Power supply system for vehicle

Abstract

The invention relates to an electric power supply system (1) for an electric or hybrid vehicle, the vehicle comprising an electric power supply bus (HV +, HV-), the system (1) comprising: a) a DC-DC voltage converter (50) and b) at least two power supply units (10, 20, 30), each power supply unit comprising: i. A rectifier (r1, r2, r3), ii. A battery (B1, B2, B3), the electric power supply system (1) being configured to operate based on an operating mode in which the power supply bus (HV +, HV-) is connected to the rectifier (r1, r2, r3). Wherein:-the DC-DC converter (50) is disconnected from the power supply bus (HV +, HV-) and each power supply unit (10, 20, 30),-only one of the power supply units (10, 20, 30) is provided with electrical energy,-all the batteries (B1, B2, B3) are connected in series,-the power supply bus (HV +, HV-) is powered on the basis of the electrical energy provided by a group of batteries (B1, B2, B3) connected in series.

Description

Technical Field

[0001] The present invention relates to the field of hybrid or electric vehicles, and more particularly to an electrical power supply system for hybrid or electric vehicles. Background Art

[0002] As is well known, an electric or hybrid vehicle includes an electric motor for propelling the vehicle and a storage battery capable of being connected to the electric motor. An inverter is connected between the battery and the electric motor and makes it possible to convert the direct current voltage supplied by the battery into an alternating current voltage, in particular a three-phase alternating current voltage, in order to supply each phase of the electric motor.

[0003] The vehicle also includes an internal electrical power supply network which makes it possible to supply electrical power to the electrical devices of the vehicle (such as windscreen wipers, headlights, dashboard warning lights, etc.).

[0004] The voltage provided by this network is for example 12 or 14 volts.

[0005] The vehicle also includes an auxiliary battery capable of supplying power to this network and a DC-DC voltage converter connected between the auxiliary battery and this battery in order to recharge the auxiliary battery. The configuration of the auxiliary battery and the associated converter in the vehicle depends on the type of vehicle, which requires a large amount of adaptation work.

[0006] In addition, each battery actually consists of a set of battery cells connected statically to each other. The charge level of each battery depends on the state of charge of each battery cell. However, these battery cells may not all have the same electrical and energy characteristics. Therefore, the size of each battery must take into account the aging phenomenon and performance of each battery cell, which is restrictive.

[0007] In addition, the components of the converter and the inverter are sized such that the voltages provided by the converter and the inverter are both limited within a wide voltage range. Therefore, since each of these elements is not sized for the optimal operating voltage, on the one hand this may result in losses after each conversion implemented by the converter or the inverter, and on the other hand it is difficult to precisely control the output power of each converter and / or inverter.

[0008] Therefore, a solution is needed that can at least partially overcome the above-mentioned drawbacks. Summary of the Invention

[0009] To this end, the present invention relates to an electrical power supply system for an electric or hybrid vehicle, the vehicle including an electrical power supply bus capable of supplying power to electrical devices installed in the vehicle, the system comprising:

[0010] a) a DC-DC voltage converter,

[0011] b) At least two power supply units, each power supply unit comprising:

[0012] i) A rectifier capable of providing an alternating voltage based on a direct current voltage and vice versa,

[0013] ii) A battery electrically connected to the rectifier, the battery being capable of operating in a discharge mode in which the battery can provide a first direct current voltage and capable of operating in a charging mode in which the battery can be recharged based on a direct current voltage,

[0014] iii) A switch unit including a switch capable of connecting the battery to the converter,

[0015] c) A set of switches capable of connecting the batteries of the power supply units to the batteries of adjacent power supply units so as to connect the batteries in series,

[0016] d) A second set of switches capable of connecting the series-connected set of batteries to the power supply bus,

[0017] e) A control unit configured to control the first set of switches, the second set of switches and each switch unit,

[0018] The power supply system is configured to operate in an operating mode in which:

[0019] a) The DC-DC converter is disconnected from the power supply bus and each power supply unit,

[0020] b) Only one of the power supply units is supplied with electrical energy,

[0021] c) The first set of switches is closed so as to connect the set of batteries in series,

[0022] d) The second set of switches is closed so as to supply electrical energy to the power supply bus based on the electrical energy provided by the set of batteries.

[0023] Thus, the power supply system enables the power supply bus to be supplied with electrical energy based only on the electrical energy provided by the series-connected batteries (rather than based on the DC-DC converter). For example, in the case where the first battery is operating in the charging mode, one or more other batteries of other power supply modules allow additional electrical energy to be provided to the electrical energy already provided by the battery being charged, and this electrical energy is required to correctly supply the power supply bus. In other words, one or more other batteries provide a certain amount of electrical energy that depends on the state of charge and the amount of electrical energy provided by the battery being charged, as well as the electrical energy required by the power supply bus.

