Charging assembly for charging an electric traction battery

Abstract

The invention relates to a charging assembly (20) for charging an electric traction battery (4) by way of a charging station (19) providing a DC electrical network (2) and a multi-phase AC electrical network (1), the charging assembly (20) comprising (i) the electric traction battery (4), (ii) an on-board charger (3) connected, on the one hand, to the AC electrical network (1) and to the DC electrical network (2) provided by the charging station (19) and, on the other hand, to the electric traction battery (4), the on-board charger (3) being configured to be able to transform an AC voltage (P1, P2, P3) provided by said AC electrical network (1) or a DC voltage (DC+, DC-) provided by the DC electrical network (2) into a high DC voltage (HV+, HV-) in order to supply said electric traction battery (4) with the high DC voltage (HV+, HV-) thus transformed, and (iii) a plurality of electrical switches (5, 6, 11, 15) configured to be able to select an electrical coupling path between the charging station (19) and the electric traction battery (4).

Description

DESCRIPTION TITLE OF THE INVENTION: ASSEMBLY FOR RECHARGING AN ELECTRIC TRACTION BATTERY [1] The present invention claims priority from French application No. 2208547 filed on 08 / 26 / 2022, the content of which (text, drawings and claims) is incorporated herein by reference. [2] The technical context of the present invention is that of electrified motor vehicles and their electric charging units. More particularly, the invention relates to an electric charging assembly for such electrified motor vehicles. [3] As is known, the electric traction batteries of electrified motor vehicles need to be regularly recharged in order to have sufficient electrical energy to power an electric machine generating a motor torque on a wheel shaft of such motor vehicles. Of course, there are many electric traction batteries, some of which are rechargeable via a direct voltage of 400 V and others which are rechargeable via a direct voltage of 800 V. Such electric traction batteries are also rechargeable through an alternating current, single-phase or multi-phase electrical network. [4] On the motor vehicle side, it is necessary to have a charging unit that is sufficiently versatile to be able to adapt to different types of charging stations as well as to different electric charging modes. Such charging units thus make it possible to connect, directly or indirectly, the electric traction battery to the charging station and to organize, if necessary, an electrical transformation of the voltage supplied by the charging station. [5] The context of the present invention more particularly addresses the problem of rapid recharging of the electric traction battery, using the direct voltage supplied by the recharging station. In particular, rapid recharging of an electrified motor vehicle having an 800V electric traction battery, is done via an 800V fast charging station: a direct voltage of 800V is then applied directly to the terminals of the 800V electric traction battery of said motor vehicle. Conversely, the fast charging of an electrified motor vehicle with a 400V electric traction battery is done via a 400V fast charging station: a direct voltage of 400V is then applied directly to the terminals of the 400V electric traction battery of said motor vehicle. [6] Thus, with known charging sets, the rapid charging of an electrified motor vehicle having an 800V electric traction battery cannot be done by a 400V charging station, the voltage available at the terminals of said charging station being less than 800V, the current delivered is zero or insufficient. In a comparable manner, the rapid charging of an electrified motor vehicle having a 400V electric traction battery cannot be done by an 800V charging station, the voltage available at the terminals of said charging station being much too high compared to that of the electric traction battery. [7] The object of the present invention is to propose a new assembly for recharging a motor vehicle in order to respond at least to a large extent to the preceding problems and to further lead to other advantages. [8] Another aim of the invention is to provide extended recharging capabilities for electric traction batteries. [9] Another aim of the invention is to enable the use of a 400V or 800V charging station with an electrified motor vehicle equipped with a 400V electric traction battery to carry out rapid charging via a high voltage direct current supplied by the charging station.

[0010] Another aim of the invention is to enable the 400V or 800V type electric traction batteries of any electrified motor vehicle to be recharged via a single-phase or multi-phase alternating current network supplied by the charging station.

[0011] According to a first aspect of the invention, at least one of the aforementioned objectives is achieved with a unit for recharging an electric traction battery of a motor vehicle by a recharging station providing an electrical network continuous and a multi-phase alternating current network, the charging unit comprising:

[0012] - the electric traction battery;

[0013] - an on-board charger connected on the one hand to the AC electrical network of the charging station in order to transform an AC voltage supplied by said AC electrical network into a high DC voltage, and on the other hand to the electric traction battery in order to supply it with the high DC voltage thus transformed, the on-board charger comprising an isolated converter comprising a transformer controlled by a primary power bridge, and;

[0014] - a switching device configured to connect the electric traction battery to the alternating current electrical network supplied by the charging station or to connect said electric traction battery to the direct current electrical network supplied by said charging station and via a positive high voltage line and a direct current reference line supplied by said direct current electrical network of the charging station;

[0015] - a configuration member configured to control the primary power bridge: (i) in half bridge if the operating voltage of the electric traction battery is less than or equal to an electrical potential difference between the positive high voltage line and the continuous reference line, (ii) in full bridge if the operating voltage of the electric traction battery is greater than or equal to the electrical potential difference between the positive high voltage line and the continuous reference line.

[0016] In the context of the invention, an electrified motor vehicle is of the type of an electric or hybrid motor vehicle. Generally speaking, the powertrain of such an electrified motor vehicle is rotated by the electric machine, electrically powered by the electric traction battery, in order to generate a motor torque used to set the motor vehicle in motion. Additionally or alternatively, the electric machine is configured to recover mechanical energy from the powertrain and convert it into electrical energy, thereby producing a braking torque on said powertrain.

