Scalable dual-output DC-DC power architecture

Abstract

An integrated motor drive (IMD) system includes; a modular multi-level inverter (MMI) including a plurality of integrated power modules each having one or more battery cells and a power electronics assembly configured to generate AC power on a set of load terminals using direct current (DC) power from the one or more battery cells connected to an internal DC bus. The plurality of integrated power modules are split between a plurality of phase groups, and each of the phase groups includes an isolated DC-DC power converter arrangement having DC input terminals connected to an internal DC bus of an integrated power module for receiving power therefrom. The isolated DC-DC power converter arrangement includes one or more isolated DC- DC converters providing isolated DC power to each of two DC output buses using power from the DC input terminals and at a different voltage than is present on the DC input terminals.

Description

Attorney Docket No. 18402-5389 (713865PCT)SCALABLE DUAL-OUTPUT DC-DC POWER ARCHITECTURECROSS REFERENCE TO RELATED APPLICATIONS

[0001] This PCT international patent application claims the benefit of U.S. Provisional Patent Application No. 63 / 779,757 filed March 28, 2025, the contents of which is incorporated herein by reference in its entirety.FIELD[00021 The present disclosure relates generally to power electronics for managing power to and from batteries and / or other DC power sources. The systems and methods of the present disclosure may have applications in electric vehicles and in non-vehicle systems.BACKGROUND

[0003] In conventional electric vehicle propulsion system, Li-ion battery cells are packaged together in series and parallel configuration to develop a battery module, and a number of battery modules together create a complete battery pack. The battery pack is the main energy source connected to the motor and its drive system through DC link. Recently, Modular multilevel inverter (MMI) is getting importance due to its integrated configuration, scalability, compact and efficient design. In this configuration, the battery cells, or modules are connected to each other through power electronics circuit such as full bridges, and half bridges which produces AC voltage to operate the eMotor. However, one of the main challenges with this configuration is to supply voltage to the HVAC system, secondary motor and other auxiliary circuits.

[0004] Existing architectures may struggle to efficiently deliver both high-voltage (360V for HVAC) and low-voltage (14V auxiliary) power from a distributed battery arrangement. Additionally, a scalable and modular power solution is needed to accommodate different power levels (e.g., increasing from IkW to 5kW) by adding more modules without requiring a complete redesign.SUMMARY

[0005] The present disclosure provides an integrated motor drive (IMD) system. The IMD system includes: a modular multi-level inverter including a plurality of integrated power modules,Attorney Docket No. 18402-5389 (713865PCT)wherein each of the integrated power modules includes one or more battery cells and a power electronics assembly physically and electrically coupled to the one or more battery cells and configured to generate AC power on a set of load terminals using direct current (DC) power from the one or more battery cells connected to an internal DC bus. The plurality of integrated power modules are split between a plurality of phase groups, with each of the phase groups including a corresponding subset of the plurality of integrated power modules, with their respective load terminals connected in series between a lower node and an AC output conductor, with the AC output conductors of the plurality of phase groups together arranged to supply the AC power to a motor. Each of the phase groups includes an isolated DC-DC power converter arrangement having DC input terminals connected to the internal DC bus of one or more integrated power modules in the corresponding subset of the plurality of integrated power modules and for receiving power therefrom, wherein the isolated DC-DC power converter arrangement comprises one or more isolated DC-DC configured to provide isolated DC power to each of a first DC output bus and a second DC output bus using DC power from the DC input terminals and at a different voltage than is present on the DC input terminals.

[0006] The present disclosure also provides an integrated motor drive (IMD) system that includes a modular multi-level inverter and a controller. The modular multi-level inverter includes a plurality of integrated power modules. Each of the integrated power modules includes one or more battery cells and a power electronics assembly physically and electrically coupled to the one or more battery cells and configured to generate AC power on a set of load terminals using direct current (DC) power from the one or more battery cells connected to an internal DC bus. The plurality of integrated power modules are split between a plurality of phase groups, with each of the phase groups including a corresponding subset of the plurality of integrated power modules with their respective load terminals connected in series between a lower node and an AC output conductor, with the AC output conductors of the plurality of phase groups together arranged to supply the AC power to a motor having windings arranged in a wye configuration and defining a center node. The corresponding subset of the plurality of integrated power modules in each of the phase groups includes two or more of the integrated power modules. Each of the phase groups includes a DC-DC power converter having DC input terminals, and wherein the DC input terminalsAttorney Docket No. 18402-5389 (713865PCT)of the DC-DC power converter are connected to the internal DC bus of a single integrated power module in the corresponding subset of the plurality of integrated power modules, and for receiving power therefrom. The IMD system also includes a controller that is configured to: determine a balance current on a conductor connected to the center node of the motor; determine a state of charge (SoC) of the one or more battery cells in the single integrated power module that is connected to the DC-DC power converter; and control operation of the power electronics assembly of the single integrated power module that is connected to the DC-DC power converter to adjust the SoC of the one or more battery cells in the single integrated power module that is connected to the DC-DC power converter and while the motor is at a standstill condition.[00 '7| The present disclosure also provides a method of operating an integrated motor drive (IMD) system having a modular multi-level inverter (MMI) that includes a plurality of integrated power modules, wherein each of the integrated power modules includes one or more battery cells and a power electronics assembly physically and electrically coupled to the one or more battery cells and configured to generate AC power on a set of load terminals using direct current (DC) power from the one or more battery cells connected to an internal DC bus. The plurality of integrated power modules are split between a plurality of phase groups, with each of the phase groups including a corresponding subset of the plurality of integrated power modules, with each of the phase groups configured to supply AC current to a corresponding winding of a motor having at least three of the windings arranged in a wye configuration and defining a center node. The corresponding subset of the plurality of integrated power modules in each of the phase groups includes two or more of the integrated power modules, and each of the phase groups includes a DC-DC power converter having DC input terminals, and wherein the DC input terminals of the DC-DC power converter are connected to the internal DC bus of a single integrated power module in the corresponding subset of the plurality of integrated power modules, and for receiving power therefrom. The method includes: determining a balance current on a conductor connected to the center node of the motor; determining a state of charge (SoC) of the one or more battery cells in the single integrated power module that is connected to the DC-DC power converter; and commanding a plurality of switches in the single integrated power module that is connected to the DC-DC power converter to selectively conduct current to adjust the SoC of the one or more batteryAttorney Docket No. 18402-5389 (713865PCT)cells in the single integrated power module that is connected to the DC-DC power converter and while the motor is at a standstill condition.|0008] These and other aspects of the present disclosure are disclosed in the following detailed description of the embodiments, the appended claims, and the accompanying figures.BRIEF DESCRIPTION OF THE DRAWINGS[0009| Further details, features and advantages of designs of the invention result from the following description of embodiment examples in reference to the associated drawings.

