Bidirectional wireless charging system and charging method based on common direct current bus of electric vehicle

Abstract

The invention discloses a bidirectional wireless charging system and charging method based on a common direct current bus of an electric vehicle. The bidirectional wireless charging system based on the common direct current bus of the electric vehicle comprises a charging device and a vehicle device, the charging device is provided with a charging inverter circuit, the automobile device is provided with a front inverter circuit and a rear inverter circuit, and the charging inverter circuit is coupled with the front inverter circuit or the rear inverter circuit of the automobile device; the front inverter circuit of the automobile device is coupled with the rear inverter circuits of other automobile devices or the rear inverter circuit of the automobile device is coupled with the front inverter circuits of other automobile devices; the charging inverter circuit, the front inverter circuit and the rear inverter circuit are respectively provided with a coil and a capacitor, and the coil and the capacitor of each circuit are connected in series or in parallel. According to the invention, bidirectional wireless charging between the charging device and the automobile device is realized by using a topological structure in which the capacitors are connected in series in a circuit, and bidirectional wireless charging between different automobile devices is realized at the same time.

Description

Technical Field

[0001] The present invention relates to the technical field of new energy vehicles, and more specifically, to a bidirectional wireless charging system and a charging method based on a common DC bus of an electric vehicle. Background Art

[0002] Electric vehicles are vehicles that are powered by an onboard power supply, use an electric motor to drive the wheels, and comply with all requirements of road traffic and safety regulations. When the onboard power supply is low, it needs to be charged. Charging methods include but are not limited to charging with a charging pile, charging gun, or wireless charging.

[0003] Wireless charging technology can transmit electric energy to the receiving end of the vehicle running within a certain range on the ground in the form of a high-frequency alternating magnetic field through the power supply rail buried in the ground. Existing wireless charging technologies include unidirectional V2G (Vehicle to Grid) technology and bidirectional V2G technology. Unidirectional V2G technology refers to the grid charging the vehicle, and bidirectional V2G technology refers to the grid charging the vehicle and the vehicle's electric energy can be transmitted to the grid. Compared with unidirectional V2G technology, bidirectional V2G technology is conducive to the bidirectional flow of energy between the vehicle and the grid, which helps to achieve the goal of "peak shaving and valley filling" in terms of electricity demand.

[0004] Reference Figure 1 As shown, Figure 1 It is a topological diagram of a bidirectional wireless charging mechanism for electric vehicles in the prior art. A Chinese patent document (authorization announcement number CN113968152B, authorization announcement date September 27, 2022) discloses a bidirectional wireless charging control method for electric vehicles. The method is used for a bidirectional wireless charging mechanism for electric vehicles. The bidirectional wireless charging mechanism for electric vehicles includes a primary side DC power supply E1', a secondary side DC power supply E2' and a bidirectional wireless charging module; the bidirectional wireless charging module includes a primary side filter capacitor C 10 ', primary side H-bridge circuit, primary side compensation network, primary side coupling coil, secondary side coupling coil, secondary side compensation network, secondary side H-bridge circuit, secondary side filter capacitor C 20 '; Primary side filter capacitor C 10 'In parallel with the positive and negative busbars of the primary DC power supply E1', the secondary filter capacitor C 20 ' is connected in parallel with the positive and negative busbars of the secondary DC power supply E2'; the primary H-bridge circuit includes four switch tubes with reverse parallel diodes, which are respectively denoted as switch tubes S 11 ', switch tube S 12 ', switch tube S 13 ' and switch tube S 14 ', where the switch tube S 11 'The emitter and switch tube S 12The collectors of ' are connected in series to form the first bridge arm on the primary side, and the switch tube S 11 'The emitter and switch tube S 12 The collector contact of ' is recorded as the midpoint A' of the first bridge arm on the primary side, and the switch tube S 13 'The emitter and switch tube S 14 The collectors of ' are connected in series to form the second bridge arm on the primary side, and the switch tube S 13 'The emitter and switch tube S 14 The collector connection point of the primary side is recorded as the midpoint B' of the second bridge arm of the primary side; the first bridge arm of the primary side and the second bridge arm of the primary side are connected in parallel between the positive and negative DC busbars of the primary DC power supply E1'; the primary side compensation network includes the primary side resonant inductor L f1 ', primary side resonant capacitor C f1 ' and the primary side compensation capacitor C1'; the primary side resonant inductor L f1 The input end of ' is connected to the midpoint A' of the first bridge arm on the primary side, and the primary side resonant inductor L f1 The output end of the primary side compensation capacitor C1' is connected in series with the input end of the primary side coupling coil, and the output end of the primary side coupling coil is connected to the middle point B' of the second bridge arm of the primary side; the primary side resonant capacitor C f1 One end of ' is connected to the primary side resonant inductor L f1 ' and the primary side compensation capacitor C1', and the other end is connected to the middle point B' of the second bridge arm on the primary side; the secondary side H bridge circuit includes 4 switch tubes with reverse parallel diodes, which are respectively denoted as switch tubes S 21 ', switch tube S 22 ', switch tube S 23 ' and switch tube S 24 ', where the switch tube S 21 'The emitter and switch tube S 22 The collectors of ' are connected in series to form the first bridge arm on the secondary side, and the switch tube S 21 'The emitter and switch tube S 22 The collector contact of ' is recorded as the midpoint a' of the first bridge arm on the secondary side, and the switch tube S 23 'The emitter and switch tube S 24 The collectors of ' are connected in series to form the second bridge arm on the secondary side, and the switch tube S 23 'The emitter and switch tube S 24 The collector connection point of the secondary side is recorded as the midpoint b' of the second bridge arm on the secondary side; the first bridge arm on the secondary side and the second bridge arm on the secondary side are connected in parallel between the positive and negative DC busbars of the secondary DC power supply E2'; the secondary side compensation network includes the secondary side resonant inductor L f2 ', secondary side resonant capacitor C f2 ' and the secondary side compensation capacitor C2'; the secondary side resonant inductor L f2The input end of ' is connected to the midpoint a' of the first bridge arm on the secondary side, and the resonant inductor L on the secondary side f2 The output end of the secondary side is connected in series with a secondary side compensation capacitor C2' and then connected to the input end of the secondary side coupling coil. The output end of the secondary side coupling coil is connected to the midpoint b' of the second bridge arm of the secondary side. The secondary side resonant capacitor C f2 One end of ' is connected between the secondary side resonant inductor L2' and the secondary side compensation capacitor C2', and the other end is connected to the midpoint b' of the second bridge arm on the secondary side; the output end of the primary side coupling coil is connected to the midpoint B' of the second bridge arm on the primary side, and the output end of the secondary side coupling coil is connected to the midpoint b' of the second bridge arm on the secondary side; the secondary side coupling coil receives the electromagnetic field emitted by the primary side coupling coil through the mutual inductance M and converts it into electrical energy. This scheme uses the topological structure of the resonant capacitor in parallel in the circuit to realize bidirectional wireless charging between the power grid and the electric vehicle. It cannot use the topological structure of the resonant capacitor in series in the circuit to realize bidirectional wireless charging between the power grid and the electric vehicle, and this scheme cannot realize wireless charging between electric vehicles. Therefore, it is a technical problem that needs to be solved urgently. Summary of the invention

[0005] In view of this, the present invention provides a bidirectional wireless charging system and charging method based on a common DC bus of an electric vehicle, which utilizes a topological structure in which capacitors are connected in series in a circuit to achieve bidirectional wireless charging between a charging device and a vehicle device, and simultaneously achieves bidirectional wireless charging between different vehicle devices.

[0006] In a first aspect, the present application provides a bidirectional wireless charging system based on a common DC bus of an electric vehicle, comprising a charging device and at least one vehicle device;

[0007] The charging device has a charging inverter circuit, the automobile device has a front inverter circuit and a rear inverter circuit, and the charging inverter circuit is used to couple with the front inverter circuit or the rear inverter circuit of the same automobile device;

[0008] A front inverter circuit of an automobile device is used to couple with a rear inverter circuit of at least one automobile device, or a rear inverter circuit of an automobile device is coupled with a front inverter circuit of at least one automobile device;

[0009] The charging inverter circuit, the front inverter circuit and the rear inverter circuit all have coils and capacitors. The coils and capacitors in the charging inverter circuit are connected in series or in parallel, the coils and capacitors in the front inverter circuit are connected in series or in parallel, and the coils and capacitors in the rear inverter circuit are connected in series or in parallel.

