FR2974462A1 - Device for charging storage unit i.e. rechargeable high voltage battery, for electric vehicle, has power factor correction module connected to connection terminals and power supply during charging phase of storage unit - Google Patents

Abstract

The device (5) has a power factor correction module (15) connected to connection terminals (17, 19) and a power supply (21) during a charging phase of a storage unit i.e. rechargeable high voltage battery (7), of a control system (1). The module comprises two branches connected in parallel between two output terminals, which are connected to the connection terminals. The branches comprise two parts, which are provided with respective switches that are connected in series with diodes. The parts of the branches are connected with the power supply during the charging phase. An independent claim is also included for a method for charging a storage unit of a control system for an electric motor.

Description

CHARGE DEVICE AND ASSOCIATED METHOD

The present invention relates to the field of charging devices of the accumulation means of the control equipment of electric motors. Power sources for recharging storage means such as for example a battery of an electric vehicle are generally AC voltage sources while the batteries operate with DC voltage. Thus, it is necessary to convert the voltage delivered by the power source to be able to recharge the battery. Moreover, the voltage obtained after conversion into DC voltage is generally different from the load acceptable by the battery. It is then necessary to adapt the supplied voltage to the acceptable load by the battery. On the other hand, to limit the cost and weight of vehicles, the trend of car manufacturers is to connect to the motor phases to recharge the battery, which optimizes the number of components used. However, this can lead to yield losses because the motor phases are not configured for charging the batteries. Acoustic, vibratory or electromagnetic problems can also be generated by the passage of the current in the phases of the motor.

The need is therefore to propose a device and a charging method making it possible to limit the number of additional components while limiting the losses and avoiding the acoustic, vibratory or electromagnetic problems linked in particular to the inductances of the charging device.

Thus, the embodiments of the present invention relate to a charging device of accumulation means of a control equipment of an electric motor, said control equipment comprising: a voltage inverter intended to feed phases of the electric motor, and - a DC-DC voltage converter connected to the accumulation means and intended to supply the voltage inverter via two electrical connection terminals, characterized in that the charging device comprises:

CFR0432 (ES7605) 2974462 -2- - said DC-DC voltage converter, and - an AC-DC voltage conversion and power factor correction module, said module being connected on the one hand to the two electrical terminals link and intended to be connected on the other hand to a power source during the charging phases of the accumulation means.

According to another aspect of the present invention, the module comprises at least two branches connected in parallel between two output terminals of said module, said branches comprising first and second parts connected in series, said first and second parts comprising a switch mounted in series with a diode, the midpoints of said branches, separating said first and second parts, being intended to be connected to the power source during the charging phases, and the two output terminals being respectively connected to the two electrical connection terminals .

According to another aspect of the present invention, the module comprises three branches connected in parallel between two output terminals.

According to another aspect of the present invention, the DC-DC voltage converter is galvanically isolated. According to another aspect of the present invention, the DC-DC voltage converter is a voltage booster.

According to another aspect of the present invention, the DC-DC voltage converter 25 is a voltage step-down.

According to another aspect of the present invention, the DC-DC voltage converter is a step-down.

According to another aspect of the present invention, the voltage inverter comprises branches

CFR0432 (ES7605) 2974462 -3- connected in parallel between two input terminals, said branches comprising a first and a second parts connected in series, said first and second parts comprising a switch, the midpoints of said branches being connected to phases respective motor terminals, and the two input terminals being connected to the two electrical connection terminals. According to another aspect of the present invention, the accumulation means are a high voltage rechargeable battery.

The invention also relates to a charging method for accumulation means of a control equipment of an electric motor, said control equipment comprising: - a voltage inverter intended to supply phases of the electric motor, and - a DC-DC voltage converter connected to the accumulation means, and for supplying the voltage inverter via two electrical connection terminals, characterized in that the method comprises: - the connection of a conversion module of AC-DC voltage and correction of a power factor on the one hand to the two electrical connection terminals and on the other hand to a power supply, - the charging of the accumulation means, the module performing an absorption sinusoidal current from the power source and the DC-DC voltage converter adapting the voltage from the module to the voltage of the accumulation means.

Other features and advantages of the invention will appear in the description which will now be made, with reference to the accompanying drawings which represent, by way of indication but not limitation, a possible embodiment. In these drawings: - Figure 1 shows a simplified diagram of a control equipment of an electric motor and the associated charging device; FIG. 2 shows a circuit diagram of a voltage inverter supplying the phases CFR0432 (ES7605) of an electric motor; - Figure 3 shows an electrical diagram of a voltage booster circuit; FIG. 4 represents an electrical diagram of a voltage-reducing circuit; FIG. 5 represents a circuit diagram of a voltage step-up circuit; FIG. 6 represents an electrical diagram of a first embodiment of a charging device comprising a voltage rectifier connected to a single-phase network; FIG. 7 represents a circuit diagram of a second embodiment of a charging device comprising a voltage rectifier connected to a three-phase network; FIG. 8 shows a circuit diagram of a control equipment of an electric motor and a third embodiment of an associated charging device; FIG. 9 represents an electrical diagram of a diode bridge; FIG. 10 represents a circuit diagram of a control equipment of an electric motor and a fourth embodiment of an associated charging device;

In all the figures, the identical elements bear the same reference numbers. In the description which follows, generally denotes:

The term "insulated gate bipolar transistor (IGBT)" means a transistor comprising a metal-oxide semiconductor field effect transistor (MOSFET) In English) at the input and a bipolar transistor at the output.

