A charging and discharging system, power supply and vehicle

Abstract

The utility model relates to a kind of charging and discharging system, power supply and vehicle, including the direct current charging interface of discharging vehicle and the direct current charging interface of charging vehicle, the direct current charging interface of discharging vehicle and the direct current charging interface of charging vehicle are connected by V2V charging line;The battery of discharging vehicle, inverter capacitor, multiple inverter power electronic devices, new power electronic device, new diode, positive direct current charging relay, boost charging relay and negative direct current charging relay;The battery of charging vehicle, positive direct current charging relay and negative direct current charging relay;Wherein, V2V charging line inside connects the DC+ interface of discharging vehicle to the DC interface of charging vehicle, connects the DC interface of discharging vehicle to the DC+ interface of charging vehicle.The utility model realizes the continuous boost or step-down charging of discharging vehicle battery to charging vehicle battery by controlling the switching frequency and duty cycle of new power electronic device, with strong voltage compatibility.

Description

Technical Field

[0001] This utility model relates to the field of new energy vehicles, and in particular to a charging and discharging system, a power supply, and a vehicle. Background Technology

[0002] With the rapid development of new energy vehicles, although significant progress has been made in the construction of electric vehicle charging infrastructure, it still falls short of meeting the ever-increasing charging demand. Currently, public charging stations suffer from insufficient numbers and uneven distribution, leading to significant range anxiety for electric vehicle users. To address this issue, vehicle-to-vehicle (V2V) charging and discharging technology has emerged. This technology enables the exchange of electrical energy between electric vehicles, providing users with more and more flexible charging options and effectively reducing the difficulty of roadside assistance when an electric vehicle runs out of power.

[0003] However, existing V2V charging and discharging technologies still have some limitations. AC V2V power achieved through bidirectional on-board chargers (OBCs) is generally low, limited by the power of the OBC itself. While DC V2V offers higher power, additional high-power DC / DC converters are needed on the charging cable or inside the vehicle to control charging and discharging voltage and current, increasing costs. Another option is to reuse the electric drive system as a Buck converter for DC V2V, but Buck converters can only step down voltage, requiring the battery voltage of the charging vehicle to be lower than that of the discharging vehicle, resulting in poor voltage compatibility.

[0004] Therefore, there is an urgent need for a low-cost, high-power, and voltage-compatible V2V charging and discharging system to better meet the bidirectional high-power charging and discharging needs between electric vehicles with different battery voltages. Utility Model Content

[0005] In view of the shortcomings of the prior art described above, the purpose of this utility model is to provide a charging and discharging system, a power supply and a vehicle, which, by controlling the switching frequency and duty cycle of the newly added power electronic devices, enables continuous boost or buck charging of the battery of the discharging vehicle to the battery of the charging vehicle, and has strong voltage compatibility.

[0006] To achieve the above objectives, the present invention adopts the following technical solution.

[0007] In a first aspect, the charging and discharging system provided by this utility model adopts the following technical solution:

[0008] The DC charging interface of the discharge vehicle and the DC charging interface of the charging vehicle are connected via a V2V charging cable.

[0009] The battery, inverter capacitor, multiple inverter power electronics, newly added power electronics, newly added diodes, positive DC charging relay, boost charging relay and negative DC charging relay of the discharge vehicle;

[0010] The battery of the charging vehicle, the positive DC charging relay, and the negative DC charging relay;

[0011] The V2V charging cable internally connects the DC+ interface of the discharging vehicle to the DC- interface of the charging vehicle, and connects the DC- interface of the discharging vehicle to the DC+ interface of the charging vehicle.

[0012] Furthermore, in the above-mentioned charging and discharging system, the plurality of inverter power electronic devices include a first power electronic device S1, a second power electronic device S2, a third power electronic device S3, a fourth power electronic device S4, a fifth power electronic device S5, and a sixth power electronic device S6, and the newly added power electronic device is a seventh power electronic device S7.

[0013] Furthermore, in the above-mentioned charging and discharging system, the first power electronic device S1, the third power electronic device S3, and the fifth power electronic device S5 remain disconnected, the second power electronic device S2, the fourth power electronic device S4, and the sixth power electronic device S6 remain closed, and the seventh power electronic device S7 opens and closes at a certain frequency and duty cycle.

[0014] Furthermore, in the above-mentioned charging and discharging system, when the seventh power electronic device S7 is closed, the positive current of the battery of the discharging vehicle flows through the seventh power electronic device S7, the three-phase winding of the motor, the second power electronic device S2 / fourth power electronic device S4 / sixth power electronic device S6, and the negative terminal of the battery of the discharging vehicle.