[0017] In the context of the invention, the electric traction battery is configured to supply electrical energy to an electric machine generating engine torque on the powertrain of the motor vehicle. By way of non-limiting example, the electric traction battery is of the high-voltage electric battery type capable of generating a direct voltage of 400V or 800V.

[0018] In the context of the invention, the on-board charger comprises in particular a converter of alternating voltage into a direct voltage. In particular, the on-board charger is configured in particular to rectify an alternating electric voltage supplied by the charging station in order to recharge the electric traction battery. The on-board charger thus makes it possible to convert an alternating current that can be supplied by the charging station into a direct current which ultimately makes it possible to recharge the electric traction battery.

[0019] Additionally, the isolated converter of the on-board charger is of the type of a DC voltage to DC voltage converter. In particular, the on-board charger is configured to amplify a DC electrical voltage supplied by the charging station in order to recharge the electric traction battery. The on-board charger thus makes it possible to convert a DC current that can be supplied by the charging station into a DC current that ultimately makes it possible to recharge the electric traction battery.

[0020] Thus, in the context of the present invention, the recharging assembly according to the first aspect of the invention makes it possible to establish at least:

[0021] - a first coupling path in which the electric traction battery is electrically coupled to the charging station via the on-board charger and via the DC electrical network in order to achieve rapid charging;

[0022] - a second coupling path in which the electric traction battery is electrically coupled to the charging station via the on-board charger and via the alternating current network in order to carry out so-called slow charging.

[0023] The positive high voltage line is configured to carry direct current and direct voltage, preferably high direct current - typically several Amperes - and high direct voltage - typically 400V or 800V for example.

[0024] The continuous reference line is an electric line at a reference electric potential, for example equal to 0 V.

[0025] The positive DC high voltage line and the DC reference line originate from the charging station, via a charging socket. Advantageously, a connection device of the charging assembly according to the first aspect of the invention makes it possible to electrically connect the electric charging assembly to the charging station via at least one electrical phase of the AC electrical network. The connection device further comprises a ground line and a high voltage line similar to the positive high voltage line and the DC reference line of the charging station respectively. The connection device is intended to be connected to the charging socket originating from the charging station in order to establish an electrical connection between the charging station and the electric traction battery.

[0026] In the context of the present invention, the charging station is preferably of the type of a 400 V or 800 V charging station. In particular, cleverly, the charging assembly according to the first aspect of the invention makes it possible to electrically couple and indifferently a 400 V or 800 V charging station to the electric traction battery in order to recharge it at said charging station.

[0027] The switching device makes it possible to establish an electrical connection or to form electrical isolation. For this purpose, as will be described later, the switching device comprises one or more switches. In the context of the invention, each switch takes the form of a switch, in the functional sense of the term. Each switch thus comprises a first terminal and a second terminal, each switch being configured to establish an electrical connection between the first terminal and the second terminal, or to electrically isolate the first terminal from the second terminal. In other words, each switch is configured to be able to assume a first state - called the closed state - in which it establishes an electrical connection between the first terminal and the second terminal, and a second state - called the open state - in which it electrically decouples the first terminal from the second terminal. Each switch is selectively controllable so that it can be configured in either of its states.

[0028] The primary power bridge configuration device makes it possible to control the power bridge in order to adapt the charging assembly, and in particular the on-board charger, to the type of charging station to which the electric traction battery is connected for charging, and depending on the type of electric traction battery. Thus:

[0029] - If the voltage at the terminals of the fast charging station is of the order of 400V and the electric traction battery is of the 800V battery type, then the configuration device controls the power bridge of the transformer of the isolated converter as a complete bridge, in order to be able to transform the 400V voltage into an 800V voltage at the terminals of the secondary of the transformer, when said transformer has a transformation ratio of 2. On the other hand, if the electric traction battery is of the 400V battery type, then the transformation ratio of the transformer of the isolated converter is adapted to 1 so as to be able to adjust the voltage transformation to the electric traction battery;

[0030] - If the voltage at the terminals of the fast charging station is of the order of 800V and the electric traction battery is of the 400V battery type, then the configuration device controls the power bridge of the transformer of the isolated converter as a half-bridge, in order to always obtain a voltage of 400V at the terminals of the primary of the transformer, and to transform it into a voltage of 400V at the terminals of the secondary of the transformer, when said transformer has a transformation ratio of 1.

[0031] Thus, the electric charging assembly according to the first aspect of the invention makes it possible to recharge an electric traction battery using a charging station and by making it possible to define several voltage amplification paths, in order, for example, to recharge the electric traction battery via a direct voltage or an alternating voltage delivered by the charging station.

[0032] More particularly, the invention according to its first aspect cleverly makes it possible to increase the power of the isolated converter by increasing the working frequency of said isolated converter, without having to modify the transformer used. This advantageous configuration thus makes it possible to take advantage of part of the components used in the on-board charger and to use them in an optimal way.

