System and method for operating a hybrid electric power system in a vehicle

Abstract

One embodiment of the present disclosure is a hybrid electric power system. The hybrid electric power system includes: one or more fuel cells configured to generate a DC power output; one or more batteries configured to generate a DC power output; one or more inverters coupled to the one or more fuel cells and the one or more storage batteries, the one or more inverters configured to convert DC power outputs of the one or more fuel cells and the one or more storage batteries to produce one or more AC power outputs; and an AC power bus coupled to the one or more inverters, the AC power bus configured to combine the AC power outputs and provide the combined AC power outputs to the motor.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. Patent Application No. 63 / 400,633, filed on August 24, 2022, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present disclosure relates to power systems for vehicles. More specifically, according to some embodiments, the present disclosure relates to systems and methods for providing required voltage and power to AC traction motors when implementing a hybrid architecture including batteries and fuel cells.

[0004] background

[0005] Some conventional vehicle powertrains are powered by gaseous fuels, such as diesel fuel. Recently, manufacturers have increasingly looked to electric technology as a way to power vehicles to replace or supplement gaseous fuels, such as diesel (e.g., using all-electric or hybrid electric powertrains). While electrically powered vehicles have many benefits, including potential economic and environmental benefits, electrically powered vehicles are not without challenges. More specifically, electric vehicles may utilize specialized equipment that may increase the cost and / or complexity of the vehicle.

[0006] Manufacturers are increasingly incorporating electric powertrains into their vehicles (e.g., all-electric or hybrid electric). While electric powertrains include many benefits, some of the equipment required for electric powertrains can be expensive and / or difficult to find. More specifically, hybrid electric powertrains that utilize batteries and fuel cells as fuel sources can require expensive and difficult to find high-voltage direct current (DC) / DC converters. The systems and methods disclosed herein illustrate hybrid electric powertrain circuit architectures that may not require such high-voltage DC / DC converters within a hybrid electric powertrain.

[0007] Overview

[0008] One embodiment of the present disclosure is a hybrid electric power system. The power system includes: one or more fuel cells configured to generate a first DC power output; one or more storage batteries configured to generate a second DC power output; one or more inverters coupled to the one or more fuel cells and the one or more storage batteries, the one or more inverters configured to convert the first DC power output and the second DC power output to generate one or more AC power outputs; and an AC power bus coupled to the one or more inverters, the AC power bus configured to receive the one or more AC power outputs and provide the AC power output to the motor.

[0009] In some embodiments, each of the one or more inverters includes one or more isolation transformers configured to step up the AC voltage generated by the one or more inverters. In some embodiments, the hybrid electric powertrain system also includes a motor control unit. The motor control unit includes one or more processing circuits, the one or more processing circuits including one or more memory devices coupled to one or more processors, the one or more memory devices configured to store instructions thereon, which instructions, when executed by the one or more processors, cause the one or more processors to: receive voltage measurements from one or more inverters, determine one or more control inputs for the motor using a motor control algorithm, the one or more control inputs being determined based on the voltage measurements and one or more operating conditions of the vehicle, and control the operation of the motor to achieve the one or more control inputs. In some embodiments, the one or more control inputs include at least one of a frequency of the motor, a voltage of the motor, a frequency of the AC power bus, or a voltage of the AC power bus. In some embodiments, the one or more processors are configured to determine at least one of the frequency of the motor, the voltage of the motor, the frequency of the AC power bus, or the voltage of the AC power bus using a motor control algorithm and based on the voltage measurement results and one or more operating conditions of the vehicle, and control the operation of the motor to achieve the determined at least one of the frequency of the motor, the voltage of the motor, the frequency of the AC power bus, or the voltage of the AC power bus. In some embodiments, the motor control unit is integrated into a controller for one or more inverters.

[0010] In some embodiments, the one or more operating conditions of the vehicle include at least one of the speed of the vehicle, the terrain the vehicle is traversing, and the operating mode of the vehicle. In some embodiments, the motor control algorithm includes at least one of vector control, direct torque control, pulse width modulation control, and space vector pulse width modulation control. In some embodiments, the hybrid electric powertrain is implemented without using a DC / DC converter.

[0011] Another embodiment of the present disclosure is a hybrid electric power system. The power system of the vehicle includes: a fuel cell configured to generate a first DC voltage; a battery configured to generate a second DC voltage; an inverter coupled to the fuel cell and the battery, the inverter configured to convert the first DC voltage and the second DC voltage into an AC voltage; an AC power bus coupled to one or more inverters and configured to provide the AC voltage to a motor; a transformer coupled to the AC power bus and configured to convert the voltage output of the AC power bus; and a cycloconverter coupled to the transformer, the cycloconverter configured to convert the frequency of the voltage output of the AC power bus.

[0012] In some embodiments, the transformer is configured to generate a fixed AC voltage of a constant frequency, and the cycloconverter converts the fixed AC voltage of a constant frequency and outputs a variable AC voltage of a variable frequency. In some embodiments, the motor control unit is integrated into a controller for the inverter. In some embodiments, the controller for the inverter is communicatively coupled to the vehicle control unit and is configured to: determine the desired speed of the motor, and achieve the desired speed of the motor via frequency changes to update the speed and torque of the motor. In some embodiments, one or more inverters are coupled in parallel to the AC power bus. In some embodiments, the motor control unit is communicatively coupled to the cycloconverter and is configured to drive one or more control outputs of the cycloconverter to adjust the speed and torque of the motor.

[0013] In some embodiments, the cycloconverter includes one or more processing circuits, the one or more processing circuits including one or more memory devices coupled to one or more processors, the one or more memory devices being configured to store instructions thereon that, when executed by the one or more processors, cause the one or more processors to: receive voltage measurements from an inverter, determine one or more control inputs for a motor using a motor control algorithm, the one or more control inputs being determined based on the voltage measurements and one or more operating conditions of a vehicle, and control operation of the motor to implement the one or more control inputs.