[0015] Furthermore, in the above-mentioned charging and discharging system, when the seventh power electronic device S7 is disconnected, the current of the three-phase winding of the motor flows through the second power electronic device S2 / fourth power electronic device S4 / sixth power electronic device S6, the negative DC charging relay of the discharging vehicle, the positive DC charging relay of the charging vehicle, the battery of the charging vehicle, the negative DC charging relay of the charging vehicle, the boost charging relay of the discharging vehicle, the newly added diode, and the three-phase winding of the motor.

[0016] Furthermore, in the above-mentioned charging and discharging system, the switching frequency of the seventh power electronic device S7 is d, the battery terminal voltage of the discharging vehicle is U1, and the terminal voltage output to the battery of the charging vehicle is U1d / (1-d).

[0017] Furthermore, in the above-mentioned charging and discharging system, the newly added power electronic device and the newly added diode are integrated inside the inverter of the discharging vehicle.

[0018] Furthermore, in the above-mentioned charging and discharging system, the discharging vehicle and the charging vehicle are any one of pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles.

[0019] Secondly, the power supply provided by this utility model adopts the following technical solution:

[0020] A power source comprising a charging and discharging system as described in any of the first aspects above.

[0021] Thirdly, the vehicle provided by this utility model adopts the following technical solution:

[0022] A vehicle comprising a charging and discharging system as described in any of the first aspects above.

[0023] In summary, compared with the prior art, the present invention has at least one of the following beneficial technical effects:

[0024] 1. Through the improved electric drive system structure, compatibility with multiple functions such as electric drive, DC charging, boost charging, and V2V charging and discharging is achieved;

[0025] 2. The V2V charging and discharging circuit can both boost and buck the voltage, achieving compatibility with different battery voltages;

[0026] 3. Reuse of electric drive system, low cost, high power;

[0027] 4. The V2V charging and discharging process is continuous and uninterrupted, which improves charging efficiency and user experience. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 This is a circuit diagram of a specific embodiment of a charging and discharging system according to the present invention. Detailed Implementation

[0030] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application. Furthermore, it should be understood that the specific embodiments described herein are only for illustration and explanation of this application and are not intended to limit this application.

[0031] It should be noted that the order of description of the following embodiments is not intended to limit the preferred order of the embodiments of this application. Furthermore, the descriptions of each embodiment in the following embodiments have their own emphasis; for parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0032] The method steps described in this utility model embodiment can be executed in the order described in the specific implementation, or the execution order of each step can be adjusted according to actual needs, provided that the technical problem can be solved. They are not listed one by one here.

[0033] Reference Figure 1 The present invention provides a charging and discharging system comprising a DC charging interface 1 for a discharging vehicle and a DC charging interface 2 for a charging vehicle. The DC charging interface 1 and the DC charging interface 2 are connected via a V2V charging cable. Internally, the V2V charging cable connects the DC+ interface of the discharging vehicle to the DC- interface of the charging vehicle, and vice versa.

[0034] The discharge vehicle includes battery 1, inverter capacitor C, multiple inverter power electronic devices S1-S6, newly added power electronic device S7, newly added diode D, positive DC charging relay K1, boost charging relay K2 and negative DC charging relay K3.

[0035] The charging vehicle includes battery 2, positive DC charging relay K4, and negative DC charging relay K5.

[0036] In some embodiments, the battery 1 of the discharging vehicle is connected to the inverter power electronics S1-S6 via the inverter capacitor C. A new power electronics S7 is connected in parallel with the inverter power electronics S1-S6. A new diode D is connected in series with the new power electronics S7. A positive DC charging relay K1 is connected between the positive terminal of the battery 1 and the positive terminal of the DC charging interface 1. A boost charging relay K2 is connected between the new diode D and the positive terminal of the DC charging interface 1. A negative DC charging relay K3 is connected between the negative terminal of the battery 1 and the negative terminal of the DC charging interface 1.

[0037] In some implementations, the positive DC charging relay K4 of the charging vehicle is connected between the positive terminal of battery 2 and the positive terminal of DC charging interface 2. The negative DC charging relay K5 is connected between the negative terminal of battery 2 and the negative terminal of DC charging interface 2.

