INTEGRATED BATTERY CURRENT CONTROL MODULE AND INVERTER SYSTEM CONTROLLER

Abstract

An automotive power system includes a circuit arrangement including an AC / DC power factor correction circuit, a transformer, and a switch connecting the transformer to a phase leg of an electric machine between the electric machine and an inverter system controller. When the switch is closed, the circuit arrangement, the electric machine, and the inverter system controller form a bidirectional AC / DC-DC / AC power converter.

Description

FIELD OF TECHNOLOGY

[0001] This disclosure relates to power systems for motor vehicles. GENERAL STATE OF THE ART

[0002] A motor vehicle can use electrical energy to power an electric machine. The electric machine can convert this electrical energy into mechanical energy to propel the vehicle. The motor vehicle can include various power electronics equipment to condition and store electrical energy. SUMMARY

[0003] A vehicle includes a traction battery, an electric machine, an inverter system controller connected between the traction battery and the electric machine, and a circuit assembly. The circuit assembly includes an AC / DC power factor correction circuit, a transformer, a switch bridge connected between the AC / DC power factor correction circuit and the transformer, and a switch connecting the transformer to a phase leg of the electric machine between the electric machine and the inverter system controller, such that when the switch is closed, the circuit assembly, the electric machine, and the inverter system controller form a bidirectional AC / DC-DC / AC power converter.

[0004] A method includes closing a switch of a circuit assembly to connect an AC / DC power factor correction circuit, a switch bridge, and a transformer of the circuit assembly via an inverter system controller connected between an electric machine and a traction battery, such that the circuit assembly, the electric machine, and the inverter system controller form a bidirectional AC / DC-DC / AC power converter that transfers power from an AC source to the traction battery.

[0005] A motor vehicle power system includes circuitry including an AC / DC power factor correction circuit, a transformer, and a switch connecting the transformer to a phase leg of an electric machine between the electric machine and an inverter system controller. The motor vehicle power system also includes a controller that closes the switch so that the circuitry, the electric machine, and the inverter system controller form a bidirectional AC / DC-DC / AC power converter that transfers power from an AC source to the traction battery. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic diagram of a system including a battery power control module. Fig. Figure 2 is a schematic diagram of a system including an inverter system controller. Fig. Figure 3 is a schematic diagram of a system including a battery power control module and an inverter system controller. DETAILED DESCRIPTION

[0006] Embodiments are described in this specification. It should be understood, however, that the disclosed embodiments are merely examples, and other embodiments may take various and alternative forms. The figures are not necessarily to scale. Some features may be exaggerated or reduced to show details of specific components. Therefore, specific structural and functional details disclosed in this specification are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art.

[0007] Various features illustrated and described with respect to any of the figures may be combined with features illustrated in one or more other figures to produce embodiments not explicitly illustrated or described. The illustrated combinations of features provide representative embodiments for typical applications. However, various combinations and modifications of the features consistent with the teachings of this disclosure may be desirable for particular applications or implementations.

[0008] Battery current control modules (BCCMs) are components in motor vehicles, particularly those with electric or hybrid powertrains. These modules play a role in managing the flow of electrical current to and from the battery. BCCMs act as control units that provide an interface between the battery, the charging system, and the electrical loads. They monitor and control various parameters, such as the battery's state of charge, voltage, and temperature, and manage the flow of current to the battery based on this information. BCCMs can facilitate charging control by overseeing the battery charging process and managing the voltage and current supplied by the charging system.By monitoring the battery's state of charge and adjusting the charging parameters accordingly, BCCMs attempt to ensure that the battery receives the appropriate level of charge to maintain performance. Similarly, BCCMs can be responsible for discharge control. They can manage the current delivered from the battery to the vehicle's electrical loads. By controlling the current flow, BCCMs can ensure a controlled power supply to the various electrical components and systems. BCCMs can also implement various actions for the battery. For example, they can monitor the battery temperature to prevent overheating. They can also detect overvoltage or undervoltage situations and implement measures to prevent short circuits or excessive current draw. BCCMs can have diagnostic capabilities.These modules can monitor the condition and performance of the battery system. They can log codes and provide diagnostic information, making maintenance easier.

