Charging device for battery of electric vehicle or like

Abstract

A charging device (A ') of an electric vehicle or the like comprises an on-board charging device (OBC) mounted on the electric vehicle, provided with: an input stage (SIN') comprising input connection terminals (C1, C2, C3, N) connectable to an external AC power supply line; a power factor correction circuit (PFC ') connected to the input stage (SIN'); a DC / DC converter circuit having an input connected to the power factor correction circuit (PFC ') and an output connected to a battery (EVB) of the electric vehicle; wherein the input stage (SIN ') comprises additional input connections (C4, C5) connected to the power factor correction circuit (PFC') and connectable to at least one 400 V DC charging post; the power factor correction circuit (PFC ') is configured to operate in two modes: a first AC mode of operation, the power factor correction circuit (PFC') operating as a conventional power factor corrector; the power factor correction circuit (PFC ') is operated as a booster, a second 400 V DC operating mode, the power factor correction circuit (PFC') is operated as a booster, and the apparatus (A) comprises a bypass circuit (SW1, SW2) of the DC / DC converter circuit configured to bypass the DC / DC converter circuit when the power factor correction circuit (PFC ') is operated in the second 400 V DC operating mode.

Description

Technical Field

[0001] The present invention relates to a charging device for a battery used in an electric vehicle or the like. Background Art

[0002] As is well known, an electric vehicle converts a part of the chemical energy stored in one or more batteries (so-called "electric vehicle batteries", EVBs) into electrical energy, and then transfers this electrical energy to an electric motor to achieve ground propulsion.

[0003] To achieve periodic charging of the battery, an electric vehicle is equipped with a special device called an on-board charger (OBC) that is already built into the vehicle.

[0004] Figure 1 A known type of charging device A is schematically shown.

[0005] Referring to this figure, it can be seen that the known OBC device is provided with an input stage SIN1, which includes one or more input connection terminals C1, C2, C3 (for example, three), which can be connected to an external AC power line (for example, single-phase, two-phase or three-phase type), and can be input with AC current passing through.

[0006] In addition, the input stage SIN1 includes an input filter F connected to each input connection terminal C1, C2, C3 in .

[0007] In a common OBC, two interconnected stages are usually used.

[0008] The first stage is a power factor corrector (PFC), the purpose of which is to obtain a current as close to a sine wave and in phase with the input voltage as possible from the power grid, so as to absorb the maximum active power without the need for absorption peaks from the power grid.

[0009] The PFC usually provides a constant or adjustable and stable DC voltage at the next stage.

[0010] The second stage is a DC / DC converter, which is usually but not necessarily implemented through an LLC circuit. The LLC circuit receives the voltage provided by the PFC and provides a variable or fixed DC voltage required by the user at the output, while achieving the necessary electrical isolation between the line voltage and the output.

[0011] In addition, an output filter F is provided downstream of the DC / DC converter OUT , for restricting the propagation of noise generated during the conversion process to the output terminal.

[0012] Therefore, the direct current flows through the output filter FOUT After that, it can be sent to the battery EVB.

[0013] In addition, in combination with an OBC device connectable to an AC power line, it is known to use a second input stage connectable to a DC charging station on an electric vehicle.

[0014] In particular, the use of rechargeable batteries with a DC voltage of 800V for rapid charging of electric vehicles is becoming increasingly popular.

[0015] This has led to an increasing number of charging stations capable of providing 800V DC.

[0016] However, since there are still a large number of charging piles in the national charging network that can provide a nominal DC voltage of 400V, it is necessary to deploy additional devices, so-called boosters, on electric vehicles in order to achieve 800V charging of the vehicle battery through the currently widely installed 400V charging piles.

[0017] As Figure 1 schematically shown, the second input stage SIN2 includes two input connection terminals C4 and C5, which can be connected to a DC voltage charging pile. The charging pile to which the second input stage SIN2 can be connected can be an 800V charging pile or a charging pile capable of providing a voltage of 400V.