[0010] FIG. 1 shows a shows a schematic block diagram of an electrical system in an electrified vehicle (EV), and in accordance with an aspect of the present disclosure;|0011 J FIG. 2 shows a schematic block diagram of a distributed DC-DC architecture, in accordance with an aspect of the present disclosure;

[0012] FIG. 3 shows a schematic block and circuit diagram of a first dual-output DC-DC power converter architecture, based on an asymmetrical half-bridge flyback converter, in accordance with an aspect of the present disclosure;

[0013] FIG. 4 shows a schematic block and circuit diagram of a second dual-output DC-DC power converter architecture, based on a full-bridge LLC resonant converter, in accordance with an aspect of the present disclosure;[0014| FIG. 5 shows a schematic block and circuit diagram of a third dual-output DC-DC power converter architecture based on multi -module power converter, in accordance with an aspect of the present disclosure;10015] FIG. 6 shows a block diagram of a system architecture of the multi-module power converter of FIG. 5, in accordance with an aspect of the present disclosure;

[0016] FIG. 7 shows a block diagram of a components in a power path of the multi-module power converter of FIG. 5, in accordance with an aspect of the present disclosure;

[0017] FIG. 8 shows a schematic block and circuit diagram of a fourth dual-output DC-DC power conversion arrangement, in accordance with an aspect of the present disclosure;Attorney Docket No. 18402-5389 (713865PCT)

[0018] FIG. 9 shows a block diagram of a system architecture with several of the fourth dual-output DC-DC power conversion arrangements, in accordance with an aspect of the present disclosure;

[0019] FIG. 10 shows a block diagram of a dual-output DC-DC power conversion arrangement based on a multi-converter power supply system, in accordance with an aspect of the present disclosure;

[0020] FIG. 11 shows a schematic block and circuit diagram of a high-power 2-phase interleaved LLC resonant converter, in accordance with an aspect of the present disclosure;

[0021] FIG. 12 shows a block diagram of a method for state-of-charge balancing for multilevel inverter system at a standstill condition, in accordance with an aspect of the present disclosure;[00221 FIG. 13 shows an electrical schematic diagram of a multilevel inverter system during a standstill SOC balancing scenario, in accordance with an aspect of the present disclosure; and

[0023] FIG. 14 shows an electrical schematic diagram of a multilevel inverter system, in accordance with an aspect of the present disclosure.DETAILED DESCRIPTION[0024| Referring to the drawings, the present invention will be described in detail in view of following embodiments.

[0025] Objectives of the present disclosure include providing a DC-DC architecture capable of delivering both 360V for HVAC and 14V for auxiliary loads efficiently from a 48V battery pack. An additional objective is to ensure modularity, allowing power scalability by adding more power modules without requiring a full system redesign, thus reducing development and manufacturing costs.[0026J The present disclosure provides a scalable modular architecture for dual-output power delivery. The architecture is designed with multiple DC-DC converter modules that can be configured in different power levels. The DC-DC converter modules may also be called DC / DCAttorney Docket No. 18402-5389 (713865PCT)converters. This modular approach allows for cost optimization, meaning manufacturers can add / remove modules to meet different power requirements with minor changes to the system (e g. transformer turns ratio). The present disclosure also provides series and parallel output configuration for voltage scalability. The outputs may include a 360V HVAC output, which may be achieved by connecting outputs in series or parallel to reach the desired high voltage. The outputs may also include a 14V DC auxiliary output, which may be achieved by connecting outputs in parallel to increase current capability. The present disclosure also provides a buck converter for parallel output voltage regulation (14V Auxiliary). A dedicated buck converter may be used after the tertiary winding output to regulate the 14V auxiliary power, so that a voltage feedback loop is not required for regulation.

[0027] FIG. 1 shows a block diagram of an electrical system 10 for operating an electrified vehicle (EV). The EV may be configured as a battery electric vehicle (BEV), a plug-in hybrid electric vehicle (PHEV) or another type of hybrid electric vehicle that uses battery electric in combination with another source of energy for propulsion. The electrical system 10 is provided in a vehicle 12 having four wheels 14. The electrical system 10 includes a first battery 16 configured to supply power to one or more auxiliary loads 18. The axillary loads may include, low-power functional elements in the vehicle 12, such as heating ventilation and air conditioning (HVAC) motors, lighting loads, such as headlights and tail lights, power steering and power brake motors, seat heaters, electrical control units (ECUs), seat actuators, window actuators, etc. The first battery 16 may be configured as a low-voltage battery, which may have an operating voltage of, for example, 12-Volts, 24-Volts, 36-Volts, 42-Volts, or48-Volts.

[0028] The electrical system 10 also includes a traction power source 20 that is configured to supply electrical power to an inverter 22 via a DC bus 21 for driving one or more traction motors 26 for propelling the vehicle 12. The traction power source 20 includes a second electrical energy storage device 40, which may be configured as a high-capacity main battery. Additionally or alternatively, the second electrical energy storage device 40 may include one or more capacitors.|0029J The traction power source 20 also includes a third electrical energy storage device 42, which may be configured as a high-performance boost battery that is capable of delivering relatively high output power for a short duration of time. In some embodiments, the third electricalAttorney Docket No. 18402-5389 (713865PCT)energy storage device 42 includes a battery, which may have a different chemistry than the first battery 16 and / or the second electrical energy storage device 40. Alternatively or additionally, the third electrical energy storage device 42 may include one or more capacitors, which may include super capacitors. The second electrical energy storage device 40 and / or the third electrical energy storage device 42 may have a relatively higher voltage, such as 400 Volts Direct Current (VDC) or 800 VDC.

[0030] The inverter 22 may include at least three pairs of solid-state switches 23, such as field effect transistors (FETs) configured to switch current from the DC bus 21 and to generate an AC power upon a set of motor leads 24. The motor leads 24 transmit electrical power between the inverter 22 and a traction motor 26. The traction motor 26 may be a permanent magnet synchronous motor (PMSM). The traction motor 26 may be used as a motor, a generator, or as a motor / generator that functions as both a motor and a generator. The traction motor 26 may include an output shaft 27 that is coupled, either directly or via a transmission or gearbox (not shown in the FIGs), to one or more of the wheels 14 of the vehicle 12 for driving the vehicle 12.[00311 A current sensor 28 is arranged to measure current in one or more of the motor leads 24. In some embodiments, and as shown on FIG. 1, the current sensor 28 measures an A-phase current ia, on a corresponding one of the motor leads 24. However, the electrical system 10 may measure current on two or more of the motor leads 24. The electrical system 10 may include other sensors, such as voltage sensors configured to measure voltages upon or between the motor leads 24. If voltage sensors are available, they can be used as inputs for the provided approach.

[0032] The electrical system 10 of FIG. 1 also includes an electronic control unit (ECU) 30, which may also be called a governing controller, in communication with the current sensor 28 to measure the currents in the motor leads 24. The ECU 30 may also be in functional communication with the inverter 22 to control operation of the inverter 22 and / or to monitor parameters measured by sensors associated with the inverter 22. The ECU 30 includes a processor 32 coupled to a storage memory 34. The storage memory 34 stores instructions, such as program code for execution by the processor 32, in an instruction storage 36. The storage memory 34 also includes data storage 38 for holding data to be used by the processor 32. The data storage 38 mayAttorney Docket No. 18402-5389 (713865PCT)record, for example, values of the parameters measured by the current sensor 28 and / or the outcome of functions calculated by the processor 32.|0033] FIG. 2 shows a schematic block diagram of a distributed DC-DC architecture 50, in accordance with an aspect of the present disclosure. The distributed DC-DC architecture 50 of FIG. 2 includes a modular multi-level inverter (MMI) 60 configured to provide 3 -phase AC power to a primary electric motor 52. The primary electric motor 52 may be used as the traction motor 26 for generating a torque used to accelerate the vehicle 12. Alternatively, the primary electric motor 52 may be used for other purposes. The primary electric motor 52 is connected to the MMI 60 via a contactor 54. A charger 56, such an AC or DC fast charger is also connected to the MMI 60 via the contactor 54 for transmitting power to the MMI 60 for charging batteries therein.[0034| The MMI 60 shown in FIG. 2 includes three phase groups 62a, 62b, 62c, each generating a single-phase of AC power for application to a corresponding stator winding of the primary motor 52 via a corresponding AC output conductor 64a, 64b, 64c and via the contactor 54, which may also be called an AC bus connector. Each of the phase groups 62a, 62b, 62c also defines a lower node 65n, and the AC output power of each of the phase groups 62a, 62b, 62c may be conducted as current between a corresponding AC output conductor 64a, 64b, 64c and the corresponding lower node 65n. Each of the phase groups 62a, 62b, 62c includes one or more integrated power modules 63. FIG. 2 shows each of the phase groups 62a, 62b, 62c with only one of the integrated power modules 63. However, the phase groups 62a, 62b, 62c may each include a plurality of the integrated power modules 63 with AC outputs connected in series to generate a given AC voltage on the corresponding AC output conductor 64a, 64b, 64c.

