A wired and wireless integrated dual-mode charging system for electric vehicles

Abstract

The application discloses a wired and wireless integrated dual-mode charging system for an electric vehicle, a power factor correction circuit, a relay switching device, a dual-inverter circuit, a dual-LCC resonant network and a dual-magnetic-coupling transmitting coil, and a receiving coil, a compensation network and a full-bridge rectifier at a receiving end; wherein the dual inverters drive respective LCC resonant networks and transmitting coils, and form a magnetic-coupling energy transmission channel with the receiving coil; the vehicle-end receiving coil is connected to an input end of the rectifier via the resonant network, and an output end of the rectifier is connected to a battery pack; the system is provided with a mode switching device, in a wireless charging mode, the inverters work in an inverting state, and energy is wirelessly transmitted to the vehicle-end via the transmitting coil; in a wired charging mode, one of the inverters is switched to a rectifying state, receives energy from the other inverter via the coupling coil, and outputs an isolated direct-current high voltage for wired charging of the electric vehicle.

Description

A wired and wireless integrated dual-mode charging system for electric vehicles Technical Field

[0001] This invention belongs to the field of electric vehicle technology, and more specifically, relates to a wired and wireless integrated dual-mode charging (CWPT) system for electric vehicles. Background Technology

[0002] The development of electric vehicles should accelerate the construction of an efficient, intelligent, and safe charging infrastructure system, and promote the research and application of new technologies such as high-power charging, wireless charging, and intelligent orderly charging. As the number of electric vehicles continues to grow, users are demanding greater convenience and diversity in charging methods. Future charging scenarios will generally involve a mix of wired fast charging and wireless slow charging or automatic charging. Building an integrated wired and wireless dual-mode charging system is gradually becoming an important technological path for future public charging networks.

[0003] Currently, research on CWPT systems both domestically and internationally largely focuses on the integrated design of vehicle-side modules. This typically involves sharing rectifiers, DC / DC converters, inductors, or compensation networks between the wired charger and wireless receiver module to reduce the complexity of the vehicle's structure. These methods are mostly based on low-power AC slow charging scenarios and are suitable for some home charging locations. At the ground assembly (GA) end, wired charging piles and wireless charging devices generally employ two physically isolated independent systems, each equipped with its own PFC rectifier, power conversion unit, inverter, compensation network, cooling system, and controller. This results in high hardware redundancy, low system integration, and high operation and maintenance costs. Although some research has attempted to merge the power bus or control system, a modularly deployable, engineering-feasible integrated dual-mode charging system architecture has yet to be established.

[0004] Most convergence solutions are limited to vehicle assembly (VA) integration, failing to effectively address the issue of redundant construction at the GA (Gateway) level. For example, inverters, power modules, cooling devices, and electromagnetic shielding structures are often independent, resulting in high equipment costs, large system size, and cumbersome maintenance. Existing solutions still face significant bottlenecks in terms of technology and engineering implementation, making it difficult to support large-scale deployment. Currently, there is a lack of a CWPT (Charging-Wide-Pedestrian) system that enables power device sharing and dynamic power path reconfiguration at the GA level, limiting its adaptability in complex scenarios. Therefore, there is an urgent need to construct a highly integrated wired and wireless dual-mode charging system architecture at the GA level, featuring shared power devices and flexible topology switching, to achieve efficient and intelligent charging across multiple vehicle models, power levels, and scenarios. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a wired and wireless integrated dual-mode charging system for electric vehicles, which realizes the unified deployment of wired and wireless charging methods, has the ability to share power devices at the GA end, recognize modes and switch roles, and improves the system integration and adaptability.

[0006] To achieve the above-mentioned objectives, this invention proposes a wired and wireless integrated dual-mode charging system for electric vehicles, characterized in that it includes: a power factor correction circuit, a relay switching device, a dual inverter circuit, a dual LCC resonant network and a dual magnetically coupled transmitting coil, as well as a receiving coil, a compensation network and a full-bridge rectifier at the receiving end.