[0018] In addition, the second input stage SIN2 includes a booster BST, which is configured to be triggered when connected to a 400V charging pile in order to provide an 800V charging voltage for the downstream-connected battery.

[0019] In order to be able to select whether to enable the booster BST, the second input stage SIN2 is provided with a bypass circuit, which is connected upstream and downstream of the booster BST and includes a switch SW that can be controlled in two configurations.

[0020] In the first 800V configuration, the switch SW is closed, thus bypassing the booster BST, and further enabling a direct connection between the 800V charging pile and the vehicle battery EVB.

[0021] In the second 400V configuration, the switch SW is open, and the booster BST is then operatively placed between the 400V charging pile and the vehicle battery EVB. In this case, the booster BST converts the 400V input voltage into an 800V output voltage to supply the battery EVB.

[0022] However, this known solution has some drawbacks.

[0023] In particular, in order for electric vehicles to be able to connect to the 400V charging piles that are still widely used at present, a step-up transformer is required, so additional equipment needs to be installed on the vehicle.

[0024] This inevitably leads to an increase in costs and requires more space to be reserved for the charging device in electric or hybrid vehicles. Summary of the Invention

[0025] The main object of the present invention is to design a charging device for the battery of electric vehicles and the like to reduce the total cost.

[0026] Another object of the present invention is to design a charging device for the battery of electric vehicles and the like to reduce the space it occupies inside the vehicle.

[0027] Another object of the present invention is to design a charging device for the battery of electric vehicles and the like to overcome the above-mentioned disadvantages of the prior art within the framework of a simple, reasonable, easy and effective solution with low cost.

[0028] The above object is achieved by the charging device for the battery of electric vehicles and the like according to the present invention, and its specific features are as described in claim 1. Brief Description of the Drawings

[0029] Other features and advantages of the present invention will become more apparent from the following description of the preferred but non-exclusive embodiments of the device for recharging the battery of electric vehicles and the like, which are shown in the drawings in a schematic rather than restrictive manner, wherein:

[0030] Figure 1 is a general schematic diagram of a known type of charging device, in which an additional boost device is used to enable a 400V charging pile to achieve charging;

[0031] Figure 2 is a general schematic diagram of the charging device according to the present invention. Detailed Description of the Invention

[0032] Specific reference is made to Figure 2 , and the reference numeral A' generally represents a charging device for the battery of electric vehicles and the like.

[0033] The device A includes on-vehicle charging equipment (OBC') installed on an electric vehicle.

[0034] The charging equipment OBC' includes an input stage SIN', and the input stage SIN' includes at least one input connection terminal C1, C2, C3, N that can be connected to an external AC power line (for example, single-phase, two-phase or three-phase type).

[0035] Reference is made to Figure 2In the example of , the input stage SIN’ includes four input terminals C1, C2, C3, N that can be respectively connected to the three phases and the neutral line of a three-phase AC line.

[0036] However, the possibility of using such an input for connecting to a single-phase or two-phase line is not excluded.

[0037] In addition, the charging device OBC’ includes a power factor correction circuit PFC’ connected to the input stage SIN’.

[0038] When the input terminals C1, C2, C3, N are connected to an AC power supply line, the circuit PFC’ is configured to draw a current from the power grid that is as sinusoidal as possible and in phase with the input voltage, so as to absorb the maximum active power without the need to absorb the absorption peak related to the electrolytic capacitor from the power grid. In this case, the circuit PFC provides a constant or variable DC voltage and stably transmits it to the next stage.

[0039] Furthermore, the charging device OBC’ includes a DC / DC converter circuit that has an input terminal and an output terminal. The input terminal is connected to the power factor correction circuit PFC, and the output terminal is connected to the battery EVB of the electric vehicle.

[0040] The DC / DC converter circuit is configured to draw the voltage provided by the circuit PFC and provide a DC voltage at the output terminal while achieving the necessary electrical isolation between the line voltage and the output terminal.