[0014] In some embodiments, the motor is a variable speed traction motor that receives a voltage output of an AC power bus, including a frequency of the voltage output converted by a cycloconverter. In some embodiments, the transformer is configured to step up the voltage output of the AC power bus from a lower voltage to a higher voltage, wherein the lower voltage is between 270 volts AC and 800 volts AC, and the higher voltage is at least 1300 volts AC. In some embodiments, the battery generates an output between 270 volts DC and 600 volts DC, wherein the fuel cell generates an output voltage between 600 volts DC and 800 volts DC.

[0015] Another embodiment of the present disclosure is a method for operating a hybrid electric powertrain in a vehicle. The method includes generating a first DC power output from one or more fuel cells, generating a second DC power output from one or more batteries, converting the first DC power output and the second DC power output to generate one or more AC power outputs, and combining the one or more AC power outputs to provide a combined AC power output to a motor. In some embodiments, the method also includes receiving voltage measurements from one or more inverters, using a motor control algorithm and determining one or more control inputs for the motor based on the voltage measurements and one or more operating conditions of the vehicle, and controlling the operation of the motor to achieve the one or more control inputs.

[0016] In some embodiments, the one or more control inputs include at least one of a frequency of the motor, a voltage of the motor, a frequency of the AC power bus, or a voltage of the AC power bus. In such embodiments, the method further includes determining at least one of the frequency of the motor, the voltage of the motor, the frequency of the AC power bus, or the voltage of the AC power bus using a motor control algorithm and based on the voltage measurement results and one or more operating conditions of the vehicle, and controlling the operation of the motor to achieve the determined at least one of the frequency of the motor, the voltage of the motor, the frequency of the AC power bus, or the voltage of the AC power bus.

[0017] This summary is illustrative only and is not intended to be limiting in any way.Other aspects, inventive features, and advantages of the devices or processes described herein will become apparent in the detailed description set forth herein in conjunction with the accompanying drawings, wherein like reference numerals refer to like elements. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a schematic diagram of a vehicle having a hybrid electric powertrain.

[0020] Figure 2 According to the illustrative embodiment Figure 1 Schematic diagram of a hybrid electric powertrain of a vehicle.

[0021] Figure 3 According to the illustrative embodiment Figure 1 Schematic diagram of another hybrid-electric powertrain for a vehicle.

[0022] Figure 4 According to the illustrative embodiment Figure 1 Schematic diagram of another hybrid-electric powertrain for a vehicle.

[0023] Detailed Description

[0024] The following is a more detailed description of various concepts and implementations of systems and methods related to hybrid electric powertrain systems without the use of expensive and hard-to-find equipment. Before turning to the accompanying drawings that show certain exemplary embodiments in detail, it should be understood that the present disclosure is not limited to the details or methods set forth in the specification or shown in the accompanying drawings. It should also be understood that the terminology used herein is for descriptive purposes only and should not be regarded as limiting.

[0025] According to various example embodiments, the systems and methods disclosed herein describe a hybrid electric powertrain that utilizes a combination of one or more batteries and one or more fuel cells to power a vehicle (eg, a motorcycle, an automobile, etc.).

[0026] Reference now Figure 1 , shows a vehicle having a hybrid electric powertrain 100 according to an example embodiment. The vehicle 100 includes a hybrid fuel system 102, a variable speed motor 104, a transmission 106, and a differential drive system. The hybrid fuel system 102 is operably coupled to the variable speed motor 104 and provides power to the vehicle 100 to propel the vehicle 100. The hybrid fuel system may include a battery and / or a fuel cell configured to provide power to the vehicle 100. Figure 2 , Figure 3 and Figure 4 Explain the hybrid fuel system in more detail. The variable speed motor 104 receives power from the hybrid fuel system 102, which provides input energy to output usable work or energy to propel the vehicle 100 in some cases. As a result of the power output from the variable speed motor 104, the transmission 106 can manipulate the speed of the rotating input shaft (e.g., crankshaft) to affect the desired drive shaft 108 speed. The rotating drive shaft 108 is received by the differential 110, which provides the rotational energy of the drive shaft 108 to the final drive 112. The final drive 112 then propels or moves the vehicle 100.

[0027] Reference now Figure 2 , an illustrative hybrid-electric powertrain system 200. Although the presently illustrated powertrain system does not include a fossil fuel powered prime mover, it should be understood that in some embodiments, elements of the present disclosure may be used in systems that include a fossil fuel powered prime mover, such as a diesel engine.

[0028] The fuel cell system 202 includes one or more fuel cells 206, an air system 208, a hydrogen (H2) storage 210, a fuel cell cooling system 212, and an exhaust system 214. The fuel cell 206 is configured to generate electrical energy using the chemical energy of a fuel and an oxidant. Figure 2In the exemplary embodiment shown, the fuel source is hydrogen stored in a hydrogen storage 210, and the oxidant is oxygen provided by an air system 208. In this embodiment, the fuel cell 206 receives hydrogen and oxygen, respectively, from a hydrogen distributor 216 and an oxygen distributor 218. The fuel cell 206 is configured to combine the hydrogen and oxygen to generate electricity (e.g., a first DC power output).

[0029] In some embodiments, the fuel cell system 202 may further include a fuel cell cooling system 212. The cooling system 212 is configured to regulate the temperature of the fuel cell 206 to ensure proper operation of the fuel cell 206. The fuel cell system 202 may further include an exhaust system 214. The exhaust system 214 is configured to receive and collect byproducts generated by the fuel cell 206. The byproducts may include unused hydrogen and water, which is generated as a byproduct of generating electricity in the fuel cell 206. The exhaust system 214 also discharges the byproducts collected from the hybrid electric power system 200 to the outside of the hybrid electric power system 200.

