Configurable active ripple energy storage circuit with intermediate bus for a system with inverter system control and battery current control module in integrated form

Abstract

A vehicle includes an electric machine, a traction battery, a first switching bridge connected between the electric machine and the traction battery, an AC / DC power converter, a transformer, a second switching bridge connected between the AC / DC power converter and the transformer, a switch bank connected to a secondary side of the transformer and connecting the secondary side between the electric machine and the first switching bridge, and an active ripple energy storage circuit connected between the AC / DC power converter and the second switching bridge.

Description

FIELD OF TECHNOLOGY

[0001] This disclosure relates to automotive power systems. 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 the electrical energy. SUMMARY

[0003] A motor vehicle power system includes a traction battery, a first switching bridge, a first circuit arrangement including an AC / DC power converter, a transformer, a second switching bridge connected between the AC / DC power converter and the transformer, and a plurality of switches connected to an output of the transformer and connecting the output to the first switching bridge such that the first switching bridge is connected between the traction battery and the transformer and the first switching bridge, the transformer, and the second switching bridge form an isolated DC / DC power converter.The system also includes an electromagnetic interference filter, one or more switches that connect the traction battery directly between the AC / DC power converter and the second switching bridge via the electromagnetic interference filter, and an active ripple energy storage circuit connected between the AC / DC power converter and the second switching bridge.

[0004] A method includes, in response to a request to charge a traction battery of a vehicle, closing first switches to connect 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 bridges form an isolated DC / DC power converter that supplies charging power from the AC / DC power converter to the traction battery, opening second switches to disconnect the traction battery from the AC / DC power converter, and opening third switches to disconnect a secondary bus from an active ripple energy storage circuit connected between the AC / DC power converter and the other switching bridge.

[0005] A vehicle includes an electric machine, a traction battery, a first switching bridge connected between the electric machine and the traction battery, an AC / DC power converter, a transformer, a second switching bridge connected between the AC / DC power converter and the transformer, a switch bank connected to a secondary side of the transformer and connecting the secondary side between the electric machine and the first 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 that supplies charging power from the AC / DC power converter to the traction battery, and an active ripple storage circuit connected between the AC / DC power converter and the second switching bridge. 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 in an integrated form. Fig. Figure 4 is a schematic diagram of a system including a battery power control module, an inverter system controller, and a high-voltage to low-voltage DC / DC converter in an integrated form. Fig. Figure 5 is a schematic diagram of a system including a battery power control module, an inverter system controller, a rectifier, and a DC / DC converter in an integrated form. Fig. Figure 6 is a schematic diagram of a system including an active ripple energy storage circuit, a battery power control module, an inverter system controller, a rectifier, and a DC / DC converter in an integrated form. 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 regulating and managing the flow of electrical current to and from the battery.

[0009] BCCMs act as control units that 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 regulate the flow of current to the battery based on this information.

[0010] BCCMs can facilitate charging control by monitoring the battery charging process and managing the voltage and current provided 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.

[0011] Likewise, BCCMs can be responsible for discharge control. They can regulate 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.

[0012] BCCMs can also implement various measures for the battery. For example, they can monitor battery temperature to prevent overheating. They can also detect overvoltage or undervoltage situations and implement measures to prevent short circuits or excessive current consumption.

[0013] BCCMs often include communication interfaces. 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 (ECU) or the body control module (BCM). 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.

[0014] 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.

[0015] 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. 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.

[0016] ISCs can act as decision-makers for the power electronics system. They can monitor various parameters such as speed, torque, and temperature of the electric motor to ensure operation.

[0017] One function of ISCs is to convert DC power from the battery into three-phase AC power suitable for the electric motor. They can use high-performance semiconductor devices, such as insulated-gate bipolar transistors (IGBTs), to control current and voltage switching. 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.

[0018] ISCs can provide control of the electric motor. They can use algorithms and control strategies to regulate 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, thereby altering the electric motor's operation.

[0019] 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 inverter system controller can control the flow of energy, diverting it back to the battery for storage.

[0020] 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 deploy cooling systems such as fans, liquid cooling, or heat sinks to dissipate excess heat and maintain operating temperatures.