[0041] The DC / DC converter circuit is preferably implemented by an LLC circuit.

[0042] In addition, the input stage SIN’ includes at least one additional input terminal C4, C5, which is connected to the power factor correction circuit PFC’ and can be connected to at least one 400V or 800V DC voltage charging pile.

[0043] Reference Figure 2 In the preferred embodiment shown, the input stage SIN’ includes two additional input terminals C4, C5, which are respectively connected to at least one of the phase C1 and the neutral line N for connection to the AC power supply line.

[0044] In addition, the power factor correction circuit PFC’ is configured to operate in two modes:

[0045] - The first AC operation mode, when the input terminals C1, C2, C3, N of the input stage SIN’ are connected to an external AC power supply line, the power factor correction circuit PFC’ operates as a conventional power factor corrector, so as to correct the ratio of the active power vector modulus to the apparent power vector modulus;

[0046] - Second 400V DC operating mode. When the additional input terminals C4 and C5 are connected to a 400V DC charging pile, the power factor correction circuit PFC’ operates as a step-up transformer to convert the 400V input voltage from the charging pile into an 800V output voltage to supply the battery EVB.

[0047] Advantageously, these two operating modes can be implemented by the same hardware of the power factor correction circuit PFC’.

[0048] Specifically, to operate in two independent operating modes, device A includes at least one connection circuit SW3, SW4, SW5, SW6 for connecting the power factor correction circuit PFC’ to an external AC power line or a 400V DC charging pile.

[0049] Preferably, the connection circuit SW3, SW4, SW5, SW6 includes:

[0050] - Multiple switches SW6, respectively arranged at the input terminals C1, C2, C3, N for connecting / disconnecting the external AC power line to / from the power factor correction circuit PFC’;

[0051] - Switch pairs SW3, SW4, respectively arranged at the additional input terminals C4, C5 for connecting / disconnecting the 400V DC charging pile to / from the input terminal of the power factor correction circuit PFC’.

[0052] Specifically, the connection circuit SW3, SW4, SW5, SW6 can be controlled in two configurations:

[0053] - First AC configuration, switch SW6 is closed, switches SW3, SW4 are open, and the power factor correction circuit PFC’

[0054] is connected to the external AC power line;

[0055] - Second 400V DC voltage configuration, switch SW6 is open, switches SW3, SW4 are closed, and the power factor correction circuit PFC’ is connected to the 400V DC voltage charging pile.

[0056] Device A also includes at least one bypass circuit SW1, SW2 of the DC / DC converter circuit, configured to bypass the DC / DC converter circuit when the power factor correction circuit PFC’ operates in the second operating mode at a 400V DC input voltage.

[0057] Therefore, in this case, the power factor correction circuit PFC’ operates as a step-up transformer and is directly connected to the 800V battery EVB.

[0058] Preferably, the bypass circuit includes a pair of switches SW1, SW2 connected to the input and output terminals of the DC / DC converter circuit and can be controlled in two configurations:

[0059] - In the first configuration, the switches SW1, SW2 are open, and then the DC / DC converter circuit is operably located between the power factor correction circuit PFC’ and the battery EVB;

[0060] - In the second bypass configuration, when the power factor correction circuit PFC’ operates in the second operating mode at a 400V DC input voltage, the switches SW1, SW2 are closed, thereby bypassing the DC / DC converter circuit, thus enabling a direct connection between the power factor correction circuit PFC’ and the vehicle battery EVB.

[0061] The device A’ is also provided with at least one input voltage detection device disposed at the input stage SIN’ and operably connected to the power factor correction circuit PFC’.

[0062] Therefore, in the case where the detection device detects an AC voltage, the power factor correction circuit PFC’ is then configured to operate in the first AC operating mode.

