Integrated AC vehicle-mounted charger

Abstract

The present disclosure provides an integrated AC on-board charger. A switch is connected between the traction battery and the transmission circuitry such that during a drive mode, the switch is open and power from the traction battery bypasses a field effect transistor of the transmission circuitry and a transformer of the transmission circuitry and flows through an inverter system controller to an electric machine, and during a charging mode, the switch is closed and power from a charging source sequentially flows through a winding of the electric machine, the inverter system controller, the transformer, and the switch to the traction battery.

Description

Technical Field

[0001] The present disclosure relates to automotive power systems. Background Art

[0002] Unlike traditional internal combustion engine vehicles, electric vehicles utilize electric motors for propulsion, drawing power from an onboard energy storage system (typically lithium-ion batteries).

[0003] Electric vehicles may require a charging solution. Certain onboard chargers convert AC power from the grid to DC power at a specified rate. Summary of the Invention

[0004] A vehicle includes a traction battery; an electric power system having an electric motor including a winding, a transmission circuit system including a plurality of field-effect transistors and a transformer, and an inverter system controller connected between the electric motor and the transmission circuit system; and a switch connected between the electric motor and the transmission circuit system. The electric power system and the switch are configured such that during a driving mode, the switch is open and power from the traction battery bypasses the field-effect transistors and the transformer and flows through the inverter system controller to the electric motor, and during a charging mode, the switch is closed and power from a charging source flows sequentially through the winding, the inverter system controller, the transformer, and the switch to the traction battery.

[0005] A method includes: in response to a driving mode, opening a switch connected between a traction battery and a transmission circuit system including a plurality of field effect transistors and a transformer, such that power from the traction battery bypasses the field effect transistors and the transformer and flows through an inverter system controller to a winding of a motor; and in response to a charging mode, closing the switch such that power from a charging source sequentially flows through the winding, the inverter system controller, the transformer, and the switch to the traction battery.

[0006] An automotive power control system includes a controller programmed to, in response to a charging mode, close a switch connected between a traction battery and a transmission circuit system and open a pair of switches of the transmission circuit system, so that power from a charging source flows through windings of an electric machine, an inverter system controller, a transformer of the transmission circuit system, and the switches to the traction battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 Schematic diagram of an AC on-board charger connected between the AC grid and the traction battery.

[0008] Figure 2 is a schematic diagram of the vehicle and some of its electrical-related components. DETAILED DESCRIPTION

[0009] Embodiments are described herein. However, it should be understood that the disclosed embodiments are merely examples and that other embodiments may take various and alternative forms. The drawings are not necessarily drawn to scale. Some features may be exaggerated or minimized to illustrate details of particular components. Therefore, the specific structural and functional details disclosed herein should not be construed as limiting, but merely as a representative basis for teaching those skilled in the art.

[0010] The various features shown and described with reference to any one of the accompanying drawings may be combined with features shown in one or more other drawings to produce embodiments not explicitly shown or described. The combinations of features shown provide representative embodiments for typical applications. However, for specific applications or implementations, various combinations and modifications of features may be desired consistent with the teachings of this disclosure.

[0011] AC onboard chargers are typically separate, closed systems consisting of electrical components distinct from the traction inverter and motor. These systems may also include power conversion modules, adaptive charging control, thermal management, and communication interfaces.

[0012] Some power conversion modules implement a highly efficient multi-stage conversion process to convert AC power to DC power. They may incorporate semiconductor devices with low on-resistance and high heat tolerance, thereby reducing energy losses during conversion.

[0013] Adaptive charging control can use algorithms to monitor the battery's state of charge (SoC), temperature, and capacity, and adjust charging power based on speed and battery health requirements. These systems can also communicate with the grid or home energy management system to charge the vehicle during off-peak hours.

[0014] The thermal management system can dissipate heat via active cooling techniques during the charging process to maintain the desired temperature of the charging components and the battery.

[0015] Communication interfaces can support standard charging protocols and allow for smart grid integration. Some can enable vehicles to participate in demand response programs, where charging can be scheduled or regulated based on grid load.