[0030] The battery system 204 includes one or more batteries 220. In some embodiments, the battery system 204 also includes a battery management system (BMS) controller 222 and / or a battery cooling system 224. The battery 220 is also configured to convert chemical energy into electrical energy to produce a second DC power output. The BMS controller 222 can be configured to control the operation of the battery 220 based on input received from a system control module 226. The BMS controller 222 can be coupled to the system control module 226. The system control module 226 is coupled to a vehicle control unit 227, which is configured to control a vehicle associated with the hybrid electric powertrain 200. In some embodiments, each battery 220 generates an output voltage of 800 volts. The cooling system 224 is configured to regulate the temperature of the battery 220.

[0031] In some embodiments, each of the battery 220 and the fuel cell 206 can be coupled to a DC / DC converter 228. The DC / DC converter can convert the voltage received from the fuel cell 206 (e.g., 600 volts) and the voltage received from the battery 220 (e.g., 800 volts) from their respective voltages to a specific predetermined voltage. For example, in some embodiments, the DC / DC converter converts the voltage from 600 volts / 800 volts to 1800 volts. Each DC / DC converter is connected to a DC power bus 230. In some embodiments, a DCAC inverter 232 is coupled to the DC power bus 230 and is configured to convert the DC voltage / current received from the DC power bus to an AC voltage / current that can be provided to an AC auxiliary load 234. The AC auxiliary load 234 represents one or more auxiliary devices configured to receive AC power. In some embodiments, a DC / DC converter 236 is coupled to the DC power bus 230 and is configured to convert the DC voltage and / or current received from the DC power bus 230 to a DC voltage / current that can be provided to a DC auxiliary load 238. DC auxiliary load 238 represents one or more auxiliary devices configured to receive DC power.

[0032] In some embodiments, a DC / AC traction inverter 240 is coupled to the DC power bus 230. The DC / AC traction inverter 240 is configured to receive a first DC power output DC voltage and a second DC power output DC voltage from the DC power bus 230 and convert the DC power output to an AC power output that can be used by the motor 242. In some embodiments, the traction inverter 240 also performs functions such as boosting, switch protection, and regenerative braking within the power system 100. In some embodiments, the motor 242 can be an AC traction motor, and thus, the DC power from the DC power bus can be converted to AC power for use by the motor 242. For example, in an example embodiment, the DC / AC traction inverter 240 converts 1800 volts DC to a lower voltage (e.g., 1000 volts AC to 1300 volts AC) required by the motor 242. In some embodiments, the DC / AC inverter 240 is coupled to a power electronics cooling system 243 that is configured to regulate the temperature of the DC / AC inverter 240. The mechanical power generated by motor 240 is provided to a transmission (not shown) that ultimately propels a vehicle associated with the powertrain forward. As a result of the power output from motor 242, the transmission (not shown) can manipulate the speed of a rotating crankshaft (not shown) to affect a desired drive shaft speed. The rotating drive shaft can be received by a differential that provides the rotational energy of the drive shaft to final drive wheels 246 to propel or move a vehicle associated with powertrain 200. While the foregoing are examples of mechanical components that may be used at the output of a hybrid electric powertrain system to move a vehicle, it should be understood that in various embodiments, various other types of components may be provided at the output of a hybrid electric powertrain system to move a vehicle in various example implementations.

[0033] The motor 242 may be coupled to a motor control unit 244 configured to control the operation of the motor 242. In some embodiments, the motor 242 may be a variable speed motor, and the motor control unit 244 may control the speed of the motor 242. The motor control unit 244 may include processing circuits, such as a processor and a memory. The processor may be implemented as a general purpose processor, an application specific integrated circuit (ASIC), one or more field programmable gate arrays (FPGA), a set of processing components, or other suitable electronic processing components. The memory (e.g., memory, memory unit, storage device, etc.) may include one or more devices (e.g., RAM, ROM, flash memory, hard disk storage device, etc.) for storing data and / or computer code to complete or facilitate the various processes, layers, and modules described in this application. The memory may be or include a volatile memory or a non-volatile memory. The memory may include a database component, an object code component, a script component, or any other type of information structure for supporting the various activities and information structures described in this application.

[0034] Memory (e.g., memory, memory unit, storage device, etc.) may include one or more devices (e.g., RAM, ROM, flash memory, hard disk storage device, etc.) for storing data and / or computer code to complete or facilitate the various processes, layers, and modules described in this application. The memory may be or include volatile memory or non-volatile memory. The memory may include a database component, an object code component, a script component, or any other type of information structure for supporting the various activities and information structures described in this application.

[0035] The following Figure 3 and Figure 4 Two exemplary embodiments of hybrid electric powertrain systems that do not use a DC / DC converter are shown. Although the illustrated embodiments do not use a DC / DC converter, it should be understood that in some embodiments, a DC / DC converter may be used for some components (e.g., so that fewer DC / DC converters are used, but the design does not completely eliminate the use of a DC / DC converter).

[0036] Reference now Figure 3 , a schematic diagram of a hybrid electric powertrain 300 of a vehicle according to an illustrative embodiment is shown. The hybrid electric powertrain 300 includes one or more fuel cell stacks 302, each fuel cell stack 302 including one or more fuel cells configured to generate a first DC power output. The hybrid electric powertrain also includes one or more batteries 304 configured to generate a second DC power output. The hybrid electric powertrain 300 also includes one or more inverters 306, an AC power bus 308, a motor 310, a motor control unit 312, and a transmission 314. The fuel cell stack 302 may include one or more fuel cells and may be similar to the fuel cell system 202 described in more detail above. Each fuel cell within the fuel cell stack 302 is configured to convert chemical energy into electrical energy to generate a first DC power output. The battery 304 is also configured to convert chemical energy into electrical energy to generate a second DC power output. In some embodiments, the fuel cell stack 302 may each generate an output voltage ranging from 270 volts DC to 600 volts DC. In some embodiments, the battery may generate an output voltage ranging from 600 volts DC to 800 volts DC.

