Integration of traction inverter with three-phase resonant DC / DC converter

Abstract

The present disclosure provides integration of a traction inverter with a three-phase resonant DC / DC converter. An automotive power system includes: an AC / DC power converter; a transformer; a switching bridge that is connected between the AC / DC power converter and the transformer; and the switch group is connected with the secondary side of the transformer. The switching block connects the secondary side between an electric machine and another switching bridge such that the electric machine, the first switching bridge, the transformer, and the second switching bridge form an isolated DC / DC power converter.

Description

Technical Field

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

[0002] Motor vehicles can use electrical energy to power electric motors. The electric motors can convert this electrical energy into mechanical energy to propel the vehicle. Motor vehicles can include various power electronics to regulate and store electrical energy. Summary of the invention

[0003] A vehicle comprises: an electric machine; a traction battery; a first switch bridge connected between the electric machine and the traction battery; and a circuit arrangement. The circuit arrangement comprises: an AC / DC power converter; a transformer; a second switch bridge connected between the AC / DC power converter and the transformer; and a switch group connected to a secondary side of the transformer. The switch group connects the secondary side between the electric machine and the first switch bridge, so that the electric machine, the first switch bridge, the transformer and the second switch bridge form an isolated DC / DC power converter.

[0004] A method includes, in response to a request to charge a traction battery of a vehicle, connecting a secondary side of a transformer having a primary side connected to an AC / DC power converter through a switching bridge between an electric machine and another switching bridge such that the transformer, the electric machine, and the switching bridge form an isolated DC / DC power converter that delivers charging power between the AC / DC power converter and the traction battery.

[0005] An automotive power system includes: an AC / DC power converter; a transformer; a switch bridge connected between the AC / DC power converter and the transformer; and a switch group connected to a secondary side of the transformer. The switch group connects the secondary side between a motor and another switch bridge, so that the motor, the first switch bridge, the transformer, and the second switch bridge form an isolated DC / DC power converter that delivers charging power from the AC / DC power converter to a traction battery connected to another switch bridge. The system also includes a controller that closes a switch of the switch group in response to a request to charge the traction battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Figure 1 is a schematic diagram of a system including a battery current control module.

[0007] Figure 2 is a schematic diagram of a system including an inverter system controller.

[0008] Figure 3 is a schematic diagram of a system including an integrated battery current control module and an inverter system controller. 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 enlarged or minimized to show details of particular components. Therefore, the specific structural details and functional details disclosed herein should not be interpreted 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 consistent with the teachings of the present disclosure may be desired.

[0011] A battery current control module (BCCM) is a component in a motor vehicle, particularly one with an electric or hybrid powertrain. These modules play a role in regulating and managing the flow of current into and out of the battery.

[0012] The BCCM acts as a control unit that interfaces between the battery, the charging system and the electrical loads. The control units monitor and control various parameters such as the battery state of charge, voltage and temperature, and based on this information they regulate the current flowing to the battery.

[0013] The BCCM can facilitate charge control by overseeing the battery's charging process and managing the voltage and current supplied by the charging system. By monitoring the battery's state of charge and adjusting charging parameters accordingly, the BCCM attempts to ensure that the battery receives the appropriate charge level to maintain performance.

[0014] Similarly, BCCMs can be responsible for discharge control. They can regulate the current output from the battery to the electrical loads in the vehicle. By controlling the current, the BCCM can ensure a controlled power supply to the various electrical components and systems.

[0015] BCCMs can also implement various actions for the battery. For example, they can monitor battery temperature to prevent overheating. They can also detect overvoltage or undervoltage conditions and implement actions to avoid short circuits or excessive current draw.

[0016] Communication interfaces are often incorporated into the BCCM. These interfaces, such as the Controller Area Network (CAN) or LIN (Local Interconnect Network), allow the BCCM to exchange information with other vehicle systems, including the Engine Control Unit (ECU) or Body Control Module (BCM). This enables coordinated operation and integrated control across various vehicle functions. The BCCM can receive commands or instructions from other control units and adjust current accordingly.

