Composite bidirectional integrated charger for vehicles

Abstract

The present disclosure provides a "composite bidirectional integrated charger for a vehicle". A vehicle includes an integrated power distribution module. The integrated power distribution module includes a hybrid transformer coupled to a charger stage, a traction battery, and an auxiliary battery. The hybrid transformer includes a first primary winding and a second primary winding coupled in series and connected to the charger stage. The primary winding has a corresponding first secondary winding coupled to the traction battery through an associated inverter. The primary winding also has a corresponding second secondary winding, which is coupled in series at opposite voltage polarities and coupled to the auxiliary battery through an associated inverter.

Description

Technical Field

[0001] The present application generally relates to an integrated charger and DC / DC converter module for an electrified vehicle. Background Art

[0002] Hybrid and electric vehicles utilize stored energy for propulsion. Energy can be received from the grid during charging events. Onboard generators can also generate energy during regenerative braking events. Electrified vehicles rely on various electrical systems to manage power and distribute it to various components. Electrified vehicles typically utilize contactors and switches to manage the flow of power between high-voltage electrical devices. However, contactors and switches can degrade over time, resulting in a situation where the flow of power cannot be managed. Summary of the invention

[0003] A vehicle includes a hybrid transformer including a first primary winding and a second primary winding electrically coupled in series and selectively electrically coupled to an external source, each of the primary windings being associated with a first secondary winding selectively electrically coupled to a traction battery and with a second secondary winding electrically coupled in series at opposite voltage polarities to define a port selectively electrically coupled to an auxiliary battery.

[0004] The first primary winding and the second primary winding may be coupled to the external source through at least one power inverter configured to bidirectionally convert power between direct current (DC) and alternating current (AC). The first primary winding and the second primary winding may be coupled to the external source through a boost converter configured to bidirectionally convert DC power levels. Each of the first secondary windings may be selectively electrically coupled to the traction battery through an inverter configured to bidirectionally convert power between direct current (DC) and alternating current (AC). The port may be selectively electrically coupled to the auxiliary battery through an inverter configured to bidirectionally convert power between direct current (DC) at the auxiliary battery and alternating current (AC) at the port. The hybrid transformer may be configured to transfer power to the traction battery through each of the first secondary windings in response to the first primary winding and the second primary winding being coupled to the external source and the external source providing power and not providing power to the auxiliary battery through the port. The hybrid transformer is configured to output an alternating current (AC) voltage to the external source through the first primary winding and to the auxiliary battery through the port in response to the traction battery being selectively coupled to the first secondary winding associated with the first primary winding to provide an AC voltage. The hybrid transformer is configured to output an AC voltage to the auxiliary battery through the port and to provide an AC voltage to the first primary winding and the second primary winding in response to the traction battery being selectively coupled to each of the first secondary windings to provide an AC voltage such that the AC voltage provided to the first secondary winding associated with the first primary winding is 180 degrees out of phase with the AC voltage provided to the first secondary winding associated with the second primary winding, so that a voltage across the series combination of the first primary winding and the second primary winding is zero.

[0005] A vehicle power distribution system includes a hybrid transformer including a first primary winding and a second primary winding electrically coupled in series to a first port selectively electrically coupleable to an external source, each associated with a first secondary winding selectively electrically coupled to a traction battery and each associated with a second secondary winding commonly coupled in series at opposite voltage polarities to define a second port selectively electrically coupleable to an auxiliary battery.

[0006] The vehicle power distribution system may further include an onboard charger including at least one bidirectional AC / DC conversion stage for selectively electrically coupling a first port to the external source. The vehicle power distribution system may further include: a first inverter circuit for selectively coupling the first secondary winding associated with the first primary winding to the traction battery; a second inverter circuit for selectively coupling the first secondary winding associated with the second primary winding to the traction battery; and a third inverter circuit for selectively coupling the second port to the auxiliary battery. The hybrid transformer may be configured to transfer power to the traction battery through each of the first secondary windings and provide zero power to the auxiliary battery through the second port in response to the first port being selectively coupled to the external source and the external source providing power. The hybrid transformer may be configured to transfer power to the external source through the first port and to the auxiliary battery through the second port in response to the traction battery being selectively coupled to the first secondary winding associated with the first primary winding. The hybrid transformer may be configured to transfer power to the auxiliary battery through the second port and provide zero power to the first port in response to selectively coupling the traction battery to each of the first secondary windings such that the voltages supplied to the first secondary windings are 180 degrees out of phase with each other. The first primary winding and the corresponding first secondary winding may be characterized by a turns ratio having the same value as the turns ratio characterizing the second primary winding and the corresponding first secondary winding. The turns ratio characterizing the first primary winding and the corresponding second secondary winding may have the same value as the turns ratio characterizing the second primary winding and the corresponding second secondary winding.

[0007] An integrated vehicle power distribution module includes: a transformer; a charger coupled to a series combination of a first primary winding and a second primary winding of the transformer; a first inverter and a second inverter, the first inverter and the second inverter coupled between a traction battery and a first secondary winding associated with each of the primary windings; and a third inverter coupled between an auxiliary battery and a second secondary winding associated with each of the primary windings and connected in series at opposite voltage polarities.