[0035] Each of the integrated power modules 63 may have a similar or identical configuration. Each of the integrated power modules 63 includes a battery module 70, a battery management system (BMS) 72, and a full-bridge power converter 74. The battery module 70 may include one or more battery cells. The BMS 72 may control DC current flow into the battery cells of the battery module 70 for cell balancing and to ensure charging and discharging meets given requirements for battery cell health. The BMS 72 is connected to the full-bridge power converter 74 via an internal DC bus 73. The full-bridge power converter 74 may function as an inverter to supply the AC power to the primary motor 52 using power from the DC bus 73. The full-bridgeAttorney Docket No. 18402-5389 (713865PCT)power converter 74 may also function as a rectifier to supply DC power to the DC bus 73 for charging the battery module 70.10036] As shown, each of the full-bridge power converters 74 defines a set of load terminals 751, 75n that include a line terminal 751 and a neutral terminal 75n. In the embodiment shown in FIG. 2, where each phase group 62a, 62b, 62c includes only one of the integrated power modules 63, the neutral terminals 75n are connected to the corresponding lower node 65n of the corresponding phase group 62a, 62b, 62c, and the line terminals 751 are connected directly to a corresponding one of the AC output conductors 64a, 64b, 64c. However, in alternative arrangement with two or more of the of the integrated power modules 63 in each the phase groups 62a, 62b, 62c, the line terminals 751 and neutral terminals 75n of the full-bridge power converters 74 in a given one of the phase groups 62a, 62b, 62c may be connected in series between the corresponding lower node 65n and a corresponding one of the AC output conductors 64a, 64b, 64c.

[0037] The distributed DC-DC architecture 50 also includes a first switch 66 configured to selectively connect the b-phase AC output conductor 64b with the c-phase AC output conductor 64c. The c-phase lower node 65n is connected to the module neutral conductor 64n. The distributed DC-DC architecture 50 also includes a second switch 68 configured to selectively connect the lower node 65n of the a-phase group 62a and the b-phase group 62b to the module neutral conductor 64n. The switches 66, 68 may be implemented using contactors or semiconductor devices and may function to connect the full-bridge power converters 74 of each of the phase groups 62a, 62b, 62c in series for DC fast charging.

[0038] In some embodiments, and as shown FIG. 2, each of the integrated power modules 63 may be configured as primary modules, including a battery module 70. The battery module 70 may have a 90-V nominal voltage. However, the battery module 70 may have a different voltage, such as 12V, 24V, or 48V. Additionally or alternatively, some of the integrated power modules 70 may be configured as secondary modules, which do not contain a battery, but instead are connected to an external battery.

[0039] As also shown in FIG. 2, each of the phase groups 62a, 62b, 62c also includes a dual-output isolated DC-DC power conversion arrangement 76. The dual-output isolated DC-DCAttorney Docket No. 18402-5389 (713865PCT)power conversion arrangement 76 includes a set of DC input terminals 78 that is connected to the internal DC bus 73 for receiving power therefrom. The dual-output isolated DC-DC power converter 76 is configured to provide a first DC output bus 80 and a second DC output bus 84. The dual-output isolated DC-DC power converter 76 is configured to provide isolated DC power to each of the first DC output bus 80 and a second DC output bus 84 using DC power from the DC input terminals 78 and at a different voltage than is present on the DC input terminals 78. The first DC output bus 80 and the second DC output bus 84 may be generated by a single multi-port converter or by a plurality of converters operating in concert.

[0040] The first DC output busses 80 of the dual-output isolated DC-DC power converters 76 may be connected in series or parallel to supply a high-voltage (HV) DC power to one or more HV loads 90.The HV DC power may be delivered at a nominal voltage of 360V for delivery to a heating, ventilation, and air conditioning (HVAC) system or other high-voltage loads. However, the first DC output busses 80 may supply the HV DC power to one or more loads at a different voltage, depending on the requirements of the connected load or system architecture. The second DC output busses 84 of the dual-output isolated DC-DC power conversion arrangement 76 are connected in parallel to supply a low-voltage (LV) DC power to one or more LV loads 92. The LV DC power may have a nominal voltage of 12 or 14V for delivery to one or more auxiliary loads, such as electronic control units (ECUs). However, the second DC output busses 84 of the dual-output isolated DC-DC power converters 76 may be configured to supply one or more LV loads 92 at a different voltage, such as 24V, 36V, 42V or 48V.

[0041] The present disclosure provides a plurality of isolated DC-DC converters connected to battery modules in each phase. The isolated DC-DC converter provides two output connection points, as shown in FIG. 2. The LV supply, whether 12V or 48V (or any others), of each module converter is connected in parallel to share the load of the auxiliary components. This is shown in purple in the simplified system architecture in FIG. 2 that has just one module per phase for ease of illustration. The power level is the LV system power requirement divided by the total number of converters.Attorney Docket No. 18402-5389 (713865PCT)

[0042] The second DC-DC converter outputs 80 are placed in series to create a HV bus 82. The voltage of each converter is the HV voltage requirement divided by the number of converters in the system. Alternatively, the converters could also be placed in parallel by using a higher step-up gain, in which case all converters should output the HV bus voltage requirement. Similarly, the power rating of the series output is the HV system power requirement divided by the number of converters.

[0043] Example of HV loads 90 may include HVAC systems such as the AC compressor motor, or a secondary traction drive for powertrain propulsion, or any other EV components that need to draw power form a HV bus. The converters can be designed as unidirectional or bidirectional if battery recharging capability is required. In the case of a multi-motor or all-wheel drive architecture, the converter may be bidirectional to accommodate regenerative charging.

[0044] The various architectures described in the subsequent sections provide precise details on converter operation such as switching frequency, voltage input and output, as well as power requirements. However, these requirements will alter according to a configuration of the overall modular multi-level converter (MMC). Thus, the present disclosure is not limited to the defined operating characteristics.

[0045] FIG. 3 shows a schematic block and circuit diagram of a first dual-output DC-DC power converter architecture 100, based on an asymmetrical half-bridge flyback converter.

[0046] The first dual-output DC-DC power converter architecture 100 of FIG. 3 includes an Asymmetrical Half-Bridge (AHB) Flyback converter module 176 with a first microcontroller 120 configured to implement power stage and feedback and control circuitry. The AHB flyback converter module 176 may be used to implement one or more of the dual-output isolated DC-DC power converters 76 in the distributed DC-DC architecture 50 of FIG. 2.

