Vehicle electrical power supply system

Abstract

The invention relates to an electrical power supply system (1) for an electric or hybrid vehicle, the vehicle comprising an electrical power supply bus (HV+, HV-), said system (1) comprising: a DC-DC voltage converter (50), at least two power cells (10, 20, 30) each comprising: a rectifier (r1, r2, r3), a battery (B1, B2, B3), the power supply system (1) is configured to operate in a mode in which: - the DC-DC converter (50) is disconnected from the power supply bus (HV+, HV-) and from each power cell (10, 20, 30), - only one of the power cells (10, 20, 30) is supplied with electrical energy, - all the batteries (B1, B2, B3) are connected in series, - the power supply bus (HV+, HV-) is powered from the electrical energy supplied by The battery pack (B1, B2, B3) is connected in series. See Figure 1 for abbreviations.

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 to an electrical power supply system for a hybrid or electric vehicle. Prior art

[0002] As is known, an electric or hybrid vehicle comprises an electric motor for vehicle propulsion, as well as a storage battery suitable for connection to the electric motor. An inverter is connected between the battery and the electric motor and converts the direct current voltage supplied by the battery into an alternating current voltage, in particular three-phase, in order to power each phase of the electric motor.

[0003] The vehicle also includes an internal electrical power supply network to power the vehicle's electrical equipment (for example, windshield wipers, headlights, dashboard indicator lights, etc.).

[0004] The voltage supplied by the network is for example 12 or 14 V.

[0005] The vehicle also includes an auxiliary battery capable of supplying power to the grid and a DC-DC voltage converter connected between the auxiliary battery and the main battery, in order to recharge the auxiliary battery. The configuration of the auxiliary batteries and associated converters in a vehicle depends on the type of vehicle, which requires significant adaptation efforts.

[0006] Furthermore, each battery is actually made up of a set of battery cells statically connected to each other. The charge level of each battery depends on the state of charge of each cell. However, the cells may not all have identical electrical and energy characteristics. The sizing of each battery must therefore take into account the aging phenomena and the performance of each cell, which is a constraint.

[0007] Furthermore, the sizing of the converter and inverter components is carried out so that the voltage supplied by the converter and inverter is defined over a wide voltage range. Thus, since the sizing of each of these elements is not carried out for an optimal operating voltage, this can lead, on the one hand, to losses after each conversion performed by the converter or inverter and, on the other hand, to difficulty in precisely controlling the output power of each converter and / or inverter.

[0008] There is therefore a need for a solution to alleviate, at least in part, the disadvantages described previously. Description of the invention

[0009] To this end, the invention relates to a power supply system for an electric or hybrid vehicle, the vehicle comprising a power supply bus capable of supplying electrical equipment mounted in the vehicle, said system comprising: a. a DC-DC voltage converter, b. at least two power supply cells, each comprising: i. a rectifier capable of supplying an alternating voltage from a direct voltage and vice versa, ii. a battery), electrically connected to the rectifier, capable of operating in a discharge mode, in which the battery is capable of supplying a first DC voltage and capable of operating in a charging mode in which the battery is capable of recharging from a DC voltage, iii. a switching cell comprising switches suitable for connecting the battery to the converter, c. a set of switches suitable for connecting the battery of one power cell to the battery of the adjacent power cell, in order to connect the batteries in series, d. a second set of switches capable of connecting all the batteries connected in series to the power supply bus, e. a control unit configured to control the first set of switches, the second set of switches, and each switching cell, The power system is configured to operate in a mode in which: a. The DC-DC converter is disconnected from the power bus and from each power cell, b. Only one of the power cells is supplied with electrical energy; c. The first set of switches is closed in order to connect all the batteries in series. d. The second set of switches is closed in order to supply the power bus with electrical energy from the battery pack.

[0010] Thus, the power supply system allows the power bus to be powered only from the electrical energy supplied by the series-connected batteries, and not from starting from the DC-DC converter. For example, with a first battery operating in charging mode, the other battery(ies) in the other power modules provide the additional electrical energy needed to properly power the power bus, supplementing that already supplied by the battery being charged. In other words, the amount of electrical energy supplied by the other battery(ies) depends on the state of charge, the amount of electrical energy supplied by the battery being charged, and the electrical energy required by the power bus.