[0033] The recharging assembly in accordance with the first aspect of the invention advantageously comprises at least one of the improvements below, the technical characteristics forming these improvements being able to be taken alone or in combination:

[0034] - the isolated converter is of the type of a bidirectional direct current-direct current converter with double active bridge, the double active bridge comprising the primary power bridge connected to a primary winding of the transformer, and a secondary power bridge connected to a secondary winding of said transformer;

[0035] - the switching device comprises (i) a first switch configured to establish an electrical connection or electrical isolation between the supplied positive high voltage line and a positive terminal of the electric traction battery, (ii) a second switch configured to establish an electrical connection or electrical isolation between the continuous reference line and a negative terminal of the electric traction battery, (iii) a third switch and a fourth switch making it possible to establish an electrical connection or electrical isolation between the continuous electrical network and the primary power bridge of the transformer of the isolated converter;

[0036] - the on-board charger comprises an output low-pass filter located in an intermediate position between the isolated converter and the electric traction battery, the output low-pass filter comprising (i) a first inductor connecting a secondary of the transformer of the isolated converter and the positive terminal of the electric traction battery, (ii) a second inductor connecting a secondary of the transformer of the isolated converter and the negative terminal of the electric traction battery, (iii) a third inductor connecting the positive high-voltage line and the third switch, and a first terminal of the third switch is connected to the third inductor of the output low-pass filter, and a second terminal of said third switch is connected to a first amplification line of the on-board charger. Each inductor thus makes it possible to attenuate current and / or voltage variations whose frequency exceeds a value threshold. Conversely, all current and / or voltage variations with a frequency lower than the threshold value are transmitted without attenuation. The output low-pass filter is located between an output of the on-board charger and the electric traction battery. In particular, the output low-pass filter is placed in parallel with the secondary power bridge of the isolated converter;

[0037] - the second terminal of the third switch is connected to the first amplification line between the primary winding of the transformer of the isolated converter and a circuit for correcting a power factor of the on-board charger. In the context of the invention, the correction circuit is configured to be able to modify a phase and / or a shape of the alternating voltage supplied by the alternating electricity network via the charging station in order to optimize the operation of the charging assembly according to the first aspect of the invention and its electrical coupling to said charging station. Additionally or alternatively, the correction circuit comprises an alternating voltage converter into a direct voltage, thus making it possible to convert the alternating voltage supplied by the alternating electricity network via the charging station into a high direct voltage necessary for recharging the electric traction battery.The correction circuit is located in an intermediate position between the charging station and the isolated converter. In particular, the correction circuit is connected in parallel with the primary power bridge of the isolated converter;

[0038] - the third switch is housed in a capacitive filter located upstream of the converter isolated relative to the electric traction battery;

[0039] - according to a first alternative embodiment, the fourth switch is placed in bypass of the transformer of the isolated converter, on a second amplification line of the on-board charger. A first terminal of the fourth switch is connected to the primary power bridge of the isolated converter, and a second terminal of said fourth switch is connected to the secondary power bridge of the isolated converter. Advantageously, in this first alternative embodiment, the fourth switch is housed in the isolated converter. This advantageous configuration thus makes it possible to limit the size of the charging assembly in accordance with the first aspect of the invention;

[0040] - according to a second variant embodiment, the output low-pass filter comprises a fourth inductor connecting the continuous reference line and the fourth switch, a first terminal of the fourth switch being connected to the fourth inductor of the output low-pass filter, and a second terminal of said fourth switch being connected to a second amplification line of the on-board charger;

[0041] - in the second embodiment, the second terminal of the fourth switch is connected to the second amplification line between the primary winding of the transformer of the isolated converter and the correction circuit of the on-board charger;

[0042] - in the second embodiment, the fourth switch is housed in the on-board charger. In particular, the fourth switch is located outside the isolated converter. This advantageous configuration thus makes it possible to limit the size of the charging assembly in accordance with the first aspect of the invention;

[0043] - in the context of the present invention, the first switch and / or the second switch and / or the third switch and / or the fourth switch are of the transistor type, and preferably of the insulated gate bipolar transistor type or of a metal-oxide gate field effect transistor type. Alternatively, the first switch and / or the second switch and / or the third switch and / or the fourth switch are of the mechanical relay type. In the context of the invention, all configurations are conceivable: all the switches may be of the transistor type, or all the switches may be of the mechanical relay type, or a first part of the switches may be of the transistor type and a second part of the switches may be of the mechanical relay type.

[0044] According to a second aspect of the invention, there is proposed a method for controlling a charging assembly in accordance with the first aspect of the invention or according to any of its improvements, the transformer of the isolated converter having a transformation ratio equal to 0.5, the control method comprising (i) a step of supplying electricity with direct voltage to the on-board charger, the direct voltage being supplied by the charging station and by via the positive high voltage line and the continuous reference line, (ii) a comparison step between an operating voltage of the electric traction battery and an electric potential difference between the positive high voltage line and the continuous reference line, (iii) a configuration step of the primary power bridge as a function of the operating voltage of the electric traction battery and the electric potential difference:

[0045] - if the operating voltage of the electric traction battery is lower than the electrical potential difference, then the primary power bridge is controlled to operate as a half-bridge;

[0046] - if the operating voltage of the electric traction battery is higher than the electrical potential difference, then the primary power bridge is controlled to operate as a full bridge.