[0047] The first dual-output DC-DC power converter architecture 100 consists of multiple AHB Flyback converter modules configured to provide dual voltage outputs: 360V HVAC (series output) and 14V auxiliary power (parallel output) from a nominal 48V (35V to 59V based on state of charge) battery pack. The system is designed to be scalable, allowing the number of AHB modules to be adjusted (e.g., 12 or 24 modules) to balance cost, efficiency, and current capacity.Attorney Docket No. 18402-5389 (713865PCT)The AHB module series outputs (Vo series) are connected in series to achieve 360V for HVAC system and the parallel outputs (Vo buck) are connected in parallel for 14V auxiliary load.10048] Each AHB module may operate at 100kHz and achieves soft-switching, reducing switching losses and improving efficiency. The three-winding transformer (Txl) provides isolation, with the primary winding connected to the AHB converter switches, the secondary winding delivering power to the 360V HVAC system, and the tertiary winding supplying power to the 14V auxiliary system.

[0049] The series output is directly regulated by sampling its voltage for feedback control. The parallel output is regulated using a buck converter, which ensures a stable 14V output.

[0050] Each module includes a capacitor-inductor-capacitor (CLC) output filter to minimize voltage and current ripple, consisting of ceramic capacitor (Col and Co3), which has lowESR, minimizes high frequency losses and filters high frequency noises, ferrite-core inductor (Lol and Lo2) that filters high frequency noise, and electrolytic capacitor (Co2 and Co4) that filters low frequency noise.

[0051] The DC-DC architecture includes a microcontroller to sample the series output voltage for regulation and provide drive signals to the AHB converter and the buck converter. Note that even though AHB flyback converter is used for this architecture, any type of DC-DC converter topology can be used.

[0052] The first dual-output DC-DC power converter architecture 100 shown in FIG. 3 may include:1) Asymmetrical Half-Bridge (AHB) Flyback Converter Modules - Convert 48V to 30V / 15V (12 modules / 24 modules) and 14V outputs with high efficiency. Each module achieves soft-switching at 100kHz. The number of modules determines system scalability.2) Resonant Tank - Consists of a resonant inductor (Lr) and capacitor (Cr), forming a resonant circuit. This helps to shape the switching waveforms and allows the AHB flyback converter achieve soft-switching and operate with high efficiency at high frequencies.Attorney Docket No. 18402-5389 (713865PCT)3) Three-Winding Transformer (Txl) - Provides isolation and voltage conversion for dual outputs. Its turns ratio is critical for achieving the desired output levels.4) MOSFET Switches (QI, Q2) - Located at the primary side of AHB. It receives the PWM signal from the microcontroller and controls power transfer by switching at high frequency.5) Rectifier Circuit (SRI, SR2) - Converts AC voltage from the transformer secondary winding and tertiary winding to DC for HVAC and auxiliary load. Synchronous rectifiers are used to achieve high efficiency. -The semiconductors can be automatically controlled using synchronous rectifier controller / driver. Alternatively, they can be actively controlled by an MCU which would enable bidirectional capability.6) Feedback and Control Circuitry (Microcontroller) - Microcontroller monitors voltage levels and adjusts switching signals to achieve tight output voltage regulation and maintains stable operation.7) Optocoupler -Transfers feedback control signals across the isolation barrier without direct electrical connection, ensuring safe operation of the microcontroller and preventing high- voltage transients from damaging control electronics.8) Buck Converter - Regulates the 14V auxiliary output according to the need of the Low Voltage system to support smooth operation and optimized charging of the Low Voltage battery.9) Output Filter - The filter includes a ceramic capacitor, ferrite inductor, and electrolytic capacitor. Its purpose is to smooth out voltage and current ripple and ensure stable DC outputs for HVAC and auxiliary loads.[00531 FIG. 4 shows a schematic block and circuit diagram of a second dual-output DC-DC power converter architecture 200, based on a full-bridge inductor-inductor-capacitor (LLC) resonant converter. The second dual-output DC-DC power converter architecture 200 includes one or more Full-Bridge LLC resonant converter modules 276 with the power stage and the feedback and control circuitry. The Full-Bridge LLC resonant converter modules 276 may be used to implement one or more of the dual-output isolated DC-DC power converters 76 in the distributed DC-DC architecture 50 of FIG. 2.Attorney Docket No. 18402-5389 (713865PCT)

[0054] The second dual-output DC -DC power converter architecture 200 may include multiple Full-Bridge LLC resonant converter modules configured to provide dual voltage outputs: 360V HVAC (series output) and 14V auxiliary power (parallel output) from a nominal 48V (35V to 59V based on state of charge) battery pack. The system is designed to be scalable, allowing the number of LLC modules to be adjusted (e.g., 12 or 24 modules) to balance cost, efficiency, and current capacity. The LLC module series outputs (Vo series) are connected in series to achieve 360V for HVAC system and the parallel outputs (Vo buck) are connected in parallel for 14V auxiliary load.

[0055] The operation frequency range for the LLC module may be between 160kHz to 290kHz depending on the battery pack voltage variation at the input. The converter achieves soft-switching, reducing switching losses and improving efficiency and will achieve the peak efficiency at 290kHz. The three-winding transformer (Txl) provides isolation, with the primary winding connected to the LLC converter switches, the secondary winding delivering power to the 360V HVAC system, and the tertiary winding supplying power to the 14V auxiliary system.[0056| The series output may be directly regulated by sampling its voltage for feedback control. The parallel output is regulated using a buck converter, which ensures a stable 14V output.

[0057] Each module includes a CLC output filter to minimize voltage and current ripple, consisting of ceramic capacitor (Col and Co3), which has low ESR, minimizes high frequency losses and filters high frequency noises, ferrite-core inductor (Lol and Lo2) that filters high frequency noise, and electrolytic capacitor (Co2 and Co4) that filters low frequency noise.

[0058] The second dual-output DC-DC power converter architecture 200 includes a second microcontroller 220 that is configured to sample the series output voltage for regulation and provide drive signals to the LLC converter and the buck converter. Note that even though LLC converter is used for this architecture, other types of DC-DC converter topology may be used.

[0059] The second dual-output DC-DC power converter architecture 200 shown in FIG. 4 may include:Attorney Docket No. 18402-5389 (713865PCT)) LLC Resonant Converter Modules (276) - Convert 48V to 30V / 15V (12 modules / 24 modules) and 14V outputs with high efficiency. Each module achieves soft-switching at 160kHz to 290kHz. The number of modules determines system scalability.) Resonant Tank - Consists of a resonant inductor (Lr) and capacitor (Cr), forming a resonant circuit. This helps to shape the switching waveforms and allows the LLC converter achieve soft-switching and operate with high efficiency at high frequencies.) Three-Winding Transformer (Txl) - Provides isolation and voltage conversion for dual outputs. Its turns ratio is critical for achieving the desired output levels.) MOSFET Switches (QI, Q2, Q3, Q4) - Located at the primary side of LLC converter. It receives the PWM signal from the microcontroller and controls power transfer by switching at high frequency.) Rectifier Circuit (SRI, SR2, SR3, SR4) - Converts AC voltage from the transformer secondary winding and tertiary winding to DC for HVAC and auxiliary load. Synchronous rectifiers may be used to achieve high-efficiency. The semiconductor switches can be automatically controlled using synchronous rectifier controller / driver. Alternatively, the semiconductor switches can be actively controlled by an MCU which may enable bidirectional capability.) Feedback and Control Circuitry (Microcontroller) 220 - Microcontroller monitors voltage levels and adjusts switching signals to achieve tight output voltage regulation and maintains stable operation.) Optocoupler -Transfers feedback control signals across the isolation barrier without direct electrical connection, ensuring safe operation of the microcontroller and preventing high- voltage transients from damaging control electronics.) Buck Converter - Regulates the 14VD auxiliary output according to the need of the Low Voltage system to support smooth operation and optimized charging of the Low Voltage battery.Attorney Docket No. 18402-5389 (713865PCT)9) Output Filter - The filter may include a ceramic capacitor, ferrite inductor, and electrolytic capacitor. Its purpose is to smooth out voltage and current ripple and ensure stable DC outputs for HVAC and auxiliary loads.