[0007] The power factor correction circuit includes an AC-DC rectifier module, a DC-DC converter module, and a capacitor. , The input terminal of the AC-DC rectifier module is connected to the power grid, and its output terminal is connected to the capacitor. After being connected in parallel, the capacitor is connected to the input terminal of the DC-DC converter module; the output terminal of the DC-DC converter module is connected to the capacitor. They are connected in parallel to form a stable DC bus voltage, which provides DC power to the dual inverters.

[0008] The relay switching device includes three relays. It enables switching between wired and wireless charging modes;

[0009] The dual inverter circuit includes a first inverter and a second inverter; wherein, the first inverter consists of an input capacitor. Switching transistor , , , This forms a full-bridge circuit, with the output connected to the input of the first resonant network and the relay. Connect the positive terminal of the busbar to the input terminal of the upper bridge arm of the first inverter, and simultaneously connect it to the relay. Connected; relay Connect the negative terminal of the busbar to the input terminal of the lower bridge arm of the first inverter; relay The other end serves as the positive port C for wired charging; relay The other end serves as the negative terminal D for wired charging; the second inverter consists of the input capacitor. Switching transistor , , , This forms a full-bridge circuit, with its positive terminal connected to the positive terminal of the bus, its negative terminal connected to the negative terminal of the bus, and its output connected to the input terminal of the second resonant network.

[0010] The dual LCC resonant network includes a first resonant network and a second resonant network; wherein, the first resonant network consists of a series inductor. Series capacitor and parallel capacitors Composition, inductance One end is connected to the midpoint of the upper arm of the first inverter, and the other end is connected to a capacitor. With capacitor ;capacitance The other end is connected to one end of the first transmitting coil; capacitor The other end is connected to the midpoint of the lower bridge arm of the first inverter and to the other end of the first transmitting coil; the second resonant network consists of a series inductor. Series capacitor and parallel capacitors The configuration and connection method are the same as the first resonant network; the entire dual LCC resonant network is used to realize soft switching of the inverter, improve energy transmission efficiency and reduce switching losses.

[0011] The dual magnetically coupled transmitting coil includes a first transmitting coil and a second transmitting coil; wherein the first transmitting coil is connected to the output terminal of the first resonant network, and the second transmitting coil is connected to the output terminal of the second resonant network; the two transmitting coils are spatially coupled in physical structure and together form a magnetic coupling channel with the receiving coil of the receiving end;

[0012] The receiving end includes a receiving coil, a compensation network, and a full-bridge rectifier; wherein, the receiving coil is connected to the capacitor... ,capacitance and inductor A compensation network is constructed for impedance matching and voltage regulation; the output of the compensation network is connected to a full-bridge rectifier, and a filter capacitor is connected in parallel to the output of the full-bridge rectifier. This generates a stable DC output voltage, which is supplied to the A and B ports of the wireless charger for wireless charging of electric vehicles.

[0013] The objective of this invention is achieved as follows:

[0014] This invention proposes a wired / wireless integrated dual-mode charging system for electric vehicles, comprising a power factor correction circuit, a relay switching device, a dual inverter circuit, a dual LCC resonant network, and dual magnetically coupled transmitting coils, as well as a receiving coil, a compensation network, and a full-bridge rectifier at the receiving end. The dual inverters each drive their respective LCC resonant networks and transmitting coils, forming a magnetically coupled energy transmission channel with the receiving coils. The vehicle-side receiving coil is connected to the rectifier input via the resonant network, and the rectifier output is connected to the battery pack. The system includes a mode switching device. In wireless charging mode, both inverters operate in inverter mode, wirelessly transmitting energy to the vehicle via the transmitting coils. In wired charging mode, one inverter switches to rectifier mode, receiving energy from the other inverter via the coupling coils and outputting an isolated DC high voltage for wired charging of the electric vehicle.