[0008] The transformer is configured to couple power to the first inverter and the second inverter through each of the first secondary windings in response to the charger being connected to an external source and the external source providing power, so that zero power is transferred to the third inverter. The transformer is configured to transfer power to the charger through the first primary winding and to the third inverter through the second secondary winding associated with the first primary winding in response to operating the first inverter to provide an alternating current (AC) voltage to the first secondary winding associated with the first primary winding. The transformer is configured to transfer power to the third inverter and transfer zero power to the charger in response to operating the first inverter and the second inverter to provide an alternating current (AC) voltage 180 degrees out of phase with each other to the first secondary winding. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 is a diagram showing an electrified vehicle including a powertrain of an electric machine and an energy storage component.

[0010] Figure 2 is a schematic diagram of a hybrid transformer.

[0011] Figure 3 is a schematic diagram of an integrated vehicle power distribution module for an electrified vehicle. DETAILED DESCRIPTION

[0012] Embodiments of the present disclosure are described herein. However, it should be understood that the disclosed embodiments are merely examples and that other embodiments may take various forms and alternative forms. The drawings are not necessarily drawn to scale; some features may be enlarged or minimized in order to show the details of a particular component. Therefore, the specific structural details and functional details disclosed herein should not be interpreted as being restrictive, but merely as a representative basis for teaching those skilled in the art to adopt the present invention in different ways. As will be understood by those of ordinary skill in the art, the various features shown and described with reference to any one of the accompanying drawings may be combined with the features shown in one or more other drawings to produce embodiments that are not explicitly shown or described. The combination of features shown provides representative embodiments for typical applications. However, various combinations and modifications of the features consistent with the teachings of the present disclosure may be desired for specific applications or implementations.

[0013] Figure 1Depict an electrified vehicle 112 that may be referred to as a plug-in hybrid electric vehicle (PHEV). The plug-in hybrid electric vehicle 112 may include one or more electric machines 114 mechanically coupled to a hybrid transmission 116. The electric machine 114 may be capable of operating as a motor or a generator. In addition, the hybrid transmission 116 is mechanically coupled to an engine 118. The hybrid transmission 116 is also mechanically coupled to a drive shaft 120, which is mechanically coupled to wheels 122. When the engine 118 is started or shut down, the electric machine 114 can provide propulsion and deceleration capabilities. The electric machine 114 can also act as a generator and can provide fuel economy benefits by recovering energy that is usually lost as heat in a friction braking system. The electric machine 114 can also reduce vehicle emissions by allowing the engine 118 to operate at a more efficient speed and allowing the hybrid electric vehicle 112 to operate in an electric mode (where the engine 118 is shut down under certain conditions). The electrified vehicle 112 may also be a battery electric vehicle (BEV). In a BEV configuration, the engine 118 may not exist.

[0014] The traction battery or battery pack 124 stores energy that can be used by the electric machine 114. The vehicle battery pack 124 can provide a high voltage direct current (DC) output. The traction battery 124 can be electrically coupled to one or more power electronics modules 126. One or more contactors 142 can isolate the traction battery 124 from other components when open, and connect the traction battery 124 to other components when closed. The power electronics module 126 is also electrically coupled to the electric machine 114 and provides the ability to transfer energy bidirectionally between the traction battery 124 and the electric machine 114. For example, the traction battery 124 can provide a DC voltage, and the electric machine 114 can operate under three-phase alternating current (AC) to function. The power electronics module 126 can convert the DC voltage into a three-phase AC current to operate the electric machine 114. In the regenerative mode, the power electronics module 126 can convert the three-phase AC current from the electric machine 114 acting as a generator into a DC voltage compatible with the traction battery 124.

[0015] The vehicle 112 may include a variable voltage converter (VVC) (not shown) electrically coupled between the traction battery 124 and the power electronics module 126. The VVC may be a DC / DC boost converter configured to increase or step up the voltage provided by the traction battery 124. By increasing the voltage, current requirements may be reduced, resulting in a reduction in wiring size of the power electronics module 126 and the electric machine 114. Additionally, the electric machine 114 may operate with better efficiency and lower losses.

[0016] In addition to providing energy for propulsion, the traction battery 124 may also provide energy to other vehicle electrical systems. The vehicle 112 may include a DC / DC converter module 128 that converts the high-voltage DC output of the traction battery 124 into a low-voltage DC power source compatible with the low-voltage vehicle load. The output of the DC / DC converter module 128 may be electrically coupled to an auxiliary battery 130 (e.g., a 12V battery) for charging the auxiliary battery 130. The low-voltage system may be electrically coupled to the auxiliary battery 130. One or more electrical loads 146 may be coupled to the high-voltage bus. The electrical load 146 may have an associated controller that operates and controls the electrical load 146 when appropriate. Examples of the electrical load 146 may be a fan, an electric heating element, and / or an air conditioning compressor.