FIG. 1 represents a simplified diagram of the control equipment 1 of an electric motor 3 and of an associated charging device intended to allow the charging of the accumulation means 7. example a high voltage rechargeable battery. The electric motor 3 is for example a three-phase electric motor. The control equipment 1 comprises a DC-DC voltage converter 9 intended to adapt the voltage coming from the battery 7, and a DC-DC converter 11 (also called a voltage inverter) intended to supply phases 13 of the motor. 3.

CFR0432 (ES7605) The charging device 5 comprises the DC-DC voltage converter 9 and an AC-DC conversion and power factor correction module 15 connected to the electrical connection terminals 17 and 19 located between the DC-DC voltage converter 9 and the DC-AC voltage converter 11. The module 15 is intended to be connected to a power source 21 during the charging phases of the battery 7. Thus, the module 15 performs the conversion of the AC voltage supplied by the power source 21, for example a single-phase or three-phase voltage network, into a DC voltage. In addition, in order to limit the losses during charging, the module 15 is configured to perform a power factor correction, that is to say a sinusoidal absorption of the current supplied by the power source 21. The general idea of the correction of the power factor is to minimize the formation of harmonics corresponding to a distortion of the signal supplied by the supply source 21. Indeed, the non-linear loads of the electrical devices connected to the source 15 power supply leads to the appearance of harmonics that deform the signal of the power source. To overcome this, a power factor correction circuit is positioned between the power source and the electrical device. The purpose of a power factor correction circuit is therefore to make the electrical circuits connected to the power source 21 appear as a pure resistance for the power source 21 despite the presence of non-linear elements in this power source. electric device. The power factor is the ratio of the active power to the apparent power. The active power P is expressed as P - 'with U the voltage, I the current and 1 the phase difference between the voltage and the current. 25 The apparent power S is expressed by

Thus the power factor correction circuit tends to reduce the power factor to 1 by putting the current and the voltage in phase (which happens when one has a pure resistance). FIG. 2 depicts an exemplary embodiment of a DC-AC voltage converter 11 corresponding to a three-phase bridge voltage inverter 23. The three-phase bridge voltage inverter CFR0432 (ES7605) 23 comprises six switches 25, generally composed of an IGBT type transistor 27 connected in parallel with a diode 29. Said six switches 25 are distributed over three branches, the midpoint (located between the two switches 25) of each branch being connected to a phase 13 The electric motor 3 is shown diagrammatically by the windings of its phases 13. FIG. 3 shows an exemplary embodiment of a DC-DC voltage converter 9. In this figure, the DC voltage converter Continuous 9 is a voltage boost circuit 31. However, it should be noted that a voltage buck circuit 45 (see FIG. g.4) or a booster-boost circuit 51 (see Fig. 5) may also be used in the context of the embodiments of the present invention. The DC-DC voltage converter 9 of FIG. 3 consists of a branch 33 comprising two switches 35 connected in series and an inductive element 37 connected to the midpoint (between the switches 35) of the branch 33. As for the voltage inverter 23, the switches 35 are generally formed of an IGBT type transistor 39 connected in parallel with a diode 41, which makes it possible to obtain a reversible converter, that is to say that the conversion can be as much of the input terminals to the output terminals as the opposite. In the latter case, the converter then becomes a voltage-reducing circuit. In the boosting direction, the DC-DC voltage converter 9 outputs a voltage greater than or equal to the input voltage, i.e. battery 7 in this case. A capacitor 43 is inserted between the electrical connection terminals 17 and 19 to control the voltage. The DC-DC voltage converter 9 of FIG. 4 corresponds to a voltage step-down circuit 45. The step-down circuit 45 comprises two switches 47 and an inductive element 49. This step-down circuit 45 corresponds to the lifting circuit 31 of FIG. which the input and output terminals have been inverted. As in the elevator circuit in FIG. 3, a capacitor 43 is connected to the output terminals 17, 19 to control the voltage. FIG. 5 shows another exemplary embodiment of a DC-DC voltage converter 9 which is a step-up circuit 51. This DC-DC voltage converter 9 comprises four switches 53 and an inductive element 55. It consists of of 2