[0010] Optionally, the coil is a resonant coil, and the coupling method is magnetic coupling.

[0011] Optionally, the charging inverter circuit, the front inverter circuit and the rear inverter circuit all have a bridge topology structure.

[0012] Optionally, both the charging device and the vehicle device are connected to the cloud platform.

[0013] Optionally, the automobile device includes a first automobile device, the first automobile device has a first front inverter circuit and a first rear inverter circuit, the first front inverter circuit is coupled to the charging inverter circuit, or the first rear inverter circuit is coupled to the charging inverter circuit.

[0014] Optionally, the automobile device includes a second automobile device and a third automobile device, the second automobile device has a second front inverter circuit and a second rear inverter circuit, and the third automobile device has a third front inverter circuit and a third rear inverter circuit;

[0015] The second rear inverter circuit is coupled to the third front inverter circuit, or the second front inverter circuit is coupled to the third rear inverter circuit.

[0016] Optionally, the charging inverter circuit comprises a charging coil and a charging capacitor, and the charging coil and the charging capacitor are connected in series;

[0017] The second front inverter circuit comprises a second front coil and a second front capacitor, the second front coil and the second front capacitor are connected in series, and the second rear inverter circuit comprises a second rear coil and a second rear capacitor, the second rear coil and the second rear capacitor are connected in series;

[0018] The third front inverter circuit has a third front coil and a third front capacitor, which are connected in series. The third rear inverter circuit has a third rear coil and a third rear capacitor, which are connected in series.

[0019] In a second aspect, the present application provides a charging method based on a common DC bus of an electric vehicle, which is applied to a bidirectional wireless charging system based on a common DC bus of an electric vehicle. The bidirectional wireless charging system based on a common DC bus of an electric vehicle comprises a charging device, a first vehicle device, a second vehicle device and a third vehicle device, and comprises the following steps:

[0020] The charging device matches information of the first automobile device, wherein the charging device has a charging inverter circuit, the first automobile device has a first front inverter circuit and a first rear inverter circuit, the charging inverter circuit matches the first front inverter circuit, or the charging inverter circuit matches the first rear inverter circuit;

[0021] The charging device charges the first automobile device, and if the charging inverter circuit matches the first front inverter circuit, the electric energy in the charging inverter circuit is transmitted to the first front inverter circuit, and if the charging inverter circuit matches the first rear inverter circuit, the electric energy in the charging inverter circuit is transmitted to the first rear inverter circuit;

[0022] The first automobile device charges the charging device, and if the charging inverter circuit matches the first front inverter circuit, the electric energy in the first front inverter circuit is transmitted to the charging inverter circuit, and if the charging inverter circuit matches the first rear inverter circuit, the electric energy in the first rear inverter circuit is transmitted to the charging inverter circuit;

[0023] and / or,

[0024] The second automobile device matches information with the third automobile device, wherein the second automobile device has a second front inverter circuit and a second rear inverter circuit, the third automobile device has a third front inverter circuit and a third rear inverter circuit, the second front inverter circuit matches the third rear inverter circuit, or the second rear inverter circuit matches the third front inverter circuit;

[0025] The second automobile device charges the third automobile device, if the second front inverter circuit matches the third rear inverter circuit, the electric energy in the second front inverter circuit is transmitted to the third rear inverter circuit, if the second rear inverter circuit matches the third front inverter circuit, the electric energy in the second rear inverter circuit is transmitted to the third front inverter circuit;

[0026] The third automobile device charges the second automobile device, if the second front inverter circuit matches the third rear inverter circuit, the electric energy in the third rear inverter circuit is transmitted to the second front inverter circuit, if the second rear inverter circuit matches the third front inverter circuit, the electric energy in the third front inverter circuit is transmitted to the second rear inverter circuit;

[0027] The first automobile device and the second automobile device are the same automobile device or different automobile devices.

[0028] Optionally, the similarity between the itinerary of the second automobile device and the itinerary of the third automobile device is not less than 80%, the distance between the second automobile device and the third automobile device does not exceed 2 km, the remaining power of the second automobile device is not less than 80% or the remaining power of the third automobile device is not less than 80%.

[0029] Optionally, when the second automobile device is charging the third automobile device, the remaining power of the second automobile device decreases to 60%, and / or the remaining power of the third automobile device increases to 90%, and the second automobile device stops charging;

[0030] When the third automotive device charges the second automotive device, the remaining power of the third automotive device decreases to 60%, and / or the remaining power of the second automotive device increases to 90%, and the third automotive device stops charging.

[0031] Compared with the prior art, the bidirectional wireless charging system and charging method based on the common DC bus of electric vehicles provided by the present invention achieve at least the following beneficial effects:

[0032] The bidirectional wireless charging system and charging method based on the common DC bus of electric vehicles provided by the present invention are both based on the common DC bus technology. The bidirectional wireless charging system based on the common DC bus of electric vehicles has a variety of charging topology strategies, and the charging topology structure includes but is not limited to the SSS topology structure. The SSS topology structure is a topology structure in which a capacitor is connected in series in a circuit. On the one hand, bidirectional wireless charging between a charging device and a vehicle device is realized to meet the power demand target of "peak shaving and valley filling". On the other hand, bidirectional wireless charging between different vehicle devices is realized to realize energy exchange between vehicles. The bidirectional wireless charging system based on the common DC bus of electric vehicles can meet the demand for electric vehicles to replenish energy at any time, solves the mileage anxiety of electric vehicle users, and can accelerate the application and popularization of new energy vehicles and the rational use of new energy. At the same time, since the remaining power of the electric vehicle can be replenished or released according to actual needs, the on-board battery inside the electric vehicle can have an ultra-long standby time, avoiding the problem of long-term performance degradation of the on-board battery, and can avoid the occurrence of various safety hazards caused by poor on-board batteries.

[0033] Of course, any product implementing the present invention does not necessarily need to achieve all of the technical effects described above at the same time.

[0034] Further features and advantages of the present invention will become apparent from the following detailed description of exemplary embodiments of the present invention with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

[0036] Figure 1 It is a topological diagram of a bidirectional wireless charging mechanism for electric vehicles in the prior art;

[0037] Figure 2 It is a topological diagram of a charging device provided by the present invention;

[0038] Figure 3 It is a topological diagram of an automobile device provided by the present invention;

[0039] Figure 4 It is a topological diagram of a cloud platform, a charging device and a car device provided by the present invention;

[0040] Figure 5 It is a functional block diagram of the interaction between a partial charging device and a vehicle device provided by the present invention;

[0041] Figure 6 It is a topological diagram of a charging device and a first automobile device provided by the present invention;

[0042] Figure 7A topological diagram of a second automobile device and a third automobile device provided by the present invention;

[0043] Figure 8 It is a functional block diagram of the interaction of some of the multiple automobile devices provided by the present invention;

[0044] Fig. 9 This is a topological diagram of a cloud platform, vehicle 1 and vehicle 2 provided by the present invention. DETAILED DESCRIPTION

[0045] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that the relative arrangement of components and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present invention unless otherwise specifically stated.

[0046] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses.

[0047] Technologies, methods, and devices known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and devices should be considered as part of the specification.

[0048] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0049] It should be noted that like reference numerals and letters refer to similar items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0050] Reference Figure 2-Figure 3 , Figure 2 It is a topological diagram of a charging device provided by the present invention; Figure 3 This is a topological diagram of an automobile device provided by the present invention.

[0051] Example 1

[0052] Combination Figure 2 and Figure 3As shown, the bidirectional wireless charging system based on the common DC bus of electric vehicles provided in this embodiment includes a charging device 1 and at least one automobile device 2. Bidirectional wireless charging can be performed between the charging device 1 and the automobile device 2. Bidirectional means that the charging device 1 can charge the automobile device 2, and vice versa, the automobile device 2 can also charge the charging device 1. The bidirectional setting realizes the bidirectional flow of energy between the charging device 1 and the automobile device 2, which helps to achieve the power demand goal of "peak shaving and valley filling". Wireless charging refers to the non-contact power transmission between the charging device 1 and the automobile device 2 through electromagnetic induction, electromagnetic resonance, radio frequency, etc., avoiding safety hazards such as leakage and leakage. At the same time, it can reduce the number of on-board batteries carried by the automobile device 2, extend its cruising range, and make power replenishment safer and more convenient. The charging device 1 can choose a charging pile, and the automobile device 2 can choose an electric car.

