managing the use of an on-board charger for a motor vehicle battery, the vehicle comprising a power supply battery, the on-board charger being connected on the one hand to said battery, and being intended to be connected on the other hand to an electrical supply network external to the vehicle capable of supplying a three-phase voltage, each phase of the network is characterized by a maximum overall usage power, the on-board charger comprises a plurality of conversion modules, each conversion module comprises a plurality of elementary power conversion units independent of each other, each elementary unit being characterized by a maximum usage power threshold, each conversion module being intended to be connected to an external power supply network phase, the method comprising the steps of: a. determine the electrical energy having passed through each elementary unit since the start of use of said elementary unit, b. determine the order of activation of the elementary units by ordering the different elementary units from the one having been traversed by the least electrical energy to the one having been traversed by the most electrical energy, c. determine the power value to be supplied by each conversion module, based on the voltage that each phase of the electrical supply network can supply and the maximum overall power usage of each phase of the network, d. assign to each elementary unit of the list determined previously a maximum power value according to: i. of the determined activation order, ii. the maximum power threshold for use of each elementary unit, iii. the maximum overall power of use of each phase of the network, e. determine the total instantaneous power that the on-board charger must provide, f. activate elementary units according to: i. the power allocated to each elementary unit, ii. the total instantaneous power that the on-board charger must provide.

[0007] The method thus presented makes it possible to adapt the power used by the on-board charger according to the power that each phase of the network can provide. In addition, this method also makes it possible to distribute the aging of the elementary units, by using first the least used elementary units, because they are the elementary units traversed by the least power. Thus, it is not always the same elementary units that are used.

[0008] Preferably, during the allocation step, the power allocated to each elementary unit is defined as follows: for each elementary unit and following the order of activation of the elementary units, the power allocated is:

[0009] a) equal to the difference between the maximum overall power of use of the phase connected to said conversion module and the value of the sum of the powers attributed to the other elementary units of the same conversion module,

[0010] b) and defined so as to be less than or equal to the maximum usage power threshold.

[0011] In this way, the power allocated to each elementary unit depends on the limits and thresholds of use of each elementary unit and depends on the power that each phase of the network can provide.

[0012] More preferably, during the activation step, the choice of the elementary units to be activated is made by selecting, following the activation order, the minimum of elementary units whose sum of the maximum powers allocated is greater than or equal to the instantaneous power.

[0013] Thus, the elementary units are not systematically activated, but they are activated only when necessary to provide the necessary instantaneous power.

[0014] The invention also relates to a power supply system for a motor vehicle comprising: a. a power supply battery, b. an on-board charger being connected on the one hand to said battery, and being intended to be connected on the other hand to an electrical supply network external to the vehicle capable of supplying a three-phase voltage, each phase of the network is characterized by a maximum overall usage power, the on-board charger comprises a plurality of conversion modules, each conversion module comprises a plurality of elementary power conversion units independent of each other, each elementary unit being characterized by a maximum usage power threshold, each conversion module being intended to be connected to a phase of the external supply network, c. a control unit capable of implementing the method as presented previously.

[0015] The invention finally relates to a motor vehicle comprising a power supply system as presented previously. Brief description of the drawings

[0016] 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:

[0017] [Fig-1] [Fig.l] is a schematic representation of the on-board charger according to the invention.

[0018] [Fig.2] [Fig.2] is a schematic representation of a method for managing the use of an on-board charger according to [Fig.l], and more precisely a method for managing the activation of the elementary units of a power factor converter of an on-board charger according to [Fig.l].

[0019] [Fig.3] [Fig.3] represents in a table the order of activation of the elementary units A, B, C, D, E, F, G, H, I, obtained after implementation of the determination step S2 of the method according to [Fig.2].

[0020] [Fig.4] [Fig.4] represents in a table the power supplied by each phase of an electrical supply network to each conversion module of the power factor corrector of the on-board charger according to [Fig.l].