[0017] BCCMs can have diagnostic capabilities. These modules can monitor the health and performance of the battery system. They can log codes and provide diagnostic information to facilitate maintenance.

[0018] Inverter system controllers (ISCs) are also components in motor vehicles with electric powertrains. They play a role in managing and controlling the flow of power between the battery and the electric motor. The function of the inverter system controller is to convert direct current (DC) from the battery into alternating current (AC) to power the electric motor.

[0019] The ISC can act as a decision maker for the power electronics system. It can monitor various parameters (such as motor speed, torque and temperature) to ensure operation.

[0020] The task of the ISC is to convert the DC power from the battery into three-phase AC power suitable for the electric motor. It can control the switching of current and voltage using high-power semiconductor devices (e.g., insulated gate bipolar transistors (IGBTs)). By modulating the pulse width and frequency of the AC waveform, the inverter system controller regulates the speed and torque output of the electric motor.

[0021] ISCs can provide control of electric motors. They can use algorithms and control strategies to regulate motor speed, torque, and direction of rotation. By adjusting the switching pattern of the IGBTs, the controller can change the frequency and amplitude of the AC waveform, thereby changing the motor operation.

[0022] ISC can facilitate regenerative braking. During deceleration or braking, the electric motor operates as a generator, converting the vehicle's kinetic energy into electrical energy. The inverter system controller can control the flow of energy, directing it back to the battery for storage.

[0023] ISCs can be responsible for managing the thermal conditions of power electronics systems. They can monitor the temperature of inverters and electric motors and employ cooling systems (such as fans, liquid cooling, or radiators) to dissipate excess heat and maintain operating temperatures.

[0024] ISCs can incorporate diagnostic capabilities to detect and prevent faults in power electronic systems. They can monitor various parameters that can indicate potential faults, such as voltage, current, and temperature values. If a fault is detected, the controller can take corrective action, such as shutting down the system, initiating other measures, or providing a fault code for diagnostic purposes.

[0025] ISCs typically have a communication interface (such as CAN or Ethernet) to enable integration with other vehicle systems. They can exchange information with the main control unit to enable coordinated operation and facilitate diagnostics and troubleshooting. The communication interface also allows the controller to receive commands or instructions from the electronic control unit (ECU) and adjust the power output accordingly.

[0026] ISCs may incorporate features such as overvoltage and undervoltage monitoring, overcurrent monitoring, and isolation monitoring.

[0027] Integrating a BCCM with an ISC is often considered a challenge due to the disconnected circuitry. Schematics of typical separate systems 10, 12 are shown in Figure 1 and Figure 2 Shown in.

[0028] refer to Figure 1 , the system 10 includes a BCCM 14, a traction battery 16, an auxiliary battery 18, and an onboard charging controller 20. The BCCM includes an AC / DC power factor correction circuit 22, an isolated high voltage DC / DC circuit 24, a link capacitor 26, and an isolated high voltage to low voltage DC / DC circuit 28. The isolated high voltage DC / DC circuit 24 is connected between the AC / DC power factor correction circuit 22 and the link capacitor 26. The link capacitor 26 is connected between the isolated high voltage DC / DC circuit 24 and the isolated high voltage to low voltage DC / DC circuit 28. The traction battery 16 and the auxiliary battery 18 are connected to the isolated high voltage to low voltage DC / DC circuit 28.

[0029] The AC / DC power factor correction circuit 22 includes an electromagnetic interference filter 30, a switch bank 32, and an AC / DC power converter circuit system 34. The switch bank 32 is connected between the electromagnetic interference filter 30 and the AC / DC power converter circuit system 34.

[0030] The isolated high voltage DC / DC circuit 24 includes a first switch bridge 36, a transformer 38, and a second switch bridge 40. The first switch bridge 36 is directly connected to the power converter circuit system 34. The transformer 38 is connected between the first switch bridge 36 and the second switch bridge 40.