[0038] This charging and discharging system enables charging from a discharging vehicle to a charging vehicle via a V2V charging cable. The system utilizes the electric drive system of the discharging vehicle as a DC-DC converter, eliminating the need for an additional high-power DC-DC converter and reducing costs. Furthermore, the system can perform both boost and buck charging, making it suitable for charging and discharging between vehicles of different voltage levels.

[0039] Furthermore, the charging and discharging system includes multiple inverter power electronic devices and a newly added power electronic device. The multiple inverter power electronic devices include a first power electronic device S1, a second power electronic device S2, a third power electronic device S3, a fourth power electronic device S4, a fifth power electronic device S5, and a sixth power electronic device S6. The newly added power electronic device is a seventh power electronic device S7.

[0040] In some implementations, S1, S3, and S5 constitute the upper arm of the inverter, and S2, S4, and S6 constitute the lower arm of the inverter. S1-S6 are used to control the current of the three-phase windings of the motor to achieve motor drive control.

[0041] In some implementations, S7 is connected between the positive terminal of the vehicle battery and the connection point of the inverter. S7 is used to control the charging process of the vehicle battery to the three-phase windings of the motor.

[0042] In some implementations, S1-S7 are all controllable switching devices, such as IGBTs or MOSFETs. These power electronic devices achieve the conversion and control of electrical energy by controlling their on and off states.

[0043] In some embodiments, the first power electronic device S1, the third power electronic device S3, and the fifth power electronic device S5 remain in an open state. The second power electronic device S2, the fourth power electronic device S4, and the sixth power electronic device S6 remain in a closed state. The seventh power electronic device S7 performs open and close operations at a certain frequency and duty cycle.

[0044] The open states of S1, S3, and S5, and the closed states of S2, S4, and S6 constitute a specific circuit topology. This structure allows current to form a loop through S2, S4, and S6, providing a basis for subsequent charging and discharging operations.

[0045] The opening and closing operation of the seventh power electronic device S7 is crucial for controlling the charging and discharging process. The switching frequency and duty cycle of S7 determine the magnitude of the charging voltage and the intensity of the charging current. By adjusting the switching frequency and duty cycle of S7, the charging and discharging system can adapt to the charging and discharging needs of vehicles with different voltage levels.

[0046] In some implementations, the switching frequency of S7 can be adjusted according to charging requirements. A higher switching frequency helps reduce current ripple and improve charging efficiency. The duty cycle of S7 directly affects the output voltage. By precisely controlling the duty cycle of S7, the charging and discharging system can achieve boost or buck charging to meet the needs of different charging scenarios.

[0047] In some implementations, when the seventh power electronic device S7 is closed, the positive current of the battery in the discharging vehicle flows through the following path:

[0048] The current starts from the positive terminal of the battery of the discharging vehicle and first flows through the seventh power electronic device S7; after passing through S7, the current enters the three-phase winding of the motor; in the three-phase winding, the current flows through the U-phase, V-phase and W-phase windings respectively.

[0049] After leaving the three-phase windings of the motor, the current passes through the second power electronic device S2, the fourth power electronic device S4, and the sixth power electronic device S6 respectively; these three power electronic devices are in a closed state, providing a path for the current.

[0050] Finally, the current converges and flows back to the negative terminal of the battery in the discharging vehicle, completing the entire circuit.

[0051] During this process, the battery of the discharging vehicle charges the three-phase windings of the motor. The three-phase windings of the motor act as energy storage components in this process, preparing for subsequent discharge to the battery of the charging vehicle.

[0052] In some implementations, when the seventh power electronic device S7 is disconnected, the current in the three-phase windings of the motor flows along the following path:

[0053] The current starts from the three-phase windings of the motor and passes through the second power electronic device S2, the fourth power electronic device S4 and the sixth power electronic device S6 respectively; these three power electronic devices are in a closed state, providing a path for the current.

[0054] After leaving S2 / S4 / S6, the current flows through the negative DC charging relay K3 of the discharging vehicle; after passing through K3, the current enters the positive DC charging relay K4 of the charging vehicle.

[0055] After passing through K4, the current enters the battery 2 of the charging vehicle to charge the battery 2; after charging is completed, the current flows out from the battery 2 and passes through the negative DC charging relay K5 of the charging vehicle.

[0056] After leaving K5, the current returns to the discharge vehicle and passes sequentially through the boost charging relay K2 and the newly added diode D;

[0057] Finally, the current returns to the three-phase windings of the motor, completing the entire circuit.