[0053] In the bidirectional wireless charging system based on the common DC bus of electric vehicles, the number of vehicle devices 2 can be one, two, four or even more. When the number of vehicle devices 2 is greater than one, bidirectional wireless charging can also be performed between different vehicle devices 2, which is similar to the case of bidirectional wireless charging between the charging device 1 and the vehicle device 2. Taking two vehicle devices 2 as an example, bidirectional means that the first vehicle device 2 can charge the second vehicle device 2, and vice versa.

[0054] The common DC bus technology is mainly used in multi-motor transmission systems. A separate rectifier or feedback device is used to provide the system with a DC power supply of a certain power, and the DC power supply is converted into AC power supply through an inverter unit when the system needs it to meet the speed regulation requirements of the motor. This technology has significant advantages in improving system safety, facilitating maintenance, and improving power efficiency. In the field of automotive wireless charging, if the wireless charging system needs to power multiple charging devices (such as cars in multiple parking spaces) at the same time, or needs to process power input from different power grids, then some principles and methods of the common DC bus technology can be used as a reference. For example, a system architecture similar to the common DC bus can be designed to convert power from different power grids into a unified DC power supply through a rectifier, and then distribute the power to each wireless charging device through an inverter unit or other means.

[0055] Figure 4 This is a topological diagram of a cloud platform, a charging device and a car device provided by the present invention. Figure 4As shown, the charging device 1 and the automobile device 2 are both connected to the cloud platform 3. The cloud platform 3 (also known as the cloud computing platform) is a service platform based on cloud computing technology, which allows users to process data and applications in a distributed manner through the network, with higher availability, lower cost, and faster response time. The core technologies of the cloud platform 3 include virtualization technology, distributed computing technology, automated management technology, data storage technology, and network technology. Through these technologies, the cloud platform 3 can realize the pooling and sharing of resources, improve the reliability and performance of the system, simplify the management process, and reduce operating costs. The charging device 1 and the automobile device 2 are both connected to the cloud platform 3. The cloud platform 3 can provide flexible, scalable, and shareable computing resources and system services for the charging device 1 and the automobile device 2. As a third party, the cloud platform 3 can protect the information security and interests of users, and has the advantages of reducing costs, improving efficiency, enhancing flexibility, improving availability, elastic expansion, and good security and ease of use.

[0056] Optionally, the charging device 1 and the cloud platform 3, as well as the automobile device 2 and the cloud platform 3, can interact through UU communication. UU communication realizes the information interaction process through the UU interface. The information interaction process includes data transmission and communication services. The UU interface is the interface between UE (User Equipment) and UTRAN (UMTS Terrestrial Radio Access Network), also known as the air interface. It is an open interface located at the physical layer, data link layer and network layer. Its main functions include broadcast paging and RRC (Radio Resource Control) Control, wireless resource control) connection processing, switching and power control decision execution, processing wireless resource management and control information, and processing baseband and RF processing information; the UU interface protocol can be subdivided into multiple protocol layers, and these protocol layers work together. The UU interface can adapt to various complex communication needs through diversified functions and detailed protocol layered design. The application of intelligent routing technology demonstrates the significant advantages of the UU interface in the field of wireless communications and provides users with efficient and stable communication services; this embodiment provides an interaction method between a charging device 1 and a cloud platform 3, and between a vehicle device 2 and a cloud platform 3. In other embodiments, the interaction method can be adaptively adjusted according to actual conditions, and is not specifically limited here.

[0057] Reference Figure 2As shown, the charging device 1 has a charging inverter circuit 10, and the charging inverter circuit 10 includes at least one charging coil Ls1 and a charging resonant capacitor C1. The charging coil Ls1 can be a resonant coil, and the resonant coil can be a magnetic resonance coil. The magnetic resonance coil has the function of transmitting radio frequency pulses and receiving magnetic resonance signals. The charging inverter circuit 10 also includes a charging resistor R1, a charging filter capacitor C0 and a bridge topology structure. The bridge topology structure is a full-bridge (also called H-bridge) topology structure, which is composed of four switch tubes, namely a first switch tube Q1, a second switch tube Q2, a third switch tube Q3 and a third switch tube Q4. Four switch tubes Q4, the emitter of the first switch tube Q1 and the collector of the second switch tube Q2 are connected in series to form a first bridge arm, and the connection point between the emitter of the first switch tube Q1 and the collector of the second switch tube Q2 is recorded as the midpoint A of the first bridge arm, the emitter of the third switch tube Q3 and the collector of the fourth switch tube Q4 are connected in series to form a second bridge arm, and the connection point between the emitter of the third switch tube Q3 and the collector of the fourth switch tube Q4 is recorded as the midpoint B of the second bridge arm, the first bridge arm and the second bridge arm are connected in parallel to the two poles of the charging filter capacitor C0, and the two poles of the charging filter capacitor C0 are respectively connected in parallel to the positive and negative busbars of the power grid (not shown in the figure).

[0058] Continue to refer to Figure 2 As shown, the charging resonant capacitor C1 can be connected in series in the charging inverter circuit 10, in which case the charging coil Ls1 and the charging resonant capacitor C1 are connected in series. The charging resonant capacitor C1 can also be connected in parallel in the charging inverter circuit 10 (not shown in the figure), in which case the charging coil Ls1 and the charging resonant capacitor C1 are connected in parallel.

[0059] This embodiment takes the charging resonant capacitor C1 connected in series in the charging inverter circuit 10 as an example. Figure 2 As shown, in the charging inverter circuit 10, the charging coil Ls1, the charging resonant capacitor C1 and the charging resistor R1 are connected in series, that is, the charging coil Ls1, the charging resonant capacitor C1 and the charging resistor R1 are electrically connected to each other, the charging coil Ls1 is located between the charging resonant capacitor C1 and the charging resistor R1, the side of the charging resonant capacitor C1 away from the charging coil Ls1 is electrically connected to the midpoint A of the first bridge arm, and the side of the charging resistor R1 away from the charging coil Ls1 is electrically connected to the midpoint B of the second bridge arm.

[0060] Reference Figure 3As shown, the automobile device 2 has a front inverter circuit 201 and a rear inverter circuit 202. The front inverter circuit 201 includes at least a front coil Ls2 and a front resonant capacitor C2. The front coil Ls2 can be a magnetic resonance coil. The front inverter circuit 201 also includes a front resistor R2 and a bridge topology structure. The bridge topology structure is a full-bridge (also known as an H-bridge) topology structure, which is composed of four switch tubes, namely a fifth switch tube Q5, a sixth switch tube Q6, a seventh switch tube Q7 and an eighth switch tube Q8. The emitter of the fifth switch tube Q5 and the collector of the sixth switch tube Q6 are connected in series to form a third bridge arm, and the emitter of the fifth switch tube Q5 and the collector of the sixth switch tube Q6 are connected in series to form a third bridge arm. The contact point of the collector of Q6 is recorded as the midpoint C of the third bridge arm, the emitter of the seventh switch tube Q7 and the collector of the eighth switch tube Q8 are connected in series to form the fourth bridge arm, and the contact point of the emitter of the seventh switch tube Q7 and the collector of the eighth switch tube Q8 is recorded as the midpoint D of the fourth bridge arm, the third bridge arm and the fourth bridge arm are connected in parallel to the positive pole Vbat+ and the negative pole Vbat- of the vehicle battery Vbat, the collector of the fifth switch tube Q5 and the collector of the seventh switch tube Q7 are both electrically connected to the positive pole Vbat+ of the vehicle battery Vbat, and the emitter of the sixth switch tube Q6 and the emitter of the eighth switch tube Q8 are both electrically connected to the negative pole Vbat- of the vehicle battery Vbat.

[0061] Continue to refer to Figure 3 As shown, the front resonant capacitor C2 can be connected in series in the front inverter circuit 201, in which case the front coil Ls2 and the front resonant capacitor C2 are connected in series. The front resonant capacitor C2 can also be connected in parallel in the front inverter circuit 201 (not shown in the figure), in which case the front coil Ls2 and the front resonant capacitor C2 are connected in parallel.