[0015] Meanwhile, the wired and wireless integrated dual-mode charging system for electric vehicles of the present invention also has the following beneficial effects:

[0016] (1) The present invention designs a relay switching device containing multiple relays, which is used to switch the output path and working role of the inverter according to the vehicle type and charging requirements. It has the ability of power device sharing, pattern recognition and role switching, and improves the system integration and adaptability.

[0017] (2) In wireless charging mode, both the first transmitting coil and the second transmitting coil can be magnetically coupled to the vehicle receiving coil to achieve energy transfer; in wired charging mode, the transmitting coil corresponding to the second inverter is responsible for energy transmission, while the transmitting coil corresponding to the first inverter serves as energy reception, thereby realizing a unified power supply architecture for the system in both wired and wireless modes.

[0018] (3) This invention supports multiple working modes of electric vehicles and is also adapted to the charging requirements of different types of electric vehicles, which meets the needs of the current development of the electric vehicle field. Compared with the traditional split charging structure, this invention significantly reduces the redundant configuration of GA end equipment, improves resource utilization and system integration, and has the ability to be compatible with multiple power levels, adapt to multiple models and switch flexible topologies. It provides key support for building intelligent, efficient and highly compatible public charging infrastructure and has good engineering feasibility and promotion value. Attached Figure Description

[0019] Figure 1 is a circuit diagram of a wired and wireless integrated dual-mode charging system for electric vehicles according to the present invention;

[0020] Figure 2 is a schematic diagram of the wireless charging mode and its equivalent simplified circuit diagram;

[0021] Figure 3 is a schematic diagram of the receiver's coilless wired charging mode and its equivalent simplified circuit diagram;

[0022] Figure 4 is a schematic diagram of the wired charging mode with coil at the receiver and its equivalent simplified circuit diagram.

[0023] Figure 5 is a flowchart of the design process for the CWPT system of an electric vehicle. Detailed Implementation

[0024] The specific embodiments of the present invention will now be described with reference to the accompanying drawings to enable those skilled in the art to better understand the invention. It should be particularly noted that in the following description, detailed descriptions of known functions and designs that might obscure the main content of the invention will be omitted here.

[0025] Example

[0026] In this embodiment, as shown in FIG1, the present invention provides a wired and wireless integrated dual-mode charging system for electric vehicles, comprising: a power factor correction circuit, a relay switching device, a dual inverter circuit, a dual LCC resonant network and a dual magnetically coupled transmitting coil, as well as a receiving coil, a compensation network and a full-bridge rectifier at the receiving end.

[0027] The power factor correction circuit includes an AC-DC rectifier module, a DC-DC converter module, and capacitors. , The input terminal of the AC-DC rectifier module is connected to the power grid, and its output terminal is connected to the capacitor. After being connected in parallel, the capacitor is connected to the input terminal of the DC-DC converter module; the output terminal of the DC-DC converter module is connected to the capacitor. They are connected in parallel to form a stable DC bus voltage, which provides DC power to the dual inverters.

[0028] The relay switching device includes three relays. It enables switching between wired and wireless charging modes;

[0029] The dual inverter circuit includes a first inverter and a second inverter; at least one of the first inverter and the second inverter is equipped with a relay switching device. Below, we will take the configuration of the first inverter with a relay switching device as an example to provide a detailed explanation of the dual inverter circuit, as follows:

[0030] The first inverter consists of an input capacitor. Switching transistor , , , This forms a full-bridge circuit, with the output connected to the input of the first resonant network and the relay. Connect the positive terminal of the busbar to the input terminal of the upper bridge arm of the first inverter, and simultaneously connect it to the relay. Connected; relay Connect the negative terminal of the busbar to the input terminal of the lower bridge arm of the first inverter; relay The other end serves as the positive port C for wired charging; relay The other end serves as the negative terminal D for wired charging; the second inverter consists of the input capacitor. Switching transistor , , , This forms a full-bridge circuit, with its positive terminal connected to the positive terminal of the bus, its negative terminal connected to the negative terminal of the bus, and its output connected to the input terminal of the second resonant network.