[0009] Communication interfaces are often included in BCCMs. These interfaces, such as a Controller Area Network (CAN) or LIN (Local Interconnect Network), allow BCCMs to exchange information with other vehicle systems, including the engine control unit or the body control module. This enables coordinated operation and integrated control across various vehicle functions. BCCMs can receive commands or instructions from other control units and adjust power flow accordingly.

[0010] Inverter system controllers (ISCs) are also components in vehicles with electric powertrains. They play a role in managing and controlling the flow of power between the battery and the electric motor. One function of an inverter system controller is to convert direct current (DC) from the battery into alternating current (AC) to power the electric motor. ISCs can act as decision makers for the power electronics system. They can monitor various parameters such as the speed, torque, and temperature of the electric motor to ensure operation. One function of ISCs is to convert DC power from the battery into three-phase AC power suitable for the electric motor.It can utilize high-power semiconductor devices, such as insulated-gate bipolar transistors (IGBTs), to control the switching of current and voltage. By modulating the pulse width and frequency of the AC waveform, the inverter system controller manages the speed and torque output of the electric motor. ISCs can provide control of the electric motor. They can use algorithms and control strategies to manage the speed, torque, and direction of rotation of the electric motor. By adjusting the switching patterns of the IGBTs, the controller can vary the frequency and amplitude of the AC waveform, altering the electric motor operation. ISCs can facilitate regenerative braking. During deceleration or braking, the electric motor acts as a generator, converting the vehicle's kinetic energy into electrical energy.The ISC can control the flow of energy, diverting it back to the battery for storage. ISCs can be responsible for managing the thermal conditions of the power electronics system. They can monitor the temperature of the inverter and electric motor and employ cooling systems such as fans, liquid cooling, or heat sinks to dissipate excess heat and maintain operating temperatures. ISCs can incorporate diagnostic capabilities to detect and protect against faults in the power electronics system. They can monitor various parameters, such as voltage, current, and temperature values, that could indicate a potential fault. If a fault is detected, the controller can take corrective action, such as shutting down the system, activating other measures, or providing error codes for diagnostic purposes.ISCs can include features such as overvoltage and undervoltage monitoring, overcurrent monitoring, and insulation monitoring.

[0011] ISCs often have communication interfaces, such as CAN or Ethernet, that enable integration with other vehicle systems. They can exchange information with the main control unit, enabling coordinated operation and facilitating diagnostics and troubleshooting. Communication interfaces also allow the controller to receive commands or instructions from the electronic control unit and adjust the power output accordingly.

[0012] Integrating the BCCM into the ISC is traditionally considered challenging due to the isolation circuitry. Schematics of typical isolated systems are shown in Fig. 1 and 2 respectively.

[0013] With reference to Fig. 1, a motor vehicle system 10 includes an isolated on-board AC / DC charger 12 and a traction battery 14. In this example, the isolated on-board AC / DC charger 12 is connected between the traction battery 14 and an AC source 16.

[0014] The isolated on-board AC / DC charger 12 includes an AC / DC power factor correction circuit 18 (single-phase / three-phase) and an isolated high-voltage DC / DC converter 20. The isolated high-voltage DC / DC converter 20 is connected between the traction battery 14 and the AC / DC power factor correction circuit 18.

[0015] The AC / DC power factor correction circuit 18 includes an electromagnetic interference filter 22 and a bidirectional column power factor correction circuit 24. The bidirectional column power factor correction circuit 24 includes a switch bank 26 and an AC / DC power converter circuit 28. The switch bank 26 is connected between the electromagnetic interference filter 22 and the AC / DC power converter circuit 28.