[0060] FIG. 5 shows a schematic block and circuit diagram of a third dual-output DC -DC power conversion arrangement 300, representing an adaptation of the full-bridge LLC resonant converter topology of FIG. 4 in which the arrangement is configured to serve a subset of the battery modules in a phase group rather than the full complement. In the illustrated embodiment, the third isolated DC-DC power arrangement 300 is configured to receive DC power from three battery modules rather than all modules, illustrating how the conversion arrangement is modular and scalable to the application requirements. As shown, the third dual-output DC-DC power conversion arrangement 300 is configured to supply power to the HV load 90 at a first output voltage Vol of 120VDC and to supply power to the LV load 92 at a second output voltageO2 of 14VDC. However, these are merely illustrative examples, and the third isolated DC-DC power arrangement 300 may be configured to generate different output voltages Vol, Vo2. The third dualoutput DC-DC power conversion arrangement 300 of FIG. 5 may be used to implement one or more of the dual-output isolated DC-DC power converters 76 in the distributed DC-DC architecture 50 of FIG. 2.

[0061] FIG. 6 shows a high-level block diagram of a system architecture 360 with three of the third dual-output DC-DC power conversion arrangements 300 of FIG. 5. As shown, the first output terminals Vol+, Vol- of the third dual-output DC-DC power conversion arrangements 300 are connected in series to define the high-voltage output bus 80, and the second output terminals Vo2+, Vo2- of the third dual-output DC-DC power conversion arrangements 300 are connected in parallel to define the low-voltage output bus 84. FIG. 7 shows a block diagram of a components in a power path 380 of the third dual-output DC-DC power conversion arrangement 300 of FIG.5.

[0062] The third dual-output DC-DC power conversion arrangement 300 includes a Fullbridge LLC converter with a three-winding transformer: the primary winding connected to a 48V nominal source (35-59V), the secondary winding outputs a high-voltage 120V supply, and the tertiary winding supplies 14V for low-voltage devices regulated by an included buck converter.Attorney Docket No. 18402-5389 (713865PCT)[0063 J The third dual-output DC-DC power conversion arrangement 300 provides a modular and isolated design, enabling scalability by adjusting the number of modules to modify both series voltage output and parallel current output. The output power for the series and parallel output is scalable and depending on various integration variables like cooling design, battery power capability, and / or power ratings of components. Each module includes a CLC output filter to minimize output voltage and current ripple. Each module may include a microcontroller that generates gating signals for the full-bridge inverter and synchronous rectifiers, while also sampling output voltage for closed-loop control.

[0064] The third dual-output DC-DC power converter architecture 300 may be adaptable to various power conversion architectures including AHB (active half bridge), dual -bridge phase-shifted (DAB), and both half-bridge and full-bridge resonant topologies. The third dual-output DC-DC power conversion arrangement 300 may be adaptable to varying input voltage, output voltage, load and power requirements.[0065J The third dual-output DC-DC power conversion arrangement 300 shown in FIG. 5 may include:1) LLC Full-Bridge Inverter Switch Network- Features 4 switching elements namely QI, Q2, Q3 and Q4 located at the primary-side of the transformer. The first pair QI and Q4 are connected in series, while the second pair Q2 and Q3 are also connected in series. The common node of QI and Q4 is coupled to one input of the resonant tank, while the common node of Q2 and Q3 is coupled to the second input of the resonant tank.- Adaptable to other switch network configurations including half-bridge and push-pull. - Adaptable to various different switch types including: metal-oxide-semiconductor fieldeffect transistor (MOSFET) devices, insulated-gate bipolar transistor (IGBT) devices, gate turn-off thyristor (GTO) devices and bipolar junction transistor (BJT) devices.2) Resonant TankAttorney Docket No. 18402-5389 (713865PCT)- Features a series resonant inductor (Lr), series resonant capacitor (Cr) and parallel inductor (Lm), which may be added externally or integrated into transformer design. - Implemented between the switch network and the primary side of the transformer.- Designed to filter the switching network waveforms to achieve soft switching.) Three-Winding Transformer- Provides isolation and voltage conversion between primary, secondary and tertiary windings. The secondary and tertiary windings can be center-tapped or non-center-tapped. ) Rectifier Switch Networks- Features two switching elements per winding for center-tapped transformers and four switching elements for non-center-tapped transformers.- Converts AC transformer output to DC output fed to the output filter.- Adaptable to diodes for high voltages, and various different types of active switches including: MOSFETs, IGBTs, GTOs and BJTs for high efficiency at low voltage outputs. -Diodes can be replaced with MOSFETs or other semiconductors to enable bidirectional capability of the boost converters) Output Filter- Attenuates the switching ripple of the rectifier output to supply the load.- Adaptable to various filter networks, including LC, pi-type and multi-stage filter designs. ) Buck Converter- Regulates the tertiary transformer winding to provide a 14V output according to the needs of the Low Voltage System.) Feedback and Control Circuitry- Detects output voltages Vol and Vo2 and adjusts switching signals to maintain output voltage regulation and stable operation.Attorney Docket No. 18402-5389 (713865PCT)

[0066] FIG. 8 shows a schematic block and circuit diagram of a fourth dual-output DC-DC power conversion arrangement 400, representing an adaptation of the full-bridge LLC resonant converter topology of FIG. 4 in which the high-voltage DC outputs Vol+, Vol- are connected in parallel rather than series. FIG. 9 shows a high-level block diagram of a system architecture 450 with several of the fourth dual-output DC-DC power conversion arrangements 400 of FIG. 8.[0067| The fourth dual-output DC-DC power conversion arrangement 400 may include multiple Full-Bridge LLC resonant converter modules configured to provide dual voltage outputs: 360V HVAC (parallel output) and 14V auxiliary power (parallel output) from a nominal 48V (35 V to 59V based on state of charge) battery pack. The system is designed to be scalable, allowing the number of LLC modules to be adjusted (e.g., 12 or 24 modules) to balance cost, efficiency, and current capacity. Both the high-voltage outputs (Vol) and low-voltage outputs (Vo2) are connected in parallel to divide the power by the number of modules.

[0068] The fourth dual-output DC-DC power conversion arrangement 400 includes a Fullbridge LLC converter with a three-winding transformer: the primary winding connected to a 48V nominal source (35-59V), the secondary winding outputs a high-voltage 360V supply, and the tertiary winding supplies 14V for low-voltage devices regulated by an included buck converter.