[0047] Thus, thanks to the control method according to the second aspect of the invention, if the electric traction battery is an 800 V electric battery and if the charging station is configured to deliver, in fast charging, a direct voltage of 800 V between the positive high voltage line and the direct reference line, then the configuration device controls the primary power bridge so that it operates as a half-bridge. In this case, the voltage of 400 V at the output of the primary power bridge is then transformed in such a way that, at the secondary power bridge of the isolated converter, a voltage of 800 V is indeed found at the terminals of the electric traction battery.On the other hand, if the electric traction battery is an 800 V electric battery and the charging station is configured to deliver, in fast charging, a direct voltage of 400 V between the positive high voltage line and the direct reference line, then the configuration device controls the primary power bridge so that it operates as a complete bridge. In this case, the voltage of 800 V supplying the primary power bridge is divided by 2 by said primary power bridge so that, at the output of said primary power bridge, a voltage of 400 V can then be transformed in such a way that, at the secondary power bridge of the isolated converter, there is indeed a voltage of 800 V at the terminals of the electric traction battery.

[0048] Advantageously, the primary power bridge comprises a first power transistor and a second power transistor, a source terminal of the first power transistor being connected to a drain terminal of the second power transistor and to a terminal of a primary winding of the transformer, the step of configuring the power bridge comprising:

[0049] - a step of controlling the first power transistor so that it is configured in a non-conducting state when the operating voltage of the electric traction battery is lower than the electrical potential difference.

[0050] - a step of controlling the first power transistor so that it is configured in an on state when the operating voltage of the electric traction battery is greater than the electrical potential difference.

[0051] Advantageously, a working frequency of the on-board charger is greater than 200 kHz, and preferably between 200 kHz and 500 kHz.

[0052] In the context of the present invention, the working frequency is that of the isolated converter, and more particularly, that of the primary power bridge.

[0053] According to a third aspect of the invention, there is provided a motor vehicle comprising a charging assembly in accordance with the first aspect of the invention or according to any of its improvements.

[0054] Various embodiments of the invention are provided, incorporating, in all their possible combinations, the various optional features set out herein.

[0055] Other characteristics and advantages of the invention will become apparent from the following description on the one hand, and from several examples of embodiment given for informational and non-limiting purposes with reference to the attached schematic drawings on the other hand, in which:

[0056] [Fig.1] illustrates a first example of embodiment of the recharging assembly in accordance with the first aspect of the invention;

[0057] [Fig.2] illustrates a second exemplary embodiment of the recharging assembly in accordance with the first aspect of the invention;

[0058] [Fig.3] illustrates a block diagram of the control method according to the second aspect of the invention.

[0059] Of course, the features, variants and different embodiments of the invention may be combined with each other, in various combinations, provided that they are not incompatible or mutually exclusive. In particular, variants of the invention may be imagined comprising only a selection of features described below in isolation from the other features described, if this selection of features is sufficient to confer a technical advantage or to differentiate the invention from the prior art.

[0060] In particular, all the variants and embodiments described can be combined with each other if there is no technical obstacle to this combination.

[0061] In FIGURES, elements common to several FIGURES retain the same reference.

[0062] With reference to FIGURES 1 to 2, the charging assembly 20 according to the invention makes it possible to establish an electrical connection with a charging station 19 external to the electric vehicle with which the charging assembly 20 is associated. The electrical connection established is defined through the charging assembly 20 among several coupling paths. Among these coupling paths, we distinguish in particular:

[0063] - a first coupling path for charging an electric traction battery 4 using a direct voltage supplied by a direct electrical network 2 made available by the charging station 19. This type of charging is called rapid charging;

[0064] - a second coupling path for charging the electric traction battery 4 using an alternating voltage supplied by an alternating electricity network 1 made available by the charging station 19. This type of charging is called slow charging.

[0065] In the examples visible in the FIGURES, such a refill assembly 20 comprises:

[0066] - the electric traction battery 4;

[0067] - an on-board charger 3 connected, on the one hand, to the alternating current network 1 and to the direct current network 2 supplied by the charging station 19 and, on the other hand, to the electric traction battery 4, the on-board charger 3 being configured to be able to transform into a direct current high voltage HV+, HV- the alternating current voltage supplied by said alternating current network 1 or the direct current voltage supplied by the direct current network 2 in order to supply said electric traction battery 4 with the direct current high voltage HV+, HV- thus transformed;

[0068] - a switching device comprising one or more switches 5, 6, 11, 15 configured to establish an electrical connection or electrically isolate certain parts of the on-board charger 3 and / or the charging assembly 20, so as to be able to establish one of the electrical coupling paths between the charging station 19 and the electric traction battery 4.

[0069] In the embodiments illustrated in the FIGURES, the charging station 19 makes it possible to supply the on-board charger 3 with a direct voltage or an alternating voltage.

[0070] The alternating voltage is supplied by the alternating electrical network 1 of single-phase or multi-phase type, allowing the charging station 19 to deliver at least one alternating voltage to the charging assembly 20. More particularly, the alternating electrical network 1 comprises, for example, a first electrical phase line P1 and / or a second electrical phase line P2 and / or a third electrical phase line P3.

[0071] The direct voltage is supplied by the direct electrical network 2, allowing the charging station 19 to deliver to the charging assembly 20 a direct voltage for example equal or substantially equal to 400 V or 800 V. More particularly, the direct electrical network 2 comprises a positive high voltage line DC+ and a direct reference line DC-.