[0058] In this process, the energy stored in the three-phase windings of the motor is transferred to the battery 2 of the charging vehicle through the aforementioned path, realizing energy transfer between vehicles. The newly added diode D plays a role in preventing reverse current flow during this process, ensuring the unidirectionality and safety of the charging process.

[0059] In some implementations, the switching frequency of the seventh power electronic device S7 is d, the battery terminal voltage of the discharging vehicle is U1, and the terminal voltage output to the battery of the charging vehicle is U1d / (1-d). This mathematical relationship describes the conversion relationship between the switching frequency d of S7 and the battery voltages U1 and U1d of the discharging vehicle and the charging vehicle.

[0060] The switching frequency d of the S7 can be continuously adjusted between 0% and 100%. When d is less than 50%, the battery of the discharging vehicle discharges at a reduced voltage to the battery of the charging vehicle. The smaller d is, the lower the output voltage. When d is greater than 50%, the battery of the discharging vehicle discharges at a increased voltage to the battery of the charging vehicle. The larger d is, the higher the output voltage.

[0061] This voltage conversion relationship allows the charging and discharging system to adapt to the charging and discharging needs of vehicles with different voltage levels. By adjusting the switching frequency d of S7, the system can achieve continuous voltage regulation, enabling effective charging regardless of whether the battery voltage of the charging vehicle is higher or lower than that of the discharging vehicle.

[0062] In some implementations, the additional power electronics and diodes are integrated within the inverter of the discharging vehicle. This integration method incorporates additional power control elements into the existing inverter structure, eliminating the need for separate external components.

[0063] The newly added power electronics are integrated into the inverter, sharing the same heat dissipation system and control circuitry as other power electronics. This design optimizes space utilization and simplifies wiring and connections.

[0064] The new diodes are also integrated inside the inverter. The diodes are carefully positioned to effectively prevent reverse current flow while minimizing parasitic inductance and resistance.

[0065] Methods for integrating these additional components within the inverter include reserving mounting locations on the inverter's printed circuit board or integrating these components directly into the inverter's power module. This integration approach not only improves system compactness but also helps enhance overall performance and reliability.

[0066] By integrating new power electronics and diodes into the inverter, the charging and discharging system achieves higher integration and a simpler structural design. This integration method helps reduce manufacturing costs, improve system reliability, and simplify the vehicle assembly process.

[0067] In some implementations, the discharging vehicle and the charging vehicle in the charging and discharging system can be any one of a pure electric vehicle, a hybrid electric vehicle, or a range-extended electric vehicle.

[0068] For pure electric vehicles, the charging and discharging system is directly connected to the vehicle's main drive battery. Pure electric vehicles typically have large-capacity battery packs, making them suitable for discharging power to other vehicles. Simultaneously, pure electric vehicles can also act as charging vehicles, utilizing the system to obtain power from other vehicles and extend their driving range.

[0069] For hybrid electric vehicles (HEVs), the charging and discharging system is connected to the vehicle's high-voltage battery system. HEVs combine the advantages of an internal combustion engine and an electric motor, and their battery capacity is typically smaller than that of a pure electric vehicle. As a discharging vehicle, a HEV can provide power to other vehicles when its battery is fully charged. As a charging vehicle, a HEV can use this system to replenish its battery, increasing the time it can operate in pure electric mode.

[0070] For range-extended electric vehicles (REEVs), the charging and discharging system is also connected to the vehicle's main drive battery. REEVs have a large-capacity battery and a small generator. As a discharging vehicle, a REEV can provide a stable power output because the generator can be started to supplement the battery when its charge is low. As a charging vehicle, a REEV can utilize this system for rapid charging, reducing reliance on the generator and improving overall energy efficiency.

[0071] The charging and discharging system is designed with the characteristics of different vehicle types in mind, employing a universal interface and control strategy to ensure system compatibility across various vehicle models. The system's voltage and current control functions enable it to adapt to the battery voltage and charging requirements of different vehicle models, achieving safe and efficient vehicle-to-vehicle charging.

[0072] In some embodiments, the present invention also provides a power supply. This power supply includes the charging and discharging system described above.

[0073] This power source can be an on-board power system used to provide electrical energy to the vehicle. The power system integrates various components of the charging and discharging system, including a DC charging interface, battery, inverter, power electronics, relays, etc.

[0074] As a crucial component of the power supply, the charging and discharging system enables vehicle-to-vehicle charging and discharging capabilities. This expands the power supply's application scenarios, allowing it not only to provide power to its own vehicle but also to exchange energy with other vehicles.