[0069] The fourth dual-output DC-DC power conversion arrangement 400 provides a modular and isolated design, enabling scalability by adjusting the number of modules to modify the power carried by each module. Each module includes a CLC output filter to minimize output voltage and current ripple. Each module may include a microcontroller that generates gating signals for the full-bridge inverter and synchronous rectifiers, while also sampling output voltage for closed-loop control.|0070] The fourth dual-output DC-DC power conversion arrangement 400 may be adaptable to various power conversion architectures including AHB (active half bridge), dualbridge phase-shifted (DAB), and both half-bridge and full-bridge resonant topologies. The third dual-output DC-DC power converter architecture may be adaptable to varying input voltage, output voltage, load and power requirements.Attorney Docket No. 18402-5389 (713865PCT)

[0071] The fourth dual -output DC-DC power conversion arrangement 400 shown in FIG.5 may include:1) LLC Full-Bridge Inverter Switch Network- Features 4 switching elements namely QI, Q2, Q3 and Q4 located at the primary-side of the transformer. The first pair QI and Q4 are connected in series, while the second pair Q2 and Q3 are also connected in series. The common node of QI and Q4 is coupled to one input of the resonant tank, while the common node of Q2 and Q3 is coupled to the second input of the resonant tank.- Adaptable to other switch network configurations including half-bridge and push-pull. - Adaptable to various different switch types including: MOSFETs, IGBTs, GTOs and BJTs.2) Resonant Tank- Features a series resonant inductor (Lr), series resonant capacitor (Cr) and parallel inductor (Lm), which may be added externally or integrated into transformer design. - Implemented between the switch network and the primary side of the transformer.- Designed to filter the switching network waveforms to achieve soft switching.3) Three-Winding Transformer- Provides isolation and voltage conversion between primary, secondary and tertiary windings. The secondary and tertiary windings can be center-tapped or non-center-tapped.4) Rectifier Switch Networks- Features two switching elements per winding for center-tapped transformers and four switching elements for non-center-tapped transformers.- Converts AC transformer output to DC output fed to the output filter.- Adaptable to diodes for high voltages, and various different types of active switches including: MOSFETs, IGBTs, GTOs and BJTs for high efficiency at low voltage outputs.Attorney Docket No. 18402-5389 (713865PCT)-Diodes can be replaced with MOSFETs or other semiconductors to enable bidirectional capability of the boost converters5) Output Filter- Attenuates the switching ripple of the rectifier output to supply the load.- Adaptable to various filter networks, including LC, pi-type and multi-stage filter designs.6) Buck Converter- Regulates the tertiary transformer winding to provide a 14V output according to the needs of the Low Voltage System.7) Feedback and Control Circuitry- Detects output voltages Vol and Vo2 and adjusts switching signals to maintain output voltage regulation and stable operation.

[0072] FIG. 10 shows a high-level block diagram of a fifth dual-output DC-DC power conversion arrangement 500 based on a multi-converter power supply system. In this embodiment, separate isolated DC-DC converters 520, 530 are dedicated to generating the high-voltage output bus 80 and to the low-voltage output bus 84, respectively, rather than using a single multi-output converter. Specifically, the fifth dual-output DC-DC power conversion arrangement 500 includes several step-up converters 520 with respective outputs all connected in parallel to define the high-voltage output bus 80. The fifth dual-output DC-DC power conversion arrangement 500 also includes a step-down converter 530 that defines the low-voltage output bus 84. This adaptation demonstrates the scalability and modularity of the proposed DC-DC power architecture, wherein the number and type of converters assigned to each output bus may be independently selected based on the system requirements. For example, the ratio of step-up converters to step-down converters need not be uniform - one step-up converter may be provided per battery module while a single step-down converter serves every three battery modules, accommodating systems with high HV power demands and moderate LV power demands. Other converter ratios and assignments are contemplated depending on the power levels, efficiency targets, cost constraints, and redundancy requirements of the specific application.Attorney Docket No. 18402-5389 (713865PCT)

[0073] Both the step-up converter 520 and step-down converter 530 in fifth dual-output DC-DC power conversion arrangement 500 may be adaptable to various power conversion topologies including AHB (active half bridge), dual-bridge phase-shifted (DAB), phase-shifted full-bridge (PSFB), and both half-bridge and full-bridge resonant topologies. All converters in the fifth dual-output DC-DC power conversion arrangement may be adaptable to varying input voltage, output voltage, load and power requirements.

[0074] FIG. 11 shows a schematic block and circuit diagram of a high-power 2-phase interleaved LLC resonant converter 600 that may be used as the step-up converter 520 in the fifth dual-output DC-DC power conversion arrangement 500 described above. In the illustrated embodiment, 2-phases are used to reduce the power per phase by half and are interleaved to enable ripple cancellation and reduce the size of the input and output filters.

[0075] FIG. 12 shows a block diagram of a method 700 for state-of-charge balancing for multi-level inverter system at a standstill scenario. FIG. 13 shows an electrical schematic diagram of a multilevel inverter system 800 during a standstill SoC balancing scenario. The multilevel inverter system 800 shown on FIG. 13 includes three phase groups 822a, 822b, 822c, each configured to generate a corresponding AC output phase current for driving a 3 -phase AC motor 826. The 3-phase AC motor 826 may be used as the traction motor 26 for propelling the vehicle 12. As shown, the 3-phase AC motor 826 has a wye configuration of windings with a center node connected to a conductor conducting a balance current I balance therefrom. Each of the three phase groups 822a, 822b, 822c in the multilevel inverter system 800 includes four modules 830 with a battery and an H-bridge power converter to supply a set of output terminals. The output terminals of the four modules 830 in each of the three phase groups 822a, 822b, 822c are connected in series between a corresponding neutral terminal and a corresponding winding of the 3-phase AC motor 826 for the corresponding phase current thereto. The neutral terminals of each of the three phase groups 822a, 822b, 822c are connected together and to the center node of the 3-phase AC motor 826. This configuration is an example and any or all of the three phase groups 822a, 822b, 822c may have a different number of the modules 830. The multilevel inverter system 800 shown on FIG. 13 also includes three DC-DC converters 850. Each of the three DC-DC convertersAttorney Docket No. 18402-5389 (713865PCT)850 is connected across a battery in one of the modules 830 in a corresponding one of the three phase groups 822a, 822b, 822c for receiving power therefrom.10076] FIG. 14 shows an electrical schematic diagram of a second multilevel inverter system 900. The second multilevel inverter system 900 may be similar or identical to the multilevel inverter system 800 shown on FIG. 13. The second multilevel inverter system 900 includes three phase groups 922a, 922b, 922c each configured to generate a corresponding AC output phase current for driving a 3-phase AC motor 926. The 3-phase AC motor 926 may be used as the traction motor 26 for propelling the vehicle 12. The three phase groups 922a, 922b, 922c in the second multilevel inverter system 900 may be similar or identical to the three phase groups 822a, 822b, 822c in the multilevel inverter system 800 shown on FIG. 13, except with eight of the modules 830 in series.

[0077] The second multilevel inverter system 900 also includes three dual output DC-DC converter arrangements 950, each connected across a battery in a module of a corresponding one of the three phase groups 922a, 922b, 922c. Each of the three dual output DC-DC converter arrangements 950 includes a high-voltage DC-DC converter 952 and a low-voltage DC-DC converter 954. The high-voltage DC-DC converter 952 may convert a 48VDC input power to 400VDC output power, and the low-voltage DC-DC converter 954 may convert the 48VDC input power to 14VDC output power. Each of the high-voltage DC-DC converters 952 are connected in parallel to define a HV output bus 956 for supplying power to one or more HV loads 90, such as an HVAC blower and / or compressor. A secondary electric drive (eDrive) 94 is also connected to the HV output bus 956 for driving a secondary traction motor in the vehicle. The dual output DC-DC converter arrangements 950 may include, for example, the fourth dual-output DC-DC power conversion arrangement 400 shown on FIG. 8.