[0017] The electrified vehicle 112 may be configured to recharge the traction battery 124 from an external power source 136. The external power source 136 may be a connection to an electrical outlet. The external power source 136 may be electrically coupled to a charger or electric vehicle supply equipment (EVSE) 138. The external power source 136 may be an electrical distribution network or grid such as provided by an electrical utility company. The EVSE 138 may provide circuitry and controls to regulate and manage energy transfer between the power source 136 and the vehicle 112. The external power source 136 may provide DC or AC power to the EVSE 138. The EVSE 138 may have a charging connector 140 for plugging into a charging port 134 of the vehicle 112. The charging port 134 may be any type of port configured to transfer power from the EVSE 138 to the vehicle 112. The charging port 134 may be electrically coupled to a charger or an onboard power conversion module 132. The power conversion module 132 may regulate the power supplied from the EVSE 138 to provide appropriate voltage and current levels to the traction battery 124. The power conversion module 132 may interface with the EVSE 138 to coordinate power delivery to the vehicle 112. The EVSE connector 140 may have pins that mate with corresponding recesses of the charging port 134. Alternatively, the various components described as electrically coupled or connected may use wireless inductive coupling to transfer power.

[0018] In some configurations, the electrified vehicle 112 may be configured to provide power to an external load. For example, the electrified vehicle may be configured to operate as a backup generator or power outlet. In such applications, the load may be connected to the EVSE connector 140 or other outlet. The electrified vehicle 112 may be configured to return power to the power source 136. For example, the electrified vehicle 112 may be configured to provide alternating current (AC) power to the grid. The voltage supplied by the electrified vehicle may be synchronized with the power line.

[0019] One or more wheel brakes 144 may be provided for decelerating the vehicle 112 and preventing the vehicle 112 from moving. The wheel brakes 144 may be hydraulically actuated, electrically actuated, or some combination thereof. The wheel brakes 144 may be part of a braking system 150. The braking system 150 may include other components that operate the wheel brakes 144. For simplicity, the drawings depict a single connection between the braking system 150 and one of the wheel brakes 144. Connections between the braking system 150 and other wheel brakes 144 are implied. The braking system 150 may include a controller to monitor and coordinate the braking system 150. The braking system 150 may monitor the braking components and control the wheel brakes 144 for vehicle deceleration. The braking system 150 may respond to driver commands and may also operate autonomously to implement features such as stability control. The controller of the braking system 150 may implement a method of applying the requested braking force when requested by another controller or sub-function.

[0020] The electronic modules in the vehicle 112 may communicate via one or more vehicle networks. The vehicle network may include multiple channels for communication. One channel of the vehicle network may be a serial bus, such as a controller area network (CAN). One of the channels of the vehicle network may include an Ethernet network defined by the Institute of Electrical and Electronics Engineers (IEEE) 802 family of standards. Additional channels of the vehicle network may include discrete connections between modules and may include power signals from the auxiliary battery 130. Different signals may be transferred via different channels of the vehicle network. For example, a video signal may be transferred via a high-speed channel (e.g., Ethernet), while control signals may be transferred via CAN or discrete signals. The vehicle network may include any hardware and software components that facilitate the transfer of signals and data between modules. The vehicle network is Figure 1 Not shown, but implied, the vehicle network may be connected to any electronic modules present in the vehicle 112. A vehicle system controller (VSC) 148 may be present to coordinate the operation of the various components.

[0021] As depicted, the vehicle 112 may include a power conversion module 132 for transferring power from an external power source 136 to a high voltage bus of the vehicle 112. The vehicle 112 also includes a DC / DC converter module 128 for converting the voltage of the high voltage bus to a voltage level (e.g., approximately 12 volts) suitable for the auxiliary battery 130 and the low voltage load 152. The vehicle 112 may also include additional switches, contactors, and circuits to selectively select the flow of power between the traction battery 124 and the DC / DC converter 128 and / or between the power conversion module 132 and the traction battery 124. In order to reduce cost and packaging complexity, it may be desirable to combine the power conversion module 132 and the DC / DC converter module 128 into a single integrated unit. The integrated unit can help enhance hardware utilization of components and can reduce the number of active and passive components present in the vehicle. In addition, the integrated unit can have improved cooling capabilities. In addition, the required packaging space can be reduced.

[0022] Integration of the power conversion module 132 and the DC / DC converter module 128 may be achieved by incorporating a transformer. Figure 2 2 is a schematic diagram of a hybrid transformer 200. The hybrid transformer 200 may be referred to as a dual transformer hybrid. The hybrid transformer may be schematically represented as two transformers (222, 224). The hybrid transformer 200 may define a plurality of ports. A port may be defined as a pair of terminals to which an electrical component or circuit may be electrically coupled. The hybrid transformer 200 may be a multi-winding configuration. The hybrid transformer 200 may include a plurality of primary windings and a plurality of secondary windings as shown.

[0023] The hybrid transformer 200 may include a pair of multi-winding transformers. For example, each multi-winding transformer may have a single primary coil and a pair of secondary coils. The first transformer 222 may include a first primary winding 210 and a corresponding first secondary winding 214 and a second secondary winding 216. The second transformer 224 may include a second primary winding 212 and a corresponding third secondary winding 218 and a fourth secondary winding 220.