[0024] More preferably, the power supply system includes a connection module that can electrically connect each power supply unit to a power supply network capable of providing an AC voltage, or to an electrical device located outside the vehicle and capable of being powered based on the AC voltage:

[0025] a) If the AC voltage provided by the power supply network or if the voltage required to power the electrical device is single-phase, the connection module can connect the single-phase voltage to at least one power supply unit,

[0026] b) If the AC voltage provided by the power supply network or if the voltage required to power the electrical device is three-phase, the connection module can connect each phase of the voltage to the power supply unit.

[0027] Therefore, the power supply system allows each battery to be charged based on a three-phase or single-phase AC voltage.

[0028] More preferably, each power supply unit includes a coil that is connected to a rectifier on one hand and to a switching unit on the other hand. Each coil enables the control of the current by adjusting the voltage across each battery.

[0029] More preferably, the power supply system includes three power supply units. For a three-phase AC voltage, it is practical that each phase of the AC voltage has a power supply unit.

[0030] Advantageously, the connection module includes:

[0031] a. A first connection terminal electrically connected to the first power supply unit,

[0032] b. A second connection terminal,

[0033] c. A third connection terminal,

[0034] d. A first switch capable of connecting the second power supply unit to the first connection terminal or the second connection terminal,

[0035] e. A second switch capable of connecting the third power supply unit to the first connection terminal or the third connection terminal.

[0036] Therefore, if the voltage provided at the first connection terminal is single-phase and powers the first power supply unit, the same voltage can also power the second and third power supply units. Additionally, if the voltage provided at the first connection terminal is three-phase: each phase is connected to a connection terminal that is itself connected to a power supply unit. Thus, the battery is charged based on a single-phase or three-phase voltage.

[0037] More preferably, when the phase of the single-phase AC voltage is connected to the first connection terminal, the first switch and the second switch of the connection module are configured such that:

[0038] a) Connect the first connection terminal to the second power supply unit and the third power supply unit, or

[0039] b) Disconnect the first connection terminal from the second power supply unit and the third power supply unit.

[0040] Therefore, power can be supplied to each power supply unit based on a single-phase voltage. Thus, the single-phase voltage can be alternately connected to each power supply unit in order to balance the charge states of all the batteries and not always charge / discharge the same battery.

[0041] The invention also relates to a motor vehicle comprising a power supply bus capable of supplying power to electrical equipment installed in the vehicle, and a power supply system as described above.

[0042] The invention also relates to a method for controlling an electrical system as described above, the method being implemented by a control unit and comprising the following steps:

[0043] a) Disconnect the DC-DC converter from the power supply bus and each power supply unit,

[0044] b) Supply electrical energy to one of the power supply units,

[0045] c) Close each switch in the first group of switches so as to connect the battery groups in series,

[0046] d) Close each switch in the second group of switches so as to supply power to the power supply bus based on the electrical energy provided by the battery groups. Description of the Drawings

[0047] Other features and advantages of the invention will become more apparent after reading the following description. This description is purely illustrative and should be read with reference to the drawings, in which:

[0048] Figure 1 is a schematic diagram of a power supply system according to the invention.

[0049] Figure 2 is for showing Figure 1 a circuit diagram of the first operating mode of the power supply system according to

[0050] Figure 3 shows Figure 1 the variation of the supply voltage provided by each power supply unit of the power supply system according to Detailed Description

[0051] Vehicle

[0052] Reference will now be made to Figure 1Describe a vehicle according to the present invention. In particular, the vehicle includes a power supply bus HV. The power supply bus HV is capable of supplying electrical energy to various electrical devices installed in the vehicle. Even more specifically, the power supply bus includes a positive terminal HV+ and a negative terminal HV-.

[0053] The vehicle further includes a power supply system 1.

[0054] Power supply system

[0055] Reference Figure 1 , the power supply system 1 includes at least two power supply units 10, 20, 30, a connection module 40, a DC-DC voltage converter 50, and a control unit (not shown in the figure).

[0056] The DC-DC converter 50 is designed to be electrically connected between the positive terminal HV+ and the negative terminal HV- of the power supply bus.

[0057] Preferably, the power supply system 1 includes a first power supply unit 10, a second power supply unit 20, and a third power supply unit 30. Each power supply unit 10, 20, 30 is capable of converting an AC voltage into a DC voltage.