[0037] The fuel cell stack 302 and the battery 304 can each be coupled to one or more inverters 306. One or more inverters 306 can be configured to convert a first DC power output and a second DC power output to generate one or more AC power outputs (e.g., AC voltage). In some embodiments, one or more inverters 306 can each include an isolation transformer 307 within the one or more inverters. The isolation transformer 307 can be configured to step up or step down the voltage received and converted / generated by the one or more inverters 306. The isolation transformer is configured to step up or step down the voltage to provide the voltage required by the motor 310. For example, the isolation transformer 307 can step up the voltage (e.g., 270 volts-600 volts) received from the fuel cell stack 302 and / or the voltage (600 volts-800 volts) received from the battery 304 to 1300 volts AC. The AC power bus 308 is coupled to one or more inverters 306 and is configured to receive one or more AC power outputs from the one or more inverters 306. The AC power bus 308 is configured to provide the AC power output to the motor 310. One or more inverters 306 may be coupled in parallel to the AC power bus 308 to increase the power capacity of the hybrid electric powertrain system 300.

[0038] The motor 310 is coupled to the AC power bus 308 and is configured to receive voltage from the AC power bus 308. The motor 310 may be a variable speed traction motor. The speed and frequency within the motor 310 may vary based on the operation of the vehicle. The motor 310 may be coupled to a motor control unit 312 configured to control the operation of the motor 310. In some embodiments, the motor control unit 312 may use a motor control algorithm to determine one or more control inputs for the motor 310. In some embodiments, one or more control inputs are determined based on voltage measurements and one or more operating conditions of the vehicle. In some embodiments, the motor control unit 312 may be added as a separate controller that controls the speed and frequency of the motor. In other embodiments, the motor control unit 312 may be integrated as part of a controller for the inverter 306. The inverter controller may be communicatively coupled to the vehicle control unit to determine the desired speed of the motor for the vehicle, and achieve the desired speed via frequency changes directly associated with the speed and torque control of the motor 310. In some embodiments, the motor control unit 312 may include a V / Hz drive control to match the required torque. The motor control unit 312 controller may include different types of motor control algorithms to control the speed / frequency of the motor. These motor control algorithms may include, but are not limited to, vector control, direct torque control, pulse width modulation control, and space vector pulse width modulation. In some embodiments, one or more microcontrollers may govern the overall operation of inverter 306 to control the operation of motor 310 .

[0039] In some embodiments, the motor control unit 312 can control the speed / frequency and voltage of the motor 310 and one or more inverters 306 / AC power bus 308. More specifically, the control inputs may include the speed / frequency of the motor 310, the voltage of the motor 310, the frequency of one or more inverters 306 / AC power bus 308, and the voltage of one or more inverters 306 / AC power bus 308. The motor control unit 312 may implement the control inputs within the motor by adjusting the speed and / or frequency of the motor 310 and the voltage required by the motor 310. The motor control algorithm may utilize the operating conditions of the vehicle as inputs to the algorithm. The operating conditions of the vehicle may include the speed of the vehicle, the terrain that the vehicle is traversing, the operating mode of the vehicle (energy-saving mode, normal mode, sport mode, etc.), or any other conditions that affect the vehicle.

[0040] The motor control unit 312 may include processing circuits, such as a processor and a memory. The processor may be implemented as a general-purpose processor, an application-specific integrated circuit (ASIC), one or more field programmable gate arrays (FPGA), a set of processing components, or other suitable electronic processing components. The memory (e.g., memory, memory unit, storage device, etc.) may include one or more memory devices (e.g., RAM, ROM, flash memory, hard disk storage device, etc.) for storing data and / or computer code to complete or facilitate the various processes, layers, and modules described in this application. The memory may be or include volatile memory or non-volatile memory. The memory may include a database component, an object code component, a script component, or any other type of information structure for supporting the various activities and information structures described in this application.

[0041] Memory (e.g., memory, memory unit, storage device, etc.) may include one or more devices (e.g., RAM, ROM, flash memory, hard disk storage device, etc.) for storing data and / or computer code to complete or facilitate the various processes, layers, and modules described in this application. The memory may be or include volatile memory or non-volatile memory. The memory may include a database component, an object code component, a script component, or any other type of information structure for supporting the various activities and information structures described in this application.

[0042] The motor 310 works with the transmission 314 to propel the vehicle forward. More specifically, as a result of the power output from the motor 310, the transmission 314 can manipulate the speed of the crankshaft (not shown) to affect the desired drive shaft speed. The rotating drive shaft (not shown) is received by the differential (not shown), which provides the rotational energy of the drive shaft to the final drive wheels (not shown) to propel or move the vehicle associated with the powertrain 300.

[0043] In some embodiments, the hybrid electric power system 300 shown in the figure can be used without using the hybrid electric power system 200 (such as Figure 2 2 and 3). In some embodiments, the inverter 306 may be implemented without the DC / DC converter 228 and / or the DC / AC traction inverter 240 in the hybrid electric powertrain 300. Compared to the hybrid electric powertrain 200, the hybrid electric powertrain 300 may provide benefits such as reducing the costs associated with the DC / DC converter 228 and / or the DC / AC traction inverter 240, simplifying the architecture of the hybrid electric powertrain to make the hybrid electric powertrain 300 easier to produce and maintain, etc. More specifically, in some cases, the cost of the inverter 306 may be lower than the cost of the DC / DC converter 228 and / or the DC / AC traction inverter 240. In addition, the one or more inverters 306 have a higher technology readiness level (e.g., which development stage of the technology, from a technology that is still in the early development stage to a technology that is well developed and being implemented) than the DC / DC converter 228, which results in the one or more inverters 306 being more easily available and easier to find and include in the hybrid electric powertrain 300.