[0011] Preferably, the power supply system includes a connection module capable of electrically connecting each power cell to a power supply network capable of providing an alternating voltage or to electrical equipment external to the vehicle capable of being powered from an alternating voltage: a. if the alternating voltage supplied by the power supply network, or if the voltage required to power the electrical equipment, is single-phase, the connection module is capable of connecting the single-phase voltage to at least one power cell, b. if the alternating voltage supplied by the power grid, or if the voltage required to supply the electrical equipment, is three-phase, the connection module is suitable for connecting each phase of said voltage to a power cell.

[0012] Thus, the power supply system allows each battery to be charged from a three-phase or single-phase alternating voltage.

[0013] Preferably, each power cell comprises a coil connected on one side to the rectifier and on the other side to the switching cell. Each coil controls the current by regulating the voltage across each battery terminal.

[0014] Preferably, the power supply system comprises three power supply cells. For a three-phase alternating voltage, it is practical to have one power supply cell per phase of said alternating voltage.

[0015] Advantageously, the connection module includes: a. a first connection terminal electrically connected to the first power supply cell, b. a second connection terminal, c. a third connection terminal, d. a first switch, capable of connecting the second power cell to the first connection terminal or to the second connection terminal, e. a second switch suitable for connecting the third power cell to the first connection terminal or to the third connection terminal.

[0016] Thus, if the voltage supplied to the first connection terminal is single-phase and powers the first power cell, this voltage can also power the second and third power cells. Furthermore, if the voltage supplied to the first connection terminal is three-phase, each phase is connected to a connection terminal, which is itself connected to a power cell. Therefore, a battery can be charged from either a single-phase or three-phase voltage.

[0017] Preferably, when the phase of a single-phase alternating voltage is connected to the first connection terminal, the first and second switches of the connection module are configured to: a. Connect the first connection terminal to the second power cell and the third power cell, or b. Disconnect the first connection terminal of the second power cell and the third power cell.

[0018] Thus, it is possible to power each power cell from a single-phase voltage. The single-phase voltage can therefore be connected alternately to each of the power cells, in order to balance the state of charge of all the batteries, and to avoid always charging / discharging the same battery.

[0019] The invention also relates to a motor vehicle comprising an electrical power bus capable of powering electrical equipment mounted in the vehicle and an electrical power supply system as previously described.

[0020] The invention also relates to a method for controlling an electrical system as described above, said method being implemented by the control unit and comprising the steps of: a. Disconnect the DC-DC converter from the power bus and from each power cell, b. Supply one of the power cells with electrical energy, c. Close each switch in the first set of switches to connect all the batteries in series. d. Close each switch in the second set of switches to power the power bus from the electrical energy supplied by the battery pack. Brief description of the drawings

[0021] 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:

[0022] [Fig.1] Fig.1 is a diagram representing the power supply system according to the invention.

[0023] [Fig.2] The [Fig.2] is an electronic diagram representing the first operating mode of the power supply system according to the [Fig.1].

[0024] [Fig. 3] [Fig. 3] represents the variation of the supply voltage provided by each of the power supply cells of the power system according to [Fig. 1]. Description of embodiments

[0025] Vehicle

[0026] With reference to [Fig. 1], a vehicle according to the invention will now be described. The vehicle includes, in particular, an HV power supply bus. The HV power supply bus is capable of providing electrical power to various electrical equipment on board the vehicle. More specifically, the power supply bus includes a positive terminal HV+ and a negative terminal HV-.

[0027] The vehicle also includes an electrical power supply system 1.

[0028] Power supply system

[0029] With reference to [Fig.1], the power supply system 1 comprises at least two power supply cells 10, 20, 30, a connection module 40, a DC-DC voltage converter 50 and a control unit (not shown in the figures).

[0030] The DC-DC converter 50 is intended to be electrically connected between the positive terminal HV+ and the negative terminal HV- of the power supply bus.

[0031] Preferably, the power supply system 1 comprises a first power supply cell 10, a second power supply cell 20 and a third power supply cell 30. Each power supply cell 10, 20, 30 is capable of converting an alternating voltage into a direct voltage.

[0032] Power supply cell 10, 20, 30

[0033] Each power cell 10, 20, 30, includes a rectifier rl, r2, r3, a battery Bl, B2, B3 and a switching cell Cio, C2o, C30.

[0034] More specifically, the rectifier rl, r2, r3 of each power supply cell 10, 20, 30 is said to be bidirectional. In other words, each rectifier rl, r2, r3 is capable of supplying an alternating voltage from a direct voltage and vice versa.