[0024] The first primary winding 210 and the second primary winding 212 may be electrically coupled in series (e.g., a series combination). The series combination may be electrically coupled between the terminals of the first port 202. The impedance of the hybrid transformer 200 measured at the first port 202 is the series impedance of the first primary winding 210 and the second primary winding 212. The first secondary winding 214 may be electrically coupled between the terminals of the second port 204, which defines an electrical connection across the first secondary winding 214. The impedance of the hybrid transformer 200 measured at the second port 204 is the impedance of the first secondary winding 214. The second secondary winding 216 and the third secondary winding 218 may be electrically coupled in series so that the voltage polarity is opposite to define the third port 206. Since the voltage polarity is opposite in the series circuit, the same voltage appearing on each of the second secondary winding 216 and the third secondary winding 218 results in zero voltage at the third port 206. The impedance of the hybrid transformer 200 measured at the third port 206 is the series impedance of the second secondary winding 216 and the third secondary winding 218. The fourth secondary winding 220 may be electrically coupled between terminals of the fourth port 208, which defines an electrical connection across the fourth secondary winding 220. The impedance of the hybrid transformer 200 measured at the fourth port 208 is the impedance of the fourth secondary winding 220.

[0025] The hybrid transformer 200 may be configured to transfer power between any combination of ports. For applications in a power distribution system for a vehicle, the hybrid transformer 200 may be configured such that when power is provided at the first port 202, power is received at the second port 204 and the fourth port 208. The hybrid transformer 200 may be further configured such that when power is provided at the second port 204, power is received at the first port 202 and the third port 206.

[0026] The voltage at one of the secondary windings is related to the voltage at the associated primary winding as follows:

[0027] V s =(N s / N p )V p (1)

[0028] Where V s is the voltage across the secondary winding, V p is the voltage across the primary winding, N s is the number of turns on the secondary winding, and N p is the number of turns on the primary winding. N s With N p The ratio of V to V is called the turns ratio. For a transformer to transfer power, the voltage must be an alternating current (AC). p and Vs Represents the AC voltage amplitude. Each of the secondary windings may have a predetermined number of turns to select a desired voltage transfer through the transformer. Each of the primary windings (e.g., 210, 212) may be configured to have the same number of turns. The number of turns may be selected to achieve an appropriate voltage level for a component electrically coupled to the port. The selection of the number of turns is further described herein.

[0029] Figure 3 A schematic diagram of an integrated vehicle power distribution module including a charger and converter module utilizing a hybrid transformer 200 is depicted. The first port 202 may be selectively electrically coupled to an external power source or load 136. The first port 202 of the hybrid transformer 200 may be electrically coupled to an onboard charger. The onboard charger may be configured to selectively couple the first port 202 to the external power source 136. The onboard charger may include one or more of the following stages. The first inverter stage 302 may be configured to convert between alternating current (AC) power and direct current (DC) power. The first inverter stage 302 may include a switching device configured to achieve bidirectional transfer of energy. The first inverter stage 302 may include a smoothing capacitor across the DC side. During vehicle charging, the first inverter stage 302 may convert an AC power input from an external source 136 into a DC output voltage. When supplying power to a grid or load, the first inverter stage 302 may convert DC power into AC power output to an external device of the vehicle. In some configurations, the first inverter stage 302 may be eliminated. For example, if the external power source 136 provides DC power to the vehicle, the first inverter stage 302 may not be necessary.

[0030] The first inverter stage 302 may be electrically coupled to a bidirectional boost converter 304. The boost converter 304 may be configured to change the voltage level of the DC voltage input to the boost converter 304. The boost converter stage 304 may be configured to operate in both directions. For example, during vehicle charging, the boost converter 304 may be operated to increase the voltage provided at the output by the first inverter stage 302. When supplying power to a grid or a load, the boost converter 304 may be operated to reduce the voltage delivered to the first inverter stage 302.

[0031] The boost converter stage 304 may be electrically coupled to a second inverter stage 306. The second inverter stage 306 may be configured to convert a DC voltage into an AC voltage. During vehicle charging, the second inverter stage 306 may be operable to convert a DC voltage provided by the boost converter 304 into an AC voltage for the hybrid transformer 200. When supplying power to a grid or a load, the second inverter stage 306 may be operable to convert an AC voltage from the hybrid transformer 200 into a DC voltage for the boost converter 304.

[0032] The first inverter stage 302 can be configured to convert voltage according to the frequency of the voltage of the external source 136. For example, if the external source 136 is a standard connection to the power grid, the frequency can be 60 Hz. The second inverter stage 306 can be configured to convert voltage according to a frequency associated with the hybrid transformer 200. This frequency can be selected to optimize the efficiency and performance of energy transfer across the hybrid transformer 200. For example, a frequency of 10 KHz can be selected.

[0033] The second port 204 of the hybrid transformer 200 may be electrically coupled to an AC side terminal of a first inverter module 308. A DC side terminal of the first inverter module 308 may be electrically coupled to the traction battery 124. The first inverter module 308 may be configured to bidirectionally convert power between AC power at the second port 204 and DC power at the traction battery 124.

[0034] The fourth port 208 of the hybrid transformer 200 may be electrically coupled to an AC side terminal of a second inverter module 312. A DC side terminal of the second inverter module 312 may be electrically coupled to the traction battery 124. The second inverter module 312 may be configured to bidirectionally convert power between AC power at the fourth port 208 and DC power at the traction battery 124.

[0035] The third port 206 of the hybrid transformer 200 may be electrically coupled to an AC side terminal of a third inverter module 310. A DC side terminal of the third inverter module 310 may be electrically coupled to the auxiliary battery 130. The third inverter module 310 may be configured to bidirectionally convert power between AC power at the third port 206 and DC power at the auxiliary battery 130.