CFR0432 (ES7605) 2974462 -7- branches 54 each comprising two switches 53 connected in series. An inductive element 55 connects the midpoints (between the switches 53) branches 54. As in the circuits in Figures 3 and 4, a capacitor 43 is connected to the output terminals 17, 19 to control the voltage. FIG. 6 shows an embodiment of an AC-DC conversion and power factor correction module for connection to a power source 21 corresponding to a single-phase voltage network 56. The module 15 comprises a first rectifier circuit 57. The first rectifier circuit 57 comprises two branches connected in parallel between two output terminals 58 and 60. Each branch comprises first and second series-connected parts. Each part comprises a switch 59 connected in series with a diode 61. The mid-points 63 and 65 of said branches, separating said first and second parts, are intended to be connected to the single-phase voltage network 56 during the charging phases. The two output terminals 58 and 60 are respectively connected to the two electrical connection terminals 17 and 19 of the diagram of FIG. 1. Thus, the AC voltage supplied by the single-phase voltage network 56 is converted into DC voltage by the first circuit. rectifier 57 then the value of the DC voltage is adjusted by the DC-DC voltage converter 9 in order to deliver the appropriate voltage to the battery 7. In addition, the first rectifier circuit 57 is configured to perform a power factor correction. the current delivered by the single-phase voltage network 56. FIG. 7 shows another embodiment of an AC-DC conversion and power factor correction module 15 intended to be connected to a power source 21 corresponding to a three-phase voltage network 67. The module 15 comprises a second rectifier circuit 69. The second rectifier circuit 69 comprises t 25 branches mounted in parallel between two output terminals 70 and 72. Each branch comprises a first and a second portion connected in series. Each part comprises a switch 71 connected in series with a diode 73. The midpoints 75, 77 and 79 of said branches separating said first and second parts are intended to be connected to the three-phase voltage network 67 during the charging phases. The two output terminals 70 and 72 are respectively connected to the two electrical connection terminals 17 and 19 of the diagram of FIG.

CFR0432 (ES7605) 2974462 -8- Thus, the AC voltage supplied by the three-phase voltage network 67 is converted into DC voltage by the second rectifier circuit 69, then the value of the DC voltage is adjusted by the DC-DC voltage converter. 9 in order to deliver the correct voltage to the battery 7. In addition, the second rectifier circuit 69 is configured to perform a correction of the power factor of the current delivered by the three-phase voltage network 67 in order to reduce the losses to the maximum during the FIG. 8 is a diagram of another embodiment of an AC-DC conversion and power factor correction module 15 for connection to a corresponding power source 21. to a single-phase voltage network 56. In this example, the DC-DC voltage converter 9 is a voltage booster 31 such as the one presented in FIG. FIG. 3. The module 15 comprises a diode bridge 81 (also called a Graetz bridge) which allows the conversion of the AC voltage supplied by the network 56 into a DC voltage. The module 15 further comprises a step-up converter 83 connected to the output terminals 85 and 86 of the diode bridge 81 and which makes it possible to carry out the sinusoidal absorption of the signal converted by the diode bridge 81. A diode bridge 81 such as shown in Figure 9 comprises two branches connected in parallel between two output terminals 85 and 86, each branch comprising two diodes 87 connected in series. The mid-points (situated between the two diodes 87 connected in series) of each branch are connected to the input terminals 89 and 90 (connected to the network 56 in FIG. 8) of the diode bridge 81. With respect to the voltage converter continued-continuous 9 illustrated in Figure 3, in the upconverter 83 of Figure 8, the switch connected to the electrical connection terminal 19 is replaced by a diode 91. Indeed, the diode bridge 81 is not reversible it is not necessary for the upconverter 83 to be reversible so that the switch can be replaced by the diode 91. The switch 93 and the impedance 95 are respectively connected to the terminals 85 and 86 of the diode bridge. 81, while the output terminals of the upconverter 83 are connected to the electrical connection terminals 17 and 19. FIG. 10 shows another embodiment of an AC-DC conversion and correction module. power factor 15 to be connected to a power source 21 corresponding to a single-phase voltage network 56. In this example,

