VEHICLE-TO-VEHICLE DC CHARGING SYSTEM

Abstract

The present invention provides a vehicle charging system (100) that facilitates vehicle-to-vehicle (V2V) direct current charging. The system (100) comprises a charging input (104), a bypass circuit (106), and a battery (102). The bypass circuit (106), with switches (110) and busbars (112), controls the direct current flow between the charging input (104) and the battery (102) during V2V charging. The bypass circuit (106) is connected in parallel to an on-board charger (OBC) (108) for alternating current charging. V2V DC charging is achieved by connecting vehicles (120, 150) via charging inputs (104, 134) using an AC adapter cable (122). The charging input (104) is a Type 2 AC plug with a 3-phase AC cable (122), and the 400 V battery (102) enables a power transfer of up to 25.6 kW during V2V DC charging, increasing efficiency and performance.

Description

TECHNICAL AREA

[0001] The present invention relates to the field of charging systems for electric vehicles (EVs). More specifically, it relates to direct current (DC) vehicle-to-vehicle (V2V) charging systems with alternating current (AC) charging cables. BACKGROUND

[0002] Electric vehicles (EVs) are enjoying increasing popularity due to their environmental benefits and technological innovations. Among these advancements, vehicle-to-vehicle (V2V) charging has emerged as a significant technological leap forward for electric vehicles, addressing range anxiety and enhancing their practicality. V2V charging allows EV owners to recharge their vehicles in emergency situations or in remote areas where access to a nearby charging station is limited. This feature has the potential to significantly improve the convenience and usability of EVs, particularly in regions with sparse charging infrastructure. However, despite its potential, this feature remains underutilized due to various limitations.

[0003] A major problem with conventional V2V charging systems is that electric vehicles often lack DC charging cables. This limits the use of V2V charging to onboard AC charging systems. However, AC charging systems have limited current transfer capacity, making charging slow and inefficient. Furthermore, the efficiency of V2V AC charging is low due to multiple power conversion stages, further limiting its effectiveness. These limitations discourage electric vehicle owners from using V2V charging, thus restricting the overall usability and convenience of electric vehicles.

[0004] Patent documents such as US20240067024A1 and CN112810470A have attempted to address these issues. US20240067024A1, for example, offers V2V charging via an EV-to-EV battery charger. The battery charger has an input and an output port to connect to the charging and receiving electric vehicles, respectively. Similarly, CN112810470A proposes a vehicle-mounted V2V fast-charging system that includes a fast-charging cable connecting a discharging vehicle (A) and a receiving vehicle (B). The fast-charging cable includes a slow-charging interface, a cable control box, and a fast-charging interface, all connected sequentially. However, these solutions still have limitations and do not fully address the specific cable requirements and efficient V2V charging needs of electric vehicles.

[0005] Therefore, it is necessary to overcome the aforementioned problems and other limitations associated with the state of the art. TASK OF INVENTION

[0006] The primary object of the present invention is to provide an on-board vehicle charging system that facilitates direct current (DC) vehicle-to-vehicle (V2V) charging.

[0007] Another object of the present invention is to provide DC V2V charging via alternating current (AC) charging cables.

[0008] Another object of the present invention is to enable increased power transfer during DC-V2V charging via AC charging cables.

[0009] Another object of the present invention is to enable DC-V2V power transmission without the need for power conversion stages. SUMMARY

[0010] The present invention describes a vehicle charging system for facilitating direct current (DC) charging from vehicle to vehicle (V2V). The system comprises a charging input, a bypass circuit, and a battery. The charging input is designed to be electrically coupled to an external AC charger and electrically connected to the battery via the bypass circuit.

[0011] The bypass circuit comprises one or more switches and a pair of series-connected power rails. The switch(es) and power rails are configured to control the DC current flow between the charging input and the battery during V2V charging. The bypass circuit also includes a microcontroller that controls the operation of the switch(es). The switches in the bypass circuit are designed as electromagnetic relays for reliable operation.