[0036] The AC voltage applied to any one of the windings of the transformer will induce an AC voltage on the other windings. The induced voltage will be a function of the turns ratio between the windings. Note that power can also be transferred between secondary windings based on the same principle. The hybrid transformer 200 can be configured so that the first primary winding 210 and the second primary winding 212 have the same number of turns. The hybrid transformer 200 can be further configured so that the first secondary winding 214 and the fourth secondary winding 220 have the same number of turns. The hybrid transformer 200 can be further configured so that the second secondary winding 216 and the third secondary winding 218 have the same number of turns.

[0037] Alternatively, the hybrid transformer 200 may be configured such that the turns ratio between the first primary winding 210 and the first secondary winding 214 is the same as the turns ratio between the second primary winding 212 and the fourth secondary winding 220. The hybrid transformer 200 may be configured such that the turns ratio between the first primary winding 210 and the second secondary winding 216 is the same as the turns ratio between the second primary winding 212 and the third secondary winding 218.

[0038] The turns ratio for the windings may be selected based on the desired voltage level. For example, the traction battery 124 may have a nominal voltage rating of 200 volts. The auxiliary battery 130 may have a nominal voltage rating of 12 volts. The turns ratio between the first primary winding 210 and the first secondary winding 214 may be a function of the traction battery voltage and the external source voltage magnitude. In charging mode, the DC voltage output of the first inverter module 308 may be configured to exceed the traction battery voltage by a predetermined margin. If a step-up or step-down transformer configuration is required, the relative voltage magnitude may be determined. Similarly, the turns ratio between the fourth secondary winding 220 and the second primary winding 212 may be a function of the traction battery voltage and the external source voltage magnitude. The turns ratio between the first primary winding 210 and the second secondary winding 216 may be a function of the auxiliary battery voltage and the traction battery voltage. The turns ratio between the second primary winding 212 and the third secondary winding 218 may be a function of the auxiliary battery voltage and the traction battery voltage. The turns ratio may be a step-down ratio to ensure that the voltage level is reduced to a level that can be handled by the low voltage bus and the auxiliary battery 130 .

[0039] The system may also include at least one controller 320 configured to manage the operation of the power distribution system. The controller 320 may be electrically coupled to the first inverter stage 302, the boost converter 304, and the second inverter stage 306. For example, the component may include a switching device for selectively coupling the external source 136 to the hybrid transformer 200. For example, the switching device is depicted as an insulated gate bipolar transistor (IGBT). Each IGBT may be operated by a gate signal that controls the conduction state of the device. The controller 320 may be configured with a circuit to provide a gate signal to the switching device. The controller 320 may be programmed to operate the inverter stage and the boost converter using algorithms and control strategies known to those of ordinary skill in the art. Although not shown, the first inverter stage 302, the boost converter 304, and the second inverter stage 306 may include voltage and current sensors to provide inputs to the controller 320 for control and monitoring.

[0040] The controller 320 may also be electrically coupled to the first inverter module 308, the second inverter module 312, and the third inverter module 310. Each of the components may include a switching device for selectively coupling the traction battery 124 or the auxiliary battery 130 to the hybrid transformer 200. For example, the switching device is depicted as an insulated gate bipolar transistor (IGBT). Each IGBT may be operated by a gate signal that controls the conduction state of the device. The controller 320 may be configured with a circuit to provide a gate signal to the switching device. The controller 320 may be programmed to operate the inverter module using algorithms and control strategies known to those of ordinary skill in the art. Although not shown, the first inverter module 308, the second inverter module 312, and the third inverter module 310 may include voltage and current sensors to provide inputs to the controller 320 for control and monitoring. It should be understood that although a single controller is depicted, multiple controllers communicating with each other may provide equivalent functions.

[0041] The controller 320 may be configured to operate various systems to manage power flow through the hybrid transformer 200. The controller 320 may select an operating mode based on the operating conditions of the vehicle. The power flow through the power distribution system depends on the operating mode. The first operating mode may be a charging mode. In the charging mode, power may be received from an external source 136 for charging the vehicle. The charging mode may be configured to provide energy to the traction battery 124 without providing energy to the auxiliary battery 130.

[0042] In charging mode, the external power source 136 may provide power to the vehicle. In particular, the received power may be used to charge the traction battery 124. Power from the external power source 136 is input to the first inverter stage 302. When the external power source 136 provides AC power, the first inverter stage 302 may be operated to convert the AC input to a DC output. The first inverter module 302 may be operated to convert the AC power from the external source 136 to DC power at the boost converter 304. The controller 320 may operate the associated switching devices to achieve the conversion.

[0043] The DC power output of the first inverter stage 302 may be provided to a boost converter 304. The boost converter 304 may be operable to adjust the DC power level. For example, the DC voltage at the output provided to the second inverter stage 306 may be increased to be greater than the DC voltage from the first inverter stage 302. The controller 320 may operate the associated switching devices to achieve a desired DC voltage at the output of the boost converter 304.