[0021] ISCs can include 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 actions, such as shutting down the system, initiating other actions, or providing error codes for diagnostic purposes.

[0022] 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 (ECU) and adjust the power output accordingly.

[0023] The ISCs can include features such as overvoltage and undervoltage monitoring, overcurrent monitoring and insulation monitoring.

[0024] Integrating the BCCM into the ISC is traditionally considered challenging due to the isolation circuitry. Schematics of typical isolated systems 10, 12 are shown in Fig. 1 and 2 respectively.

[0025] With reference to Fig. 1, the system 10 includes a BCCM 14, a traction battery 16, an auxiliary battery 18, and an on-board charging controller 20. The BCCM includes an AC / DC power factor correction circuit 22, an isolated high-voltage DC / DC circuit 24, a DC link capacitor 26, and an isolated high-voltage-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 DC link capacitor 26. The DC link capacitor 26 is connected between the isolated high-voltage DC / DC circuit 24 and the isolated high-voltage-low-voltage DC / DC circuit 28. The traction battery 16 and the auxiliary battery 18 are connected to the isolated high-voltage-low-voltage DC / DC circuit 28.

[0026] 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 34. The switch bank 32 is connected between the electromagnetic interference filter 30 and the AC / DC power converter circuit 34.

[0027] The isolated high-voltage DC / DC circuit 24 includes a first switching bridge 36, a transformer 38, and a second switching bridge 40. The first switching bridge 36 is directly connected to the power converter circuit 34. The transformer 38 is connected between the first and second switching bridges 36, 40.

[0028] 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 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 intermediate circuit capacitor 26 and the high-voltage-to-low-voltage power converter circuit 46. The high-voltage-to-low-voltage power converter circuit 46 is directly connected to the auxiliary battery 18.

[0029] The on-board charging control 20 is available with the Fig. 1 illustrated components in communication and / or exercises their control.

[0030] With reference to Fig. 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.

[0031] The ISC 50 includes a three-phase inverter designed to drive the electric machine 48 and operates at a significantly higher power than the BCCM 14. The BCCM 14 also includes three circuits configured as three-phase inverter / rectifiers. Two isolation circuits are required to utilize the ISC's three-phase inverter when charging / discharging the traction battery 16. The first isolation circuit is used to isolate the electric motor 48 from the ISC 50, and the second isolation circuit is used to isolate the ISC 50 from the traction battery 52. ​​The contactors used in these isolation circuits must carry the full current of the ISC. Adding these contactors increases the number of required components, making electrical integration unfavorable.However, assembly-level integration can provide advantages by reducing the overall size and / or weight of the assembly and the number of connectors and wires. A new circuit topology is proposed here that solves some of the problems of the isolation circuit. Schematics of such a system 54 are shown in [Figure 54]. Fig. 3 within the context of a vehicle 55.

[0032] With reference to Fig. 3, the system 54 includes an electromagnetic interference filter 56, a switch bank 58, an AC / DC power converter 60, a switching bridge 62, a capacitor bank 64, a transformer 66, a capacitor bank 68, a switch bank 70, an electric machine 72, a switching bridge 74, a traction battery 76, and a controller 78.

[0033] Switch bank 58 is connected between the electromagnetic interference filter 56 and the AC / DC power converter 60. Switch bridge 62 is connected between the AC / DC power converter 60 and the capacitor bank 64. Transformer 66 is connected between the capacitor banks 64 and 68. Capacitor bank 68 is connected between the transformer and switch bank 70. Transformer 66 is thus also connected between the switch bridge 62 and the switch bank 70.

[0034] The switching bridge 74 is connected between the electric machine 72 and the traction battery 76.

[0035] The control 78 is connected to the Fig. 3 illustrated components in communication and / or exercises their control.