[0012] The bypass circuit is connected in parallel to the vehicle's on-board charger (OBC), which enables AC charging. V2V DC charging is achieved by connecting the vehicles via their respective charging ports using an AC adapter cable.

[0013] The charging input is a Type 2 AC connector, which is connected via a 3-phase AC adapter cable. When used with a 400 V battery, the system can deliver up to 25.6 kW of power during V2V DC charging.

[0014] This innovative charging system enables efficient V2V charging by utilizing the existing AC infrastructure for DC power transmission, thus increasing the flexibility and utility of electric vehicles.

[0015] The preceding sections were given as a general introduction and are not intended to limit the scope of the following claims. The described embodiments, along with further advantages, are best understood by reference to the following detailed description in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1: Schematic representation of a vehicle charging system for vehicle-to-vehicle DC charging. Fig. 2: Schematic representation of vehicle-to-vehicle DC charging using the diagram in Fig. 1 of the charging system shown. DETAILED DESCRIPTION

[0016] Aspects of the present invention are best understood by reference to the description contained herein. All aspects described herein will be better appreciated and understood when considered in conjunction with the following descriptions. However, it should be understood that the following descriptions, although they highlight preferred aspects and numerous specific details thereof, serve only for illustration and should not be considered as limitations. Changes and modifications may be made within the scope described herein without altering the spirit and scope of the invention, and the present invention includes all such modifications.

[0017] The present invention relates to an in-vehicle charging system that enables the charging of vehicles with direct current (DC) (V2V). The charging system allows two vehicles to be connected via alternating current (AC) charging cables during DC V2V charging.

[0018] Fig. Figure 1 shows an onboard vehicle charging system 100 for DC V2V charging according to an embodiment of the invention. The system 100 comprises a battery 102, a charging input 104, and a bypass circuit 106. The charging input 104 is designed to be electrically connected to an external AC charging cable (not shown). The charging input 104 is electrically connected to the battery 102 via the bypass circuit 106.

[0019] The bypass circuit 106 is configured to allow a DC current flow between the charging input 104 and the battery 102 during DC-V2V charging. The bypass circuit 106 comprises one or more switches 110 and a pair of busbars 112. The one or more switches 110 are connected in series with the pair of busbars 112. The switches 110 are configured to open and close the electrical coupling between the charging input 104 and the battery 102. The one or more switches 110 are configured to remain closed during the DC-V2V charging process. The busbar pair 112 is connected between the battery 102 and the charging input 104 and is configured to split the DC current flowing from the battery 102 to the charging input 104. The busbar pair 112 facilitates the connections between a multitude of power connections of the charging input 104 and a pair of battery connections.

[0020] In one embodiment, the one or more switches 110 in the bypass circuit 106 are one or more electromagnetic relays. The electromagnetic relays provide reliable and efficient switching options for connecting and disconnecting the electrical connection between the charging input 104 and the battery 102.

[0021] In one embodiment, the bypass circuit 106 also includes a microcontroller (not shown) configured to control the operation of the switches 110 to regulate the flow of direct current between the battery 102 and the charging input 104. In one embodiment, the one or more switches 110 are one or more electromagnetic relays. The microcontroller generates control signals to activate or deactivate the relays as needed. By controlling the relays, the microcontroller manages the flow of direct current between the battery 102 and the charging input 104, optimizing the charging process and ensuring safe operation of the V2V charging system.

[0022] Furthermore, the bypass circuit 106 is connected in parallel to an on-board charger (OBC) 108 of the vehicle. The OBC 108 is arranged between the charging input 104 and the battery 102 to charge the vehicle with alternating current. During AC charging of the vehicle, the OBC 108 receives AC from the charging input and then converts the received AC into direct current suitable for charging the battery 102. This configuration allows the vehicle to utilize the standard AC charging infrastructure under normal conditions. In one embodiment, the OBC 108 comprises an AC / DC converter 118 and a DC / DC converter 116. The AC / DC converter 118 is connected to the charging input 104 to receive AC from the charging input 104 and converts the received AC into direct current.The DC / DC converter 116, which is connected between the AC / DC converter 118 and the battery 102, then adjusts the DC voltage level of the converted DC current to the requirements of the battery 102. In one embodiment, the one or more switches 110 in the bypass circuit 106 are configured to remain open during normal AC charging operation, so that AC current can flow through the OBC 108 to facilitate AC charging of the vehicle.