[0031] The isolated high-voltage to low-voltage DC / DC circuit 28 includes an electromagnetic interference filter 42, a capacitor 44, and a high-voltage to low-voltage power converter circuit system 46. The electromagnetic interference filter 42 is connected across the capacitor 44 and directly connected to the traction battery 16. The capacitor 44 is connected between the link capacitor 26 and the high-voltage to low-voltage power converter circuit system 46. The high-voltage to low-voltage power converter circuit system 46 is directly connected to the auxiliary battery 18.

[0032] On-board charging controller 20 and Figure 1 Communicate with and / or exert control over the components shown in FIG.

[0033] refer to Figure 2 , the system 12 includes an electric machine 48, an ISC 50, and a traction battery 52. ​​The ISC 50 is connected between the electric machine 48 and the traction battery 52.

[0034] The ISC 50 has a three-phase inverter designed to drive the electric motor 48 and operates at a much higher power than the BCCM 14. The BCCM 14 also has three circuits configured as a three-phase inverter / rectifier. Two disconnect circuits are required to charge / discharge the traction battery 16 using the three-phase inverter of the ISC. The first disconnect circuit is used to disconnect the electric motor 48 from the ISC 50, and the second disconnect circuit is used to disconnect the ISC 50 from the traction battery 52. ​​The contactors used in these disconnect circuits must carry the full current of the ISC. Adding these contactors increases the bill of materials count, thus making level integration disadvantageous. However, package-level integration can provide advantages because it reduces the overall package size and / or weight and the number of connectors and wires. Here, a new circuit topology is proposed that solves some of the problems of the disconnect circuit system. Figure 3 , a schematic diagram of such a system 54 is shown against the background of a vehicle 55 .

[0035] refer to Figure 3 , system 54 includes an electromagnetic interference filter 56 , a switch bank 58 , an AD / DC power converter 60 , a switch bridge 62 , a capacitor bank 64 , a transformer 66 , a capacitor bank 68 , a switch bank 70 , a motor 72 , a switch bridge 74 , a traction battery 76 , and a controller 78 .

[0036] The switch bank 58 is connected between the electromagnetic interference filter 56 and the AC / DC power converter 60. The switch bridge 62 is connected between the AC / DC power converter 60 and the capacitor bank 64. The transformer 66 is connected between the capacitor banks 64, 68. The capacitor bank 68 is connected between the transformer and the switch bank 70. Therefore, the transformer 66 is also connected between the switch bridge 62 and the switch bank 70.

[0037] A switch bridge 74 is connected between the electric machine 72 and a traction battery 76 .

[0038] Controller 78 and Figure 3 Communicate with and / or exert control over the components shown in FIG.

[0039] The switch group 70 is connected to the secondary side of the transformer 66: when the switches of the switch group 70 are closed, the transformer 66 is connected between the motor 72 and the switch bridge 74, so that the switch bridge 62, the transformer 66, the motor 72 and the switch bridge 74 form an isolated DC / DC power converter. The controller 78 can close the switches of the switch group 70 in response to a request to charge the traction battery 76. When closed, the energy received at the electromagnetic interference filter 56, which is received from, for example, the grid via L1, L2, L3 and N, can be conditioned and passed to the traction battery 76 through the now formed isolated DC / DC power converter. When the switches of the switch group 70 are closed (i.e., during the charging mode), the controller 78 can operate the switches of the AC / DC power converter 60 and the switch bridges 62, 64, for example, at 300kHz. When charging is completed, the controller 78 can open the switches of the switch group 70. When the switches of the switch group 70 are open (e.g., during the driving mode), the controller 78 can operate the switches of the switch bridge 64, for example, at 30kHz (or less). Of course, other switching speeds may be used.