[0016] refer to Figure 1A typical AC vehicle charger 10 includes diodes 12, 14, 16, 18, 20, 22, 24, active switches 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, capacitors 48, 50, inductors 52, 54, 56, 58, and a high-frequency transformer 60. Diodes 12 and 14 are connected in series, and diodes 16 and 18 are connected in series. Diodes 12 and 14 are connected in parallel with diodes 16 and 18. Diode 20 is connected in series with inductor 54, diode 22 is connected in series with inductor 56, and diode 24 is connected in series with inductor 58. The three preceding components are connected in parallel. The terminals of active switch 26 are connected between diode 24 and inductor 58. The terminals of active switch 28 are connected between diode 22 and inductor 56. The terminals of active switch 30 are connected between diode 20 and inductor 54. Active switches 32 and 34 are connected in series. Active switches 36 and 38 are connected in series. Active switches 40 and 42 are connected in series. Active switches 44 and 46 are connected in series. Active switches 32 and 34 are connected in parallel with active switches 36 and 38. Active switches 40 and 42 are connected in parallel with active switches 44 and 46. Capacitor 48 is connected in parallel with active switches 32 and 34. Capacitor 50 is connected in parallel with active switches 44 and 46. High-frequency transformer 60 includes a pair of coils 62 and 64. The terminals of coil 62 are connected between active switches 32 and 34 and 36 and 38. The terminals of coil 64 are connected between active switches 40 and 42 and 44 and 46.

[0017] The AC onboard charger 10 is connected between the AC grid 66 and the traction battery 68. The capacitor 50 is connected in parallel with the traction battery 68. In summary, the AC onboard charger 10 includes seven diodes, eleven active switches, four inductors, two capacitors, and a high-frequency transformer to achieve three-phase interleaved AC onboard charging from the AC grid 66 to the traction battery 68. Some AC onboard chargers include more than Figure 1 The number of components shown is not sufficient. Therefore, such chargers may take up a considerable amount of space and have a certain weight.

[0018] As shown in the figure, a power factor correction circuit and a high frequency transformer are necessary. The former is used to meet the power factor requirements and regulatory standards of the AC power grid 66, while the latter realizes galvanic isolation.

[0019] Here, an AC onboard charger is presented that uses components from the electric drive system, such as the inverter and the motor. This allows the use of existing and already present electrical components of the vehicle to reduce the number of additional components, and thus the size and weight of the AC onboard charger. In one example, the AC onboard charger utilizes the inverter system controller and the motor windings. The components include four diodes, eight active switches, one inductor, one power capacitor, one high frequency transformer, and one relay. Additional contactors are also used, but the additional contactors are already part of the high voltage battery system. This can reduce the component count by three diodes, three active switches, three inductors, and one power capacitor compared to the AC onboard charger 10, while enabling three-phase interleaved AC onboard charging from the grid to the traction battery. Also, this can reduce the inverter DC bus capacitance, as two capacitors are in parallel during vehicle operation.

[0020] Reference Figure 2 The vehicle 70 includes a traction battery 72, a transmission circuitry 74, an inverter system controller 76, an electric machine 78 (e.g., a motor), a rectifier 80, a controller 82, a switch 84 (e.g., a relay), and an inductor 86. The transmission circuit 74 is connected between the traction battery 72 and the inverter system controller 76. The inverter system controller 76 is connected between the transmission circuit 74 and the electric machine 78. The electric machine 78 is connected between the inverter system controller 76 and the rectifier 80. The controller 82 is in communication with / exerts control over the components of Figure 2 The controller 82 can implement the algorithms and control strategies contemplated herein.

[0021] The transmission circuit 74 includes a capacitor 88, active switches 90, 92, 94, 96, 98, 100, 102, 104 (e.g., field effect transistors with body diodes, such as metal oxide semiconductor field effect transistors), a high frequency transformer 106, and switches 108, 110 (e.g., contactors). The active switches 90, 92 are in series. The active switches 94, 96 are in series. The active switches 98, 100 are in series. The active switches 102, 104 are in series. The active switches 90, 92 and 94, 96 are in parallel. The active switches 98, 100 and 102, 104 are in parallel. The capacitor 88 is in parallel with the active switches 90, 92.