[0044] Reference now Figure 4 , a schematic diagram of a hybrid electric power system 400 of a vehicle according to an illustrative embodiment is shown. The hybrid electric power system 400 includes one or more fuel cell stacks 302, each fuel cell stack 302 including one or more fuel cells configured to generate a first DC power output. The hybrid electric power system also includes one or more batteries 304 configured to generate a second DC power output. The hybrid electric power system 400 also includes one or more inverters 406, an AC power bus 308, a transformer 410, a cycloconverter 412, a motor 310, a motor control unit 312, and a transmission 314. The fuel cell stack 302 may include one or more fuel cells and may be similar to the fuel cell system 202 described in more detail above. Each fuel cell in the fuel cell stack 302 is configured to convert chemical energy into electrical energy to generate a first DC power output. The battery 304 is also configured to convert chemical energy into electrical energy to generate a second DC power output. In some embodiments, the fuel cell stack 302 can generate an output voltage ranging from 270 volts DC to 600 volts DC. In some embodiments, the battery generates an output voltage in the range of 600 volts DC - 800 volts DC.

[0045] The fuel cell stack 302 and the battery 304 may each be coupled to one or more inverters 406. One or more inverters 406 may convert the first DC power output and the second DC power output received from the fuel cell stack 302 and the battery 304 into an AC power voltage. The AC power bus 308 is coupled to one or more inverters 406 and is configured to receive one or more AC power outputs from one or more inverters 406. The AC power bus 308 is configured to provide an AC power output to the motor 310. Specifically, the AC power bus 308 may be configured to combine one or more AC power outputs to provide a combined AC power output to the motor 310. One or more inverters 406 may be coupled to the AC power bus 308 in parallel to increase the power capacity of the hybrid electric power system 400. In some embodiments, the voltage as measured in the AC power bus 308 may be a low voltage (e.g., 270 volts-800 volts). Therefore, the voltage of the AC power bus 308 may need to be boosted by the transformer 410. The AC power bus 308 is coupled to a transformer 410, which is configured to convert the voltage output of the AC power bus 308. Specifically, the transformer 410 is configured to step up or step down the voltage from the AC power bus 308 to provide the voltage required by the motor 310. For example, the transformer 410 can step up the voltage in the AC power bus from a low voltage (e.g., 270 volts-800 volts) to a higher voltage (e.g., 1300 volts AC).

[0046] The transformer 410 can be coupled to the cycloconverter 412. The cycloconverter 412 can convert the frequency of the AC voltage output of the AC power bus 308, which is boosted by the transformer 410, into the frequency required by the motor. More specifically, the cycloconverter 412 can convert an AC voltage of one frequency into a different AC voltage with a lower but adjustable frequency without an intermediate DC stage. For example, the transformer 410 can be configured to generate a fixed AC voltage of a constant frequency. The cycloconverter 412 can then convert the fixed AC voltage of a constant frequency from the transformer 410 and output a variable AC voltage of a variable frequency. The cycloconverter 412 can convert the fixed AC voltage of a constant frequency to output a variable AC voltage of a variable frequency. The motor 310 can be a variable speed motor, which requires the frequency of the voltage output (e.g., variable AC voltage output) of the AC power bus to be converted by the cycloconverter 412.

[0047] In some embodiments, cycloconverter 412 may include processing circuits, such as processors and memory. The processor may be implemented as a general purpose processor, an application specific integrated circuit (ASIC), one or more field programmable gate arrays (FPGA), a group of processing components or other suitable electronic processing components. Memory (e.g., memory, memory unit, storage device, etc.) may include one or more memory devices (e.g., RAM, ROM, flash memory, hard disk storage device, etc.) for storing data and / or computer code to complete or promote the various processes, layers and modules described in this application. Memory may be or include volatile memory or non-volatile memory. Memory may include database components, object code components, script components or any other type of information structure for supporting the various activities and information structures described in this application.

[0048] Memory (e.g., memory, memory unit, storage device, etc.) may include one or more devices (e.g., RAM, ROM, flash memory, hard disk storage device, etc.) for storing data and / or computer code to complete or facilitate the various processes, layers, and modules described in this application. The memory may be or include volatile memory or non-volatile memory. The memory may include a database component, an object code component, a script component, or any other type of information structure for supporting the various activities and information structures described in this application.

[0049] The motor 310 is coupled to the cycloconverter 412 and is configured to receive voltage from the cycloconverter 412. The motor 310 may be a variable speed traction motor that requires a variable AC voltage and frequency output by the cycloconverter 412. The speed and frequency within the motor 310 may vary based on the operation of the vehicle. The motor 310 may be coupled to a motor control unit 312 configured to control the operation of the motor 310. In some embodiments, the motor control unit 312 may control the speed and frequency of the motor 310 and the voltage required by the motor 310 to meet the torque and speed requirements of the vehicle. In some embodiments, the motor control unit 312 may utilize a motor control algorithm that will adjust the voltage required by the motor 310 and the required frequency. Specifically, the motor control unit 312 may be configured to: receive voltage measurements from one or more inverters 306, determine one or more control inputs for the motor 310 using a motor control algorithm, the one or more control inputs being determined based on the voltage measurements and one or more operating conditions of the vehicle, and control the operation of the motor 310 to achieve the one or more control inputs. In some embodiments, one or more control inputs include at least one of the frequency of the motor, the voltage of the motor, the frequency of the AC power bus, or the voltage of the AC power bus. In some embodiments, the motor control unit 312 may be configured to use a motor control algorithm and determine at least one of the frequency of the motor, the voltage of the motor, the frequency of the AC power bus, or the voltage of the AC power bus based on the voltage measurement results and one or more operating conditions of the vehicle. The motor control unit 312 may also be configured to control the operation of the motor to achieve at least one of the determined frequency of the motor, the voltage of the motor, the frequency of the AC power bus, or the voltage of the AC power bus. In some embodiments, the motor control unit 312 may be added as a separate controller that controls the speed and frequency of the motor 310. In other embodiments, the motor control unit 312 may be integrated as part of a controller for the inverter 406. The inverter controller may be communicatively coupled to the vehicle control unit to determine the desired speed of the motor for the vehicle, and to achieve the desired speed via a frequency change directly associated with the speed and torque control of the motor 310. Specifically, the inverter controller may update the speed and torque of the motor 310 via a frequency change to achieve the desired speed of the motor. In some embodiments, the motor control unit 312 may include a V / Hz drive control to match the required torque. The motor control unit 312 controller may include different types of motor control algorithms to control the speed / frequency of the motor. These control algorithms may include, but are not limited to, vector control, direct torque control, pulse width modulation control, and space vector pulse width modulation. In some embodiments, one or more microcontrollers may dominate the overall operation of the inverter 306 to control the operation of the motor 310.