[0078] Problem Statement: In multilevel inverter systems, DC-DC converters may be employed to supply power to auxiliary loads. A conventional approach involves connecting a DC-DC converter to each battery module, which can be prohibitively expensive. To reduce costs, an alternative method involves connecting the DC-DC converter to a single module (i.e. only one module) in each phase. While this approach decreases the number of converters required, it introduces a risk of State of Charge (SoC) imbalances, particularly during standstill conditionsAttorney Docket No. 18402-5389 (713865PCT)when other battery modules are not actively operated. During these standstill conditions, conventional SoC balancing algorithms become ineffective. These traditional methods typically rely on active operation and dynamic load conditions to redistribute charge among battery modules. However, when the system is in a standstill state, the lack of movement and operational activity prevents these algorithms from functioning. This raises a critical challenge: how to charge the last module from other modules during standstill conditions without causing torque in the electric machine.

[0079] It is an objective of the present disclosure to provide a method to charge selected modules from other modules at standstill condition. It is a further objective of the present disclosure to ensure that the proposed method does not result in any torque being generated by the electric machine.

[0080] The provided method of controlling battery modules, combined with the utilization of motor windings as a filter choke, provides a robust solution for SoC balancing in multilevel inverter system at a standstill condition. At the standstill condition, the battery modules connected with extra DC-DC converters may suffer from low SOC compared to others. Therefore, the balancing algorithm described here focuses on charging the last module with a DC-DC converter connection. However, the proposed method can be applied to charging any battery modules with lower SoC at the standstill condition, in a multi-level inverter system.

[0081] The method of controlling the battery modules may include:1. Control of the Charging Process:- Battery Modules Connected to the DC-DC Converter:o For the battery modules connected to the DC-DC converter, switches S2 and S4 are closed and si and S3 are opened to ensure that the neutral current flows into the positive terminal of the battery module, facilitating the charging process.Battery Modules Not Connected to the DC-DC Converter:o For the battery modules not connected to the DC-DC converter, the full bridge connected to these battery modules may be configured to operate as full-bridgeAttorney Docket No. 18402-5389 (713865PCT)DC-DC converters. This configuration allows these modules to participate actively in the charging process.Control Target and Reference Balancing Current:o The control target is defined as the difference between the average State of Charge (SoC) of all battery modules and the average SoC of the modules connected to the DC-DC converter.o A digital controller processes this SoC difference to generate a reference balancing current.o This reference balancing current is then controlled with a digital controller by comparing the machine neutral current flowing into the battery module connected to the DC-DC converter.2. Utilization of Motor Windings:- By accessing the neutral point of the electric motor, the motor windings are utilized as a filter choke. This setup ensures that the current flowing through the motor windings is effectively filtered and regulated during the charging process.3. Current Flow and Rotor Stability:The design ensures that the same amount of current flows through all three-phase windings of the motor in the same direction. This condition does not produce a rotating magnetic field. As a result, the rotor of the motor remains stationary, and the motor will not generate torque during the charging process.

[0082] The proposed method effectively charges the selected battery module while maintaining rotor stability, addressing the limitations of conventional SoC balancing algorithms during standstill conditions. This approach not only enhances the efficiency and longevity of the battery modules but also contributes to the overall cost-effectiveness of the multilevel inverter system.

[0083] Voltage Control for Multi Motor Configuration: The architectures described in the present disclosure create a HV bus that can be used for a secondary eDrive or other HV loads as shown in the figure below. This HV bus is created using controlled DCDC converters and thus, the voltage level of the HV bus can be regulated.Attorney Docket No. 18402-5389 (713865PCT)

[0084] Controlling the DC input voltage to a traction inverter and motor helps in optimizing the performance and efficiency of the electric drive system. Maintaining an optimal voltage level can reduce thermal stress on the motor and inverter components. By dynamically adjusting the DC-link voltage to match the motor's operating conditions, the inverter can operate at voltage levels that minimize the energy lost during switching events. Switching losses occur during the transition of semiconductor devices (such as IGBTs or MOSFETs) from the on-state to the off-state and vice versa. The energy lost in each switching event is proportional to the voltage across the device and the current flowing through it at the time of switching. By optimizing the DC-link voltage, the inverter can reduce the voltage stress on the switching devices, thereby lowering the switching losses. Additionally, the inverter can produce a more optimal and cleaner output waveform. By optimizing the DC-link voltage, the inverter can reduce the harmonics, leading to a cleaner waveform and lower harmonic losses in the electric motor. Furthermore, increased efficiency from voltage control can help in maximizing the regenerative braking efficiency, allowing more energy to be recaptured and stored in the battery, thus extending the vehicle's range. Overall, a controllable DC input voltage enables superior performance, efficiency, and reliability of the traction system.|0085[ The present disclosure proposes an optimal voltage regulation strategy to maximize the efficiency of the secondary eDrive. The optimal voltage regulation strategy includes:1) For each torque-speed load point, determine an optimal DC input voltage to maximize eDrive efficiency. Tabulate an optimal predefined DC voltage request for each load point.2) While driving, the optimal HV bus voltage is calculated, and request is sent to the DCDC converters.3) The DCDC converters regulate the DC bus voltage to the commanded HV bus commanded voltage.

[0086] The system, methods and / or processes described above, and steps thereof, may be realized in hardware, software or any combination of hardware and software suitable for a particular application. The hardware may include a general-purpose computer and / or dedicated computing device or specific computing device or particular aspect or component of a specific computing device. The processes may be realized in one or more microprocessors,Attorney Docket No. 18402-5389 (713865PCT)microcontrollers, embedded microcontrollers, programmable digital signal processors or other programmable devices, along with internal and / or external memory. The processes may also, or alternatively, be embodied in an application specific integrated circuit, a programmable gate array, programmable array logic, or any other device or combination of devices that may be configured to process electronic signals. It will further be appreciated that one or more of the processes may be realized as a computer executable code capable of being executed on a machine readable medium.

[0087] The computer executable code may be created using a structured programming language such as C, an object oriented programming language such as C++, or any other high-level or low-level programming language (including assembly languages, hardware description languages, and database programming languages and technologies) that may be stored, compiled or interpreted to run on one of the above devices as well as heterogeneous combinations of processors, processor architectures, combinations of different hardware and software, or any other machine capable of executing program instructions.[0088| Thus, in one aspect, each method described above and combinations thereof may be embodied in computer executable code that, when executing on one or more computing devices performs the steps thereof. In another aspect, the methods may be embodied in systems that perform the steps thereof, and may be distributed across devices in a number of ways, or all of the functionalities may be integrated into a dedicated, standalone device or other hardware. In another aspect, the means for performing the steps associated with the processes described above may include any of the hardware and / or software described above. All such permutations and combinations are intended to fall within the scope of the present disclosure.

[0089] The foregoing description is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.

Claims

Attorney Docket No. 18402-5389 (713865PCT)CLAIMSWhat is claimed is:

1. An integrated motor drive (IMD) system, comprising:a modular multi-level inverter including a plurality of integrated power modules, wherein each of the integrated power modules includes: one or more battery cells connected to an internal DC bus, and a power electronics assembly physically and electrically coupled to the one or more battery cells and configured to generate AC power on a set of load terminals using direct current (DC) power from the one or more battery cells;wherein the plurality of integrated power modules are split between a plurality of phase groups, with each of the phase groups including a corresponding subset of the plurality of integrated power modules with their respective load terminals connected in series between a lower node and an AC output conductor, with the AC output conductors of the plurality of phase groups together arranged to supply the AC power to a motor; andwherein each of the phase groups includes an isolated DC-DC power converter arrangement having DC input terminals connected to the internal DC bus of one or more of the integrated power modules in the corresponding subset of the plurality of integrated power modules for receiving power therefrom, wherein the isolated DC-DC power converter arrangement comprises one or more isolated DC-DC converters configured to provide isolated DC power to each of a first DC output bus and a second DC output bus using DC power from the DC input terminals and at a different voltage than is present on the DC input terminals.Attorney Docket No. 18402-5389 (713865PCT)2. The IMD system of Claim 1, wherein each of the integrated power modules further includes a battery management system (BMS) connected between the internal DC bus and the one or more battery cells and configured to regulate power transferred therebetween.