[0022] High-frequency transformer 106 includes a pair of coils 112 and 114. Coil 112 has terminals connected between active switches 90, 92 and 94, 96. Coil 114 has terminals connected between active switches 98, 100 and 102, 104. Switches 108 and 110 are on the positive and negative rails of transmission circuit 74, respectively. A terminal of switch 108 shares a node 116 with the positive terminal of traction battery 72 and a terminal of switch 84. The other terminal of switch 108 is connected to inverter system controller 76. Switch 110 is connected between traction battery 72 and inverter system controller 76.

[0023] The inverter system controller 76 includes a capacitor 118 and active switches 120, 122, 124, 126, 128, 130 (e.g., field-effect transistors incorporating diodes, such as insulated gate bipolar transistors or metal oxide semiconductor field-effect transistors). Active switches 120 and 122 are connected in series. Active switches 124 and 126 are connected in series. Active switches 128 and 130 are connected in series. Capacitor 118 is connected in parallel with active switches 102, 104 and 120, 122 and is connected between them.

[0024] The motor 78 includes windings 132, 134, 136. The terminals of the winding 132 are connected between the active switches 120, 122. The terminals of the winding 134 are connected between the active switches 124, 126. The terminals of the winding 136 are connected between the active switches 128, 130.

[0025] Rectifier 80 includes diodes 138, 140, 142, and 144. Diodes 138 and 140 are connected in series. Diodes 142 and 144 are connected in series. Diodes 138 and 140 and 142 and 144 are connected in parallel. The other terminals of each of windings 132, 134, and 136 are connected together and share a node with the cathodes of diodes 138 and 140.

[0026] During operation of the vehicle 70, switches 108, 110 are closed, switch 84 is open, active switches 90, 92, 94, 96, 98, 100, 102, 104 are off, and the AC grid 146 (charging source) is not connected to the vehicle 70. The inverter system controller 76 operates the active switches 120, 122, 124, 126, 128, 130 via pulse width modulation to convert DC power from the traction battery 72 to AC power to drive the motor 78 and propel the vehicle 70. Thus, the traction battery 72 delivers power to the motor 78 and the vehicle 70 during motoring mode through the inverter system controller 76. During generating mode, the generated power is sent back to the traction battery 72 through the motor 78 and the inverter system controller 76. As suggested above, the capacitor 118 may be sized relative to the Figure 1The size of is reduced. Capacitors 88 and 118 are connected in parallel during operation of vehicle 70.

[0027] During AC onboard charging mode, inductor 86 is connected between diodes 138, 140 and AC grid 146 (which is connected to the input of rectifier 80), switches 108, 110 are open, and switch 84 is closed. The inverter system controller 76, windings 132, 134, 136, and rectifier 80 work together to achieve power factor correction by controlling the inverter system controller 76 to meet the efficiency, power factor requirements, and regulatory standards of AC grid 146: active switches 120, 124, 128 are turned off, and active switches 122, 126, 130 are pulse-width modulated. Active switches 90, 92, 94, 96, 98, 100, 102, 104 are controlled to boost the voltage to charge traction battery 72: they are pulse-width modulated. Here, high-frequency transformer 106 performs both voltage step-up and high-voltage isolation functions. If any short circuit occurs, switch 84 can be opened to manage the situation.

[0028] These topologies and strategies can be used with, for example, 400V and 800V electric drive systems.Because the inverter system controller 76 and motor 78 are utilized as described, the power factor correction circuitry can be common between 400V and 800V electric drive systems.