[0072] Advantageously, the charging station 19 is electrically connected to an electrical connection device making it possible to connect the electrical charging assembly 20 to the charging station 19, either through the alternating current electrical network 1, or through the direct current electrical network 2.

[0073] The switches 5, 6, 11, 15 of the switching device are chosen from those of the mechanical relay or transistor type. In particular, when one of the switches is of the transistor type, then it is preferably of the insulated gate bipolar transistor type or of a metal-oxide gate field effect transistor type. Of course, all the switches 5, 6, 11, 15 forming the switching device may be of the transistor type, or all the switches 5, 6, 11, 15 forming the switching device may be of the mechanical relay type, or a first part of the switches 5, 6, 11, 15 forming the switching device may be of the transistor type and a second part of the switches 5, 6, 11, 15 forming the switching device may be of the mechanical relay type.

[0074] More particularly, in the embodiments illustrated in the FIGURES, the on-board charger 3 comprises:

[0075] - an input low-pass filter 7 configured to attenuate high-frequency variations of alternating current or alternating voltage, i.e. those which are greater than a threshold value characteristic of the input low-pass filter 7. The input low-pass filter 7 is electrically connected to the charging station 19 via the electrical connection device, not shown in the FIGURES;

[0076] - a correction circuit 8 configured to be able to modify a phase and / or a shape of the alternating voltage supplied by the alternating electrical network 1 via the charging station 19 in order to optimize the operation of the charging assembly 20 in accordance with the first aspect of the invention and its electrical coupling to said charging station 19. Complementarily or alternatively, the correction circuit 8 comprises a converter of alternating voltage into a direct voltage, thus making it possible to convert the alternating voltage supplied by the alternating electrical network 1 via the charging station 19 into a high direct voltage HV+, HV- necessary for recharging the electric traction battery 4. By way of non-limiting example, the correction circuit 8 thus comprises a rectifier 81 making it possible to rectify each of the at least one electrical phase line supplied by the charging station 19.The correction circuit 8 is placed in parallel with the input low-pass filter 7, so that the input low-pass filter 7 is located in an intermediate position between the charging station 19 and said correction circuit 8;.

[0077] - a capacitive filter 9 connected in parallel with the correction circuit 8, so that the correction circuit 8 is located in an intermediate position between the input low-pass filter 7 and the capacitive filter 9;

[0078] - an isolated converter 12 configured to transform, i.e. attenuate or, preferably, amplify a DC voltage into a high DC voltage HV+, HV- allowing the electric traction battery 4 to be charged. Advantageously, the isolated converter 12 comprises a transformer 13 controlled by a primary power bridge 13P connected to a primary winding of the transformer 13, and by a secondary power bridge 13S connected to a secondary winding of said transformer 13. The isolated converter 12 is placed in parallel with the capacitive filter 9, so that the capacitive filter 9 is located in an intermediate position between the correction circuit 8 and the isolated converter 12;

[0079] - an output low-pass filter 14 configured to attenuate high-frequency variations of the high direct voltage HV+, HV- leaving the on-board charger 3 and entering the electric traction battery 4, i.e. those which are greater than a threshold value characteristic of the input low-pass filter 7. The output low-pass filter 14 is placed in parallel with the isolated converter 12, so that the isolated converter 12 is located in an intermediate position between the capacitive filter 9 and the output low-pass filter 14. Furthermore, the output low-pass filter 14 is located in an intermediate position between the isolated converter 12 and the electric traction battery 4.

[0080] As seen in the FIGURES, the input low-pass filter 7 comprises a first inductance LE1, a second inductance LE2, a third inductance LE3 and possibly a fourth inductance LE4 respectively connecting the first electrical phase line P1, the second electrical phase line P2 and the third electrical phase line P3 to the correction circuit 8.

[0081] The rectifier 81 of the correction circuit 8 comprises a transistor bridge which rectifies each of the electrical phase lines P1, P2, P3 in order to convert an alternating voltage supplied by each of the electrical phase lines P1, P2, P3 into a high continuous voltage HV+, HV- allowing the electric traction battery 4 to be recharged.

[0082] The capacitive filter 9 includes in particular a capacitor which extends in parallel with the correction circuit 8.

[0083] The primary power bridge 13P of the isolated converter 12 comprises:

[0084] - a first branch formed of a first transistor 131 and a second transistor 132 connected to each other by their drain terminal and their source terminal and further connected, at the level of these terminals B+, B- connected to each other, to one of the terminals B+, B- of the primary winding of the transformer 13; and

[0085] - a second branch formed of a third transistor 133 and a fourth transistor 134 connected to each other by their drain terminal and their source terminal and further connected, at the level of these terminals B+, B- connected to each other, to the other of the terminals B+, B- of the primary winding of the transformer 13.

[0086] The transformer 13 of the isolated converter 12 preferably has a winding ratio equal to 2. Optionally, the winding ratio of the transformer 13 can be adaptive depending on the transformation needs of the isolated converter 12.