[0063] However, in the case where the detection device detects a 400V DC voltage, the power factor correction circuit PFC’ is configured to operate in the second operating mode at a 400V DC input voltage.

[0064] According to a preferred embodiment, the device A’ can also be connected to an 800V DC voltage charging pile.

[0065] In this case, the device A’ can be used for charging through an 800V DC voltage charging pile.

[0066] According to Figure 2 the possible and preferred embodiment shown, the 800V DC voltage charging pile can be connected to the device A’ through the same additional input connection terminals C4, C5 as the input stage SIN’.

[0067] Specifically, in this case, the connection circuit SW3, SW4, SW5, SW6 includes at least one additional switch SW5 for bypassing the power factor correction circuit PFC’.

[0068] Conveniently, according to a preferred embodiment, in addition to the power factor correction circuit PFC’, the additional switch SW5 is also configured to bypass the DC / DC converter circuit.

[0069] Specifically, the additional switch SW5 is connected between at least one additional input connection terminal C4 and the battery EVB, downstream of the DC / DC converter circuit.

[0070] Therefore, when connected to an 800V charging pile, high power can be directly transmitted to the battery EVB while bypassing both the power factor correction circuit PFC’ and the DC / DC converter circuit.

[0071] Specifically, in this case, the connection circuits SW3, SW4, SW5, SW6 and the bypass circuits SW1, SW2 can be controlled in three configurations:

[0072] - First AC configuration, switch SW6 is closed, switches SW1, SW2, SW3, SW4, SW5 are open, the power factor correction circuit PFC’ is then connected to the external AC power line, while the DC / DC converter circuit is operably located between the power factor correction circuit PFC’ and the battery EVB;

[0073] - Second 400V DC voltage configuration, switches SW5, SW6 are open, switches SW1, SW2, SW3, SW4 are closed, the power factor correction circuit PFC’ is then connected to a 400V DC voltage charging pile while bypassing the DC / DC converter circuit, achieving a direct connection between the power factor correction circuit PFC’ and the vehicle battery EVB;

[0074] - Third 800V DC voltage configuration, switches SW4, SW6 are open, switches SW3, SW5 are closed, the power factor correction circuit PFC’ and the DC / DC converter circuit are bypassed, achieving a direct connection between the 800V charging pile and the vehicle battery EVB.

[0075] Conveniently, the input stage SIN’ can include at least one input filter (not shown in Figure 2 ) connected to each input connection terminal C1, C2, C3, N.

[0076] Additionally, the device A’ can include at least one output filter FOUT connected downstream of the DC / DC converter circuit and upstream of the battery EVB. The output filter FOUT is configured to limit the noise generated during the conversion to the battery EVB.

[0077] Referring to Figure 2 the preferred embodiment shown in, the bypass circuits SW1, SW2 are configured to bypass both the output filter FOUT and the DC / DC converter circuit simultaneously when the device is connected to a 400V or 800V charging pile.

[0078] Furthermore, in this case, switches SW3 and SW5 are connected between the additional input connection terminals C4, C5 and the battery EVB, downstream of the output filter FOUT.

[0079] However, other embodiments are not excluded, in which the filter is not bypassed and is suitably arranged to filter the voltage signal during charging via a 400V or 800V charging pile.

[0080] It should also be noted that reference to a 400V or 800V charging pile refers to all charging piles with a nominal reference voltage of 400V and 800V, but the actual output voltage can vary between different voltage values.

[0081] In practice, it has been determined that the described invention achieves the intended purpose.

[0082] In particular, the fact is emphasized that using the same power factor correction circuit as a booster reduces the overall cost and size of the device.