[0029] The algorithms, methods or processes disclosed herein may be capable of being delivered to or implemented by a computer, controller or processing device, which may include any dedicated electronic control unit or programmable electronic control unit. Similarly, the algorithms, methods or processes may be stored in various forms as data and instructions that can be executed by a computer or controller, including but not limited to information permanently stored on a non-writable storage medium such as a read-only memory device and information that can be modified and stored on a writable storage medium such as an optical disc, a random access memory device or other magnetic and optical media. The algorithms, methods or processes may also be implemented as software executable objects. Alternatively, suitable hardware components (such as application specific integrated circuits, field programmable gate arrays, state machines or other hardware components or devices) or a combination of firmware, hardware and software components may be used to embody the algorithms, methods or processes in whole or in part.

[0030] While exemplary embodiments have been described above, these embodiments are not intended to describe all possible forms encompassed by the claims. Furthermore, the words used in the specification are intended to be descriptive rather than limiting, and it should be understood that various changes may be made without departing from the spirit and scope of these disclosed materials. For example, the terms "controller" and "controllers" may be used interchangeably herein because the functionality of a controller may be distributed across several controllers / modules that can all communicate via standard technologies.

[0031] As previously described, features of the various embodiments may be combined to form additional embodiments of the invention that may not be explicitly described or shown. Although various embodiments may have been described as providing advantages or being preferred over other embodiments or prior art implementations with respect to one or more desired characteristics, it will be recognized by those skilled in the art that one or more features or characteristics may be compromised to achieve desired overall system properties, depending on the specific application and implementation. These properties may include, but are not limited to, strength, durability, marketability, appearance, packaging, size, serviceability, weight, manufacturability, ease of assembly, etc. Therefore, embodiments described as being less desirable than other embodiments or prior art implementations with respect to one or more characteristics are not outside the scope of this disclosure and may be desirable for a particular application.

[0032] According to the present invention, a vehicle is provided having: a traction battery; an electric power system having an electric motor including a winding, transmission circuitry including a plurality of field-effect transistors and a transformer, and an inverter system controller connected between the electric motor and the transmission circuitry; and a switch connected between the electric motor and the transmission circuitry, the electric power system and the switch being configured such that, during a driving mode, the switch is open and power from the traction battery bypasses the field-effect transistors and the transformer and flows through the inverter system controller to the electric motor, and during a charging mode, the switch is closed and power from a charging source flows sequentially through the winding, the inverter system controller, the transformer, and the switch to the traction battery.

[0033] According to one embodiment, the transmission circuitry includes a pair of switches configured to be closed during the driving mode and open during the charging mode.

[0034] According to one embodiment, one of the pair of switches shares a node with the positive terminal of the traction battery and a terminal of the switch.

[0035] According to one embodiment, the invention further features a rectifier connected to the winding such that during the charging mode, power from the charging source flows first through the rectifier and then through the winding.

[0036] According to one embodiment, the rectifier comprises a plurality of diodes, and wherein the winding shares a node with cathodes of some of the diodes.

[0037] According to one embodiment, the transmission circuitry comprises a capacitor configured to be connected in parallel with the traction battery when the switch is closed.

[0038] According to one embodiment, the invention also features a controller programmed to selectively open and close the switch in response to predefined conditions.

[0039] According to one embodiment, some of the field effect transistors are connected on one side of the transformer, and other of the field effect transistors are connected on the other side of the transformer.

[0040] According to the present invention, a method includes: in response to a driving mode, opening a switch connected between a traction battery and a transmission circuit system including a plurality of field-effect transistors and a transformer, so that power from the traction battery bypasses the field-effect transistors and the transformer and flows through an inverter system controller to a winding of a motor; and in response to a charging mode, closing the switch so that power from a charging source sequentially flows through the winding, the inverter system controller, the transformer, and the switch to the traction battery.

[0041] In one aspect of the invention, the method includes closing a pair of switches of the transmission circuitry in response to the drive mode.

[0042] In one aspect of the invention, the method includes opening the pair of switches in response to the charging mode.