[0036] The switch bank 70 is connected to a secondary side of the transformer 66. When switches of the switch bank 70 are closed, the transformer 66 is connected between the electric machine 72 and the switching bridge 74 such that the switching bridge 62, the transformer 66, the electric machine 72, and the switching bridge 74 form an isolated DC / DC power converter. The controller 78 can close the switches of the switch bank 70 in response to a request to charge the traction battery 76. When closed, energy received, for example, from a grid at the electromagnetic interference filter 56 via L1, L2, L3, and N can be conditioned and transferred to the traction battery 76 by the now-formed isolated DC / DC power converter. The controller 78 can operate switches of the AC / DC power converter 60 and the switching bridges 62, 64 at, for example, 300 kHz when the switches of the switch bank 70 are closed (ieDuring charging mode). When charging is complete, the controller 78 may open the switches of switch bank 70. For example, the controller 78 may operate the switches of the switching bridge 64 at 30 kHz (or less) when the switches of switch bank 70 are open (e.g., during drive mode). Other switching speeds may, of course, be used.

[0037] The Fig. The circuit topology shown in Figure 3 enables the integration of a BCCM (the electromagnetic interference filter 56, the switch bank 58, the AC / DC power converter 60, the switching bridge 62, the capacitor bank 64, the transformer 66, the capacitor bank 68, and the switch bank 70) into an ISC without using high-current contactors. The auxiliary circuit interfaces directly with the ISC without disconnecting the electric machine or the traction battery. The auxiliary circuit includes a front-end AC / DC power factor correction circuit and portions of the isolated high-voltage DC / DC circuit that is part of the BCCM. Three relays are added to isolate the auxiliary circuit from the ISC during drive mode. The high-voltage DC / DC circuit of the BCCM can be designed taking into account the stator winding impedance of the electric machine and its variations with respect to the rotor position.When the vehicle is connected to the AC grid, the auxiliary circuit, the ISC, and the electric motor form a bidirectional AC / DC-DC / AC power converter. The BCCM's high-voltage DC / DC power converter can be configured to switch at a frequency significantly higher than the ISC's switching frequency.

[0038] With reference to Fig. 4, a system 80 includes an electromagnetic interference filter 82, a switch bank 84, an AC / DC power converter 86, a switching bridge 88, a capacitor bank 90, a transformer 92, a capacitor bank 94, a switch bank 96, an electric machine 98, a switching bridge 100, a traction battery 102, a high-voltage to low-voltage DC / DC power converter 104, an auxiliary battery 106, and a controller 110. These components are shown in the context of a vehicle 112. The controller 110 is connected to the Fig. 4 illustrated components in communication and / or exercises their control.

[0039] The electromagnetic interference filter 82, the switch bank 84, the AC / DC power converter 86, the switching bridge 88, the capacitor bank 90, the transformer 92, the capacitor bank 94, the switch bank 96, the electric machine 98, the switching bridge 100 and the traction battery 102 are arranged in a similar manner as in Fig. 3 and can thus be operated by the controller 110.

[0040] The high-voltage-to-low-voltage DC / DC power converter 104 is connected between the switching bridge 100 and the traction battery 102. It is further connected to the auxiliary battery 108 such that, when the high-voltage-to-low-voltage DC / DC power converter 104 is operating, power can flow from the switching bridge 100 through the high-voltage-to-low-voltage DC / DC power converter 104 to the auxiliary battery 108.

[0041] Integrating the BCCM (the electromagnetic interference filter 82, the switch bank 84, the AC / DC power converter 86, the switching bridge 88, the capacitor bank 90, the transformer 92, the capacitor bank 94, and the switch bank 96) into the inverter system controller (the switch bank 100) increases the ISC package size by an estimated 50%. With a larger package size, the module location may be restricted. Therefore, there is a need to reduce the package size.

[0042] The high-voltage-to-low-voltage DC / DC power converter 104 contributes to the required package size. In some configurations, the high-voltage circuit of the high-voltage-to-low-voltage DC / DC power converter 104 consumes almost half of its overall size. The following topology eliminates the high-voltage circuit.

[0043] With reference to Fig. 5, a system 114 includes an electromagnetic interference filter 116, a switch bank 118, an AC / DC power converter 120, a switching bridge 122, a capacitor bank 124, a transformer 126, a capacitor bank 128, a switch bank 130, an electric machine 132, a switching bridge 134, a traction battery 136, an electromagnetic interference filter 138, a switch bank 140, a rectifier 142, a DC / DC power converter, an auxiliary battery 146, and a controller 148. These components are shown in the context of a vehicle 150.