[0062] In this embodiment, the front resonant capacitor C2 is connected in series in the front inverter circuit 201 as an example. Figure 3 As shown, in the front inverter circuit 201, the front coil Ls2, the front resonant capacitor C2 and the front resistor R2 are connected in series with each other, that is, the front coil Ls2, the front resonant capacitor C2 and the front resistor R2 are electrically connected to each other, the front coil Ls2 is located between the front resonant capacitor C2 and the front resistor R2, the side of the front resonant capacitor C2 away from the front coil Ls2 is electrically connected to the midpoint C of the third bridge arm, and the side of the front resistor R2 away from the front coil Ls2 is electrically connected to the midpoint D of the fourth bridge arm.

[0063] Continue to refer to Figure 3As shown, the rear inverter circuit 202 has the same structure as the front inverter circuit 201. The rear inverter circuit 202 includes at least one rear coil Ls3 and a rear resonant capacitor C3. The rear coil Ls3 can be a magnetic resonance coil. The rear inverter circuit 202 also includes a rear resistor R3 and a bridge topology structure. The bridge topology structure is a full-bridge (also called an H-bridge) topology structure, which is composed of four switch tubes, namely a ninth switch tube Q9, a tenth switch tube Q10, an eleventh switch tube Q11 and a twelfth switch tube Q12. The emitter of the ninth switch tube Q9 and the collector of the tenth switch tube Q10 are connected in series to form a fifth bridge arm, and the emitter of the ninth switch tube Q9 and the collector of the tenth switch tube Q10 are connected in series to form a fifth bridge arm. The contact point of the electrodes is recorded as the midpoint E of the fifth bridge arm, the emitter of the eleventh switch tube Q11 and the collector of the twelfth switch tube Q12 are connected in series to form the sixth bridge arm, and the contact point of the emitter of the eleventh switch tube Q11 and the collector of the twelfth switch tube Q12 is recorded as the midpoint F of the sixth bridge arm, the fifth bridge arm and the sixth bridge arm are connected in parallel to the positive pole Vbat+ and the negative pole Vbat- of the vehicle battery Vbat, the collector of the ninth switch tube Q9 and the collector of the eleventh switch tube Q11 are both electrically connected to the positive pole Vbat+ of the vehicle battery Vbat, and the emitter of the tenth switch tube Q10 and the emitter of the twelfth switch tube Q12 are both electrically connected to the negative pole Vbat- of the vehicle battery Vbat.

[0064] Continue to refer to Figure 3 As shown, the rear resonant capacitor C3 can be connected in series in the rear inverter circuit 202, in which case the rear coil Ls3 and the rear resonant capacitor C3 are connected in series. The rear resonant capacitor C3 can also be connected in parallel in the rear inverter circuit 202 (not shown in the figure), in which case the rear coil Ls3 and the rear resonant capacitor C3 are connected in parallel.

[0065] In this embodiment, the rear resonant capacitor C3 is connected in series in the rear inverter circuit 202 as an example. Figure 3 As shown, in the rear inverter circuit 202, the rear coil Ls3, the rear resonant capacitor C3 and the rear resistor R3 are connected in series with each other, that is, the rear coil Ls3, the rear resonant capacitor C3 and the rear resistor R3 are electrically connected to each other, the rear coil Ls3 is located between the rear resonant capacitor C3 and the rear resistor R3, the side of the rear resonant capacitor C3 away from the rear coil Ls3 is electrically connected to the midpoint E of the fifth bridge arm, and the side of the rear resistor R3 away from the rear coil Ls3 is electrically connected to the midpoint F of the sixth bridge arm.

[0066] Combination Figure 2 and Figure 3 As shown, when bidirectional wireless charging is performed between the charging device 1 and the automobile device 2, the charging inverter circuit 10 is coupled with the front inverter circuit 201 of the automobile device 2 (not shown in the figure), or the charging inverter circuit 10 is coupled with the rear inverter circuit 202 of the automobile device 2 (as shown in the figure). Figure 5As shown), coupling refers to the phenomenon that two or more circuits, systems or elements affect each other through interaction. The coupling method can be magnetic coupling. Magnetic coupling refers to the phenomenon that the current change of a coil generates an induced electromotive force in an adjacent coil. This coupling method mainly relies on the magnetic field, that is, when the current in a coil changes, a changing magnetic field will be generated around it, and this changing magnetic field will in turn affect the other coil, causing the latter to generate an induced electromotive force. Magnetic coupling is widely used in fields such as radio communications. In this way, two circuits can be isolated to prevent signal interference and mutual influence. The realization of magnetic coupling is based on Faraday's law of electromagnetic induction, that is, a changing magnetic field will generate an induced electromotive force in the wire, and this electromotive force can drive current, thereby realizing the transmission of signals or energy. The working principle of magnetic coupling is the existing technology in this field and will not be repeated here.

[0067] Figure 5 It is a functional block diagram of the interaction between a partial charging device and a vehicle device provided by the present invention; Figure 6 1 is a topological diagram of a charging device and a first automobile device provided by the present invention. In an optional embodiment, the automobile device 2 includes a first automobile device 21, the structure of the first automobile device 21 is completely the same as that of the automobile device 2, and the first automobile device 21 has a first front inverter circuit 2101 and a first rear inverter circuit 2102, and the first front inverter circuit 2101 is magnetically coupled to the charging inverter circuit 10 (not shown in the figure), or the first rear inverter circuit 2102 is coupled to the charging inverter circuit 10 (as shown in the figure). Figure 5 As shown), this embodiment takes the magnetic coupling between the first rear inverter circuit 2102 and the charging inverter circuit 10 as an example, referring to Figure 6 As shown, the first rear inverter circuit 2102 includes a first rear coil Ls31, a first rear resonant capacitor C31, a first rear resistor R31, a ninth switch tube Q91, a tenth rear switch tube Q101, an eleventh rear switch tube Q111 and a twelfth rear switch tube Q121. The connection positions and connection methods of the above structures in the first rear inverter circuit 2102 can refer to the rear inverter circuit 202, and will not be repeated here.

[0068] Combination Figure 5 and Figure 6 As shown, the working principle of bidirectional wireless charging between the charging device 1 and the first automobile device 21 is as follows:

[0069] (1) When the charging device 1 charges the first automobile device 21, the charging coil Ls1 is close to the first rear coil Ls31, and the electric energy on the grid side is converted into a DC voltage Udc through the AC / DC converter. The full-bridge topology structure inside the charging device 1 converts the rectified DC power Udc into a high-frequency AC power. The charging coil Ls1 and the charging resonant capacitor C1 form a resonant circuit at the end of the charging device 1, generating a strong resonant magnetic field. At the same time, in the first automobile device 21, the first rear coil Ls31 and the first rear resonant capacitor C31 form a first device rear end resonant circuit. When the resonant frequency of the first device rear end resonant circuit matches the resonant frequency of the charging device 1 end resonant circuit, the first rear coil Ls31 absorbs the energy in the resonant magnetic field generated by the charging coil Ls1, and AC power is generated on the first rear coil Ls31. The first rear inverter circuit 2102 converts the AC power into a DC voltage Up, and the DC voltage Up is charged into the vehicle battery Vbat, so that the charging device 1 charges the first automobile device 21; wherein, the AC / DC converter is a power conversion device that converts alternating current (AC) into direct current (DC).

[0070] (2) When the first automobile device 21 charges the charging device 1, the charging coil Ls1 is close to the first rear coil Ls31, and the DC voltage Up in the vehicle battery Vbat is converted into AC power through the first rear inverter circuit 2102. The first rear coil Ls31 and the first rear resonant capacitor C31 form a resonant circuit at the rear end of the first automobile device 21, generating a strong resonant magnetic field. At the same time, in the charging device 1, the charging coil Ls1 and the charging resonant capacitor C1 form a resonant circuit at the end of the charging device 1. When the resonant frequency of the resonant circuit at the end of the charging device 1 matches the resonant frequency of the resonant circuit at the rear end of the first automobile device 21, the charging coil Ls1 absorbs the energy in the resonant magnetic field generated by the first rear coil Ls31, and a high-frequency AC power is generated on the charging coil Ls1. The AC power is converted into a DC voltage Udc through a full-bridge topology structure, and the DC voltage Udc is converted into AC power through an AC / DC converter. Part of the AC power is stored inside the charging device 1, and part of it is returned to the grid side.