CFR0432 (ES7605) 2974462 the DC-DC voltage converter 9 is a voltage step-down circuit 45 such as that shown in Figure 4. In this embodiment, the module 15 comprises a diode bridge 81. For example the diode bridge 81 corresponds to the diode bridge shown in FIG. 9. The module 15 further comprises a converter 97 providing sinusoidal absorption and voltage rise. The converter 97 comprises a branch comprising two switches 99 connected in series. A first end of the branch is connected on the one hand to the first output terminal 85 of the diode bridge 81 and on the other hand to the electrical connection terminal 17. A second end of the branch is connected to the second electrical terminal The midpoint of the branch (located between the two switches 99) is connected to the second output terminal 86 of the diode bridge 81. It should be noted that with the embodiment shown in FIG. it is not necessary to introduce a capacitance between the electrical connection terminals 17 and 19 because the voltage is already controlled due to the absence of impedance in the charging device. The embodiments of AC-DC conversion and power factor correction modules discussed above are representative but not limiting so that the invention extends to all AC voltage conversion module configurations. continuous, for example a configuration similar to an inverter in the case of a three-phase voltage source. According to an alternative embodiment, the DC-DC voltage converter 9 can be galvanically isolated in order to comply with electromagnetic compatibility (EMC) standards and to ensure the safety of users. The charging device 5 and the charging method according to the invention allow efficient charging of the battery 7 while reusing certain components of the control equipment 1. In fact, the DC-DC voltage converter 9 of the equipment 1 is reused in the charging device 5, which makes it possible to limit the number of components required for the charging device 5. In addition, thanks to the AC-DC conversion and power factor correction module 15 connected to the electrical connection terminals 17 and 19, the inductances corresponding to the phases 13 of the motor 3 are not used during the charging of the accumulation means 7. Thus, the acoustic, vibratory or electromagnetic problems, in particular

CFR0432 (ES7605) 2974462 -10- particular those related to a passage of currents in the phases 13 of the motor 3, are reduced or even eliminated. In addition, during the charging of the accumulation means 7, the efficiency losses are reduced because the AC-DC conversion and power factor correction module 15 is configured for the charge of the battery 7. The The invention is not limited to the embodiments described. In particular, the power source 21 may have one or more phases; the electric motor 3 may have a number of phases greater or less than 3. CFR0432 (ES7605)

Claims (10)

REVENDICATIONS1. Charging device (5) for accumulating means (7) of a control equipment (1) of an electric motor (3), said control equipment (1) comprising: - a voltage inverter (11) intended to supplying phases (13) of the electric motor (3), and - a DC-DC voltage converter (9) connected to the accumulation means (7) and for supplying the voltage inverter (11) via two electrical connection terminals (17 and 19), characterized in that the charging device (5) comprises: - said DC-DC voltage converter (9), and - an AC-DC voltage conversion module and correction of a power factor (15), said module (15) being connected on the one hand to the two electrical connection terminals (17 and 19) and intended to be connected on the other hand to a power supply (21 ) during the charging phases of the accumulation means (7). 2. Charging device (5) according to claim 1, wherein the module (15) comprises at least two branches connected in parallel between two output terminals (58 and 60; 70 and 72) of said module (15), said branches comprising first and second series-connected parts, said first and second parts comprising a switch (59, 71) connected in series with a diode (61, 73), the mid-points (63 and 65, 75, 77 and 79) said branches, separating said first and second parts, being intended to be connected to the power source (21) during the charging phases, and the two output terminals (58 and 60; 70 and 72) being respectively connected to the two electrical connection terminals (17 and 19). 3. Charging device (5) according to claim 2, wherein the module (15) comprises three branches connected in parallel between two output terminals (70 and 72). 4. Charging device (5) according to one of the preceding claims in CFR0432 (ES7605) -12- wherein the DC-DC voltage converter (9) is galvanically isolated. 5. Charging device (5) according to one of the preceding claims, wherein the DC-DC voltage converter (9) is a voltage booster (31). 6. Charging device (5) according to one of claims 1 to 4, wherein the DC-DC voltage converter (9) is a voltage step-down (45). 7. Charging device (5) according to one of claims 1 to 4, wherein the DC-DC voltage converter (9) is a voltage step-down (51). 8. charging device (5) according to one of the preceding claims, wherein the voltage inverter (11) comprises branches connected in parallel between two input terminals, said branches comprising a first and a second mounted parts 15 in series, said first and second parts comprising a switch (25), the midpoints of said branches being connected to respective phases (13) of the motor (3), and the two input terminals being connected to the two electrical connection terminals (17 and 19). 9. Charging device (5) according to one of the preceding claims, wherein the accumulation means (7) are a high voltage rechargeable battery. 10. A charging method for accumulation means (7) of a control equipment (1) of an electric motor (3), said control equipment (1) comprising: - a voltage inverter (11) intended to supplying phases (13) of the electric motor (3), and 25 - a DC-DC voltage converter (9) connected to the accumulation means (7) and for supplying the voltage inverter (11) via two electrical connection terminals (17 and 19), characterized in that the method comprises: - the connection of an AC-DC conversion and power factor correction module (15) of a the two electrical connection terminals (17 and 19) and CFR0432 (ES7605) 2974462 -13- on the other hand to a power source (21), - the load of the accumulation means (7), the module ( 15) performing a sinusoidal absorption of the current from the power source (21) and the DC-DC voltage converter (9) adapting the voltage ion from the module (15) to the voltage of the means 5 of accumulation (7). CFR0432 (ES7605)