[0031] The dual LCC resonant network includes a first resonant network and a second resonant network; wherein, the first resonant network consists of a series inductor. Series capacitor and parallel capacitors Composition, inductance One end is connected to the midpoint of the upper arm of the first inverter, and the other end is connected to a capacitor. With capacitor ;capacitance The other end is connected to one end of the first transmitting coil; capacitor The other end is connected to the midpoint of the lower bridge arm of the first inverter and to the other end of the first transmitting coil; the second resonant network consists of a series inductor. Series capacitor and parallel capacitors The configuration and connection method are the same as the first resonant network; the entire dual LCC resonant network is used to realize soft switching of the inverter, improve energy transmission efficiency and reduce switching losses.

[0032] The dual magnetically coupled transmitting coil includes a first transmitting coil and a second transmitting coil; wherein, the first transmitting coil is connected to the output terminal of the first resonant network, and the second transmitting coil is connected to the output terminal of the second resonant network; the two transmitting coils are spatially coupled in physical structure and together form a magnetic coupling channel with the receiving coil of the receiving end;

[0033] The receiving end includes a receiving coil, a compensation network, and a full-bridge rectifier; wherein, the receiving coil is connected to the capacitor... ,capacitance and inductor A compensation network is constructed for impedance matching and voltage regulation; the output of the compensation network is connected to a full-bridge rectifier, and a filter capacitor is connected in parallel to the output of the full-bridge rectifier. This generates a stable DC output voltage, which is supplied to the A and B ports of the wireless charger for wireless charging of electric vehicles.

[0034] In this embodiment, the relay switching device switches the inverter's output path and working role according to the type of electric vehicle and charging requirements;

[0035] When the electric vehicle itself does not have a receiving coil, the inverter with a relay switching device switches to rectification mode, receives the energy output from another inverter through the magnetically coupled transmitting coil, and then outputs high-voltage DC from the charging ports C and D to complete the wired charging of the electric vehicle.

[0036] When the electric vehicle has its own receiving coil and wireless charging is selected, both inverters work in transmitting mode. The transmitting coil is driven by the resonant network to magnetically couple with the receiving coil at the vehicle end. The energy is rectified and then wirelessly charged by charging ports A and B for the electric vehicle.

[0037] When an electric vehicle has its own receiving coil but chooses wired charging, the vehicle-side rectifier remains in a short-circuit conducting state, and the inverter with a relay switching device switches to the rectifier role. After receiving energy through coupling, it outputs high-voltage DC from the charging ports C and D to complete the wired charging of the electric vehicle.

[0038] In this embodiment, the first transmitting coil and the second transmitting coil have mutual inductance coefficients with the receiving coil. , The two have a mutual inductance coefficient. The formula for calculating the mutual inductance between transmitting coil 1, transmitting coil 2, and receiving coil is as follows:

[0039] , , ;

[0040] in, The coupling coefficient between the transmitting coil 1, transmitting coil 2, and receiving coil is... The inductance of the transmitting coil 1, transmitting coil 2, and receiving coil. and resonance, and and resonance, and resonance, and and Resonance, VA is consistent with the aforementioned configuration.

[0041] ;

[0042] ;

[0043] ;

[0044] in, , , The parallel resonant capacitor, series resonant capacitor, and series resonant inductor of the first resonant network, the second resonant network, and the VA terminal compensation network, wherein... The resonant frequency is given; the equivalent impedance and current at the VA terminal in wireless charging mode are given.

[0045] ;

[0046] ;

[0047] The equivalent impedance of the VA terminal is... The equivalent resistance of the rectifier, the The current of the VA coil, the , The resonant currents of the first and second resonant network coils are given, and the root mean square (RMS) of the inverter output voltage is given.

[0048] ;

[0049] in, , The root mean square voltage and phase angle of the first inverter and the second inverter are given. The DC bus voltage of the power factor correction circuit is [value], and the resonant current is [value].

[0050] , ;

[0051] The resonant capacitor and resonant inductor are configured as follows

[0052] , ;

[0053] The equivalent impedance of the transmitting coil terminal is

[0054] ;

[0055] ;

[0056] in, The equivalent impedances of the first and second transmitting coil terminals are given, and the equivalent input impedance of the inverter is given.