[0044] The output of the boost converter 304 may be provided to a second inverter stage 306. The second inverter stage 306 may be operable to convert a DC voltage at an input to an AC voltage at an output of the second inverter stage 306. The controller 320 may operate an associated switching device to achieve the conversion. The AC voltage output may have a predetermined amplitude and frequency. The frequency may be selected to minimize losses through the hybrid transformer 200. The AC voltage output is provided to the first port 202 of the hybrid transformer 200. As an example, a frequency of 20 KHz may be selected for transferring energy through the hybrid transformer 200. The controller 320 operates the switching device to achieve the desired frequency and amplitude.

[0045] In the charging operation mode, an AC voltage is applied across the series combination of the first primary winding 210 and the second primary winding 212. The AC voltage will induce a voltage in the corresponding secondary winding. The AC voltage can be provided across the series combination of the first primary winding 210 and the second primary winding 212 (for example, across the first port 202). The AC voltage induces a voltage in each of the secondary windings according to the corresponding turns ratio. The hybrid transformer 200 can be configured so that the induced voltage across the second secondary winding 216 and the third secondary winding 218 is the same. Since the second secondary winding 216 and the third secondary winding 218 are electrically connected in series at opposite voltage polarities, the voltage generated at the third port 206 is zero. The voltage induced at the second secondary winding 216 is offset by the voltage at the third secondary winding 218. Therefore, no power is provided to the auxiliary battery 130.

[0046] An AC voltage is induced at the first secondary winding 214 (e.g., the second port 204). The AC voltage may be input to the AC side of the first inverter module 308. The first inverter module 308 may be operable to convert the AC voltage to a DC voltage at the DC side of the first inverter module 308 coupled to the traction battery 124. In addition, an AC voltage is induced in the fourth secondary winding 220 (e.g., the fourth port 208). The AC voltage may be input to the AC side of the second inverter module 312. The second inverter module 312 may be operable to convert the AC voltage to a DC voltage at the DC side of the second inverter module 312 coupled to the traction battery 124. In this way, power from an external source is provided to the traction battery 124.

[0047] The second operating mode may be an external power mode. In the external power mode, the traction battery 124 and / or the high voltage bus may provide power to the external source 136. This mode allows the vehicle to power electrical loads plugged into the vehicle. This mode also allows power to be provided to the grid during peak demand periods.

[0048] In the external power mode, the traction battery 124 is used to provide power to an external load. The external load may be an external source 136 and may provide power to the grid. For example, during a peak energy usage period, it may be beneficial to return the energy stored in the traction battery 124 and recharge the traction battery 124 at a later time. The first inverter module 308 is operable to convert the DC power from the traction battery 124 into AC power at the hybrid transformer 200. The AC power is provided across the second port 204 of the hybrid transformer 200. Therefore, the AC power is transferred to the first port 202 and the third port 206 through the hybrid transformer 200. This mode of operation allows power to be transferred to both the external load and the auxiliary battery 130. The third inverter module 310 may receive AC power from the third port 206. The third inverter module 310 is operable to convert the AC signal into a DC voltage across the auxiliary battery 130 and / or the low voltage power bus.

[0049] The second inverter stage 306 may receive AC power from the first port 202. The second inverter stage 306 may be operable to convert the AC power into DC power for input to the boost converter stage 304. The boost converter stage 304 may be operable to deliver a DC voltage to the first inverter stage 302. The first inverter stage 302 may be operable to convert the DC voltage received from the boost converter stage 304 into an AC power signal that is compatible with the external source 136 or external load. For example, if the system provides power to the grid or an electrical outlet, the AC signal may be controlled to be 110VAC at a frequency of 60Hz.

[0050] The third operating mode may be a vehicle operating mode. In the low voltage power bus supply mode, the traction battery 124 and / or the high voltage bus may provide power for operating the low voltage power bus without providing power to the onboard charging subsystem. In this mode, the first inverter module 308 is operable to provide an AC voltage to the second port 204 of the hybrid transformer 200. The second inverter module 312 is operable to provide an AC voltage to the fourth port 208 of the hybrid transformer 200, which is 180 degrees out of phase with the AC voltage provided to the second port 204. By operating the inverter module in this way, the contribution of each of the AC voltages is offset at the first port 202. When the polarity is opposite, the voltage across the first primary winding 210 and the second primary winding 212 will be offset. In this way, no power is provided to the onboard charger system. In addition, power is provided to the third port 206 of the hybrid transformer 200. The third inverter module 310 can convert the power received at the third port 206 into DC power compatible with the low voltage power bus and the auxiliary battery 130. This mode of operation may be used during a vehicle drive cycle and / or when the vehicle is powered on (eg, ignition on condition).

[0051] Advantages of using the hybrid transformer 200 include reduced packaging complexity. The hybrid transformer 200 allows control of power flow between the traction battery 124, the auxiliary battery 130, and the electrical utility without the need for additional switches and contactors. This reduces power losses through the system. In addition, switches and contactors may be prone to arcing and degradation under certain conditions. In addition, when the DC / DC converter and the on-board charger are integrated, the number of components is reduced. When current is shared between the second port 204 and the fourth port 208, component stress can be reduced.

[0052] The process, method or algorithm disclosed herein may be provided / implemented by a processing device, a controller or a computer, which may include any existing programmable electronic control unit or a dedicated electronic control unit. Similarly, the process, method or algorithm may be stored as data and instructions that can be executed by a controller or a computer in many forms, including but not limited to information permanently stored on non-writable storage media such as ROM devices and information stored in a changeable manner on writable storage media, such as floppy disks, tapes, CDs, RAM devices and other magnetic and optical media. The process, method or algorithm may also be implemented in a software executable object. Alternatively, the process, method or algorithm may be implemented in whole or in part using suitable hardware components, such as an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), a state machine, a controller or other hardware component or device, or a combination of hardware, software and firmware components.