[0050] In some embodiments, the motor control unit 312 can control the speed / frequency and voltage of the motor 310 and one or more inverters 406 / AC power bus 308. More specifically, the control input may include the speed / frequency of the motor 310, the voltage of the motor 310, the frequency of one or more inverters 406 / AC power bus 308, and the voltage of one or more inverters 406 / AC power bus 308. The motor control unit 312 can implement and drive the control input to the cycloconverter 412 to adjust the speed and torque of the motor. The motor control algorithm can use the operating conditions of the vehicle as the input of the algorithm. The operating conditions of the vehicle may include the speed of the vehicle, the terrain that the vehicle is crossing, the operating mode of the vehicle (energy-saving mode, normal mode, sports mode, etc.), or any other conditions that affect the vehicle. In some embodiments, the motor control algorithm can be implemented by the cycloconverter 412.

[0051] The motor control unit 312 may include processing circuits, such as a processor and a memory. The processor may be implemented as a general-purpose processor, an application-specific integrated circuit (ASIC), one or more field programmable gate arrays (FPGA), a set of processing components, or other suitable electronic processing components. The memory (e.g., memory, memory unit, storage device, etc.) may include one or more memory devices (e.g., RAM, ROM, flash memory, hard disk storage device, etc.) for storing data and / or computer code to complete or facilitate the various processes, layers, and modules described in this application. The memory may be or include volatile memory or non-volatile memory. The memory may include a database component, an object code component, a script component, or any other type of information structure for supporting the various activities and information structures described in this application.

[0052] Memory (e.g., memory, memory unit, storage device, etc.) may include one or more devices (e.g., RAM, ROM, flash memory, hard disk storage device, etc.) for storing data and / or computer code to complete or facilitate the various processes, layers, and modules described in this application. The memory may be or include volatile memory or non-volatile memory. The memory may include a database component, an object code component, a script component, or any other type of information structure for supporting the various activities and information structures described in this application.

[0053] The motor 310 works with the transmission 314 to propel the vehicle forward. More specifically, as a result of the power output from the motor 310, the transmission 314 can manipulate the speed of the crankshaft (not shown) to affect the desired drive shaft speed. The rotating drive shaft (not shown) is received by the differential (not shown), which provides the rotational energy of the drive shaft to the final drive wheels (not shown) to propel or move the vehicle associated with the powertrain 400.

[0054] In some embodiments, the hybrid electric powertrain 400 shown in the figure may be used without using the hybrid electric powertrain 200 (such as Figure 2 4. In the embodiment of the present invention, the hybrid electric power system 400 is implemented without the DC / DC converter 228 and / or the DC / AC traction inverter 240 in the hybrid electric power system 200. Compared with the hybrid electric power system 200, the hybrid electric power system 400 can provide reduced costs such as those associated with the DC / DC converter 228 and / or the DC / AC traction inverter 240, and also simplify the architecture of the hybrid electric power system to make the hybrid electric power system 400 easier to produce and maintain. More specifically, the cost of the inverter 406 is lower than the cost of the DC / DC converter 228 and / or the DC / AC traction inverter 240. In addition, the one or more inverters 406 have a higher technology readiness level (e.g., which development stage of the technology, from a technology that is still in the early development stage to a technology that is well developed and being implemented) than the DC / DC converter 228, which results in the one or more inverters 406 being more easily available and easier to find and include in the hybrid electric power system 400.

[0055] As used herein, the terms "approximately," "about," "substantially," and similar terms are intended to have a broad meaning consistent with common and accepted usage by those of ordinary skill in the art to which the subject matter of the present disclosure relates. Those skilled in the art who review the present disclosure should understand that these terms are intended to allow for the description of certain features described and claimed without limiting the scope of such features to the precise numerical ranges provided. Accordingly, these terms should be interpreted as indicating that insubstantial or inconsequential modifications or alterations to the subject matter described and claimed are considered to be within the scope of the disclosure as described in the appended claims.

[0056] It should be noted that the term "exemplary" and variations thereof as used herein to describe various embodiments are intended to indicate that these embodiments are possible examples, representations, or illustrations of possible embodiments (and these terms are not intended to imply that these embodiments are necessarily the most specific or superlative examples).

[0057] As used herein, the term "coupled" and its variations refer to two components being directly or indirectly connected to each other. Such a connection may be static (e.g., permanent or fixed) or movable (e.g., removable or releasable). Such a connection may be achieved by coupling the two components directly to each other, by coupling the two components to each other using one or more separate intermediate components, or by coupling the two components to each other using an intermediate component that is integrally formed as a single integral body with one of the two components. If "coupled" or its variations are modified by additional terms (e.g., directly coupled), the general definition of "coupled" provided above is modified by the plain language meaning of the additional terms (e.g., "directly coupled" means the connection of the two components without any separate intermediate components), resulting in a narrower definition than the general definition of "coupled" provided above. Such coupling may be mechanical, electrical, or fluidic. For example, circuit A being communicatively "coupled" to circuit B may mean that circuit A communicates directly with circuit B (i.e., without an intermediary) or indirectly with circuit B (e.g., through one or more intermediaries).

[0058] References to element positions herein (e.g., "top," "bottom," "above," "below") are only used to describe the orientation of various elements in the drawings. It should be noted that according to other exemplary embodiments, the orientation of various elements may be different, and such variations are intended to be encompassed by the present disclosure.