3. The IMD system of Claim 1, wherein the isolated DC-DC power converter arrangement in each of the phase groups is configured as a dual-output DC-DC converter.

4. The IMD system of Claim 3, wherein the dual-output DC-DC converter includes a full-bridge inverter switch network coupled to the DC input terminals, and a transformer having a primary winding, a secondary winding, and a tertiary winding,wherein the primary winding is connected to the full-bridge inverter switch network, the secondary winding is arranged to supply power to the first DC output bus, and the tertiary winding is arranged to supply power to the second DC output bus.

5. The IMD system of Claim 4, wherein the dual-output DC-DC converter further includes an inductor-inductor-capacitor (LLC) resonant tank connected between the full-bridge inverter switch network and the primary winding of the transformer.

6. The IMD system of Claim 1, wherein the first DC output buses of the isolated DC-DC power converter arrangements in each of the phase groups are connected in series or parallel to supply a high-voltage (HV) DC power to one or more HV loads.Attorney Docket No. 18402-5389 (713865PCT)7. The IMD system of Claim 1, wherein the second DC output buses of the isolated DC-DC power converter arrangements in each of the phase groups are connected in parallel to supply a low-voltage (LV) DC power to one or more LV loads.

8. The IMD system of Claim 1, wherein at least one of the isolated DC-DC power converter arrangements includes an Asymmetrical Half-Bridge (AHB) Flyback converter module.

9. The IMD system of Claim 1, wherein at least one of isolated DC-DC power converter arrangements includes one or more Full-Bridge LLC resonant converter modules.

10. The IMD system of Claim 1, wherein at least one of the isolated DC-DC power converter arrangements includes:a full-bridge LLC converter with a three-winding or five-winding center-tapped transformer having a primary winding and a plurality of secondary windings, wherein the plurality of secondary windings are each configured to supply a corresponding one of the first DC output bus and the second DC output bus via a capacitor-inductor-capacitor (CLC) output filter.

11. The IMD system of Claim 10, wherein the at least one of the isolated DC-DC power converter arrangements further includes a buck converter to reduce a DC voltage of power supplied on the second DC output bus.

12. An integrated motor drive (IMD) system, comprising:Attorney Docket No. 18402-5389 (713865PCT)a modular multi-level inverter including a plurality of integrated power modules, wherein each of the integrated power modules includes one or more battery cells and a power electronics assembly physically and electrically coupled to the one or more battery cells and configured to generate AC power on a set of load terminals using direct current (DC) power from the one or more battery cells connected to an internal DC bus,wherein the plurality of integrated power modules are split between a plurality of phase groups, with each of the phase groups including a corresponding subset of the plurality of integrated power modules, with their respective load terminals connected in series between a lower node and an AC output conductor, with the AC output conductors of the plurality of phase groups together arranged to supply the AC power to a motor having windings arranged in a wye configuration and defining a center node,wherein the corresponding subset of the plurality of integrated power modules in each of the phase groups includes two or more of the integrated power modules, andwherein each of the phase groups includes a DC-DC power converter having DC input terminals, and wherein the DC input terminals of the DC-DC power converter are connected to the internal DC bus of a single integrated power module in the corresponding subset of the plurality of integrated power modules, and for receiving power therefrom; anda controller configured to:determine a balance current on a conductor connected to the center node of the motor;determine a state of charge (SoC) of the one or more battery cells in the single integrated power module that is connected to the DC-DC power converter; andAttorney Docket No. 18402-5389 (713865PCT)control operation of the power electronics assembly of the single integrated power module that is connected to the DC-DC power converter to adjust the SoC of the one or more battery cells in the single integrated power module that is connected to the DC-DC power converter and while the motor is at a standstill condition.

13. The IMD system of Claim 12, wherein the controller is further configured to : determine an average SoC of the one or more battery cells in all of the integrated power modules in a phase group;determine a difference between the average SoC of the one or more battery cells in all of the integrated power modules in a phase group and the state of charge (SoC) of the one or more battery cells in the single integrated power module that is connected to the DC-DC power converter;determine a balance current reference based on the difference between the average SoC of the one or more battery cells in all of the integrated power modules in a phase group and the state of charge (SoC) of the one or more battery cells in the single integrated power module that is connected to the DC-DC power converter; anddetermine a difference between the balance current reference and the balance current on a conductor connected to the center node of the motor; andwherein controlling operation of the power electronics assembly of the single integrated power module that is connected to the DC-DC power converter includes controlling the operation of the power electronics assembly based on the difference between the balance current reference and the balance current on a conductor connected to the center node of the motor.Attorney Docket No. 18402-5389 (713865PCT)14. A method of operating an integrated motor drive (IMD) system having a modular multi-level inverter (MMI) including a plurality of integrated power modules, wherein each of the integrated power modules includes one or more battery cells and a power electronics assembly physically and electrically coupled to the one or more battery cells and configured to generate AC power on a set of load terminals using direct current (DC) power from the one or more battery cells connected to an internal DC bus,wherein the plurality of integrated power modules are split between a plurality of phase groups, with each of the phase groups including a corresponding subset of the plurality of integrated power modules, with each of the phase groups configured to supply AC current to a corresponding winding of a motor having at least three of the windings arranged in a wye configuration and defining a center node,wherein the corresponding subset of the plurality of integrated power modules in each of the phase groups includes two or more of the integrated power modules, andwherein each of the phase groups includes a DC-DC power converter having DC input terminals, and wherein the DC input terminals of the DC-DC power converter are connected to the internal DC bus of a single integrated power module in the corresponding subset of the plurality of integrated power modules, and for receiving power therefrom, the method comprising:determining a balance current on a conductor connected to the center node of the motor; determining a state of charge (SoC) of the one or more battery cells in the single integrated power module that is connected to the DC-DC power converter; andAttorney Docket No. 18402-5389 (713865PCT)commanding a plurality of switches in the single integrated power module that is connected to the DC-DC power converter to selectively conduct current to adjust the SoC of the one or more battery cells in the single integrated power module that is connected to the DC-DC power converter and while the motor is at a standstill condition.

15. The method of Claim 14, further comprising:determining an average SoC of the one or more battery cells in all of the integrated power modules in a phase group;determining a difference between the average SoC of the one or more battery cells in all of the integrated power modules in a phase group and the state of charge (SoC) of the one or more battery cells in the single integrated power module that is connected to the DC-DC power converter;determining a balance current reference based on the difference between the average SoC of the one or more battery cells in all of the integrated power modules in a phase group and the state of charge (SoC) of the one or more battery cells in the single integrated power module that is connected to the DC-DC power converter; anddetermining a difference between the balance current reference and the balance current on a conductor connected to the center node of the motor,wherein commanding the plurality of switches in the single integrated power module that is connected to the DC-DC power converter includes commanding the plurality of switches to selectively conduct current further based on the difference between the balance current reference and the balance current on a conductor connected to the center node of the motor.

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