[0053] Although exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms covered by the claims. The words used in the specification are descriptive rather than limiting, and it should be understood that various changes can be made without departing from the spirit and scope of the present disclosure. As previously mentioned, the features of the various embodiments can be combined to form other embodiments of the present invention that may not be explicitly described or illustrated. Although various embodiments can be described as providing advantages or being superior to other embodiments or prior art implementations relative to one or more desired characteristics, it is recognized by those of ordinary skill in the art that one or more features or characteristics can be deducted to achieve the desired overall system properties, depending on the specific application and implementation. These properties may include, but are not limited to, cost, strength, durability, life cycle cost, marketability, appearance, packaging, size, maintainability, weight, manufacturability, ease of assembly, etc. Therefore, it is described as not as good as other embodiments. Embodiments or prior art implementations regarding one or more characteristics are not outside the scope of the present disclosure and may be desirable for specific applications.

[0054] According to the present invention, a vehicle is provided having a hybrid transformer including a first primary winding and a second primary winding electrically coupled in series and selectively electrically coupled to an external source, each of the primary windings being associated with a first secondary winding selectively electrically coupled to a traction battery and with a second secondary winding electrically coupled in series at opposite voltage polarities to define a port selectively electrically coupled to an auxiliary battery.

[0055] According to one embodiment, the first primary winding and the second primary winding may be coupled to the external source through at least one power inverter configured to bidirectionally convert power between direct current (DC) and alternating current (AC).

[0056] According to one embodiment, the first primary winding and the second primary winding are coupled to the external source through a boost converter configured to bidirectionally convert DC power levels.

[0057] According to one embodiment, each of the first secondary windings is selectively electrically coupled to the traction battery through an inverter configured to bidirectionally convert power between direct current (DC) and alternating current (AC).

[0058] According to one embodiment, the port is selectively electrically coupled to the auxiliary battery through an inverter configured to bidirectionally convert power between direct current (DC) at the auxiliary battery and alternating current (AC) at the port.

[0059] According to one embodiment, the hybrid transformer is configured to transfer power to the traction battery through each of the first secondary windings and to provide no power to the auxiliary battery through the port in response to the first primary winding and the second primary winding being coupled to the external source and the external source providing power.

[0060] According to one embodiment, the hybrid transformer is configured to output an alternating current (AC) voltage to the external source through the first primary winding and to the auxiliary battery through the port in response to the traction battery being selectively coupled to the first secondary winding associated with the first primary winding to provide AC voltage.

[0061] According to one embodiment, the hybrid transformer is configured to output the AC voltage to the auxiliary battery through the port and provide the AC voltage to the first primary winding and the second primary winding in response to the traction battery being selectively coupled to each of the first secondary windings to provide an alternating current (AC) voltage such that the AC voltage provided to the first secondary winding associated with the first primary winding is 180 degrees out of phase with the AC voltage provided to the first secondary winding associated with the second primary winding, such that a voltage across the series combination of the first primary winding and the second primary winding is zero.

[0062] According to the present invention, a vehicle power distribution system is provided having a hybrid transformer including a first primary winding and a second primary winding electrically coupled in series to a first port selectively electrically coupleable to an external source, each associated with a first secondary winding selectively electrically coupled to a traction battery and each associated with a second secondary winding commonly coupled in series at opposite voltage polarities to define a second port selectively electrically coupleable to an auxiliary battery.

[0063] According to one embodiment, the above invention is further characterized by an on-board charger comprising at least one bidirectional AC / DC conversion stage for selectively electrically coupling the first port to the external source.

[0064] According to one embodiment, the above invention is further characterized by a first inverter circuit, which is used to selectively couple the first secondary winding associated with the first primary winding to the traction battery; a second inverter circuit, which is used to selectively couple the first secondary winding associated with the second primary winding to the traction battery; and a third inverter circuit, which is used to selectively couple the second port to the auxiliary battery.

[0065] According to one embodiment, the hybrid transformer is configured to transfer power to the traction battery through each of the first secondary windings and provide zero power to the auxiliary battery through the second port in response to the first port being selectively coupled to the external source and the external source providing power.

[0066] According to one embodiment, the hybrid transformer may be configured to transfer power to the external source through the first port and to the auxiliary battery through the second port in response to the traction battery being selectively coupled to the first secondary winding associated with the first primary winding.

[0067] According to one embodiment, the hybrid transformer is configured to transfer power to the auxiliary battery through the second port and provide zero power to the first port in response to selectively coupling the traction battery to each of the first secondary windings so that voltages supplied to the first secondary windings are 180 degrees out of phase with each other.

[0068] According to one embodiment, the first primary winding and the corresponding first secondary winding are characterized by a turns ratio having the same value as a turns ratio characterizing the second primary winding and the corresponding first secondary winding.

[0069] According to one embodiment, a turns ratio characterizing the first primary winding and the corresponding second secondary winding has the same value as the turns ratio characterizing the second primary winding and the corresponding second secondary winding.