[0040] Figure 3 The circuit topology presented in allows the BCCM (electromagnetic interference filter 56, switch group 58, AC / DC power converter 60, switch bridge 62, capacitor group 64, transformer 66, capacitor group 68 and switch group 70) to be integrated with the ISC without the use of high current contactors. The additional circuit system is directly connected to the ISC without disconnecting the motor or traction battery. The additional circuit system includes the front-end AC / DC power factor correction circuit and the parts of the isolated high-voltage DC / DC circuit that are part of the BCCM. Three relays are added to disconnect the additional circuit system from the ISC during the drive mode. The high-voltage DC / DC circuit of the BCCM can be designed taking into account the stator winding impedance of the motor and its changes relative to the rotor position. When the vehicle is plugged into the AC grid, the additional circuit, ISC and electric motor form a bidirectional AC / DC to DC / AC power converter. The high-voltage DC / DC power converter of the BCCM can be designed to switch at a frequency much higher than the switching frequency of the ISC.

[0041] The algorithm, method or process disclosed herein may be 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 algorithm, method or process 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 changed and stored on a writable storage medium such as an optical disk, a random access memory device or other magnetic and optical media. The algorithm, method or process may also be implemented with a software executable object. Alternatively, the algorithm, method or process may be implemented in whole or in part using a combination of suitable hardware components (such as an application specific integrated circuit, a field programmable gate array, a state machine or other hardware components or devices) or firmware, hardware and software components.

[0042] Although exemplary embodiments are described above, these embodiments are not intended to describe all possible forms covered by the claims. The capacitor banks 64, 68 may alternatively be inductor banks or capacitor and inductor banks. Therefore, the symbols used to represent the capacitors of the capacitor banks 64, 68 may also represent the inductors of such inductor banks, or the capacitors and inductors of such capacitor and inductor banks. Depending on the topology and functional requirements, etc., the switch bridges 62, 74 may be n-phase inverters or n-phase rectifiers. For example, the switch bridge 62 can be configured as a single-phase inverter by removing one of its phase bridges.

[0043] The words used in the specification are 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 may all communicate via standard techniques.

[0044] As previously mentioned, the 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 appreciated by those of ordinary skill 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, and the like. Therefore, embodiments that are described as less desirable than other embodiments or prior art implementations with respect to one or more characteristics are within the scope of the present disclosure and may be desirable for a particular application.

[0045] According to the present invention, a vehicle is provided, having: an electric machine; a traction battery; a first switching bridge connected between the electric machine and the traction battery; and a circuit arrangement, the circuit arrangement comprising: an AC / DC power converter; a transformer; a second switching bridge connected between the AC / DC power converter and the transformer; and a switch group connected to a secondary side of the transformer and configured to connect the secondary side between the electric machine and the first switching bridge, so that the electric machine, the first switching bridge, the transformer and the second switching bridge form an isolated DC / DC power converter.

[0046] According to an embodiment, the invention is also characterized by a controller programmed to close the switches of the switch pack in response to a request to charge the traction battery.

[0047] According to an embodiment, the controller is further programmed to operate the switches of the first switching bridge at a frequency that is an order of magnitude greater when the switches of the switch group are closed than when the switches of the switch group are open.

[0048] According to an embodiment, the invention is also characterized by a set of capacitors connected between the first switching bridge and the transformer.

[0049] According to an embodiment, the invention also features a set of inductors connected between the first switching bridge and the transformer.

[0050] According to an embodiment, the first switching bridge is an n-phase inverter.

[0051] According to an embodiment, the first switching bridge is an n-phase rectifier.

[0052] According to an embodiment, the second switching bridge is an n-phase inverter.

[0053] According to an embodiment, the second switching bridge is an n-phase rectifier.

[0054] According to the present invention, a method includes, in response to a request to charge a traction battery of a vehicle, connecting a secondary side of a transformer having a primary side connected to an AC / DC power converter via a switching bridge between an electric machine and another switching bridge, such that the transformer, the electric machine, and the switching bridge form an isolated DC / DC power converter configured to deliver charging power between the AC / DC power converter and the traction battery.

[0055] In one aspect of the invention, the method comprises operating switches of the further switching bridge at a frequency one order of magnitude greater when the secondary side is connected between the motor and the further switching bridge than when the secondary side is disconnected from the motor and the further switching bridge.

[0056] In one aspect of the invention, the method comprises disconnecting the secondary side from the motor and the further switching bridge after the charging is completed.