[0071] It should be noted that: (1) The resonant frequency (also called the natural frequency) refers to the specific frequency at which the resonance phenomenon occurs in the circuit. When the capacitor and coil in the circuit interact at a certain frequency so that the voltage and current in the circuit reach their maximum values, this frequency is called the resonant frequency. The resonant frequency is an inherent parameter of the circuit. The capacitor and coil in the circuit remain unchanged, and the resonant frequency of the circuit is a fixed value; (2) The basic principle of magnetically coupled resonant wireless power transmission is based on the physical phenomena of electromagnetism and magnetoelectricity. It is through two coils with the same resonant frequency. At the rated frequency, the two coils resonate at the same time, which is similar to the resonance phenomenon in physics. Energy can be transferred from one coil to another. This is the prior art in the field and will not be elaborated here; (3) The first automobile device 21 that performs bidirectional wireless charging with the charging device 1 can be a stationary automobile or a moving automobile. This is not specifically limited here.

[0072] The above describes how to achieve bidirectional wireless charging between the charging device 1 and the first automobile device 21 by coupling the first rear inverter circuit 2102 with the charging inverter circuit 10. The method and principle of achieving bidirectional wireless charging between the charging device 1 and the first automobile device 21 by coupling the first front inverter circuit 2101 with the charging inverter circuit 10 are the same and will not be repeated here.

[0073] Figure 7 A topological diagram of a second automobile device and a third automobile device provided by the present invention; Figure 8 It is a functional block diagram of a part of the interaction of multiple automobile devices provided by the present invention. In an optional embodiment, the automobile device 2 includes a second automobile device 22 and a third automobile device 23. The structures of the second automobile device 22 and the third automobile device 23 are completely the same as the structure of the automobile device 2. The second automobile device 22 has a second front inverter circuit 2201 and a second rear inverter circuit 2202. Figure 7 As shown, the second front inverter circuit 2201 includes a second front coil Ls22, a second front resonant capacitor C22, a second front resistor R22, a fifth switch tube Q52 of the second car, a sixth switch tube Q62 of the second car, a seventh switch tube Q72 of the second car and an eighth switch tube Q82 of the second car. The connection positions and connection methods of the above structures in the second front inverter circuit 2201 can refer to the front inverter circuit 201. The second rear inverter circuit 2202 includes a second rear coil Ls32, a second rear resonant capacitor C32, a second rear resistor R32, a ninth switch tube Q91 of the second car, a tenth switch tube Q102 of the second car, an eleventh switch tube Q112 of the second car and a twelfth switch tube Q122 of the second car. The connection positions and connection methods of the above structures in the second rear inverter circuit 2202 can refer to the rear inverter circuit 202.

[0074] Similarly, continue to refer to Figure 7As shown, the third vehicle device 23 has a third front inverter circuit 2301 and a third rear inverter circuit 2302. The third front inverter circuit 2301 includes a third front coil Ls23, a third front resonant capacitor C23, a third front resistor R23, a third vehicle fifth switch tube Q53, a third vehicle sixth switch tube Q63, a third vehicle seventh switch tube Q73 and a third vehicle eighth switch tube Q83. The connection positions and connection methods of the above structures in the third front inverter circuit 2301 can refer to the front inverter circuit 201. The third rear inverter circuit 2302 includes a third rear coil Ls33, a third rear resonant capacitor C33, a third rear resistor R33, a third vehicle ninth switch tube Q93, a third vehicle tenth switch tube Q103, a third vehicle eleventh switch tube Q113 and a third vehicle thirteenth switch tube Q123.

[0075] There are two methods for bidirectional wireless charging between the second automobile device 22 and the third automobile device 23. The first method is to couple the second rear inverter circuit 2202 with the third front inverter circuit 2301; the second method is to couple the second front inverter circuit 2201 with the third rear inverter circuit 2302. Either method can realize bidirectional wireless charging between the second automobile device 22 and the third automobile device 23.

[0076] Combination Figure 7 and Figure 8 As shown, in this embodiment, the second rear inverter circuit 2202 is coupled with the third front inverter circuit 2301 to realize bidirectional wireless charging between the second automobile device 22 and the third automobile device 23. The working principle is as follows:

[0077] (1) When the second automobile device 22 charges the third automobile device 23, the second rear coil Ls32 is close to the third front coil Ls23, and the DC voltage Up in the onboard battery Vbat of the second automobile device 22 is converted into high-frequency AC power through the full-bridge topology structure in the second rear inverter circuit 2202. The second rear coil Ls32 and the second rear resonant capacitor C32 form a rear-end resonant circuit of the second automobile device 22, generating a strong resonant magnetic field. At the same time, in the third automobile device 23, the third front coil Ls23 and the third front resonant capacitor C23 form a third automobile device 23. The front-end resonant circuit of the third automobile device 23, when the resonant frequency of the front-end resonant circuit of the third automobile device 23 matches the resonant frequency of the rear-end resonant circuit of the second automobile device 22, the third front coil Ls23 absorbs the energy in the resonant magnetic field generated by the second rear coil Ls32, and AC power is generated on the third front coil Ls23. The full-bridge topology structure in the third front inverter circuit 2301 converts the AC power into a DC voltage Up, and the DC voltage Up is charged into the on-board battery Vbat of the third automobile device 23, thereby realizing the charging of the third automobile device 23 by the second automobile device 22.

[0078] (2) When the third automobile device 23 charges the second automobile device 22, the second rear coil Ls32 is close to the third front coil Ls23, and the DC voltage Up in the onboard battery Vbat of the third automobile device 23 is converted into high-frequency AC power through the full-bridge topology structure in the third front inverter circuit 2301. The third front coil Ls23 and the third front resonant capacitor C23 form a front-end resonant circuit of the third automobile device 23, generating a strong resonant magnetic field. At the same time, in the second automobile device 22, the second rear coil Ls32 and the second rear resonant capacitor C32 form a second automobile device 23. The rear end resonant circuit of the second automobile device 22, when the resonant frequency of the rear end resonant circuit of the second automobile device 22 matches the resonant frequency of the front end resonant circuit of the third automobile device 23, the second rear coil Ls32 absorbs the energy in the resonant magnetic field generated by the third front coil Ls23, and AC power is generated on the second rear coil Ls32. The full-bridge topology structure in the second rear inverter circuit 2202 converts the AC power into a DC voltage Up, and the DC voltage Up is charged into the on-board battery Vbat of the second automobile device 22, so that the third automobile device 23 charges the second automobile device 22.

[0079] The above describes how to achieve bidirectional wireless charging between the second automobile device 22 and the third automobile device 23 by coupling the second rear inverter circuit 2202 with the third front inverter circuit 2301. In other embodiments, bidirectional wireless charging between the second automobile device 22 and the third automobile device 23 can be achieved by coupling the second front inverter circuit 2201 with the third rear inverter circuit 2302. The method and principle of coupling the second front inverter circuit 2201 with the third rear inverter circuit 2302 are the same as those of coupling the second rear inverter circuit 2202 with the third front inverter circuit 2301, and will not be repeated here.

[0080] When the charging device 1 , the first automobile device 21 , the second automobile device 22 and the third automobile device 23 exist at the same time, the first automobile device 21 and the second automobile device 22 may be the same vehicle or different vehicles, or the first automobile device 21 and the third automobile device 23 may be the same vehicle or different vehicles, which is not limited here.

[0081] From the perspective of topological structure, the traditional topological structure can be roughly divided into four topological structures according to the connection mode of capacitors in series or in parallel in the circuit, and the connection mode between the charging device 1 and the vehicle device 2 can be divided into: series-series (SS) topology, series-parallel (SP) topology, parallel-series (PS) topology and (PP) topology. The bidirectional wireless charging system based on the common DC bus of electric vehicles provided in this embodiment is designed based on the series-series (SS) solution.