[0021] [Fig.5] [Fig.5] represents in a table the maximum power allocated to each elementary unit A, B, C, D, E, F, G, H, I of the power factor corrector of the on-board charger according to [Fig.l]. Description of the embodiments

[0022] Typically, a vehicle comprises an electric battery, configured to power various electrical equipment of the vehicle. In order to recharge said electric battery, the vehicle comprises an on-board charger.

[0023] More specifically, the on-board charger includes a power factor corrector, more commonly called “PFC” for “Power Factor Corrector” in English, and a control unit.

[0024] With reference to [Fig.l], the power factor corrector 1 of the on-board charger is intended to be electrically connected to a charging terminal B10 external to the vehicle. The charging terminal B10 is connected to an electrical power supply network external to the vehicle. The external power supply network corresponds to a three-phase voltage, each phase of said voltage does not necessarily provide the same voltage level. In other words, the power provided by each of the phases is limited by an overall maximum power Pmax of use. For example, the first phase is capable of providing 8 kW, the second phase is not capable of providing any power (0 kW) and the third phase is capable of providing 6 kW.

[0025] The power factor corrector 1 makes it possible to convert the voltage supplied by said network of the charging station B10 in order to recharge the vehicle battery.

[0026] For clarification, the type of charging station presented here may be known to those skilled in the art by the name “EVSE” for “Electrical Vehicle Supply Equipment” in English.

[0027] For this purpose, the power factor corrector 1 comprises several power conversion modules, in other words, several stages. According to the example presented in [Fig.l], the corrector comprises three power conversion modules E1, E2, E3. Each power conversion module El, E2, E3 is intended to be connected to one phase of the voltage supplied by the power supply network.

[0028] Each power conversion module E1, E2, E3 comprises a plurality of elementary power conversion units A, B, C, D, E, F, G, H, I, commonly called "bank" by those skilled in the art, and independent of each other. According to the example presented here, each conversion module E1, E2, E3 comprises three elementary units. The first conversion module E1, intended to be connected to a first phase of the external electrical power supply network, comprises three elementary units A, B, C, the second stage E2, intended to be connected to a second phase of the external electrical power supply network, comprises three load modules D, E, F and the third stage E3 intended to be connected to a third phase of the external electrical power supply network comprises three load modules G, H, I.

[0029] Each elementary unit A, B, C, D, E, F, G, H, I is characterized by a maximum threshold Smax of usage power. Usually, the maximum threshold Smax is identical for all the elementary units A, B, C, D, E, F, G, H, I. For example, the maximum threshold Smax is equal to 3.6 kW for each elementary unit A, B, C, D, E, F, G, H, I.

[0030] The control unit, represented by the reference 40, is connected to each elementary unit A, B, C, D, E, F, G, H, I and is capable of controlling each elementary unit A, B, C, D, E, F, G, H, I. More precisely, the control unit is configured to define which elementary units A, B, C, D, E, F, G, H, I of each conversion module E1, E2, E3 are to be activated, and the power supplied by each of the elementary units A, B, C, D, E, F, G, H, I activated.

[0031] The control unit 40 is also configured to obtain, in other words recover, the value of the overall maximum power Pmax of use of each phase of the charging terminal B10.

[0032] More specifically, the control unit 40 is configured to: a. determine, for each elementary unit A, B, C, D, E, F, G, H, I, the electrical energy having passed through said elementary unit A, B, C, D, E, F, G, H, I, during the lifetime of said elementary unit A, B, C, D, E, F, G, H, I, b. determine the order of activation of the elementary units A, B, C, D, E, F, G, H, I by ordering the different elementary units from that having passed through the least electrical energy to that having passed through the most electrical energy, each elementary unit A, B, C, D, E, F, G, H, I, is therefore associated with a rank, c. determine the power value to be supplied by each conversion module El, E2, E3, depending on the voltage that each phase of the network can supply power supply and the overall maximum power Pmax of use of each phase of the voltage supplied by the charging station B10, d. assign to each elementary unit A, B, C, D, E, F, G, H, I, from the list determined previously a power value to be supplied according to: i. the activation order determined, ii. the maximum threshold Smax of power use of each elementary unit A, B, C, D, E, F, G, H, I, iii. the power value to be supplied by each conversion module El, E2, E3.