[0016] The isolated high-voltage DC / DC converter 20 includes a first switching bridge 30, a transformer 32, a second switching bridge 34, an electromagnetic interference filter 36, a pair of capacitors 38, 40, and a DC link capacitor 42. The transformer 32 is connected between the capacitors 38, 40, which are commonly connected between the first and second switching bridges 30, 34. The first switching bridge 30 is connected between the AC / DC power factor correction circuit 18 and the capacitor 38. The second switching bridge 34 is connected between the capacitor 40 and the DC link capacitor 42. The electromagnetic interference filter 36 is connected between the DC link capacitor 42 and the traction battery 14. Power from the AC source 16 can thus flow through the isolated on-board AC / DC charger 12 to charge the traction battery 14 during operation.

[0017] With reference to Fig. 2, the system 44 includes an electric machine 46 and an ISC 48. The ISC 48 is connected between the traction battery 14 and the electric machine 46.

[0018] The ISC 48 has a three-phase inverter designed to drive the electric machine 46 and at a much higher power than the BCCM from Fig. 1. The BCCM from Fig. 1 also includes an AC / DC circuit configured as a three-phase inverter / rectifier. Two isolation circuits are required to utilize the ISC's three-phase inverter when charging / discharging the traction battery 14. The first isolation circuit is used to isolate the electric motor 46 from the ISC 48, and the second isolates the ISC 48 from the traction battery 14. The contactors used in these isolation circuits must carry the full current of the ISC. Adding these contactors increases the required components, making integration at the electrical level unfavorable. However, integration at the package level can provide advantages by reducing the overall package size and the number of connectors and wires.

[0019] A circuit topology is proposed that solves the isolation circuit problems. It enables the integration of a BCCM with an ICS without using high-current contactors. An auxiliary circuit interfaces directly with an ISC without disconnecting an electric motor or battery. The auxiliary circuit includes a front-end AC / DC power factor correction circuit and sections of an isolated high-voltage DC / DC circuit that is part of the BCCM. A relay is added to isolate the auxiliary circuit from the ISC inverter during drive mode. The relay is designed to handle only the BCCM power demand. When the vehicle is connected to an AC grid, the auxiliary circuit, the ISC, and the electric motor form a bidirectional AC / DC-DC / AC power converter. During charging operation, the traction inverter is configured as a half-bridge. The inverter bus capacitor is split into two capacitors.The secondary side of the transformer forms an interface between one of the inverter branches and the capacitors. The high-voltage DC / DC circuit of the BCCM is designed to account for the stator winding impedance of the electric machine and its variations with respect to the rotor position. The high-voltage DC / DC of the BCCM can be designed to switch at a frequency much higher than the switching frequency of the ISC (e.g., the high-voltage DC / DC switch at 300 kHz and the ISC at <30 kHz).

[0020] With reference to Fig.3, a vehicle 50 includes an electric machine 52, an ISC 54, a traction battery 56, an auxiliary circuit 58, and a controller 60. The ISC 54 is connected between the electric machine 52 and the traction battery 56. The controller 60 communicates with / exerts control of the electric machine 52, the ISC 54, the traction battery 56, and an auxiliary circuit 58.

[0021] The ISC 54 includes a plurality of switches 62 and capacitors 64, 66. The switches 62 are connected between the electric machine 52 and the capacitors 64, 66. The capacitors 64, 66 are connected in series and between the switches 62 and the traction battery 56. The series-connected capacitors 64, 66 are connected in parallel to the traction battery 56.

[0022] The auxiliary circuit 58 includes an AC / DC power factor correction circuit 68, a switch bridge 70, a transformer 72, a pair of capacitors 74, 76, and a switch 78. The switch bridge 70 is connected between the AC / DC power factor correction circuit 68 and the capacitor 74. The capacitor 74 is connected between the switch bridge 70 and the transformer 72. The transformer 72 is connected between the capacitors 74, 76. The capacitor 76 is connected between the transformer 72 and the switch 78. The switch 78 is connected between the capacitor 76 and a phase leg of the electric machine 52, between the electric machine 52 and the inverter system controller 54. One terminal of a coil of the transformer 72 is connected between the capacitors 64, 66.