[0087] The secondary power bridge 13S of the isolated converter 12 comprises:

[0088] - a first branch formed of two transistors connected to each other by their drain terminal and their source terminal and further connected, at the level of these terminals B+, B- connected to each other, to one of the terminals B+, B- of the secondary winding of the transformer 13; and

[0089] - a second branch formed of two transistors connected to each other by their drain terminal and their source terminal and further connected, at the level of these terminals B+, B- connected to each other, to the other of the terminals B+, B- of the secondary winding of the transformer 13.

[0090] The control of the transformer 13, the primary power bridge 13P and the secondary power bridge 13S thus makes it possible to carry out the DC / DC transformation in order to produce, at the output of the isolated converter 12, the high direct voltage HV+, HV- necessary for recharging the electric traction battery 4.

[0091] As seen in the FIGURES, the output low-pass filter 14 comprises:

[0092] - a first inductor LS1 connecting the isolated converter 12 to the first high voltage line HV+ supplying the positive terminal B+ of the electric traction battery 4;

[0093] - a second inductor LS2 connecting the isolated converter 12 to the second high voltage line HV- supplying the negative terminal B- of the electric traction battery 4;

[0094] - a third inductor LS3 connecting the positive high voltage line DC+ supplied by the charging station 19 to the capacitive filter 9; and possibly,

[0095] - a fourth inductor LS4 connecting the second high voltage line HV- supplying the negative terminal B- of the electric traction battery 4 to the capacitive filter 9.

[0096] Additionally, the present invention further provides for incorporating into the switching device of the charging assembly 20 as described above one or more switches 5, 6, 11, 15 making it possible to establish an electrical connection between the electric traction battery 4 and the charging station 19 according to a predetermined coupling path. The FIGURES illustrate several exemplary embodiments of the charging assembly 20, in which variations of the switching device are proposed.

[0097] In FIGURES 1 and 2, the switching device comprises:

[0098] - a first switch 5 configured to establish an electrical connection or electrical isolation between the positive high voltage line DC+ supplied by the direct current electrical network 2 of the charging station 19 and the positive terminal B+ of the electric traction battery 4;

[0099] - a second switch 6 configured to establish the electrical connection or electrical isolation between a continuous reference line DC- supplied by the continuous electrical network 2 of the charging station 19 and the negative terminal B- of the electric traction battery 4;

[0100] - a third switch 15 and a fourth switch 11 making it possible to establish an electrical connection or electrical isolation between the continuous electrical network 2 and the primary power bridge 13P of the transformer 13 of the isolated converter 12 of the on-board charger 3. In particular, the third switch 15 establishes an electrical connection or electrical isolation between the positive high voltage line DC+ and a first amplification line A1 of the on-board charger 3, and the fourth switch 11 establishes an electrical connection or electrical isolation between the second high voltage line HV- and a second amplification line A2 of the on-board charger 3.

[0101] In FIGURES 1 and 2, the third switch 15 is advantageously embedded and housed in the capacitive filter 9. A first terminal of the third switch 15 is connected to the third inductor LS3 of the output low-pass filter 14, and a second terminal of said third switch 15 is connected to the first amplification line A1 of the on-board charger 3, taken at the level of the capacitive filter 9.

[0102] In FIGURE 1, the output low-pass filter 14 comprises the fourth inductor LS4 connecting the continuous reference line DC- and the fourth switch 11. Thus, a first terminal of the fourth switch 11 is connected to the fourth inductor LS4 of the output low-pass filter 14, and a second terminal of said fourth switch 11 is connected to the second amplification line A2 of the on-board charger 3, and more particularly between the primary power bridge 13P of the transformer 13 of the isolated converter 12 and the correction circuit 8 of the on-board charger 3. The fourth switch 11 is advantageously housed in the on-board charger 3, outside the isolated converter 12.

[0103] In FIGURE 2, the output low-pass filter 14 comprises only the first inductor LS1, the second inductor LS2 and the third inductor LS3. The fourth switch 11 is then placed in direct bypass of the transformer 13 of the isolated converter 12, on the second amplification line A2 of the on-board charger 3, so that a first terminal of the fourth switch 11 is connected to the primary power bridge 13P of the isolated converter 12 and a second terminal of said fourth switch 11 is connected to the secondary power bridge 13S of said isolated converter 12, in the direct extension of the third inductor LS3 of the output low-pass filter 14. The fourth switch 11 is then advantageously housed in the isolated converter 12.

[0104] In the following paragraphs, the rapid recharging of the electric traction battery 4 will now be explained with regard to the present invention. As a reminder, the rapid recharging of the electric traction battery 4 is ensured by the continuous electrical network 2 supplied by the recharging station 19.

[0105] To do this, the AC power grid 1 of the charging station 19 is disconnected from the charging assembly 20. Furthermore, the first switch 5 is configured in its open state and the second switch 6 is configured in its closed state. Finally, the third switch 15 and the fourth switch 11 are configured in their closed state so as to electrically connect the capacitive filter 9 to the DC electrical network 2 supplied by the charging station 19, via the positive high voltage line DC+ and the DC reference line DC-. Thus, the isolated converter 12 is correctly supplied with electrical energy, via the DC electrical network 2 supplied by the charging station 19, via the positive high voltage line DC+ and the DC reference line DC-.