[0035] Each rectifier rl, r2, r3 comprises two input terminals and two output terminals.

[0036] More specifically, in the present case, each rectifier rl, r2, r3 comprises a first switch connected between a high point PH and a first midpoint PMI, a second switch connected between the first midpoint PMI and a low point PB, a third switch connected between the high point PH and a second midpoint PM2, and a fourth switch connected between the second midpoint PM2 and the low point PB. The two input terminals of each rectifier rl, r2, r3 designate the first midpoint PMI and the second midpoint PM2. The two output terminals designate the high point PH and the low point PB.

[0037] The battery Bl, B2, B3 of each power cell 10, 20, 30 is capable of operating in a discharge mode, in which the battery Bl, B2, B3 is capable of supplying a DC voltage. The value of the DC voltage supplied by each battery Bl, B2, B3 is also controllable. Furthermore, the battery Bl, B2, B3 of each power cell 10, 20, 30 is also capable of operating in a charge mode in which the battery Bl, B2, B3 is recharged.

[0038] Furthermore, the battery Bl, B2, B3 of each power supply cell 10, 20, 30 is connected to the corresponding rectifier rl, r2, r3. More precisely, each battery Bl, B2, B3 is connected between the two output terminals of the corresponding rectifier rl, r2, r3.

[0039] The switching cell Cio, C2o, C30 of each power cell 10, 20, 30 is suitable for connecting the battery Bl, B2, B3 to the DC-DC converter 50. In other words, the switching cell Cio, C2o, C30 is connected on one side to the battery Bl, B2, B3 and on the other side to the DC-DC converter 50.

[0040] Each switching cell Cio, C20, C30 includes a first switch 110, 120, 130 and a second switch 110', 120', 130'.

[0041] The first switch 110,120,130 of each power cell 10, 20, 30 allows a first terminal of the battery Bl, B2, B3 to be connected to a terminal of the DC-DC converter 50.

[0042] The second switch 110', 120', 130' of each power cell 10, 20, 30 allows a second terminal of the battery B1, B2, B3 to be connected to a second terminal of the DC-DC converter 50.

[0043] coils

[0044] In addition, each power supply cell 10, 20, 30 includes a coil L1, L2, L3, connected to the input of the rectifier rl, r2, r3, in other words, a coil is connected on one side to the rectifier rl, r2, r3 and intended to be connected on the other side to an alternating voltage.

[0045] The power supply system 1 also includes a first set of switches 13 and a second set of switches 14.

[0046] First set of switches 13

[0047] The first set of switches 13 is suitable for connecting the battery B1, B2, B3 of a power cell 10, 20, 30 to the battery Bl, B2, B3 of the neighboring power cell 10, 20, 30, in order to connect the batteries Bl, B2, B3 in series.

[0048] For this purpose, the first set of switches 13 comprises: a. a switch connected on one side to battery Bl of the first power cell Cio and on the other side to battery B2 of the second power cell C20, b. a switch connected on one side to battery B2 of the second cell C2o power supply, on the other hand to battery B3 of the third power supply cell C30.

[0049] Thus, the batteries Bl, B2, B3 can be connected in series, it is then said that the batteries form a power branch.

[0050] Second set of switches 14

[0051] The second set of switches 14 allows the battery B1 of the first power cell Cio to be connected to the HV power bus, in particular to connect the branch of batteries Bl, B2, B3 connected in series to the HV power bus.

[0052] Connection module 40

[0053] The connection module 40 is suitable for being connected on the one hand to an electrical power supply network or to electrical equipment external to the vehicle and on the other hand to at least one of the power supply cells 10, 20, 30.

[0054] When the connection module 40 is connected to a power supply network, then the power supply network allows at least one battery Bl, B2, B3 to be recharged from at least one power cell 10, 20, 30 connected to said connection module 40.

[0055] When the connection module 40 is connected to an electrical equipment, then at least one battery Bl, B2, B3 of the at least one power cell 10, 20, 30 connected to said connection module 40 allows to supply energy to said equipment.

[0056] More specifically, if the alternating voltage supplied by the power supply network, or if the voltage required to supply the electrical equipment, is single-phase, then the connection module 40 is suitable for connecting the single-phase voltage to at least one power supply cell 10, 20, 30. If the alternating voltage supplied by the power supply network, or if the voltage required to supply the electrical equipment, is three-phase, then the connection module 40 is suitable for connecting each phase of said alternating voltage to a power supply cell 10, 20, 30 of its own.