[0023] The AC / DC power factor correction circuit 68 includes an electromagnetic interference filter 80 and a bidirectional column power factor correction circuit 82. The bidirectional column power factor correction circuit 82 includes a switch bank 84 and an AC / DC power converter circuit 86. The switch bank 84 is connected between the electromagnetic interference filter 80 and the AC / DC power converter circuit 86. The AC / DC power converter circuit 86 is connected between the switch bank 84 and the switch bridge 70.

[0024] The auxiliary circuit 68 is connected to an AC source 88. During charging of the traction battery 56, the auxiliary circuit 58, the electric machine 52, and the ISC 54 (with switch 78 closed) form a bidirectional AC / DC-DC / AC power converter, as suggested above. In drive mode, the switch 78 is open.

[0025] The algorithms, methods, or processes disclosed in this document may be executable by or implemented by a computer, controller, or processing device, which may include any dedicated electronic control unit or programmable electronic control unit. Furthermore, the algorithms, methods, or processes may be stored in many forms as computer- or controller-executable data and instructions, including, but not limited to, information permanently stored on non-writable storage media, such as read-only memory devices, and information modifiably stored on writable storage media, such as compact discs, random access memory devices, or other magnetic and optical media. The algorithms, methods, or processes may also be implemented in software-executable objects.Alternatively, the algorithms, methods, or processes may be implemented in whole or in part using 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.

[0026] Although exemplary embodiments are described above, these embodiments are not intended to describe all possible forms encompassed by the claims. Furthermore, the terms used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the disclosed subject matter. For example, the terms "controller" and "controllers" may be used interchangeably herein, since the functionality of a controller may be distributed across multiple controllers / modules, all of which may communicate using standard techniques.

[0027] As previously described, the features of various embodiments may be combined to form further embodiments of the invention that may not be explicitly described or illustrated. While various embodiments may have been described as providing advantages or being preferred over other prior art embodiments or implementations with respect to one or more desired characteristics, one of ordinary skill in the art will understand that one or more features or characteristics may be compromised to achieve desired overall system attributes depending on the specific application and implementation. These attributes may include, but are not limited to, strength, durability, marketability, appearance, installation, size, serviceability, weight, manufacturability, ease of assembly, etc.Thus, embodiments that are described as less desirable than other embodiments or prior art implementations with respect to one or more characteristics are not outside the scope of the disclosure and may be desirable for particular applications.

[0028] According to the present invention, a vehicle is provided comprising: a traction battery; an electric machine, an inverter system controller connected between the traction battery and the electric machine; and circuitry including an AC / DC power factor correction circuit, a transformer, a switch bridge connected between the AC / DC power factor correction circuit and the transformer, and a switch configured to connect the transformer to a phase leg of the electric machine between the electric machine and the inverter system controller such that, when the switch is closed, the circuitry, the electric machine, and the inverter system controller form a bidirectional AC / DC-DC / AC power converter.

[0029] According to one embodiment, the inverter system controller includes capacitors connected in series, and wherein the transformer is connected between the capacitors.

[0030] According to one embodiment, the capacitors are connected in parallel to the traction battery.

[0031] According to one embodiment, the inverter system controller further includes a plurality of switches, and wherein the capacitors are connected between the switches and the traction battery.

[0032] According to one embodiment, the AC / DC power factor correction circuit includes a bidirectional totem pole power factor correction circuit.

[0033] According to one embodiment, the AC / DC power factor correction circuit further includes an electromagnetic interference filter, and wherein the bidirectional column power factor correction circuit is connected between the electromagnetic interference filter and the switch bridge.

[0034] According to one embodiment, the switch is configured to be open during a drive mode and closed during a charge mode.

[0035] According to the present invention, a method includes: closing a switch of a circuit arrangement to connect an AC / DC power factor correction circuit, a switch bridge, and a transformer of the circuit arrangement via an inverter system controller connected between an electric machine and a traction battery, such that the circuit arrangement, the electric machine, and the inverter system controller form a bidirectional AC / DC-DC / AC power converter configured to transfer power from an AC source to the traction battery.

[0036] In one aspect of the invention, the method includes opening the switch after charging the traction battery.