[0043] According to the present invention, an automotive power control system is provided having a controller programmed to, in response to a charging mode, close a switch connected between a traction battery and a transmission circuit system and open a pair of switches of the transmission circuit system, so that power from a charging source flows through windings of a motor, an inverter system controller, a transformer of the transmission circuit system, and the switches to the traction battery.

[0044] According to one embodiment, the controller is further programmed to, in response to a driving mode, open the switch and close the pair of switches such that power from the traction battery flows through the inverter system controller and to the electric machine while bypassing the switch and the transformer.

[0045] According to one embodiment, one of the pair of switches shares a node with the positive terminal of the traction battery and a terminal of the switch.

[0046] According to one embodiment, the invention further features a rectifier connected to the winding such that during the charging mode, power from the charging source flows first through the rectifier and then through the winding.

[0047] According to one embodiment, the transmission circuitry comprises a capacitor configured to be connected in parallel with the traction battery when the switch is closed.

[0048] According to one embodiment, the transmission circuitry includes a plurality of field effect transistors, and wherein some of the field effect transistors are connected on one side of the transformer and others of the field effect transistors are connected on another side of the transformer.

Claims

1. A vehicle comprising: traction batteries; an electric power system having an electric machine including a winding, a transmission circuit system including a plurality of field effect transistors and a transformer, and an inverter system controller connected between the electric machine and the transmission circuit system; as well as a switch connected between the motor and the transmission circuitry, the power system and the switch being configured such that, during a driving mode, the switch is open and power from the traction battery bypasses the field effect transistor and the transformer and flows through the inverter system controller to the motor, and during a charging mode, the switch is closed and power from a charging source flows sequentially through the winding, the inverter system controller, the transformer, and the switch to the traction battery. 2 . The vehicle of claim 1 , wherein the transmission circuitry includes a pair of switches configured to be closed during the driving mode and open during the charging mode.

3. The vehicle of claim 2, wherein one of the pair of switches shares a node with a positive terminal of the traction battery and a terminal of the switch.

4. The vehicle of claim 1 further comprising a rectifier connected to the winding such that during the charging mode, power from the charging source flows first through the rectifier and then through the winding. 5 . The vehicle of claim 4 , wherein the rectifier comprises a plurality of diodes, and wherein the winding shares a node with cathodes of some of the diodes. 6 . The vehicle of claim 1 , wherein the transmission circuitry includes a capacitor configured to be connected in parallel with the traction battery when the switch is closed.

7. The vehicle of claim 1 further comprising a controller programmed to selectively open and close the switch in response to predefined conditions. 8 . The vehicle of claim 1 , wherein some of the field effect transistors are connected on one side of the transformer, and other of the field effect transistors are connected on the other side of the transformer.

9. A method comprising: In response to a driving mode, opening a switch connected between a traction battery and a transmission circuit system including a plurality of field effect transistors and a transformer so that power from the traction battery bypasses the field effect transistors and the transformer and flows through an inverter system controller to windings of a motor; and In response to a charging mode, closing the switch causes power from a charging source to flow sequentially through the winding, the inverter system controller, the transformer, and the switch to the traction battery.

10. The method of claim 9, further comprising closing a pair of switches of the transmission circuitry in response to the drive mode. The method of claim 10 , further comprising opening the pair of switches in response to the charging mode.

12. An automotive power control system, comprising: A controller is programmed to, in response to a charging mode, close a switch connected between a traction battery and a transmission circuit system and open a pair of switches of the transmission circuit system so that power from a charging source flows through windings of the electric machine, an inverter system controller, a transformer of the transmission circuit system, and the switches to the traction battery.

13. The automotive power control system of claim 12, wherein the controller is further programmed to open the switch and close the pair of switches in response to a driving mode such that power from the traction battery flows through the inverter system controller and to the electric machine while bypassing the switch and the transformer.

14. The automotive power control system of claim 12, wherein one of the pair of switches shares a node with a positive terminal of the traction battery and a terminal of the switch.

15. The automotive power control system of claim 12, further comprising a rectifier connected to the winding such that during the charging mode, power from the charging source first flows through the rectifier and then flows through the winding.

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