[0059] As described above, and in one configuration, "circuit" can be implemented in a machine-readable medium for execution by various types of processors such as processors. The identification circuit of the executable code may, for example, include one or more physical or logical blocks of computer instructions, which may, for example, be organized as objects, processes, or functions. However, the executable file of the identified circuit is not necessarily physically located together, but may include different instructions stored in different locations, which when logically connected together include the circuit and realize the purpose of the circuit. In fact, the circuit of the computer-readable program code may be a single instruction or multiple instructions, and may even be distributed on several different code segments, between different programs, and across several memory devices. Similarly, operating data may be identified and shown in the circuit herein, and may be embodied in any suitable form and organized in any suitable type of data structure. The operating data may be collected as a single data set, or may be distributed in different locations, including on different storage devices, and may exist, at least in part, only as an electronic signal on a system or network.

[0060] Although the term "processor" is briefly defined above, the terms "processor" and "processing circuit" should be interpreted broadly. In this regard, as described above, a "processor" can be implemented as one or more general-purpose processors, application-specific integrated circuits (ASICs), field programmable gate arrays (FPGAs), digital signal processors (DSPs), or other suitable electronic data processing components configured to execute instructions provided by a memory. One or more processors can take the form of a single-core processor, a multi-core processor (e.g., a dual-core processor, a triple-core processor, a quad-core processor, etc.), a microprocessor, etc. In some embodiments, one or more processors can be outside the device, for example, one or more processors can be remote processors (e.g., cloud-based processors). Alternatively or additionally, one or more processors can be inside the device and / or local. In this regard, a given circuit or its components can be arranged locally (e.g., as part of a local server, a local computing system, etc.) or remotely (e.g., as part of a remote server such as a cloud-based server). To this end, a "circuit" as described herein can include components distributed in one or more locations.

[0061] Embodiments within the scope of the present disclosure include program products, which include machine-readable media for carrying or having machine-executable instructions or data structures stored thereon. Such machine-readable media can be any available media, which can be accessed by a general-purpose or special-purpose computer or other machine with a processor. For example, such machine-readable media may include RAM, ROM, EPROM, EEPROM or other optical disk storage devices, disk storage devices or other magnetic storage devices, or any other medium that can be used to carry or store the desired program code in the form of machine-executable instructions or data structures and can be accessed by a general-purpose or special-purpose computer or other machine with a processor. The above combination is also included in the scope of machine-readable media. Machine-executable instructions include instructions and data that, for example, enable a general-purpose computer, a special-purpose computer or a special-purpose processing machine to perform a certain function or a group of functions.

[0062] Although the drawings and description may show a particular order of method steps, the order of these steps may be different from that depicted and described, unless otherwise specified above. In addition, two or more steps may be performed simultaneously or partially simultaneously, unless otherwise specified above. For example, such variations may depend on the selected software and hardware systems and the designer's choice. All of these variations are within the scope of the present disclosure. Similarly, software implementations of the described methods can be accomplished with standard programming techniques with rule-based logic and other logic to accomplish various connection steps, processing steps, comparison steps, and decision steps.

[0063] It is important to note that the construction and arrangement of the hybrid electric powertrain systems 300 and 400 as shown in the various exemplary embodiments are illustrative only. In addition, any element disclosed in one embodiment may be combined or used with any other embodiment disclosed herein. Although only one example of an element from one embodiment that may be combined or utilized in another embodiment is described above, it should be understood that other elements of the various embodiments may be combined or used with any other embodiment disclosed herein.

[0064] In addition, this disclosure includes the following examples:

[0065] Example 1. A hybrid electric powertrain for a vehicle, the powertrain comprising: one or more fuel cells configured to generate a first DC power output; one or more batteries configured to generate a second DC power output; one or more inverters coupled to the one or more fuel cells and the one or more batteries, the one or more inverters configured to convert the first DC power output and the second DC power output to generate one or more AC power outputs; and an AC power bus coupled to the one or more inverters, the AC power bus configured to receive the one or more AC power outputs and provide the AC power output to a motor.

[0066] Example 2. The hybrid electric powertrain system of Example 1, wherein the hybrid electric powertrain system is implemented without using a DC / DC converter.

[0067] Example 3. A hybrid electric powertrain for a vehicle, the powertrain comprising: a fuel cell configured to generate a first DC voltage; a battery configured to generate a second DC voltage; an inverter coupled to the fuel cell and the battery, the inverter configured to convert the first DC voltage and the second DC voltage into an AC voltage; an AC power bus coupled to one or more inverters and configured to provide the AC voltage to a motor; a transformer coupled to the AC power bus and configured to convert a voltage output of the AC power bus; and a cycloconverter coupled to the transformer, the cycloconverter configured to convert a frequency of the voltage output of the AC power bus.

[0068] Example 4. A hybrid electric powertrain system according to Example 3, wherein the cycloconverter includes one or more processing circuits, the one or more processing circuits including one or more memory devices coupled to one or more processors, the one or more memory devices being configured to store instructions thereon that, when executed by the one or more processors, cause the one or more processors to: receive voltage measurements from the inverter; determine one or more control inputs for the motor using a motor control algorithm, the one or more control inputs being determined based on the voltage measurements and one or more operating conditions of the vehicle; and control operation of the motor to implement the one or more control inputs.

[0069] Example 5. A hybrid electric powertrain system according to example 3 or example 4, wherein the motor is a variable speed traction motor that receives a voltage output of an AC power bus, including a frequency of the voltage output converted by a cycloconverter.

[0070] Example 6. A method for operating a hybrid electric powertrain in a vehicle, the method comprising: generating a first DC power output from one or more fuel cells; generating a second DC power output from one or more batteries; converting the first DC power output and the second DC power output to generate one or more AC power outputs; and combining the one or more AC power outputs to provide a combined AC power output to a motor.

[0071] Example 7. The method of Example 6, wherein the method further comprises: receiving voltage measurements from one or more inverters; determining one or more control inputs for the motor using a motor control algorithm and based on the voltage measurements and one or more operating conditions of the vehicle; and controlling operation of the motor to implement the one or more control inputs.