[0037] According to the present invention, a motor vehicle power system is provided, comprising: circuitry including an AC / DC power factor correction circuit, a transformer, and a switch configured to connect the transformer to a phase leg of an electric machine between the electric machine and an inverter system controller; and a controller programmed to close the switch such that the circuitry, the electric machine, and the inverter system controller form a bidirectional AC / DC-DC / AC power converter configured to transfer power from an AC source to the traction battery.

[0038] According to one embodiment, the circuit arrangement further includes a switch bridge connected between the AC / DC power factor correction circuit and the transformer.

[0039] According to one embodiment, the AC / DC power factor correction circuit includes a bidirectional totem pole power factor correction circuit.

[0040] According to one embodiment, the AC / DC power factor correction circuit further includes an electromagnetic interference filter.

[0041] According to one embodiment, the bidirectional column power factor correction circuit is connected between the electromagnetic interference filter and the switch bridge.

[0042] According to one embodiment, the circuit arrangement further includes capacitors and wherein the transformer is connected between the capacitors.

[0043] According to one embodiment, the controller is further programmed to open the switch after charging the traction battery.

[0044] According to one embodiment, the switch is a relay.

Claims

[1] Vehicle comprising: a traction battery; an electrical machine; an inverter system controller connected between the traction battery and the electric machine; and a circuit arrangement including an AC / DC power factor correction circuit, a transformer, a switch bridge connected between the AC / DC power factor correction circuit and the transformer, and a switch configured to connect the transformer to a phase leg of the electric machine between the electric machine and the inverter system controller such that, when the switch is closed, the circuit arrangement, the electric machine, and the inverter system controller form a bidirectional AC / DC-DC / AC power converter. [2] The vehicle of claim 1, wherein the inverter system controller includes capacitors connected in series, and wherein the transformer is connected between the capacitors. [3] A vehicle according to claim 2, wherein the capacitors are connected in parallel to the traction battery. [4] The vehicle of claim 3, wherein the inverter system controller further includes a plurality of switches, and wherein the capacitors are connected between the switches and the traction battery. [5] The vehicle of claim 1, wherein the AC / DC power factor correction circuit includes a bidirectional totem pole power factor correction circuit. [6] The vehicle of claim 5, wherein the AC / DC power factor correction circuit further includes an electromagnetic interference filter, and wherein the bidirectional column power factor correction circuit is connected between the electromagnetic interference filter and the switch bridge. [7] The vehicle of claim 1, wherein the switch is configured to be open during a drive mode and closed during a charge mode. [8] Method comprising: Closing a switch of a circuit arrangement to connect an AC / DC power factor correction circuit, a switch bridge, and a transformer of the circuit arrangement via an inverter system controller connected between an electric machine and a traction battery, such that the circuit arrangement, the electric machine, and the inverter system controller form a bidirectional AC / DC-DC / AC power converter configured to transfer power from an AC source to the traction battery. [9] The method of claim 8, further comprising opening the switch after charging the traction battery. [10] Motor vehicle power system comprising: a circuit arrangement including an AC / DC power factor correction circuit, a transformer, and a switch configured to connect the transformer to a phase leg of an electric machine between the electric machine and an inverter system controller; and a controller programmed to close the switch such that the circuitry, electric machine, and inverter system controller form a bidirectional AC / DC-DC / AC power converter configured to transfer power from an AC source to the traction battery. [11] The automotive power system of claim 10, wherein the circuit arrangement further includes a switch bridge connected between the AC / DC power factor correction circuit and the transformer. [12] The automotive power system of claim 11, wherein the AC / DC power factor correction circuit includes a bidirectional totem pole power factor correction circuit. [13] The automotive power system of claim 12, wherein the AC / DC power factor correction circuit further includes an electromagnetic interference filter. [14] The automotive power system of claim 13, wherein the bidirectional column power factor correction circuit is connected between the electromagnetic interference filter and the switch bridge. [15] The automotive power system of claim 10, wherein the circuit arrangement further includes capacitors and wherein the transformer is connected between the capacitors.

Images