[0057] ;

[0058] ;

[0059] in, The equivalent input impedance of the first inverter and the second inverter is [value], and the output power in wireless charging mode is [value].

[0060] ;

[0061] ;

[0062] in, The output power, The phase angle at the battery pack end. This refers to the DC bus voltage of the battery pack. The current at terminal VA is... The current of the DC bus of the battery pack is [value], and the power loss is [value].

[0063] ;

[0064] in, The power loss of the wireless charging mode, The equivalent resistance is the series resonant inductance of the first resonant network, the second resonant network, and the VA terminal compensation network. The on-resistance of the switch transistor. The equivalent resistance of the first resonant network, the second resonant network, and the VA terminal coil.

[0065] DC-DC efficiency in wireless charging mode for

[0066] ;

[0067] The equivalent voltage of the wired charging mode compensation network port without coils at the VA end is:

[0068] ;

[0069] ;

[0070] in, To compensate for the equivalent voltage of network port 1 and network port 2.

[0071] The output power of the wired charging mode without coils at the VA terminal is

[0072] ;

[0073] The power loss in wired charging mode without coils at the VA end is

[0074] ;

[0075] in, The power loss of the mode is denoted as .

[0076] DC / DC efficiency of the mode for

[0077] ;

[0078] The rectified current of the VA terminal with coil in wired charging mode is

[0079] ;

[0080] in, The resonant current on the rectifier side is; the power loss of the mode is...

[0081] ;

[0082] in, The power loss of the mode. The DC / DC efficiency of the mode. for

[0083] ;

[0084] Figure 2 shows the schematic diagram and its equivalent simplified circuit diagram of the wireless charging mode in an embodiment of the present invention. In this mode, the system achieves energy transfer through the magnetic coupling between the transmitting coil and the receiving coil. The dual resonant network works in conjunction with the inverter to ensure that the system has a good power factor and efficient energy transfer performance in the resonant state, thus ensuring stable system operation.

[0085] Figure 3 shows the schematic diagram and its equivalent simplified circuit of the wired charging working mode of the present invention when there is no receiving coil at the VA end. In this mode, the vehicle end does not contain a magnetic coupling structure, and the battery pack at the VA end is only connected through the CD end configured in the system; the inverter with relay in the system switches to rectification, and another inverter performs inversion, which supplies power to the rectifier through the magnetic coupling path and completes wired charging.

[0086] Figure 4 shows the operating mode of the present invention, in which a receiving coil is provided at the VA end but a wired charging path is selected, and its equivalent simplified circuit diagram. In this mode, although the VA end is equipped with a receiving coil, its receiving function is not activated. Instead, the rectifier MOSFET is short-circuited by the controller, and the energy is still supplied to the rectifier input end with relay conversion through the magnetic coupling path, thus realizing wired output.

[0087] Figure 5 shows a flowchart of the design method for the electric vehicle CWPT system provided by this invention. The flowchart includes key steps such as vehicle charging parameter calculation, coil parameter calculation, resonant network configuration, efficiency evaluation, and feedback correction, forming a complete system design closed loop. This flowchart is used to describe the dynamic adaptation strategy of the dual-mode system in practical deployment applications and the key decision-making paths in its design process.

[0088] Although the illustrative specific embodiments of the present invention have been described above to enable those skilled in the art to understand the invention, it should be understood that the invention is not limited to the scope of the specific embodiments. For those skilled in the art, various changes are obvious as long as they are within the spirit and scope of the invention as defined and determined by the appended claims, and all inventions utilizing the concept of the present invention are protected.