[0044] The electromagnetic interference filter 116, the switch bank 118, the AC / DC power converter 120, the switching bridge 122, the capacitor bank 124, the transformer 126, the capacitor bank 128, the switch bank 130, the electric machine 132, the switching bridge 134 and the traction battery 136 are arranged in a similar manner as in Fig. 3 and Fig. 4 and can thus be operated by the controller 148. The components from Fig. 5 are thus in communication with the controller 148 and / or are controlled by it.

[0045] The electromagnetic interference filter 138 is directly connected between the AC / DC power converter 120 and the switch bank 122. The switch bank 140 is arranged to directly connect the electromagnetic interference filter 138 to the traction battery 136 such that power output from the AC / DC power converter 120 can flow directly to the traction battery 136 via the electromagnetic interference filter 138 and the switch bank 140.

[0046] Rectifier 142 is magnetically coupled to transformer 126 via a low-voltage coil and a common core. DC / DC power converter 144 is connected between rectifier 142 and auxiliary battery 146 such that power can flow from transformer 142 through rectifier 142 and DC / DC power converter 144 to auxiliary battery 146. DC / DC power converter 144 can provide additional power management to auxiliary battery 146.

[0047] Rectifier 142 can be implemented as a center-tapped rectifier, full-bridge rectifier, half-bridge rectifier, current doubler, etc. The low-voltage coil can be implemented as a center-tapped coil or a single-coil coil. Rectifier 142 rectifies the voltage induced across the low-voltage coil to deliver DC power to auxiliary battery 146.

[0048] As indicated above, switch bank 140 electrically connects traction battery 136 to the BCCM's DC intermediate bus. When vehicle 150 is disconnected from the AC grid or in drive mode, all other relays, including switch bank 130, are open. The BCCM's DC intermediate bus is energized by closing switch bank 140. An isolated high-voltage to low-voltage DC / DC power converter is thus configured to charge auxiliary battery 146. The transformer's primary windings and low-voltage coil are energized to charge / discharge auxiliary battery 146.

[0049] When the vehicle 150 is connected to the AC grid, the controller 148 generates commands such that the switch bank 140 is open and the switch bank 130 is closed. The switch bank 118 is configured depending on the grid type (e.g., single-phase, two-phase, three-phase, etc.). All transformer windings are energized to allow bidirectional power flow between the AC grid and the traction battery 136 and between the traction battery 136 and the auxiliary battery 146.

[0050] While this level of integration allows for the elimination of the rectifier and electromagnetic interference filter, which are part of the AC / DC battery charger, there is still the potential to further reduce the package size. The electromagnetic interference filter 138 and the series capacitors (electrolytic capacitor bank) of the AC / DC power converter 120 can occupy 50% of the total space. Here, an active ripple energy storage circuit is proposed to reduce the size of the electrolytic capacitor by up to 70%, for example. This active ripple energy storage circuit can be configured as a bidirectional DC / DC converter to provide additional functionality when the vehicle is disconnected from the AC grid.

[0051] With reference to Fig. 6, a system 152 includes an electromagnetic interference filter 154, a switch bank 156, an AC / DC power converter 158, an active ripple energy storage circuit 159, switches 160, a secondary bus 161, a switching bridge 162, a capacitor bank 164, a transformer 166, a capacitor bank 168, a switch bank 170, an electric machine 172, a switching bridge 174, a traction battery 176, an electromagnetic interference filter 178, a switch bank 180, a rectifier 182, an auxiliary battery 184, and a controller 186. These components are shown within the context of a vehicle 188.

[0052] The electromagnetic interference filter 154, the switch bank 156, the AC / DC power converter 158, the switching bridge 162, the capacitor bank 164, the transformer 166, the capacitor bank 168, the switch bank 170, the electric machine 172, the switching bridge 174 and the traction battery 176 are (with the exception of the active ripple energy storage circuit 159, the switches 160 and the secondary bus 161) in a similar manner as in Fig. 3 and Fig. 4 and can thus be operated by the controller 186. The components from Fig. 6 are thus in communication with the controller 186 and / or are controlled by it.