[0023] In one embodiment, the charging input 104 is a Type 2 AC connector. The Type 2 AC connector comprises four power terminals, including three phase terminals (L1, L2, L3) and one neutral terminal (N), as well as three control terminals, including one protective earth (PE) terminal and two signaling terminals (CP, PP). The busbar pair 112 consists of two busbars BB1, BB2, each having one input terminal and two output terminals to enable power distribution, as shown in Fig. Figure 1 shows the busbar BB1 comprising one input terminal A1 and two output terminals B1 and B2. Busbar BB2 comprising one input terminal A2 and two output terminals B3 and B4. To facilitate the DC current flow between the charging input 104 and the battery 102 during DC V2V charging, the input terminals A1 and A2 of the busbar pair 112 are connected to the positive and negative terminals of the battery 102 via switches 110. Furthermore, the output terminals B1-B4 of the busbar pair 112 are connected to the power terminals L1-L3 and N of the Type 2 AC connector 104. The connection arrangement between the battery 102, the one or more switches 110, the busbar pair 112, and the charging input 104 enables optimal and efficient current distribution and sharing to provide a high-performance DC V2V charge.

[0024] In Fig. 2. DC-V2V charging between two vehicles will be implemented using the [unclear text]. Fig. The charging system 100 shown in Figure 1 is shown. Vehicles 120 and 150 each include charging systems 100 and 130, respectively. Charging system 130 comprises a charging input 134, a battery 132, and a bypass circuit 136. The bypass circuit 136 is connected in parallel to an OBC 138. The bypass circuit 136 also includes one or more switches 140 and a pair of busbars 142. The OBC 138 comprises an AC / DC converter 148 and a DC / DC converter 146. With further reference to Fig. 2. The charging input 134, the battery 132, the bypass circuit 136, the OBC 138, one or more switches 140, the pair of busbars 142, the AC / DC converter 148 and the DC / DC converter 146, as non-limiting examples, can be substantially the same as the charging input 104, the battery 102, the bypass circuit 106, the OBC 108, one or more switches 110, the pair of busbars 112, the AC / DC converter 118 and the DC / DC converter 116, as previously described herein.

[0025] Furthermore, V2V DC charging is facilitated by connecting the vehicles 120, 150 to their respective charging inputs 104, 134 via an AC adapter cable 122. In one embodiment, the AC adapter cable 122 is a standard 3-phase / 1-phase AC charging cable typically used for AC charging of electric vehicles.

[0026] In one embodiment, the charging inputs 104, 134 of vehicles 120, 150 are Type 2 AC connectors connected to the AC adapter cable 122, which has Type 2 connectors at both ends to facilitate power transfer during V2V DC charging. In another embodiment, the charging inputs 104, 134 and the AC adapter cable 122 are three-phase Type 2 connectors, and the batteries 102, 132 operate at 400 V, so that a power transfer of up to 25.6 kW is possible during V2V DC charging between vehicles 120, 150. However, with conventional V2V AC charging using the given configuration, only a power transfer of up to 22 kW is possible.In another embodiment, where the charging inputs 104, 134 and the AC adapter cable 122 are single-phase Type 2 connectors and the batteries 102, 132 are operated at 400 V, power transfer during V2V DC charging between the vehicles 120, 150 is facilitated to up to 19.2 kW. However, with conventional V2V AC charging using the given configuration, only a power transfer of up to 11 kW is possible. Tables I and II below illustrate V2V AC and DC charging using a Type 2 AC cable. Table I: V2V AC charging with Type 2 AC cable Phase V(rms) I(rms) Strom 3-Phasen 230 32 3*230*32 =22kW 1-Phase 230 48 230*48 = 11kW Table II: V2V DC charging with AC cable type 2 V(dc) I(dc) Strom 400 32(Idc1) + 32(Idc2) 400*64= 25,6kW 400 32(Idc1) 400*32= 19,2kW

[0027] V2V DC charging is facilitated by connecting the vehicles to each other via their respective charging ports using an AC adapter cable. This approach simplifies the charging process and eliminates the need for additional devices or infrastructure.