[0082] When combining the mutual charging scheme between the vehicle and the charging pile and the mutual charging scheme between vehicles, in the newly added automobile device 2, it is not limited to whether the capacitor is connected in series or in parallel in the circuit. The topological structures of the charging device 1, the first automobile device 21, the second automobile device 22 and the third automobile device 23 are integrated. The topological structure in the bidirectional wireless charging system based on the common DC bus of electric vehicles provided in this embodiment can be considered as an 'SSS' topological structure. In other embodiments, the topological structure in the bidirectional wireless charging system based on the common DC bus of electric vehicles can be an 'SSP' topological structure, an 'SPS' topological structure, an 'SPP' topological structure, a 'PSS' topological structure, a 'PSP' topological structure, a 'PPS' topological structure or a 'PPP' topological structure, etc., which are not specifically limited here.

[0083] Combination Figure 4 , Figure 7 and Figure 8 As shown, the second automobile device 22 and the third automobile device 23 can both be automobiles in motion. During the driving of the vehicles, the second automobile device 22 and the third automobile device 23 perform information matching through the cloud platform 3. After the two are matched successfully, one can charge the other. If the two are not matched successfully, the charging function cannot be realized.

[0084] The conditions for successful information matching between the second automobile device 22 and the third automobile device 23 include:

[0085] (1) The similarity between the itinerary of the second automobile device 22 and the itinerary of the third automobile device 23 is not less than 80%; the similarity of vehicle itineraries refers to a measure of the similarity between the itinerary trajectories of two vehicles, which is based on a comprehensive consideration of multiple dimensions such as the vehicle driving path, speed, and time. A high similarity of vehicle itineraries means that the vehicles move on similar spatiotemporal paths, which can reflect the high consistency of the vehicle driving routes or the similarity of vehicle activities within a specific time period; the similarity between the itinerary of the second automobile device 22 and the itinerary of the third automobile device 23 is required to be not less than 80%. This setting ensures that the paths of the second automobile device 22 and the third automobile device 23 are as consistent as possible during driving, avoiding the impact of the charging effect due to excessive deviation between the paths of the two. In other embodiments, the minimum value of the similarity between the itinerary of the second automobile device 22 and the itinerary of the third automobile device 23 can be adaptively adjusted according to actual conditions, and is not specifically limited here.

[0086] (2) The distance between the second automobile device 22 and the third automobile device 23 does not exceed 2 km. The distance between the second automobile device 22 and the third automobile device 23 is limited to avoid the problem that the distance between the second automobile device 22 and the third automobile device 23 is too far and affects the charging effect. In other embodiments, the distance between the second automobile device 22 and the third automobile device 23 can be adaptively adjusted according to actual conditions and is not specifically limited here.

[0087] (3) The remaining power of the second automobile device 22 is not less than 80%, or the remaining power of the third automobile device 23 is not less than 80%: It can be understood that when the second automobile device 22 charges the third automobile device 23, the remaining power of the second automobile device 22 cannot be less than 80%, and when the third automobile device 23 charges the second automobile device 22, the remaining power of the third automobile device 23 cannot be less than 80%; the automobile device 2 that can charge other automobile devices 2 is a charging vehicle, and the automobile device 2 that receives the charge from other automobile devices 2 is a charged vehicle. The charging vehicle itself needs to have a relatively high remaining power. Part of this remaining power is charged to the charged vehicle, and the other part is used to ensure that the charging vehicle can use itself. If the remaining power of the charging vehicle itself is too low, after charging the remaining power to the charged vehicle, the charging vehicle itself is insufficient and cannot drive normally, which may easily cause the vehicle to stop halfway or block traffic. Limiting the minimum value of the remaining power of the charging vehicle can avoid the above problems. In other embodiments, the minimum value of the remaining power of the charging vehicle can be adaptively adjusted according to actual conditions, and is not specifically limited here.

[0088] Fig. 9 The present invention provides a cloud platform, a vehicle and a topological diagram of the vehicle. Fig. 9 As shown in the figure, during driving, the steps of charging and discharging of two cars are as follows:

[0089] Step s1: Driver 1 drives vehicle 1. Driver 1 obtains the remaining power of vehicle 1 based on the display on the instrument panel and independently determines whether vehicle 1 needs to be charged. Alternatively, if driver 1 does not notice the remaining power of vehicle 1, the car system detects that the remaining power of vehicle 1 drops below a critical value and issues a low power reminder. After receiving the reminder, driver 1 knows that the car needs to be charged.

[0090] Among them, the critical value of the remaining power of vehicle 1 can be 20%, that is, when the remaining power of vehicle 1 is lower than 20%, the vehicle system monitoring will issue a reminder. The low remaining power of the electric vehicle will cause various hazards, mainly including difficulty in starting, electronic equipment failure, dim lights, insufficient power, charging system failure, fault code storage, vehicle performance degradation, short-distance endurance problems, shortened battery life, etc.; in other embodiments, the critical value of the remaining power of the vehicle can be adaptively adjusted according to actual conditions, and is not specifically limited here.

[0091] Step s2: Vehicle 1 continues to drive, and driver 1 opens the driving charging application on cloud platform 3. The application is completed by UU communication between vehicle 1 and cloud platform 3. After cloud platform 3 receives the driving charging application, it matches the relevant information needs for vehicle 1 based on big data information, and finds a vehicle that can successfully match the information of vehicle 1. When there are multiple vehicles that can successfully match the information of vehicle 1, the best vehicle 2 is selected, and the demand application is made to vehicle 2.

[0092] Among them, the requirements for vehicles that can successfully match the information of vehicle 1 can refer to the conditions for successful information matching between the second automobile device 22 and the third automobile device 23, including that the similarity of the itineraries of the two vehicles is not less than 80%, the distance between the two vehicles is not more than 2 km, and the remaining power of the charging vehicle is not less than 80%. Among all vehicles that can successfully match the information of vehicle 1, the optimal selection requirements for vehicle 2 are the highest itinerary similarity with vehicle 1, the shortest distance with vehicle 1, and the highest remaining power of the vehicle.

[0093] Step s3: The driver 2 of the vehicle 2 responds to the demand of the cloud platform 3 based on his own specific situation, and the response includes whether the vehicle 1 can be charged or not.

[0094] Step s4: If it is inconvenient for vehicle 2 to charge vehicle 1, cloud platform 3 continues to search for the next vehicle until a suitable vehicle is found; if it is convenient for vehicle 2 to charge vehicle 1, vehicle 2 responds to the demand of cloud platform 3 and exchanges information with vehicle 1 based on UU communication of cloud platform 3 to complete the communication needs between vehicle 1 and vehicle 2.

[0095] Step s5: Vehicle 1 and vehicle 2 shake hands to prepare for charging. After vehicle 1 and vehicle 2 complete the handshake, vehicle 2 starts wireless charging of vehicle 1. The principle of the charging process can be referred to Figure 7 The bidirectional wireless charging method between the second automobile device 22 and the third automobile device 23 will not be described in detail here.

[0096] Step s6: When the conditions for terminating charging are met, the handshake protocol between vehicle 1 and vehicle 2 is terminated, and the charging of vehicle 1 by vehicle 2 is terminated.

[0097] Among them, the conditions for ending charging include at least the following:

[0098] The first method is that the driver 1 in vehicle 1 independently determines the timing to end charging. When the driver 1 believes that vehicle 1 does not need to be charged anymore, vehicle 1 can send a request to end charging to vehicle 2 through the cloud platform 3. After vehicle 2 responds, the handshake protocol between vehicle 1 and vehicle 2 is disconnected, and vehicle 2 ends charging vehicle 1.

[0099] The second is that the driver 2 in vehicle 2 independently determines the time to end charging. When the driver 2 believes that charging can be ended or that vehicle 1 cannot be charged at present, vehicle 2 can send a request that charging cannot be completed to vehicle 1 through the cloud platform 3. After vehicle 1 responds, the handshake protocol between vehicle 1 and vehicle 2 is disconnected, and the charging of vehicle 1 by vehicle 2 is terminated; wherein, vehicle 1 has a reaction time after receiving the request of vehicle 2. During the reaction time, vehicle 1 responds to the request of vehicle 2, the handshake protocol between vehicle 1 and vehicle 2 is disconnected, and the charging of vehicle 1 by vehicle 2 is terminated. If vehicle 1 does not respond to the request of vehicle 2 after the reaction time is exceeded, vehicle 1 can directly disconnect the handshake protocol with vehicle 1 without the response of vehicle 1, and forcibly terminate the charging of vehicle 1 by vehicle 2. The reaction time can be 30S. In other embodiments, the reaction time can be adaptively adjusted according to actual conditions, and is not specifically limited here.