[0106] Depending on the type of charging station 19, a direct voltage of 400V or 800V is thus brought to the terminals B+, B- of the primary power bridge 13P of the isolated converter 12. Subsequently, it is possible to operate the isolated converter 12 at its full power, for example 50 kW, which is thus significantly higher than the operating power of said isolated converter. 12 when the latter is used during slow charging through the alternating current network 1, generally between 11 kW and 22 kW.

[0107] A working frequency of the on-board charger 3, and more particularly that of the isolated converter 12, and more particularly still, that of the primary power bridge 13P, is greater than 200 kHz, or even between 200 kHz and 500 kHz.

[0108] Cleverly, the invention also aims to control the primary power bridge 13P according to the type of charging station 19 connected to the electric traction battery 4 and its type.

[0109] To this end, with reference to FIGURE 3, the invention relates to a method 30 for controlling the charging assembly 20 as described previously, the transformer 13 of the isolated converter 12 having a transformation ratio equal to 0.5, the control method 30 comprising:

[0110] - a step 31 of supplying electricity with direct voltage to the on-board charger 3, the direct voltage being supplied by the charging station 19 and via the positive high voltage line DC+ and the direct reference line DC-;

[0111] - a comparison step 32 between an operating voltage of the electric traction battery 4 and an electrical potential difference between the positive high voltage line DC+ and the continuous reference line DC-;

[0112] - a configuration step 33 of the primary power bridge 13P as a function of the operating voltage of the electric traction battery 4 and the electric potential difference:

[0113] - if the operating voltage of the electric traction battery 4 is lower than the electrical potential difference, then the primary power bridge 13P is controlled to operate in half-bridge;

[0114] - if the operating voltage of the electric traction battery 4 is greater than the electrical potential difference, then the primary power bridge 13P is controlled to operate in full bridge.

[0115] Thus, if the electric traction battery 4 is a 400 V electric battery and if the charging station 19 is configured to deliver, in fast charging, a direct voltage of 800 V between the positive high voltage line DC+ and the direct reference line DC-, then the primary power bridge 13P is controlled so that it operates as a complete bridge. In this case, the voltage of 400 V at the output of the primary power bridge 13P is then transformed by the transformer 13, and through its winding ratio of 0.5, in such a way that, at the secondary power bridge 13S of the isolated converter 12, there is indeed a voltage of 800 V at the terminals B+, B- of the electric traction battery 4.On the other hand, if the electric traction battery 4 is an 800 V electric battery and the charging station 19 is configured to deliver, in fast charging, a direct voltage of 400 V between the positive high voltage line DC+ and the direct reference line DC-, then the primary power bridge 13P is controlled so that it operates as a half-bridge. In this case, the voltage of 800 V supplying the primary power bridge 13P is divided by 2 by said primary power bridge 13P so that, at the output of said bridge. primary power 13P, a voltage of 400V can then be transformed by the transformer 13, and through its winding ratio of 0.5, in such a way that, at the secondary power bridge 13S of the isolated converter 12, a voltage of 800V is found at the terminals B+, B- of the electric traction battery 4.

[0116] Advantageously, the primary power bridge 13P comprises a first power transistor 131 and a second power transistor 132, a source terminal of the first power transistor 131 being connected to a drain terminal of the second power transistor 132 and to a terminal of a primary winding of the transformer 13, the configuration step 33 of the power bridge comprising:

[0117] - a step of controlling the first power transistor 131 so that it is configured in a non-conducting state when the operating voltage of the electric traction battery 4 is lower than the electrical potential difference.

[0118] - a step of controlling the first power transistor 131 so that it is configured in an on state when the operating voltage of the electric traction battery 4 is greater than the electrical potential difference.

[0119] It is thus possible to charge any type of electric traction battery 4 with any type of charging station 19.

[0120] In summary, the invention relates to a recharging assembly 20 of an electric traction battery 4 by a recharging station 19 providing a direct current electrical network 2 and a multi-phase alternating current electrical network 1, the recharging assembly 20 comprising (i) the electric traction battery 4, (ii) an on-board charger 3 connected, on the one hand, to the alternating current electrical network 1 and to the direct current electrical network 2 provided by the recharging station 19 and, on the other hand, to the electric traction battery 4, the on-board charger 3 being configured to be able to transform into a direct current high voltage HV+, HV- an alternating voltage provided by said alternating current electrical network 1 or a direct current voltage provided by the direct current electrical network 2 in order to supply said electric traction battery 4 with the direct current high voltage HV+, HV- thus transformed, and (iii) several electrical switches 5, 6, 11, 15 configured to be able to select an electrical coupling path between the charging station 19 and the electric traction battery 4.

[0121] Of course, the invention is not limited to the examples which have just been described and numerous adjustments can be made to these examples without departing from the scope of the invention. In particular, the different characteristics, forms, variants and embodiments of the invention can be associated with each other in various combinations insofar as they are not incompatible or mutually exclusive. In particular, all the variants and embodiments described above can be combined with each other.