[0028] Since the charging input is a Type 2 AC connector connected to a three-phase AC adapter cable, and the battery is a 400 V battery, the charging system can deliver up to 25.6 kW of power during V2V DC charging. This high power delivery reduces charging time and increases charging efficiency.

[0029] The present invention offers several advantages over conventional solutions. For example, existing AC cables can be used for DC-to-V2V charging, saving electric vehicle owners money. Furthermore, the power transfer during DC charging is significantly higher, increasing from 22 kW to at least 25.6 kW. In addition, efficiency is increased because no energy conversion takes place during the charging process, making charging faster and more efficient, thus increasing convenience for electric vehicle owners.

[0030] These exemplary embodiments serve only to illustrate the inventive concepts contained herein. Other embodiments and modifications can be made to the compositions and processes without departing from the spirit and scope of the invention. Therefore, the scope of the present invention should not be limited to the embodiments described herein, but should be defined by the appended claims and their equivalents. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] US 20240067024A1

[0004] CN 112810470A

[0004]

Claims

Vehicle charging system (100) for facilitating vehicle-to-vehicle (V2V) direct current (DC) charging, wherein the charging system comprises: a charging input (104) adapted for electrical coupling with an external alternating current (AC) charger; a bypass circuit (106); and a battery (102); wherein the charging input (104) is electrically coupled to the battery (102) via the bypass circuit (106) and the bypass circuit (106) is configured to facilitate a DC current flow between the charging input (104) and the battery (102) during DC V2V charging. Vehicle charging system (100) according to claim 1, wherein the bypass circuit (106) comprises: one or more switches (110); and a pair of busbars (112) connected in series with the one or more switches (110); wherein the one or more switches (110) are configured to connect and disconnect the electrical coupling of the charging input (104) with the battery (102); and wherein the pair of busbars (112) is connected between the battery (102) and the charging input (104) and the pair of busbars (112) is configured to split the direct current flowing from the battery (102) to the charging input (104) to facilitate connections between a plurality of power terminals of the charging input (104) and a pair of battery terminals. Vehicle charging system (100) according to claim 2, wherein the bypass circuit (106) further comprises a microcontroller configured to control the operation of one or more switches (110) to control the flow of direct current between the battery (102) and the charging input (104). Vehicle charging system (100) according to claim 1, wherein the bypass circuit (106) is connected in parallel to an on-board charger (OBC) (108) of a vehicle, wherein the OBC (108) is arranged between the charging input (104) and the battery (102) to provide AC charging of the vehicle. Vehicle charging system (100) according to claim 1, wherein V2V DC charging is facilitated by connecting vehicles (120, 150) through their respective charging inputs (104, 134) via an AC adapter cable (122). Vehicle charging system (100) according to claim 5, wherein the charging input (104) is a type 2 AC plug connected to a 3-phase AC adapter cable (122), and the battery (102) is a 400 V battery, wherein the vehicle charging system (100) enables a power transfer of up to 25.6 kW during V2V DC charging. Vehicle charging system (100) according to claim 2, wherein L1-L3 and N power terminals of a type 2 AC plug are connected as charging input (104) to B1-B4 terminals of the pair of busbars (112), thereby providing the connection between the power terminals of the charging input (104) and the pair of battery terminals. Vehicle charging system (100) according to claim 2, wherein the one or more switches (110) are one or more electromagnetic relays.

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