[0100] The third type is that the car system of vehicle 1 monitors the current remaining power of vehicle 1. When the current remaining power of vehicle 1 reaches 90%, the car system believes that charging can be terminated. Vehicle 1 can send a request to terminate charging to vehicle 2 through cloud platform 3. After vehicle 2 responds, the handshake protocol between vehicle 1 and vehicle 2 is disconnected, and vehicle 2 ends charging of vehicle 1.

[0101] Fourthly, the automobile system of vehicle 2 monitors the current remaining power of vehicle 2. When the current remaining power of vehicle 2 is reduced to 60%, the automobile system believes that it is unable to continue charging vehicle 1. The automobile system informs driver 2 of the current remaining power of vehicle 2 and requests driver 2 to disconnect the charging function in order to ensure the mileage requirement of vehicle 2. Vehicle 2 can send a request to end charging to vehicle 1 through cloud platform 3 and inform vehicle 1 of the current situation of vehicle 2. After vehicle 1 responds, the handshake protocol between vehicle 1 and vehicle 2 is disconnected, and the charging of vehicle 1 by vehicle 2 is terminated.

[0102] Reference Figure 8As shown, the same automobile device 2 can perform bidirectional wireless charging with two different automobile devices 2. For example, the automobile device 2 includes a fourth automobile device, a fifth automobile device and a sixth automobile device (not shown in the figure), and the structures of the fourth automobile device, the fifth automobile device and the sixth automobile device are similar to Figure 3 The structure of the automobile device 2 shown is the same. The fourth automobile device includes a fourth front inverter circuit and a fourth rear inverter circuit. The fifth automobile device includes a fifth front inverter circuit and a fifth rear inverter circuit. The sixth automobile device includes a sixth front inverter circuit and a sixth rear inverter circuit. The fourth rear inverter circuit and the fifth front inverter circuit are coupled to realize bidirectional wireless charging between the fourth automobile device and the fifth automobile device. At the same time, the fifth rear inverter circuit and the sixth front inverter circuit are coupled to realize bidirectional wireless charging between the fifth automobile device and the sixth automobile device. Parameters such as the order and time of charging between the fourth automobile device, the fifth automobile device and the sixth automobile device can be adaptively adjusted according to actual conditions and are not specifically limited here.

[0103] It should be noted that:

[0104] (1) This embodiment mainly introduces bidirectional wireless charging between the charging device 1 and the first automobile device 21, and bidirectional wireless charging between the second automobile device 22 and the third automobile device 23, both of which are cases where the capacitor is connected in series in the inverter circuit. In other embodiments, the capacitor is connected in series in the inverter circuit or the capacitor is connected in parallel in the inverter circuit. The principle of bidirectional wireless charging is basically the same. For example, in another optional embodiment, bidirectional wireless charging is performed between the charging device 1 and the first automobile device 21, and the capacitor in the charging device 1 is connected in series in the inverter circuit, and the capacitor in the first automobile device 21 is connected in parallel in the inverter circuit. In another optional embodiment, bidirectional wireless charging is performed between the second automobile device 22 and the third automobile device 23, and the capacitor in the second automobile device 22 is connected in parallel in the inverter circuit, and the capacitor in the third automobile device 23 is connected in parallel in the inverter circuit, etc., which are not specifically limited here.

[0105] (2) The bidirectional wireless charging system based on the common DC bus of electric vehicles provided in this embodiment complies with the SAE J2954 standard. The SAE J2954 standard is a standard formulated by the Society of Automotive Engineers (SAE International) of the United States for the application of wireless power transmission (WPT) in light PHEV (Plug-in hybrid electric vehicle) or EV (Electric Vehicle). This standard covers wireless power transmission and calibration methods, and aims to establish a set of unified requirements for the mass production of wireless electric vehicle charging systems; according to the SAE J2954 standard, the operating frequency of the coil involved in this embodiment is 85KHz.

[0106] Example 2

[0107] Combination Figure 2-Figure 8 As shown, this embodiment provides a charging method based on a common DC bus of an electric vehicle. The method belongs to a bidirectional wireless charging technology and can be applied to a bidirectional wireless charging system based on a common DC bus of an electric vehicle in Embodiment 1. The bidirectional wireless charging system based on a common DC bus of an electric vehicle comprises a charging device 1, a first vehicle device 21, a second vehicle device 22 and a third vehicle device 23.

[0108] When bidirectional wireless charging is performed between the charging device 1 and the first vehicle device 21, the charging method based on the shared DC bus of the electric vehicle includes the following steps:

[0109] Step S1: the charging device 1 matches information with the first automobile device 21, wherein the charging device 1 has a charging inverter circuit 10, the first automobile device 21 has a first front inverter circuit 2101 and a first rear inverter circuit 2102, the charging inverter circuit 10 matches the first front inverter circuit 2101, or the charging inverter circuit 10 matches the first rear inverter circuit 2102;

[0110] Step S2: the charging device 1 charges the first automobile device 21. If the charging inverter circuit 10 matches the first front inverter circuit 2101, the electric energy in the charging inverter circuit 10 is transmitted to the first front inverter circuit 2101. If the charging inverter circuit 10 matches the first rear inverter circuit 2102, the electric energy in the charging inverter circuit 10 is transmitted to the first rear inverter circuit 2102.

[0111] Step S3: The first automobile device 21 charges the charging device 1. If the charging inverter circuit 10 matches the first front inverter circuit 2101, the electric energy in the first front inverter circuit 2101 is transmitted to the charging inverter circuit 10. If the charging inverter circuit 10 matches the first rear inverter circuit 2102, the electric energy in the first rear inverter circuit 2102 is transmitted to the charging inverter circuit 10.

[0112] It should be noted that: (1) Step S2 must be located after Step S1, and Step S3 must be located after Step S1. The order of Step S2 and Step S3 can be adjusted and is not limited here. (2) Regarding the structure and working principle of the charging device 1 and the first automobile device 21, please refer to Example 1 and will not be repeated here.

[0113] When the second automobile device 22 and the third automobile device 23 are bidirectionally wirelessly charged, the charging method based on the shared DC bus of electric vehicles includes the following steps:

[0114] Step S1′: information matching between the second automobile device 22 and the third automobile device 23, wherein the second automobile device 22 has a second front inverter circuit 2201 and a second rear inverter circuit 2202, and the third automobile device 23 has a third front inverter circuit 2301 and a third rear inverter circuit 2302, and the second front inverter circuit 2201 matches the third rear inverter circuit 2302, or the second rear inverter circuit 2202 matches the third front inverter circuit 2301;

[0115] Step S2′: the second automobile device 22 charges the third automobile device 23. If the second front inverter circuit 2201 matches the third rear inverter circuit 2302, the electric energy in the second front inverter circuit 2201 is transmitted to the third rear inverter circuit 2302. If the second rear inverter circuit 2202 matches the third front inverter circuit 2301, the electric energy in the second rear inverter circuit 2202 is transmitted to the third front inverter circuit 2301.

[0116] Step S3′: the third automobile device 23 charges the second automobile device 22. If the second front inverter circuit 2201 matches the third rear inverter circuit 2302, the electric energy in the third rear inverter circuit 2302 is transmitted to the second front inverter circuit 2201. If the second rear inverter circuit 2202 matches the third front inverter circuit 2301, the electric energy in the third front inverter circuit 2301 is transmitted to the second rear inverter circuit 2202.

[0117] It should be noted that: (1) step S2' must be located after step S1', and step S3' must be located after step S1'. The order of step S2' and step S3' can be adjusted and is not limited here; (2) the structure and working principle of the second automobile device 22 and the third automobile device 23 can be referred to in Example 1 and will not be repeated here.