[0033] Depending on the power allocated to each elementary unit A, B, C, D, E, F, G, H, I and the instantaneous consumption, in other words the power consumed by the vehicle battery, the control unit 40 is configured to control the activation or not of the elementary units A, B, C, D, E, F, G, H, I. This will be explained in more detail in the description of the method below.

[0034] Method

[0035] With reference to Figures 2 to 5, the method for managing the use of an on-board charger, as described previously, will now be presented in detail. The method, according to [Fig. 2], is particularly described in the case where a charging terminal B10 is connected to the power factor corrector. The method is implemented by the control unit 40 as described previously.

[0036] For this, each phase of the charging terminal B10 is previously connected to a conversion module El, E2, E3, during a prior step S0.

[0037] The method firstly comprises a step of determining the electrical energy SI having passed through each elementary unit A, B, C, D, E, F, G, H, I during its life.

[0038] For this, a voltage and current measurement is carried out, in order to determine the power in KiloJoule for each elementary unit A, B, C, D, E, F, G, H, I. All of the measurements can be received or directly measured by the control unit 40.

[0039] The method then comprises a step of determining the activation order S2 of the elementary units A, B, C, D, E, F, G, H, I by ordering the different elementary units A, B, C, D, E, F, G, H, I from the one having been traversed by the least electrical energy (rank 1) to the one having been traversed by the most electrical energy (rank 9). With reference to [Fig. 3], the order, in other words the rank, of activation associated with each elementary unit A, B, C, D, E, F, G, H, I, obtained following the determination step S2, is represented in a table. This step therefore makes it possible to create an activation list of the elementary units A, B, C, D, E, F, G, H, I, as a function of the energy traveled by each elementary unit A, B, C, D, E, F, G, H, I.

[0040] The method also comprises a step S3 of determining the power value to be supplied by each conversion module E1, E2, E3, according to the maximum overall power Pmax of use that each phase of the electrical supply network can supply. Indeed, in the present case, each phase of the charging station B10 does not supply the same power. Thus, with reference to [Fig.4], it can for example be determined that the first conversion module E1 obtains from the first phase of the charging station B10 a maximum of 8 kW, the second conversion module E2 does not obtain any power from the second phase of the charging station B10 and the third conversion module E3 obtains from the third phase of the charging station B10 a maximum of 6 kW.

[0041] The method then comprises a step S4 of allocating to each conversion unit A, B, C, D, E, F, G, H, I of the previously determined list a maximum power value as a function of: a. the order of activation in the list, b. of the maximum threshold Smax of power use of each elementary unit A, B, C, D, E, F, G, H, I, c. the value of the power supplied by each phase to the conversion module El, E2, E3 specific to it, (in other words the overall maximum powers Pmax of use of each phase of the voltage supplied by the charging station B10).

[0042] First, the allocation step S4 comprises an initialization step, during which the set of allocated power values ​​is set to 0 kW.

[0043] Then, the power allocated to each elementary unit A, B, C, D, E, F, G, H, I is defined as follows: for each elementary unit A, B, C, D, E, F, G, H, I and according to the determined order of activation of the elementary units A, B, C, D, E, F, G, H, I, the maximum power allocated is: a. equal to the difference between the overall maximum power Pmax of use of the phase connected to said conversion module El, E2, E3 and the value of the sum of the powers attributed to the other elementary units A, B, C, D, E, F, G, H, I, of the same conversion module El, E2, E3, b. and defined to be less than or equal to the maximum threshold Smax of usage power.

[0044] With reference to [Fig.5], the maximum power allocated to each elementary unit A, B, C, D, E, F, G, H, I is shown.