[0075] The power system integrates charging and discharging systems, enabling multiple operating modes. During normal driving, the power supply provides electrical energy to the vehicle. In charging mode, the power supply can obtain power from external charging stations or other vehicles. In discharging mode, the power supply can supply electrical energy to other vehicles.

[0076] The integration of the charging and discharging system enhances the flexibility and functionality of the power supply. The power supply can switch between various operating modes to meet the energy needs of vehicles in different scenarios, depending on the specific usage requirements.

[0077] In some embodiments, the present invention also provides a vehicle. This vehicle includes the charging and discharging system as described above.

[0078] The vehicle can be an electric vehicle, a hybrid vehicle, or a range-extended electric vehicle. The vehicle integrates various components of the charging and discharging system, including a DC charging interface, battery, inverter, power electronics, relays, etc.

[0079] As an important component of a vehicle, the charging and discharging system enables the vehicle to charge and discharge other vehicles. This function expands the vehicle's application scenarios, allowing it not only to drive normally but also to exchange energy with other vehicles.

[0080] The vehicle integrates a charging and discharging system, enabling multiple operating modes. During normal driving, the charging and discharging system provides the vehicle with electrical power. In charging mode, the vehicle can obtain electrical energy from external charging stations or other vehicles. In discharging mode, the vehicle can supply electrical energy to other vehicles.

[0081] The integration of the charging and discharging system enhances the vehicle's flexibility and functionality. The vehicle can switch between various operating modes to meet energy demands in different scenarios, depending on the specific usage requirements.

[0082] The above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model.

Claims

1. A charging and discharging system, characterized in that, include: The DC charging interface of the discharge vehicle and the DC charging interface of the charging vehicle are connected via a V2V charging cable. The battery, inverter capacitor, multiple inverter power electronics, newly added power electronics, newly added diodes, positive DC charging relay, boost charging relay and negative DC charging relay of the discharge vehicle; The battery of the charging vehicle, the positive DC charging relay, and the negative DC charging relay; The V2V charging cable internally connects the DC+ interface of the discharging vehicle to the DC- interface of the charging vehicle, and connects the DC- interface of the discharging vehicle to the DC+ interface of the charging vehicle.

2. The charging and discharging system according to claim 1, characterized in that, The plurality of inverter power electronic devices include a first power electronic device S1, a second power electronic device S2, a third power electronic device S3, a fourth power electronic device S4, a fifth power electronic device S5, and a sixth power electronic device S6, and the newly added power electronic device is a seventh power electronic device S7.

3. The charging and discharging system according to claim 2, characterized in that, The first power electronic device S1, the third power electronic device S3, and the fifth power electronic device S5 remain open, the second power electronic device S2, the fourth power electronic device S4, and the sixth power electronic device S6 remain closed, and the seventh power electronic device S7 opens and closes at a certain frequency and duty cycle.

4. The charging and discharging system according to claim 3, characterized in that, When the seventh power electronic device S7 is closed, the positive current of the battery of the discharge vehicle flows through the seventh power electronic device S7, the three-phase winding of the motor, the second power electronic device S2 / fourth power electronic device S4 / sixth power electronic device S6, and the negative terminal of the battery of the discharge vehicle.

5. The charging and discharging system according to claim 4, characterized in that, When the seventh power electronic device S7 is disconnected, the current of the three-phase winding of the motor flows through the second power electronic device S2 / the fourth power electronic device S4 / the sixth power electronic device S6, the negative DC charging relay of the discharge vehicle, the positive DC charging relay of the charging vehicle, the battery of the charging vehicle, the negative DC charging relay of the charging vehicle, the boost charging relay of the discharge vehicle, the newly added diode, and the three-phase winding of the motor.

6. The charging and discharging system according to claim 3, characterized in that, The switching frequency of the seventh power electronic device S7 is d, the battery terminal voltage of the discharging vehicle is U1, and the terminal voltage output to the battery of the charging vehicle is U1d / (1-d).

7. The charging and discharging system according to claim 1, characterized in that, The newly added power electronic devices and the newly added diodes are integrated inside the inverter of the discharge vehicle.

8. The charging and discharging system according to claim 1, characterized in that, The discharge vehicle and the charging vehicle are any one of pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles.

9. A power supply, characterized in that, The power source includes the charging and discharging system as described in any one of claims 1-8.

10. A vehicle, characterized in that, The vehicle includes a charging and discharging system as described in any one of claims 1-8.

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