[0053] The electromagnetic interference filter 178 is directly connected between the active ripple energy storage circuit 159 and the switch bank 162. The active ripple energy storage circuit 159 is thus connected between the AC / DC power converter 158 and the switching bridge 162. The switch bank 180 is arranged to directly connect the electromagnetic interference filter 178 to the traction battery 176 such that a power output from the AC / DC power converter 158 can flow directly to the traction battery 176 via the electromagnetic interference filter 178 and the switch bank 180.

[0054] The rectifier 182 is magnetically coupled to the transformer 166 via a low-voltage coil and a common core, so that power can flow from the transformer 142 through the rectifier 182 to the auxiliary battery 184. As with Fig.5, this topology may include a DC / DC power converter to provide additional power regulation to the auxiliary battery 184.

[0055] Rectifier 182 can be implemented as a center-tapped rectifier, full-bridge rectifier, half-bridge rectifier, current doubler, etc. The low-voltage coil can be implemented as a center-tapped coil or a single coil. Rectifier 182 rectifies the voltage induced across the low-voltage coil to deliver DC power to auxiliary battery 184.

[0056] As indicated above, switch bank 180 electrically connects traction battery 176 to the BCCM's DC intermediate bus. When vehicle 188 is disconnected from the AC grid or in drive mode, all other relays, including switch bank 170, are open. The BCCM's DC intermediate bus is energized by closing switch bank 180. An isolated high-voltage to low-voltage DC / DC power converter is configured to charge auxiliary battery 184. The transformer's primary windings and low-voltage coil are energized to charge / discharge auxiliary battery 184.

[0057] When the vehicle 188 is connected to the AC grid, the controller 186 generates commands such that the switch bank 180 is open and the switch bank 170 is closed. The switch bank 156 is configured depending on the grid type (e.g., single-phase, two-phase, three-phase, etc.). All transformer windings are energized to allow bidirectional power flow between the AC grid and the traction battery 176 and between the traction battery 176 and the auxiliary battery 184.

[0058] The active ripple energy storage circuit 159 is designed to absorb the low-frequency ripple voltage across the electrolytic capacitors during single-phase operation. This converter acts as a charge / discharge circuit with zero net power. It is further designed using a bidirectional buck / boost converter. The high-voltage input is connected to the BCCM's intermediate DC bus, and the low-voltage output is connected to a film capacitor coupled to a jack via circuit breakers.

[0059] While the vehicle 188 is disconnected from an AC grid or in drive mode, the high-voltage-to-low-voltage DC / DC converter is powered from the BCCM's intermediate DC bus to charge the auxiliary battery 184. The switch bank 180 is closed to couple the traction battery 176 to the BCCM's intermediate DC bus, and the switch bank 170 is opened to disconnect the switching bridge 174 from the BCCM circuit. The active ripple energy storage circuit 159 is used to form a non-isolated buck converter for stepping down the voltage of the traction battery 176 (e.g., 800 V) to a lower voltage level (e.g., 400 V). The switches 160 are closed to connect loads (not directly connected to the traction battery 176) to the secondary (non-isolated) bus 184.

[0060] For vehicle-to-vehicle DC charging (while the vehicle 188 is not in drive mode), the switches are configured to form two cascaded power conversion circuits. The first stage is an isolated high-voltage DC / DC converter, and the second stage is a non-isolated step-down converter. Switch bank 180 is opened to isolate the BCCM's intermediate DC bus from the traction battery 176. Switch bank 170 is closed to connect the switching bridge 174 to the BCCM circuit. Switches 160 are closed to couple the step-down converter's output to a receptacle, allowing plugging into another vehicle. The high-voltage to low-voltage DC / DC converter is powered directly from the traction battery 176 via the switching bridge 174. Power flows through the transformer secondary windings and the low voltage coil to the auxiliary battery 184.The intermediate DC bus voltage supplies power to the auxiliary buck converter. Power flows from the traction battery 176 through the transformer's secondary windings to the transformer's primary windings. For vehicle-to-vehicle charging, the buck converter's output voltage / current is controlled to change an external high-voltage battery based on a reference command.