[0058] Power supply units 10, 20, 30

[0059] Each power supply unit 10, 20, 30 includes: rectifiers r1, r2, r3; batteries B1, B2, B3; and a switch unit C 10 , C 20 , C 30 .

[0060] More specifically, the rectifiers r1, r2, r3 of each power supply unit 10, 20, 30 are bidirectional. In other words, each rectifier r1, r2, r3 is capable of providing an AC voltage based on a DC voltage and vice versa.

[0061] Each rectifier r1, r2, r3 includes two input terminals and two output terminals.

[0062] More specifically, in the present case, each rectifier r1, r2, r3 includes a first switch connected between a high point PH and a first midpoint PM1, a second switch connected between the first midpoint PM1 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 r1, r2, r3 specify the first midpoint PM1 and the second midpoint PM2. The two output terminals specify the high point PH and the low point PB.

[0063] The batteries B1, B2, B3 of each power supply unit 10, 20, 30 can operate in a discharge mode, in which the batteries B1, B2, B3 can provide a DC voltage. In addition, the value of the DC voltage provided by each of the batteries B1, B2, B3 is controllable. Further, the batteries B1, B2, B3 of each power supply unit 10, 20, 30 can also operate in a charging mode, in which the batteries B1, B2, B3 are recharged.

[0064] In addition, the batteries B1, B2, B3 of each power supply unit 10, 20, 30 are connected to respective rectifiers r1, r2, r3. More specifically, each of the batteries B1, B2, B3 is connected between two output terminals of the respective rectifier r1, r2, r3.

[0065] The switch unit C of each power supply unit 10, 20, 30 10 , C 20 , C 30 can connect the batteries B1, B2, B3 to the DC-DC converter 50. In other words, the switch unit C 10 , C 20 , C 30 is connected to the batteries B1, B2, B3 on one hand and to the DC-DC converter 50 on the other hand.

[0066] Each switch unit C 10 , C 20 , C 30 includes a first switch I10, I20, I30 and a second switch I10', I20', I30'.

[0067] The first switches I10, I20, I30 of each power supply unit 10, 20, 30 enable the first terminals of the batteries B1, B2, B3 to be connected to the terminals of the DC-DC converter 50.

[0068] The second switches I10', I20', I30' of each power supply unit 10, 20, 30 enable the second terminals of the batteries B1, B2, B3 to be connected to the second terminals of the DC-DC converter 50.

[0069] Coil

[0070] In addition, each power supply unit 10, 20, 30 includes coils L1, L2, L3 connected to the inputs of the rectifiers r1, r2, r3; in other words, the coils are connected to the rectifiers r1, r2, r3 on one hand and to the AC voltage on the other hand.

[0071] The power supply system 1 further includes a first group of switches I3 and a second group of switches I4.

[0072] First group of switches I3

[0073] The first set of switches I3 can connect the batteries B1, B2, B3 of the power supply units 10, 20, 30 to the batteries B1, B2, B3 of the adjacent power supply units 10, 20, 30 so as to connect the batteries B1, B2, B3 in series.

[0074] For this purpose, the first set of switches I3 includes:

[0075] a. A switch that is connected on the one hand to the battery B1 of the first power supply unit C 10 and on the other hand to the battery B2 of the second power supply unit C 20 .

[0076] b. A switch that is connected on the one hand to the battery B2 of the second power supply unit C 20 and on the other hand to the battery B3 of the third power supply unit C 30 .

[0077] Thus, the batteries B1, B2, B3 can be connected in series; it is said that these batteries form a power supply branch.

[0078] Second group of switches I4

[0079] The second set of switches I4 enables the battery B1 of the first power supply unit C 10 to be connected to the power supply bus HV, in particular in order to connect the branch of the batteries B1, B2, B3 connected in series to the power supply bus HV.

[0080] Connection module 40

[0081] The connection module 40 is capable of being connected on the one hand to the power supply network or an electrical device external to the vehicle and on the other hand to at least one of the power supply units 10, 20, 30.

[0082] When the connection module 40 is connected to the power supply network, the power supply network enables at least one of the batteries B1, B2, B3 of at least one of the power supply units 10, 20, 30 connected to the connection module 40 to be recharged.

[0083] When the connection module 40 is connected to an electrical device, at least one of the batteries B1, B2, B3 of at least one of the power supply units 10, 20, 30 connected to the connection module 40 enables the device to be powered.

[0084] More specifically, if the alternating current voltage provided by the power supply network or the voltage required to supply power to the electrical equipment is single-phase, the connection module 40 can connect the single-phase voltage to at least one of the power supply units 10, 20, 30. If the alternating current voltage provided by the power supply network or if the voltage required to supply power to the electrical equipment is three-phase, the connection module 40 can connect each phase of the alternating current voltage to its own power supply unit 10, 20, 30.