[0045] In particular here, since no power is supplied by the second phase of the power supply network to the second conversion module E2, the power allocated to each elementary unit D, E, F, of the second conversion module E2 remains at the power value assigned during the preliminary SO initialization step, in other words: at 0 kW.

[0046] Then, the elementary unit H is considered, which is the first in the activation list. The maximum power thus allocated to said elementary unit H is equal to the maximum threshold Smax, and therefore to 3.6 kW in the example presented here.

[0047] Then, the calculated maximum allocated power corresponds to that of the elementary unit C, which is in the third activation rank (the maximum power allocated to the elementary unit F being in the second activation rank has already been defined at 0 kW). The power allocated to the elementary unit C is equal to the maximum threshold Smax, and therefore to 3.6 kW in the example presented here.

[0048] Subsequently, the maximum allocation power of the elementary unit I (defined at activation rank 4) is calculated by performing the following calculation: 6 kW - 3.6 - 0 = 2.4 kW.

[0049] Then, the maximum allocation power of the elementary unit G, defined at activation rank 7, is calculated (the load modules E and D being respectively at activation rank 5 and 6, but their allocated power has already been defined at 0 kW), by performing the following calculation: 6 kW - 3.6 - 2.4 kW = 0 kW. In other words, the elementary units H and I already provide the maximum power available for the third conversion module E3.

[0050] Then the maximum power allocated to the elementary unit B (defined at activation rank 8) is determined by performing the following calculation: 8 kW - 3.6 kW - 0 kW = 4.4 kW. However, the maximum power allocated must be less than or equal to the maximum threshold Smax, and therefore less than or equal to 3.6 kW. Therefore the maximum power allocated to the elementary unit B is defined at 3.6 kW.

[0051] Finally, the maximum power allocated for elementary unit A (at activation rank 9) is determined, for which the maximum power allocated is calculated as follows: 8 kW - 3.6 - 3.6 = 0.8 kW.

[0052] The method then comprises a step S5 of activating the charging modules A, B, C, D, E, F, G, H, I, as a function of: a. the maximum power allocated to each elementary unit A, B, C, D, E, F, G, H, I, b. the instantaneous power, corresponding to the power consumed by the vehicle battery, in other words the power which must be supplied by the PFC power factor corrector to compensate for the battery consumption.

[0053] More precisely, during the activation step S5, only certain elementary units A, B, C, D, E, F, G, H, I are activated. The choice of the elementary units A, B, C, D, E, F, G, H, I to be activated is made by selecting, following the order activation, the minimum of elementary units A, B, C, D, E, F, G, H, I whose sum of the attributed powers is greater than or equal to the instantaneous power.

[0054] For example, if the instantaneous power is equal to 8 kW, then the elementary units A, B, C, D, E, F, G, H, I to be activated will correspond to the elementary units H, C, and I (because the sum of the maximum powers attributed to these elementary units is equal to 9.6 kW).

[0055] For example, if the instantaneous power is equal to 10 kW, then activating the elementary units H, C and I will not be enough. It will also be necessary to activate the next elementary unit in the activation list: corresponding here to the elementary unit B (whose maximum allocated power is 3.6 kW).

[0056] Thus, the maximum power allocation for each elementary unit A, B, C, D, E, F, G, H, I depends on the power having passed through each elementary unit A, B, C, D, E, F, G, H, I. The power having passed through each elementary unit A, B, C, D, E, F, G, H, I makes it possible to represent the “aging”, in other words the utilization rate of each elementary unit A, B, C, D, E, F, G, H, I. Thus, the activation of each elementary unit A, B, C, D, E, F, G, H, I depends on the aging of each elementary unit A, B, C, D, E, F, G, H, I.

[0057] Thus, this makes it possible to balance and standardize overall the use of all the elementary units A, B, C, D, E, F, G, H, I. In other words, it is not always the same elementary units A, B, C, D, E, F, G, H, I which are requested to be used. This makes it possible to avoid premature aging of some or all of the elementary units A, B, C, D, E, F, G, H, I.