Claims

1. A wired and wireless integrated dual-mode charging system for electric vehicles, characterized in that, include: The system includes a power factor correction circuit, a relay switching device, a dual inverter circuit, a dual LCC resonant network, and dual magnetically coupled transmitting coils, as well as a receiving coil, a compensation network, and a full-bridge rectifier at the receiving end; the power factor correction circuit includes an AC-DC rectifier module, a DC-DC converter module, and capacitors. 、 The input terminal of the AC-DC rectifier module is connected to the power grid, and its output terminal is connected to the capacitor. After being connected in parallel, the capacitor is connected to the input terminal of the DC-DC converter module; the output terminal of the DC-DC converter module is connected to the capacitor. The inverters are connected in parallel to form a stable DC bus voltage, providing DC power to the dual inverters; the relay switching device includes three relays. This enables switching between wired and wireless charging modes; the dual inverter circuit includes a first inverter and a second inverter; wherein, the first inverter consists of an input capacitor. Switching transistor 、 、 、 This forms a full-bridge circuit, with the output connected to the input of the first resonant network and the relay. Connect the positive terminal of the busbar to the input terminal of the upper bridge arm of the first inverter, and simultaneously connect it to the relay. Connected; relay Connect the negative terminal of the busbar to the input terminal of the lower bridge arm of the first inverter; relay The other end serves as the positive port C for wired charging; relay The other end serves as the negative terminal D for wired charging; the second inverter consists of the input capacitor. Switching transistor 、 、 、 A full-bridge circuit is formed, with its positive terminal connected to the positive terminal of the busbar and its negative terminal connected to the negative terminal of the busbar. The output is connected to the input terminal of the second resonant network. The dual LCC resonant network includes a first resonant network and a second resonant network. The first resonant network consists of a series inductor. Series capacitor and parallel capacitors Composition, inductance One end is connected to the midpoint of the upper arm of the first inverter, and the other end is connected to a capacitor. With capacitor ;capacitance The other end is connected to one end of the first transmitting coil; capacitor The other end is connected to the midpoint of the lower bridge arm of the first inverter and to the other end of the first transmitting coil; the second resonant network consists of a series inductor. Series capacitor and parallel capacitors The configuration is the same as that of the first resonant network; the entire dual LCC resonant network is used to achieve soft switching of the inverter, improve energy transmission efficiency, and reduce switching losses; the dual magnetically coupled transmitting coil includes a first transmitting coil and a second transmitting coil; wherein, the first transmitting coil is connected to the output terminal of the first resonant network, and the second transmitting coil is connected to the output terminal of the second resonant network; the two transmitting coils are spatially coupled in physical structure and together form a magnetic coupling channel with the receiving coil of the receiving end; the receiving end includes a receiving coil, a compensation network, and a full-bridge rectifier; wherein, the receiving coil is connected to the capacitor ,capacitance and inductor A compensation network is constructed for impedance matching and voltage regulation; the output of the compensation network is connected to a full-bridge rectifier, and a filter capacitor is connected in parallel to the output of the full-bridge rectifier. This generates a stable DC output voltage, which is supplied to the A and B ports of the wireless charger for wireless charging of electric vehicles.

2. The wired and wireless integrated dual-mode charging system for electric vehicles according to claim 1, characterized in that, At least one of the first inverter and the second inverter is equipped with a relay switching device.

3. The wired and wireless integrated dual-mode charging system for electric vehicles according to claim 1, characterized in that, The relay switching device switches the inverter's output path and operating role according to the type of electric vehicle and charging requirements. Specifically, when the electric vehicle does not have its own receiving coil, the inverter with the relay switching device switches to rectification mode, receiving energy from another inverter via a magnetically coupled transmitting coil, and then outputting high-voltage DC from charging ports C and D to complete wired charging of the electric vehicle. When the electric vehicle has its own receiving coil and wireless charging is selected, both inverters operate in inversion mode, driving the transmitting coil to magnetically couple with the vehicle-side receiving coil via a resonant network. The energy is rectified and then wirelessly charged from charging ports A and B. When the electric vehicle has its own receiving coil but wired charging is selected, the vehicle-side rectifier remains short-circuited, and the inverter with the relay switching device switches to rectification mode, receiving energy via coupling and then outputting high-voltage DC from charging ports C and D to complete wired charging of the electric vehicle.

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