[0061] While the vehicle 188 is connected to an AC grid, the switches are configured to form isolated high-voltage AC / DC-DC / AC and high-voltage-low-voltage DC / DC charging / discharging circuits. Switch bank 180 is opened to disconnect the BCCM's intermediate DC bus from the traction battery 176. Switch bank 170 is closed to connect the switching bridge 174 to the BCCM. Switches 160 are opened to disconnect the secondary bus 184 from the active ripple energy storage circuit 159. The circuit operates as previously described except when the vehicle 188 is plugged into a single-phase grid. The active ripple energy storage circuit 159 is activated when a single-phase input is detected to minimize the low-frequency ripple voltage across the electrolytic capacitors.

[0062] 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.

[0063] Although exemplary embodiments are described above, these embodiments are not intended to describe all possible forms encompassed by the claims. The capacitor banks 124, 128 could instead be inductor banks or capacitor and inductor banks. The symbols used to represent capacitors of the capacitor banks 124, 128 can thus also represent inductors of such inductor banks or represent capacitors and inductors of such capacitor and inductor banks. The switching bridges 122, 134 can be n-phase inverters or n-phase rectifiers depending on topology and functionality requirements, etc. The switching bridge 122 can be configured as a single-phase inverter, for example, by removing one of its phase legs.

[0064] 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 throughout this specification, since the functionality of a controller may be distributed across multiple controllers / modules, all of which may communicate using standard techniques.

[0065] 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.

[0066] According to the present invention, there is provided a motor vehicle power system comprising: a traction battery; a first switching bridge; a first circuit arrangement including an AC / DC power converter, a transformer, a second switching bridge connected between the AC / DC power converter and the transformer, and a plurality of switches connected to an output of the transformer and configured to connect the output to the first switching bridge such that the first switching bridge is connected between the traction battery and the transformer and the first switching bridge, the transformer, and the second switching bridge form an isolated DC / DC power converter; an electromagnetic interference filter;one or more switches configured to directly connect the traction battery between the AC / DC power converter and the second switching bridge via the electromagnetic interference filter; and an active ripple energy storage circuit connected between the AC / DC power converter and the second switching bridge.

[0067] According to one embodiment, the invention is further characterized by a secondary bus connected to the active ripple energy storage circuit such that the active ripple energy storage circuit is connected between the AC / DC power converter and the secondary bus.

[0068] According to one embodiment, the active ripple energy storage circuit includes an energy storage element, further comprising a pair of switches connected between the energy storage element and the secondary bus.

[0069] According to one embodiment, the energy storage element is an inductor.

[0070] According to one embodiment, the AC / DC power converter includes energy storage capacitors, and wherein the active ripple energy storage circuit is configured to absorb ripple voltage across the energy storage capacitors while the pair of switches is open.

[0071] According to one embodiment, the active ripple energy storage circuit is configured to act as a non-isolated buck converter to step down traction battery voltage for the secondary bus while the pair of switches is closed.

[0072] According to one embodiment, during a drive mode, the one or more switches and the pair of switches are closed and the plurality of switches are open.

[0073] According to one embodiment, during a traction battery charging mode, the one or more switches and the pair of switches are open and the plurality of switches are closed.

[0074] According to one embodiment, during a battery charging mode, the one or more switches are open and the pair of switches and the plurality of switches are closed.

[0075] According to the present invention, a method includes: in response to a request to charge a traction battery of a vehicle, closing first switches to connect 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 bridges form an isolated DC / DC power converter configured to deliver charging power from the AC / DC power converter to the traction battery, opening second switches to disconnect the traction battery from the AC / DC power converter, and opening third switches to disconnect a secondary bus from an active ripple energy storage circuit connected between the AC / DC power converter and the other switching bridge.

[0076] In one aspect of the invention, the method includes opening the first switches and closing the second and third switches after charging is complete.

[0077] In one aspect of the invention, the method includes, in response to a request to provide power to the secondary bus from the traction battery, closing the first and third switches and opening the second switches.

[0078] According to the present invention, a vehicle is provided comprising: an electric machine; a traction battery; a first switching bridge connected between the electric machine and the traction battery; an AC / DC power converter; a transformer; a second switching 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 the electric machine and the first 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 configured to deliver charging power from the AC / DC power converter to the traction battery;and an active ripple energy storage circuit connected between the AC / DC power converter and the second switching bridge;

[0079] According to one embodiment, the invention is further characterized by a secondary bus connected to the active ripple energy storage circuit such that the active ripple energy storage circuit is connected between the AC / DC power converter and the secondary bus.