[0057] More specifically, the connection module 40 includes a first connection terminal 41, a second connection terminal 42 and a third connection terminal 43.

[0058] When the alternating voltage supplied by the power grid, or when the voltage required to power the electrical equipment, is three-phase, then each phase of said voltage is connected to its own connection terminal 41, 42, 43. Conversely, when the alternating voltage supplied by the power grid, or when the voltage required to power the electrical equipment, is single-phase, the phase of said voltage is connected to the first connection terminal 4L

[0059] Furthermore, the first connection terminal 41 is connected to the first switching cell 10, more precisely to an input terminal of the rectifier rl of the first switching cell 10.

[0060] The connection module 40 also includes: a. a first switch 15, configured to: i. according to a first position: connect the first connection terminal 41 to the second power supply cell 20, and more specifically to an input terminal of the rectifier r2 of the second power supply cell 20, ii. according to a second position: connect the second connection terminal 42 to the second power supply cell 20, and more specifically to an input terminal of the rectifier r2 of the second power supply cell 20, b. a second switch 16 configured for: i. according to a first position: connect the first connection terminal 41 to the third power supply cell 30, and more specifically to an input terminal of the rectifier r3 of the third power supply cell 30, ii. according to a second position: in particular when the alternating voltage supplied by the power supply network, or when the voltage required to supply the electrical equipment, is three-phase, connect the third connection terminal 43 to the third power supply cell 30, and more specifically to an input terminal of the rectifier r3 of the third power supply cell 30.

[0061] In addition, the connection module 40 is also connected to the neutral line of the alternating voltage and the connection module 40 is configured to connect the neutral line to the second input terminal of each rectifier rl, r2, r3.

[0062] Furthermore, each power supply cell 10, 20, 30 may also include an EMC filter, for "electromagnetic compatibility", connected between each rectifier rl, r2, r3 and the connection module 40.

[0063] The control unit (not shown in the figures) is configured to control the opening and closing of switches 15, 16 of the connection module 40, the first set of switches 13, the second set of switches 14, and each switch of each switching cell C10, C20, C30 and of each rectifier 11, r2, r3. The control unit is also capable of controlling the voltage supplied and generated by each battery B1, B2, B3 in order, for example, to regulate the current in the inductors L1, L2, L3 or to regulate the voltage supplied to the DC-DC converter 50.

[0064] operating modes

[0065] With reference to [Fig.2], one of the modes of operation will now be described. The operation of the power supply system 1 is as previously described. Recall that the control unit is responsible for controlling each of the switches in order to implement the operating mode described below.

[0066] The control unit also controls the disconnection between the DC-DC converter 50 and the HV power supply bus.

[0067] The control unit also commands the closing of each switch in the first set of switches 13 in order to connect the battery sets Bl, B2, B3 in series. Similarly, the control unit commands the closing of each switch in the second set of switches 14 in order to supply the power bus with electrical energy from the battery set Bl, B2, B3.

[0068] In addition, the switches of each switching cell Cio, C2o, C30> are open, so as to disconnect the set of power supply cells 10, 20, 30 from the DC-DC converter 50.

[0069] Finally, the control unit commands the connection module 40 so that only one and only one power cell 10, 20, 30 of the power system 1 is connected to a voltage (single-phase or three-phase) via the connection module 40. For example here, only the first power cell 10 is supplied with electrical energy, and only the first battery B1 is in charge mode or discharge mode.

[0070] Thus, the operating mode described above allows the power supply bus to be powered only from the series-connected batteries Bl, B2, B3, and no longer via the DC-DC converter 50.

[0071] For example, with reference to [Fig. 3], the first power supply cell 10 is connected to the connection module 40 and provides a rectified voltage V10, which may, for example, have a sinusoidal portion. The second power supply cell 20 and the third power supply cell 30 each provide a supply voltage V20 / 30 in order, on the one hand, to compensate for the sinusoidal portion of the rectified voltage V10 supplied by the first power supply cell 10 and, on the other hand, to obtain a DC voltage value VHv necessary for supplying the power bus. In other words, the second power supply cell 20 and the third power supply cell 30 compensate for variations in the voltage supplied by the first power supply cell 10 so that the voltage supplied by the entire set of power supply cells 10, 20, and 30 is DC and allows the power bus to be supplied.