[0085] More specifically, the connection module 40 includes a first connection terminal 41, a second connection terminal 42, and a third connection terminal 43.

[0086] When the alternating current voltage provided by the power supply network or the voltage required to supply power to the electrical equipment is three-phase, each phase of the voltage is connected to its own connection terminal 41, 42, 43. On the contrary, when the alternating current voltage provided by the power supply network or when the voltage required to supply power to the electrical equipment is single-phase, the phase of the voltage is connected to the first connection terminal 41.

[0087] In addition, the first connection terminal 41 is connected to the first switch unit 10, more specifically to the input terminal of the rectifier r1 of the first switch unit 10.

[0088] The connection module 40 further includes:

[0089] a) A first switch I5, which is configured to:

[0090] i) In the first position: connect the first connection terminal 41 to the second power supply unit 20, and more specifically to the input terminal of the rectifier r2 of the second power supply unit 20,

[0091] ii) In the second position: connect the second connection terminal 42 to the second power supply unit 20, and more specifically to the input terminal of the rectifier r2 of the second power supply unit 20,

[0092] b) A second switch I6, which is configured to:

[0093] i) In the first position: connect the first connection terminal 41 to the third power supply unit 30, and more specifically to the input terminal of the rectifier r3 of the third power supply unit 30,

[0094] ii) In the second position: especially when the alternating current voltage provided by the power supply network or when the voltage required to supply power to the electrical equipment is three-phase, connect the third connection terminal 43 to the third power supply unit 30, and more specifically to the input terminal of the rectifier r3 of the third power supply unit 30.

[0095] In addition, the connection module 40 is also connected to the neutral line of the AC voltage, and the connection module 40 is configured to connect the neutral line to the second input terminals of each of the rectifiers r1, r2, r3.

[0096] In addition, each of the power supply units 10, 20, 30 may further include an EMC (electromagnetic compatibility) filter connected between each of the rectifiers r1, r2, r3 and the connection module 40.

[0097] The control unit (not shown in the figure) is configured to control the switches I5, I6 of the connection module 40, the first group of switches I3, the second group of switches I4, and each of the switch units C 10 、C 20 、C 30 and the opening and closing of each switch of each of the rectifiers r1, r2, r3. The control unit is also capable of controlling the voltages provided and generated by each of the batteries B1, B2, B3, so as to, for example, regulate the current in the inductors L1, L2, L3 or regulate the voltage to be provided to the DC-DC converter 50.

[0098] Operating mode

[0099] Now, one of the operating modes of the power supply system 1 described above will be described with reference to Figure 2 . Recall that the control unit is responsible for controlling each of the switches in order to implement the following operating modes.

[0100] The control unit also controls the disconnection between the DC-DC converter 50 and the power supply bus HV.

[0101] The control unit also controls the closing of each switch in the first group of switches I3 in order to connect the battery sets B1, B2, B3 in series. Similarly, the control unit controls the closing of each switch in the second group of switches I4 in order to supply power to the power supply bus based on the electrical energy provided by the battery sets B1, B2, B3.

[0102] In addition, the switches of each of the switch units C 10 、C 20 、C 30 are opened to disconnect the power supply units 10, 20, 30 from the DC-DC converter 50.

[0103] Finally, the control unit controls the connection module 40 such that the individual power supply units 10, 20, 30 of the power supply system 1 are connected to the (single-phase or three-phase) voltage via the connection module 40. For example, here, only the first power supply unit 10 is supplied with electrical energy, and only the first battery B1 is in the charging mode or the discharging mode.

[0104] Thus, the above-described operation mode enables power supply to the power supply bus based only on the serially-connected batteries B1, B2, B3, without passing through the DC-DC converter 50 any more.

[0105] For example, referring to Figure 3 , the first power supply unit 10 is connected to the connection module 40 and provides a rectified voltage V 10 , which may have a sinusoidal part, for example. The second power supply unit 20 and the third power supply unit 30 each provide a power supply voltage V 20 / 30 in order to, on the one hand, compensate for the sinusoidal part of the rectified voltage V 10 provided by the first power supply unit 10 and, on the other hand, obtain the DC voltage value V HV required for power supply to the power supply bus. In other words, the second power supply unit 20 and the third power supply unit 30 enable, in this case, compensation for the variation of the voltage provided by the first power supply unit 10 such that the voltage provided by this set of power supply units 10, 20, 30 is a DC voltage and enables power supply to the power supply bus.