[0057] According to the present invention, there is provided an automotive power system having: an AC / DC power converter; a transformer; a switch bridge connected between the AC / DC power converter and the transformer; a switch group connected to a secondary side of the transformer and configured to connect the secondary side between a motor and another switch bridge, so that the motor, the first switch bridge, the transformer and the second switch bridge form an isolated DC / DC power converter, the isolated DC / DC power converter being configured to deliver charging power from the AC / DC power converter to a traction battery connected to the another switch bridge; and a controller configured to close a switch of the switch group in response to a request to charge the traction battery.

[0058] According to an embodiment, the controller is further programmed to operate the switches of the switch bridge when the switches of the switch group are closed at a frequency that is an order of magnitude greater than when the switches of the switch group are open.

[0059] According to an embodiment, the invention is also characterized by a group of capacitors connected between the further switching bridge and the transformer.

[0060] According to an embodiment, the invention is also characterized by a set of inductors connected between the further switching bridge and the transformer.

[0061] According to an embodiment, the switching bridge is an n-phase inverter or an n-phase rectifier.

[0062] According to an embodiment, the further switching bridge is an n-phase inverter or an n-phase rectifier.

Claims

1. A vehicle comprising: Motor; Traction batteries; a first switch bridge connected between the motor and the traction battery; as well as A circuit arrangement, the circuit arrangement comprising: an AC / DC power converter; a transformer; a second switch bridge, the second switch bridge being connected between the AC / DC power converter and the transformer; and a switch group, the switch group being connected to the secondary side of the transformer and being configured to connect the secondary side between the motor and the first switch bridge, so that the motor, the first switch bridge, the transformer and the second switch bridge form an isolated DC / DC power converter.

2. The vehicle of claim 1 further comprising a controller programmed to close switches of the switch pack in response to a request to charge the traction battery.

3. The vehicle of claim 2, wherein the controller is further programmed to operate the switches of the first switch bridge at a frequency that is an order of magnitude greater when the switches of the switch bank are closed than when the switches of the switch bank are open.

4. The vehicle of claim 1 further comprising a bank of capacitors connected between the first switching bridge and the transformer.

5. The vehicle of claim 4 further comprising a set of inductors connected between the first switching bridge and the transformer.

6. The vehicle of claim 1, wherein the first switching bridge is an n-phase inverter.

7. The vehicle of claim 1, wherein the first switching bridge is an n-phase rectifier.

8. The vehicle of claim 1, wherein the second switching bridge is an n-phase inverter.

9. The vehicle of claim 1, wherein the second switching bridge is an n-phase rectifier.

10. A method comprising: In response to a request to charge a traction battery of a vehicle, a secondary side of a transformer having a primary side connected to an AC / DC power converter via a switch bridge is connected between a motor and another switch bridge such that the transformer, the motor, and the switch bridge form an isolated DC / DC power converter configured to deliver charging power from the AC / DC power converter to the traction battery.

11. The method of claim 10, further comprising: When the secondary side is connected between the motor and the further switching bridge, the switches of the further switching bridge are operated at a frequency which is one order of magnitude greater than when the secondary side is disconnected from the motor and the further switching bridge.

12. The method of claim 10, further comprising disconnecting the secondary side from the motor and the other switch bridge after the charging is completed.

13. An automotive power system, comprising: AC / DC power converters; transformer; a switch bridge connected between the AC / DC power converter and the transformer; a switch bank connected to a secondary side of the transformer and configured to connect the secondary side between an electric machine and another switch bridge such that the electric machine, the first switch bridge, the transformer, and the second switch bridge form an isolated DC / DC power converter configured to deliver charging power from the AC / DC power converter to a traction battery connected to the another switch bridge; as well as A controller is configured to close switches of the switch pack in response to a request to charge the traction battery.

14. The automotive power system of claim 13, wherein the controller is further programmed to operate the switches of the switch bridge at a frequency an order of magnitude greater when the switches of the switch bank are closed than when the switches of the switch bank are open.

15. The automotive power system of claim 13, further comprising a group of capacitors or a group of inductors connected between the other switching bridge and the transformer.

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