Claims

Claims

1. Method for managing the use of an on-board charger for a motor vehicle battery, the vehicle comprising a power supply battery, the on-board charger being connected on the one hand to said battery, and being intended to be connected on the other hand to an electrical supply network external to the vehicle capable of supplying a three-phase voltage, each phase of the network is characterized by an overall maximum power (Pmax) of use, the on-board charger comprises a plurality of conversion modules (El, E2, E3), each conversion module (El, E2, E3) comprises a plurality of elementary power conversion units (A, B, C, D, E, F, G, H, I) independent of each other, each elementary unit (A, B, C, D, E, F, G, H, I) being characterized by a maximum power threshold of use (Smax), each conversion module (El, E2, E3) being intended to be connected to an external power supply network phase,the method comprising the steps of:, a. determine (SI) the electrical energy having passed through each elementary unit (A, B, C, D, E, F, G, H, I) since the start of use of said elementary unit (A, B, C, D, E, F, G, H, I), b. determine (S2) the order of activation of the elementary units (A, B, C, D, E, F, G, H, I) by ordering the different elementary units (A, B, C, D, E, F, G, H, I) from the one having been traversed by the least electrical energy to the one having been traversed by the most electrical energy, c. determine (S3) the power value to be supplied by each conversion module (El, E2, E3), as a function of the voltage that each phase of the electrical supply network can supply and the overall maximum power (Pmax) of use of each phase of the network, d. assign (S4) to each elementary unit (A, B, C, D, E, F, G, H, I) of the list determined previously a maximum power value according to: i. the determined activation order, ii. the maximum power usage threshold (Smax) of each elementary unit (A, B, C, D, E, F, G, H, I), iii. the overall maximum power (Pmax) of use

2.

3.

4. of each phase of the network, e. determine the total instantaneous power that the on-board charger must provide, f. activate (S5) the elementary units (A, B, C, D, E, F, G, H, I) according to: i. the power assigned to each elementary unit (A, B, C, D, E, F, G, H, I), ii. the total instantaneous power that the on-board charger must provide. Method according to the preceding claim, in which, during the allocation step, the power allocated to each elementary unit (A, B, C, D, E, F, G, H, I) is defined as follows: for each elementary unit (A, B, C, D, E, F, G, H, I) and following the order of activation of the elementary units (A, B, C, D, E, F, G, H, I), the power allocated is: a. equal to the difference between the overall maximum power (Pmax) of use of the phase connected to said conversion module (El, E2, E3) and the value of the sum of the powers attributed to the other elementary units (A, B, C, D, E, F, G, H, I,) of the same conversion module (El, E2, E3), b. and defined to be less than or equal to the maximum threshold (Smax) of power usage. Method according to the preceding claim, in which, during the activation step (S5), the choice of the elementary units (A, B, C, D, E, F, G, H, I) to be activated is carried out by selecting, following the activation order, the minimum of elementary units (A, B, C, D, E, F, G, H, I) whose sum of the maximum powers allocated is greater than or equal to the instantaneous power. Power supply system (1) for a motor vehicle comprising: a. a power supply battery, b. an on-board charger being connected on the one hand to said battery, and being intended to be connected on the other hand to an electrical supply network external to the vehicle capable of providing a three-phase voltage, each phase of the network is ca characterized by an overall maximum power (Pmax) of use, the on-board charger comprises a plurality of conversion modules (El, E2, E3), each conversion module (El, E2, E3) comprises a plurality of elementary power conversion units (A, B, C, D, E, F, G, H, I) independent of each other, each elementary unit (A, B, C, D, E, F, G, H, I) being characterized by a maximum threshold of power of use (Smax), each conversion module (El, E2, E3) being intended to be connected to an external power supply network phase, c. a control unit capable of implementing the method according to any one of the preceding claims.

5. Motor vehicle comprising a power supply system according to the preceding claim.