Claims

1. A power supply system (1) intended to be installed in an electric or hybrid vehicle, the vehicle comprising a power supply bus (HV+, HV-) capable of supplying electrical equipment installed in the vehicle, the system (1) comprising: a) A DC-DC voltage converter (50), b) At least two power supply units (10, 20, 30), each power supply unit comprising: i) A rectifier (r1, r2, r3) capable of providing an alternating voltage based on a direct current voltage and vice versa, ii) A battery (B1, B2, B3), the battery being electrically connected to the rectifier (r1, r2, r3), the battery being capable of operating in a discharge mode in which the battery (B1, B2, B3) can provide a first direct current voltage and being capable of operating in a charging mode in which the battery (B1, B2, B3) can be recharged based on a direct current voltage, iii) Switching unit (C 10 , C 20 , C 30 ), which includes switches (I10, I10', I20, I20', I30, I30') capable of connecting the batteries (B1, B2, B3) to the converter (50). c) A first set of switches (I3) capable of connecting the batteries (B1, B2, B3) of the power supply units (10, 20, 30) to the batteries (B1, B2, B3) of adjacent power supply units (10, 20, 30) so as to connect the batteries (B1, B2, B3) in series, d) A second set of switches (I4) capable of connecting the series-connected group of batteries (B1, B2, B3) to the power supply bus (HV+, HV-), e) A control unit configured to control the first set of switches (I3), the second set of switches (I4), and each switching unit (C 10 , C 20 , C 30 ). f) A connection module (40) capable of electrically connecting each power supply unit (10, 20, 30) to a power supply network capable of providing an alternating voltage or to an electrical device located outside the vehicle and capable of being powered based on an alternating voltage, The power supply system (1) is configured to operate in an operating mode in which: - The DC-DC converter (50) is disconnected from the power supply bus (HV+, HV-) and each power supply unit (10, 20, 30), - Only one of the power supply units (10, 20, 30) is supplied with electrical energy, - The first set of switches (I3) is closed so as to connect the group of batteries (B1, B2, B3) in series, - The second set of switches (I4) is closed so as to supply the power supply bus (HV+, HV-) with electrical energy based on the electrical energy provided by the group of batteries (B1, B2, B3).

2. The power supply system (1) according to the previous claim, wherein, The connection module (40) is configured to operate as follows: a) If the alternating voltage provided by the power supply network or if the voltage required to supply the electrical device is single-phase, the connection module (40) is capable of connecting the single-phase voltage to at least one power supply unit (10, 20, 30), b) If the alternating voltage provided by the power supply network or if the voltage required to supply the electrical device is three-phase, the connection module (40) is capable of connecting each phase of the voltage to the power supply units (10, 20, 30).

3. The power supply system (1) according to any one of the preceding claims, wherein, Each power supply unit (10, 20, 30) includes coils (L1, L2, L3), the coils being connected to the rectifier (r1, r2, r3) and intended to be connected to an alternating voltage.

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

5. The power supply system (1) according to claims 2 to 4, wherein, The connection module (40) comprises: a) a first connection terminal (41) electrically connected to the first power supply unit (10), b) a second connection terminal (42), c) a third connection terminal (43), d) a first switch (I5) capable of connecting the second power supply unit (20) to the first connection terminal (41) or the second connection terminal (42), e) a second switch (I6) capable of connecting the third power supply unit (30) to the first connection terminal (41) or the third connection terminal (43).

6. The power supply system (1) according to the previous claim, wherein, When the phase of the single-phase AC voltage is connected to the first connection terminal (41), the first switch (I5) and the second switch (I6) of the connection module (40) are configured to: a) connect the first connection terminal (41) to the second power supply unit (20) and the third power supply unit (30), or b) disconnect the first connection terminal (41) from the second power supply unit (20) and the third power supply unit (30).

7. A motor vehicle, comprising a power supply bus (HV+, HV-) capable of supplying power to electrical equipment installed in the vehicle and a power supply system (1) according to any one of the preceding claims.

8. A method for controlling a power supply system (1) according to any one of the preceding claims, the method being implemented by a control unit and comprising the following steps: a) disconnecting the DC-DC converter (50) from the power supply bus (HV+, HV-) and each power supply unit (10, 20, 30), b) supplying electrical energy to one of the power supply units (10, 20, 30), c) closing each switch of the first set of switches (I3) so as to connect the battery packs (B1, B2, B3) in series, d) closing each switch of the second set of switches (I4) so as to supply power to the power supply bus (HV+, HV-) based on the electrical energy provided by the battery packs (B1, B2, B3).

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