[0080] According to one embodiment, the active ripple energy storage circuit includes an energy storage element, further comprising a pair of switches connected between the energy storage element and the secondary bus.

[0081] According to one embodiment, the AC / DC power converter includes energy storage capacitors, and wherein the active ripple energy storage circuit is configured to absorb ripple voltage across the energy storage capacitors while the pair of switches is open.

[0082] According to one embodiment, during a drive mode, the pair of switches is closed and the plurality of switches is open.

[0083] According to one embodiment, during a charging mode, the pair of switches is open and the plurality of switches is closed.

Claims

[1] Motor vehicle power system comprising: a traction battery; a first switching bridge; a first circuit arrangement including an AC / DC power converter, a transformer, a second switching bridge connected between the AC / DC power converter and the transformer, and a plurality of switches connected to an output of the transformer and configured to connect the output to the first switching bridge such that the first switching bridge is connected between the traction battery and the transformer and the first switching bridge, the transformer, and the second switching bridge form an isolated DC / DC power converter; an electromagnetic interference filter; one or more switches configured to connect the traction battery directly between the AC / DC power converter and the second switching bridge via the electromagnetic interference filter; and an active ripple energy storage circuit connected between the AC / DC power converter and the second switching bridge. [2] The automotive power system of claim 1, further comprising a secondary bus connected to the active ripple energy storage circuit such that the active ripple energy storage circuit is connected between the AC / DC power converter and the secondary bus. [3] The automotive power system of claim 2, further comprising a battery connected to the secondary bus. [4] The automotive power system of claim 3, wherein the active ripple energy storage circuit includes an energy storage element, further comprising a pair of switches connected between the energy storage element and the battery. [5] The automotive power system of claim 4, wherein the energy storage element is an inductor. [6] The automotive power system of claim 4, wherein the AC / DC power converter includes energy storage capacitors, and wherein the active ripple energy storage circuit is configured to absorb ripple voltage across the energy storage capacitors while the pair of switches is open. [7] The automotive power system of claim 4, wherein the active ripple energy storage circuit is configured to act as a non-isolated buck converter to step down traction battery voltage for the secondary bus while the pair of switches is closed. [8] The automotive power system of claim 4, wherein during a drive mode, the one or more switches and the pair of switches are closed and the plurality of switches are open. [9] The automotive power system of claim 4, wherein during a traction battery charging mode, the one or more switches and the pair of switches are open and the plurality of switches are closed. [10] The automotive power system of claim 4, wherein during a battery charging mode, the one or more switches are open and the pair of switches and the plurality of switches are closed. [11] A method comprising: in response to a request to charge a traction battery of a vehicle, Closing first switches to connect a secondary side of a transformer having a primary side connected to an AC / DC power converter by a switching bridge between an electric machine and another switching bridge such that the transformer, the electric machine and the switching bridges form an isolated DC / DC power converter configured to deliver charging power from the AC / DC power converter to the traction battery, Opening second switches to disconnect the traction battery from the AC / DC power converter, and Opening third switches to disconnect a battery from an active ripple energy storage circuit connected between the AC / DC power converter and the other switching bridge. [12] The method of claim 11, further comprising, upon completion of the charge, opening the first switches and closing the second and third switches. [13] The method of claim 11, further comprising, in response to a request to charge the battery with power from the traction battery, closing the first and third switches and opening the second switches. [14] Vehicle comprising: an electrical machine; a traction battery; a first switching bridge connected between the electric machine and the traction battery; an AC / DC power converter; a transformer; a second switching 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 the electric machine and the first 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 configured to deliver charging power from the AC / DC power converter to the traction battery; and an active ripple energy storage circuit connected between the AC / DC power converter and the second switching bridge. [15] The vehicle of claim 14, further comprising a secondary bus connected to the active ripple energy storage circuit such that the active ripple energy storage circuit is connected between the AC / DC power converter and the secondary bus.

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