[0070] According to the present invention, an integrated vehicle power distribution module is provided, comprising: a transformer; a charger coupled to a series combination of a first primary winding and a second primary winding of the transformer; a first inverter and a second inverter, the first inverter and the second inverter being coupled between a traction battery and a first secondary winding associated with each of the primary windings; and a third inverter, the third inverter being coupled between an auxiliary battery and a second secondary winding associated with each of the primary windings and connected in series at opposite voltage polarities.

[0071] According to one embodiment, the transformer is configured to transfer power through each of the first secondary windings to the first inverter and the second inverter in response to the charger being coupled to an external source and the external source providing power, such that zero power is transferred to the third inverter.

[0072] According to one embodiment, the transformer is configured to transfer power through the first primary winding to the charger and through the second secondary winding associated with the first primary winding to the third inverter in response to operating the first inverter to provide an alternating current (AC) voltage to the first secondary winding associated with the first primary winding.

[0073] According to one embodiment, the transformer is configured to transfer power to the third inverter and transfer zero power to the charger in response to operating the first inverter and the second inverter to provide alternating current (AC) voltages to the first secondary winding that are 180 degrees out of phase with each other.

Claims

1. A vehicle comprising: A hybrid transformer comprising a first primary winding and a second primary winding directly coupled in series with opposite polarities and selectively electrically coupled to an external source, and further comprising a first secondary winding and a second secondary winding associated with the first primary winding and a third secondary winding and a fourth secondary winding associated with the second primary winding, the first secondary winding and the fourth secondary winding being selectively electrically coupled to a traction battery, the second secondary winding and the third secondary winding being directly coupled in series with the same polarity to define a port selectively electrically coupled to an auxiliary battery.

2. The vehicle of claim 1, wherein the first primary winding and the second primary winding are coupled to the external source through at least one power inverter configured to bidirectionally convert power between direct current and alternating current.

3. The vehicle of claim 2, wherein the first primary winding and the second primary winding are coupled to the external source through a boost converter configured to bidirectionally convert DC power levels.

4. The vehicle of claim 1, wherein each of the first secondary winding and the fourth secondary winding is selectively electrically coupled to the traction battery through an inverter configured to bidirectionally convert power between direct current and alternating current.

5. The vehicle of claim 1, wherein the port is selectively electrically coupled to the auxiliary battery through an inverter configured to bidirectionally convert power between direct current at the auxiliary battery and alternating current at the port.

6. The vehicle of claim 1 , wherein the hybrid transformer is configured to deliver power to the traction battery through each of the first secondary winding and the fourth secondary winding and not provide power to the auxiliary battery through the port in response to the first primary winding and the second primary winding being coupled to the external source and the external source providing power.

7. The vehicle of claim 1 , wherein the hybrid transformer is configured to output an AC voltage to the external source through the first primary winding and to the auxiliary battery through the port in response to the traction battery being coupled to the first secondary winding to provide an AC voltage.

8. The vehicle of claim 1 , wherein the hybrid transformer is configured to output the AC voltage through the port to the auxiliary battery and to provide the AC voltage to the first primary winding and the second primary winding in response to the traction battery being coupled to each of the first secondary winding and the fourth secondary winding to provide an AC voltage such that the AC voltage provided to the first secondary winding is 180 degrees out of phase with the AC voltage provided to the fourth secondary winding such that a voltage across the series combination of the first primary winding and the second primary winding is zero.

9. An integrated vehicle power distribution module, comprising: A transformer comprising a first primary winding and a second primary winding directly coupled in series with opposite polarities, and further comprising a first secondary winding and a second secondary winding associated with the first primary winding and a third secondary winding and a fourth secondary winding associated with the second primary winding, the second secondary winding and the third secondary winding being directly coupled in series with the same polarity; a charger coupled to the series combination of the first primary winding and the second primary winding; a first inverter and a second inverter, the first inverter being coupled between a traction battery and the first secondary winding, the second inverter being coupled between the traction battery and the fourth secondary winding; as well as A third inverter is coupled between the auxiliary battery and the second and third secondary windings.

10. The integrated vehicle power distribution module of claim 9, wherein the transformer is configured to deliver power to the first inverter and the second inverter through each of the first secondary winding and the fourth secondary winding in response to the charger being coupled to an external source and the external source providing power, such that zero power is delivered to the third inverter.

11. The integrated vehicle power distribution module of claim 9, wherein the transformer is configured to deliver power to the charger through the first primary winding and to the third inverter through the second secondary winding in response to operating the first inverter to provide an AC voltage to the first secondary winding.

12. The integrated vehicle power distribution module of claim 9, wherein the transformer is configured to deliver power to the third inverter and deliver zero power to the charger in response to operating the first inverter and the second inverter to provide AC voltages 180 degrees out of phase with each other to the first secondary winding and the fourth secondary winding.

13. The integrated vehicle power distribution module of claim 9, wherein the first primary winding and the first secondary winding are characterized by a turns ratio having the same value as a turns ratio characterizing the second primary winding and the fourth secondary winding.

14. The integrated vehicle power distribution module of claim 9, wherein a turns ratio characterizing the first primary winding and the second secondary winding has the same value as a turns ratio characterizing the second primary winding and the third secondary winding.

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