Claims

1. A charging device (A') for an electric vehicle or the like, comprising an on-vehicle charging device (OBC) mounted on the electric vehicle, the on-vehicle charging device (OBC) having: An input stage (SIN'), including at least one input connection terminal (C1, C2, C3, N) connectable to an external AC power line; A power factor correction circuit (PFC'), connected to the input stage (SIN'); A DC / DC converter circuit, having an input terminal and an output terminal, the input terminal being connected to the power factor correction circuit (PFC'), and the output terminal being connected to the battery (EVB) of the electric vehicle; Characterized in that: The input stage (SIN') includes at least one additional input connection terminal (C4, C5), the additional input connection terminal (C4, C5) being connected to the power factor correction circuit (PFC') and connectable to at least one 400V DC charging pile; The power factor correction circuit (PFC') is configured to operate in two modes: a first AC operation mode, when at least one of the input connection terminals (C1, C2, C3, N) of the input stage (SIN') is connected to an external AC power line, the power factor correction circuit (PFC') operates as a conventional power factor corrector, thereby for correcting the ratio of the active power vector modulus to the apparent power vector modulus; A second 400V DC operation mode, when at least one of the additional input connection terminals (C4, C5) is connected to a 400V DC charging pile, the power factor correction circuit (PFC') operates as a booster, thereby for converting a 400V input voltage into an 800V output voltage to supply the battery (EVB); The device (A) includes a bypass circuit (SW1, SW2) of at least one of the DC / DC converter circuits, the bypass circuit (SW1, SW2) being configured to bypass the DC / DC converter circuit when the power factor correction circuit (PFC') operates in the second 400V DC operation mode.

2. The device (A') according to claim 1, Characterized in that, Including at least one connection circuit (SW3, SW4, SW5, SW6) of the power factor correction circuit (PFC') for connecting the power factor correction circuit (PFC') to the external AC power line or the 400V DC charging pile.

3. The device (A') according to claim 2, Characterized in that, The connection circuit (SW3, SW4, SW5, SW6) includes: A plurality of switches (SW6), provided on the input connection terminals (C1, C2, C3, N) for connecting the external AC power line to the power factor correction circuit (PFC') / disconnecting from the power factor correction circuit (PFC'); A switch pair (SW3, SW4), provided on the additional input connection terminals (C4, C5) for connecting the 400V DC charging pile to the input terminal of the power factor correction circuit (PFC') / disconnecting from the input terminal of the power factor correction circuit (PFC').

4. The device (A’) according to one or more of the preceding claims, characterized in that, it comprises at least one input voltage detection device provided at the input stage (SIN’), and the input voltage detection device is operably connected to the power factor correction circuit (PFC’).

5. The device (A’) according to one or more of the preceding claims, characterized in that, the bypass circuit comprises a switch pair (SW1, SW2), and the switch pair (SW1, SW2) is connected to the input end and the output end of the DC / DC converter circuit and can be controlled in two configurations: A first configuration, in which the switches (SW1, SW2) are disconnected, and then the DC / DC converter circuit is operably located between the power factor correction circuit (PFC’) and the battery (EVB); A second bypass configuration, in which the switches (SW1, SW2) are closed, so as to bypass the DC / DC converter circuit and realize a direct connection between the power factor correction circuit (PFC’) and the vehicle battery (EVB).

6. The device (A’) according to claim 5, characterized in that, the bypass circuit comprises a switch pair (SW1, SW2) respectively connected to the input end and the output end of the DC / DC converter circuit.

7. The device (A’) according to one or more of claims 2 to 6, characterized in that, the connection circuit (SW3, SW4, SW5, SW6) comprises at least one additional switch (SW5), and the additional switch (SW5) is configured to bypass the power factor correction circuit (PFC’) when connecting the additional input connection terminals (C4, C5) to an 800V DC charging pile.

8. The device (A’) according to one or more of the preceding claims, characterized in that, the input stage (SIN’) comprises at least one input filter (FIN) connected to each input connection terminal (C1, C2, C3, N).

9. The device (A’) according to one or more of the preceding claims, characterized in that, it comprises at least one output filter (FOUT), and the at least one output filter (FOUT) is connected downstream of the DC / DC converter circuit and upstream of the battery (EVB).

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