Claims

CLAIMS

1. Recharging assembly (20) of an electric traction battery (4) of a motor vehicle by a recharging station (19) providing a direct current electrical network (2) and a multi-phase alternating current electrical network (1), the recharging assembly (20) comprising: - the electric traction battery (4); - an on-board charger (3) connected on the one hand to the alternating current network (1) of the charging station (19) in order to transform an alternating voltage supplied by said alternating current network (1) into a high direct voltage (HV+, HV-), and on the other hand to the electric traction battery (4) in order to supply it with the high direct voltage (HV+, HV-) thus transformed, the on-board charger (3) comprising an isolated converter (12) comprising a transformer (13) controlled by a primary power bridge (13P), and; - a switching device configured to connect the electric traction battery (4) to the alternating current electrical network (1) supplied by the charging station (19) or to connect said electric traction battery (4) to the direct current electrical network (2) supplied by said charging station (19) and via a positive high voltage line (DC+) and a direct current reference line (DC-) supplied by said direct current electrical network (2) of the charging station (19); characterized in that the charging assembly (20) comprises a configuration member configured to control the primary power bridge (13P): - in half bridge if the operating voltage of the electric traction battery (4) is less than or equal to an electrical potential difference between the positive high voltage line (DC+) and the continuous reference line (DC-); - in full bridge if the operating voltage of the electric traction battery (4) is greater than the electrical potential difference between the positive high voltage line (DC+) and the continuous reference line (DC-).

2. Charging assembly (20) according to the preceding claim, in which the isolated converter (12) is of the type of a bidirectional direct current-direct current converter with double active bridge, the double active bridge comprising the primary power bridge (13P) connected to a primary winding of the transformer (13), and a secondary power bridge (13S) connected to a secondary winding of said transformer (13).

3. A charging assembly (20) according to any preceding claim, wherein the switching device comprises: - a first switch (5) configured to establish an electrical connection or electrical isolation between the positive high voltage line (DC+) supplied and a positive terminal (B+) of the electric traction battery (4); - a second switch (6) configured to establish an electrical connection or electrical isolation between the continuous reference line (DC-) and a negative terminal (B-) of the electric traction battery (4); - a third switch (15) and a fourth switch (11) for establishing an electrical connection or electrical isolation between the continuous electrical network (2) and the primary power bridge (13P) of the transformer (13) of the isolated converter (12).

4. Charging assembly (20) according to the preceding claim, in which the on-board charger (3) comprises an output low-pass filter (14) located in an intermediate position between the isolated converter (12) and the electric traction battery (4), the output low-pass filter (14) comprising: - a first inductor (LS1) connecting a secondary of the transformer (13) of the isolated converter (12) and the positive terminal (B+) of the electric traction battery (4); - a second inductor (LS2) connecting a secondary of the transformer (13) of the isolated converter (12) and the negative terminal (B-) of the electric traction battery (4); - a third inductor (LS3) connecting the positive high voltage line (DC+) and the third switch (15); and wherein a first terminal of the third switch (15) is connected to the third inductor (LS3) of the output low-pass filter (14), and a second terminal of said third switch (15) is connected to a first amplification line (A1) of the on-board charger (3).

5. A charging assembly (20) according to any one of claims 3 or 4, wherein the fourth switch (11) is placed in derivation of the transformer (13) of the isolated converter (12), on a second amplification line (A2) of the on-board charger (3).

6. Charging assembly (20) according to claim 4, wherein the output low-pass filter (14) comprises a fourth inductor (LS4) connecting the continuous reference line (DC-) and the fourth switch (11), a first terminal of the fourth switch (11) being connected to the fourth inductor (LS4) of the output low-pass filter (14), and a second terminal of said fourth switch (11) being connected to a second amplification line (A2) of the on-board charger (3).

7. Charging assembly (20) according to the preceding claim, wherein the second terminal of the fourth switch (11) is connected to the second amplification line (A2) between the primary winding of the transformer (13) of the isolated converter (12) and the correction circuit (8) of the on-board charger (3).

8. Method for controlling (30) a charging assembly (20) according to any one of the preceding claims, the transformer (13) of the isolated converter (12) having a transformation ratio equal to 0.5, the control method (30) comprising: - a step of supplying (31) direct voltage electricity to the on-board charger (3), the direct voltage being supplied by the charging station (19) and via the positive high voltage line (DC+) and the direct reference line (DC-); - a comparison step (32) between an operating voltage of the electric traction battery (4) and an electrical potential difference between the positive high voltage line (DC+) and the continuous reference line (DC-); - a configuration step (33) of the primary power bridge (13P) as a function of the operating voltage of the electric traction battery (4) and the electrical potential difference: - if the operating voltage of the electric traction battery (4) is lower than the electrical potential difference, then the primary power bridge (13P) is controlled to operate as a half-bridge; - if the operating voltage of the electric traction battery (4) is greater than the electrical potential difference, then the primary power bridge (13P) is controlled to operate as a full bridge.

9. Driving method (30) according to the preceding claim, in which the primary power bridge (13P) comprises a first power transistor (131) and a second power transistor (132), a source terminal of the first power transistor (131) being connected to a drain terminal of the second power transistor (132) and to a terminal of a primary winding of the transformer (13), the step of configuring (33) the power bridge comprising: - a step of controlling the first power transistor (131) so that it is configured in a non-conducting state when the operating voltage of the electric traction battery (4) is lower than the electrical potential difference. - a step of controlling the first power transistor (131) so that it is configured in an on state when the operating voltage of the electric traction battery (4) is greater than the electrical potential difference.

10. Control method (30) according to any one of claims 8 or 9, in which a working frequency of the on-board charger (3) is greater than 200 kHz, preferably between 200 kHz and 500 kHz.

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