[0118] In the above-mentioned charging method based on the common DC bus of the electric vehicle, whether the charging device 1 and the first automobile device 21 are bidirectionally wirelessly charged and whether the second automobile device 22 and the third automobile device 23 are bidirectionally wirelessly charged are independent of each other and do not interfere with each other, that is, the charging device 1 and the first automobile device 21 are bidirectionally wirelessly charged while the second automobile device 22 and the third automobile device 23 are not bidirectionally wirelessly charged, or, the charging device 1 and the first automobile device 21 are bidirectionally wirelessly charged while the second automobile device 22 and the third automobile device 23 are bidirectionally wirelessly charged, or, the charging device 1 and the first automobile device 21 are not bidirectionally wirelessly charged while the second automobile device 22 and the third automobile device 23 are bidirectionally wirelessly charged, and the first automobile device 21 and the second automobile device 22 can be the same automobile device 2 or different automobile devices 2, which are not limited here.

[0119] It can be seen from the above embodiments that the bidirectional wireless charging system and charging method based on the shared DC bus of electric vehicles provided by the present invention at least achieve the following beneficial effects:

[0120] The bidirectional wireless charging system and charging method based on the common DC bus of electric vehicles provided by the present invention are both based on the common DC bus technology. The bidirectional wireless charging system based on the common DC bus of electric vehicles has a variety of charging topology strategies, and the charging topology structure includes but is not limited to the SSS topology structure. The SSS topology structure is a topology structure in which a capacitor is connected in series in a circuit. On the one hand, bidirectional wireless charging between a charging device and a vehicle device is realized to meet the power demand target of "peak shaving and valley filling". On the other hand, bidirectional wireless charging between different vehicle devices is realized to realize energy exchange between vehicles. The bidirectional wireless charging system based on the common DC bus of electric vehicles can meet the demand for electric vehicles to replenish energy at any time, solves the mileage anxiety of electric vehicle users, and can accelerate the application and popularization of new energy vehicles and the rational use of new energy. At the same time, since the remaining power of the electric vehicle can be replenished or released according to actual needs, the on-board battery inside the electric vehicle can have an ultra-long standby time, avoiding the problem of long-term performance degradation of the on-board battery, and can avoid the occurrence of various safety hazards caused by poor on-board batteries.

[0121] Although some specific embodiments of the present invention have been described in detail by way of example, it will be appreciated by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the present invention. It will be appreciated by those skilled in the art that the above embodiments may be modified without departing from the scope and spirit of the present invention. The scope of the present invention is defined by the appended claims.

Claims

1. A bidirectional wireless charging system based on a common DC bus of electric vehicles, characterized in that: comprising a charging device and at least one vehicle device; The charging device has a charging inverter circuit, the automobile device has a front inverter circuit and a rear inverter circuit, and the charging inverter circuit is used to couple with the front inverter circuit or the rear inverter circuit of the same automobile device; The front inverter circuit of one of the automobile devices is used to couple with the rear inverter circuit of at least one of the automobile devices, or the rear inverter circuit of one of the automobile devices is coupled with the front inverter circuit of at least one of the automobile devices; The charging inverter circuit, the front inverter circuit and the rear inverter circuit all have coils and capacitors. The coils and capacitors in the charging inverter circuit are connected in series or in parallel, the coils and capacitors in the front inverter circuit are connected in series or in parallel, and the coils and capacitors in the rear inverter circuit are connected in series or in parallel.

2. The bidirectional wireless charging system based on the shared DC bus of electric vehicles according to claim 1 is characterized in that: The coil is a resonance coil, and the coupling method is magnetic coupling.

3. The bidirectional wireless charging system based on the common DC bus of electric vehicles according to claim 1 is characterized in that: The charging inverter circuit, the front inverter circuit and the rear inverter circuit all have a bridge topology structure.

4. The bidirectional wireless charging system based on a common DC bus of electric vehicles according to claim 1 is characterized in that: The charging device and the automobile device are both connected to a cloud platform.

5. The bidirectional wireless charging system based on the shared DC bus of electric vehicles according to claim 1 is characterized in that: The automobile device includes a first automobile device having a first front inverter circuit and a first rear inverter circuit. The first front inverter circuit is coupled to the charging inverter circuit, or the first rear inverter circuit is coupled to the charging inverter circuit.

6. The bidirectional wireless charging system based on the shared DC bus of electric vehicles according to claim 1 is characterized in that: The automobile device comprises a second automobile device and a third automobile device, the second automobile device comprises a second front inverter circuit and a second rear inverter circuit, and the third automobile device comprises a third front inverter circuit and a third rear inverter circuit; The second rear inverter circuit is coupled to the third front inverter circuit, or the second front inverter circuit is coupled to the third rear inverter circuit.

7. The bidirectional wireless charging system based on the shared DC bus of electric vehicles according to claim 6 is characterized in that: The charging inverter circuit comprises a charging coil and a charging capacitor, wherein the charging coil and the charging capacitor are connected in series; The second front inverter circuit comprises a second front coil and a second front capacitor, the second front coil and the second front capacitor are connected in series, and the second rear inverter circuit comprises a second rear coil and a second rear capacitor, the second rear coil and the second rear capacitor are connected in series; The third front inverter circuit has a third front coil and a third front capacitor, and the third front coil and the third front capacitor are connected in series. The third rear inverter circuit has a third rear coil and a third rear capacitor, and the third rear coil and the third rear capacitor are connected in series.

8. A charging method based on a common DC bus of an electric vehicle, applied to a bidirectional wireless charging system based on a common DC bus of an electric vehicle as claimed in any one of claims 1 to 7, wherein the bidirectional wireless charging system based on a common DC bus of an electric vehicle comprises a charging device, a first vehicle device, a second vehicle device and a third vehicle device, wherein: The following steps are involved: The charging device matches the information of the first automobile device, wherein the charging device has a charging inverter circuit, the first automobile device has a first front inverter circuit and a first rear inverter circuit, the charging inverter circuit matches the first front inverter circuit, or the charging inverter circuit matches the first rear inverter circuit; The charging device charges the first automobile device, and if the charging inverter circuit matches the first front inverter circuit, the electric energy in the charging inverter circuit is transmitted to the first front inverter circuit; if the charging inverter circuit matches the first rear inverter circuit, the electric energy in the charging inverter circuit is transmitted to the first rear inverter circuit; The first automobile device charges the charging device, and if the charging inverter circuit matches the first front inverter circuit, the electric energy in the first front inverter circuit is transmitted to the charging inverter circuit; if the charging inverter circuit matches the first rear inverter circuit, the electric energy in the first rear inverter circuit is transmitted to the charging inverter circuit; and / or, The second automobile device matches information of the third automobile device, wherein the second automobile device has a second front inverter circuit and a second rear inverter circuit, the third automobile device has a third front inverter circuit and a third rear inverter circuit, the second front inverter circuit matches the third rear inverter circuit, or the second rear inverter circuit matches the third front inverter circuit; The second automobile device charges the third automobile device, and if the second front inverter circuit matches the third rear inverter circuit, the electric energy in the second front inverter circuit is transmitted to the third rear inverter circuit; if the second rear inverter circuit matches the third front inverter circuit, the electric energy in the second rear inverter circuit is transmitted to the third front inverter circuit; The third automobile device charges the second automobile device, and if the second front inverter circuit matches the third rear inverter circuit, the electric energy in the third rear inverter circuit is transmitted to the second front inverter circuit; if the second rear inverter circuit matches the third front inverter circuit, the electric energy in the third front inverter circuit is transmitted to the second rear inverter circuit; The first automobile device and the second automobile device are the same automobile device or different automobile devices.

9. The charging method based on the common DC bus of electric vehicles according to claim 8 is characterized in that: In the information matching between the second automobile device and the third automobile device, the similarity between the itinerary of the second automobile device and the itinerary of the third automobile device is not less than 80%, the distance between the second automobile device and the third automobile device does not exceed 2 km, and the remaining power of the second automobile device is not less than 80% or the remaining power of the third automobile device is not less than 80%.

10. The charging method based on the shared DC bus of electric vehicles according to claim 9, characterized in that: When the second automobile device is charging the third automobile device, the remaining power of the second automobile device decreases to 60%, and / or the remaining power of the third automobile device increases to 90%, and the second automobile device stops charging; When the third automobile device charges the second automobile device, the remaining power of the third automobile device decreases to 60%, and / or the remaining power of the second automobile device increases to 90%, and the third automobile device stops charging.

Images