Claims

Demands

1. Electrical power supply system (1) intended to be installed in an electric or hybrid vehicle, the vehicle comprising an electrical power supply bus (HV+, HV-) capable of supplying electrical equipment installed in the vehicle, said system (1) comprising: a. a DC-DC voltage converter (50), b. at least two power supply cells (10, 20, 30) each comprising: i. a rectifier (rl, r2, r3) capable of supplying an alternating voltage from a direct voltage and vice versa, ii. a battery (B1, B2, B3), electrically connected to the rectifier (r1, r2, r3), capable of operating in a discharge mode, in which the battery (B1, B2, B3) is capable of supplying a first DC voltage and capable of operating in a charging mode in which the battery (B1, B2, B3) is capable of recharging from a DC voltage, iii. a switching cell (Cio, C2o, C30) comprising switches (110,110', 120,120', 130,130') suitable for connecting the battery (Bl, B2, B3) to the converter (50), c. a first set of switches (13) suitable for connecting the battery (B1, B2, B3) of a power cell (10, 20, 30) to the battery (B1, B2, B3) of the adjacent power cell (10, 20, 30), in order to connect the batteries (B1, B2, B3) in series, d. a second set of switches (14) suitable for connecting all the batteries (B1, B2, B3) connected in series to the electrical power supply bus (HV+, HV-), e. a control unit configured to control the first set of switches (13), the second set of switches (14) and each switching cell (Cio, C2o, C30), f. a connection module (40) capable of electrically connecting each power cell (10, 20, 30) to an electrical power supply network capable of providing alternating voltage or to electrical equipment external to the vehicle capable of being powered from an alternating voltage, the power supply system (1) is configured to operate in a mode of operation in which: - the DC-DC converter (50) is disconnected from the power bus (HV+, HV-) and from each power cell (10, 20, 30), - only one of the power cells (10, 20, 30) is supplied with electrical energy, - the first set of switches (13) is closed in order to connect all the batteries (B1, B2, B3) in series, - the second set of switches (14) is closed in order to supply the power bus (HV+, HV-) from the electrical energy supplied by the set of batteries (B1, B2, B3).

2. Power supply system (1) according to the preceding claim in which the connection module (40) is configured to operate as follows: a. if the AC voltage supplied by the power supply network, or if the voltage required to supply the electrical equipment, is single-phase, the connection module (40) is capable of connecting the single-phase voltage to at least one power cell (10, 20, 30), b. if the AC voltage supplied by the power supply network, or if the voltage required to supply the electrical equipment, is three-phase, the connection module (40) is capable of connecting each phase of said voltage to a power cell (10, 20, 30).

3. Power supply system (1) according to any one of the preceding claims wherein each power supply cell (10, 20, 30) comprises a coil (L1, L2, L3) connected to the rectifier (rl, r2, r3) and intended to be connected to an alternating voltage.

4. Power supply system (1) according to any one of the preceding claims, comprising three power supply cells (10, 20, 30).

5. Power supply system (1) according to claims 2 to 4, wherein the connection module (40) comprises:

6.

7.

8. a. a first connection terminal (41) electrically connected to the first power supply cell (10), b. a second connection terminal (42), c. a third connection terminal (43), d. a first switch (15), suitable for connecting the second power supply cell (20) to the first connection terminal (41) or to the second connection terminal (42), e. a second switch (16) suitable for connecting the third power supply cell (30) to the first connection terminal (41) or to the third connection terminal (43). Power supply system (1) according to the preceding claim, wherein, when the phase of a single-phase alternating voltage is connected to the first connection terminal (41), the first switch (15) and the second switch (16) of the connection module (40) are configured to: a. Connect the first connection terminal (41) to the second power cell (20) and to the third power cell (30), or b. Disconnect the first connection terminal (41) from the second power cell (20) and the third power cell (30). Motor vehicle comprising an electrical power bus (HV+, HV-) capable of powering electrical equipment mounted in the vehicle and an electrical power supply system (1) according to any one of the preceding claims. A method for controlling a power supply system (1) according to any one of the preceding claims, said method being implemented by the control unit and comprising the steps of: a. Disconnect the DC-DC converter (50) from the power bus (HV+, HV-) and from each power cell (10, 20, 30), b. Supply one of the power cells (10, 20, 30) with electrical energy, c. Close each switch in the first set switch (13) to connect all the batteries (B1, B2, B3) in series, d. Close each switch in the second set of switches (14) to supply the power bus (HV+, HV-) with electrical energy supplied by the battery set (B1, B2, B3).

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