[0072] Example 8. The method of Example 6 or Example 7, wherein the one or more control inputs include at least one of a frequency of the motor, a voltage of the motor, a frequency of the AC power bus, or a voltage of the AC power bus, and wherein the method further comprises: determining at least one of the frequency of the motor, the voltage of the motor, the frequency of the AC power bus, or the voltage of the AC power bus using a motor control algorithm and based on voltage measurements and one or more operating conditions of the vehicle; and controlling operation of the motor to achieve the determined at least one of the frequency of the motor, the voltage of the motor, the frequency of the AC power bus, or the voltage of the AC power bus.

[0073] Example 9. The hybrid electric powertrain of Example 1, wherein each of the one or more inverters includes one or more isolation transformers configured to step up an AC voltage generated by the one or more inverters.

[0074] Example 10. The hybrid electric powertrain system according to any of the preceding examples further includes a motor control unit coupled to the motor, the motor control unit including one or more processing circuits, the one or more processing circuits including one or more memory devices coupled to one or more processors, the one or more memory devices being configured to store instructions thereon, which instructions, when executed by the one or more processors, cause the one or more processors to: receive voltage measurements from one or more inverters; determine one or more control inputs for the motor using a motor control algorithm, the one or more control inputs being determined based on the voltage measurements and one or more operating conditions of the vehicle; and control operation of the motor to implement the one or more control inputs.

[0075] Example 11. A hybrid electric powertrain system according to Example 10, wherein the one or more control inputs include at least one of a frequency of the motor, a voltage of the motor, a frequency of the AC power bus, or a voltage of the AC power bus, and wherein the one or more processors are configured to: determine at least one of the frequency of the motor, the voltage of the motor, the frequency of the AC power bus, or the voltage of the AC power bus using a motor control algorithm and based on voltage measurements and one or more operating conditions of the vehicle; and control operation of the motor to achieve the determined at least one of the frequency of the motor, the voltage of the motor, the frequency of the AC power bus, or the voltage of the AC power bus.

[0076] Example 12. The hybrid electric powertrain of example 10 or example 11, wherein the one or more control inputs include at least one of a frequency of the motor, a voltage of the motor, a frequency of the AC power bus, and / or a voltage of the AC power bus.

[0077] Example 13. A hybrid electric powertrain according to any one of Examples 10 to 12, wherein the motor control unit is integrated into a controller for the inverter.

[0078] Example 14. A hybrid electric powertrain system according to any of Examples 10 to 13, wherein the one or more operating conditions of the vehicle include at least one of a speed of the vehicle, a terrain the vehicle is traversing, and an operating mode of the vehicle.

[0079] Example 15. A hybrid electric powertrain system according to any one of Examples 10 to 14, wherein the motor control algorithm includes at least one of vector control, direct torque control, pulse width modulation control, and space vector pulse width modulation control.

Claims

1. A hybrid electric power system for a vehicle, the power system comprising: one or more fuel cells configured to generate a first DC power output; one or more batteries configured to generate a second DC power output; one or more inverters coupled to the one or more fuel cells and the one or more batteries, the one or more inverters configured to convert the first DC power output and the second DC power output to produce one or more AC power outputs; as well as An AC power bus is coupled to the one or more inverters and is configured to receive the one or more AC power outputs and provide the AC power output to the motor.

2. The hybrid electric powertrain system according to claim 1, wherein: Each of the one or more inverters includes one or more isolation transformers configured to step up an AC voltage generated by the one or more inverters.

3. The hybrid electric powertrain system of claim 1 , further comprising a motor control unit coupled to the motor, the motor control unit comprising one or more processing circuits, the one or more processing circuits comprising one or more memory devices coupled to the one or more processors, the one or more memory devices being configured to store instructions on the one or more memory devices that, when executed by the one or more processors, cause the one or more processors to: receiving voltage measurements from the one or more inverters; One or more control inputs for the motor are determined using a motor control algorithm, the one or more control inputs being determined based on: the voltage measurement result; and one or more operating conditions of the vehicle; and Operation of the motor is controlled to achieve the one or more control inputs.

4. The hybrid electric powertrain system according to claim 3, wherein: The one or more control inputs include at least one of a frequency of the motor, a voltage of the motor, a frequency of the AC power bus, or a voltage of the AC power bus, and wherein the one or more processors are configured to: determining, using the motor control algorithm and based on the voltage measurements and the one or more operating conditions of the vehicle, the at least one of a frequency of the motor, a voltage of the motor, a frequency of the AC power bus, or a voltage of the AC power bus; as well as Operation of the motor is controlled to achieve a determined at least one of a frequency of the motor, a voltage of the motor, a frequency of the AC power bus, or a voltage of the AC power bus.

5. The hybrid electric powertrain system according to claim 3, wherein: The motor control unit is integrated into a controller for the one or more inverters.

6. The hybrid electric powertrain system according to claim 3, wherein: The one or more operating conditions of the vehicle include at least one of a speed of the vehicle, a terrain the vehicle is traversing, and an operating mode of the vehicle.

7. The hybrid electric powertrain system according to claim 3, wherein: The motor control algorithm includes at least one of vector control, direct torque control, pulse width modulation control, and space vector pulse width modulation control.

8. The hybrid electric powertrain system according to claim 1, wherein: The hybrid electric powertrain is implemented without using a DC / DC converter.

9. A hybrid electric power system for a vehicle, the power system comprising: a fuel cell configured to generate a first DC voltage; a battery configured to generate a second DC voltage; an inverter coupled to the fuel cell and the battery, the inverter configured to convert the first DC voltage and the second DC voltage into an AC voltage; an AC power bus coupled to the one or more inverters and configured to provide the AC voltage to the motor; a transformer coupled to the AC power bus, the transformer configured to transform a voltage output of the AC power bus; as well as A cycloconverter is coupled to the transformer, the cycloconverter being configured to convert a frequency of the voltage output of the AC power bus.

10. The hybrid electric powertrain system according to claim 9, wherein: The transformer is configured to generate a fixed AC voltage of a constant frequency, and wherein the cycloconverter converts the fixed AC voltage of the constant frequency and outputs a variable AC voltage of a variable frequency.

11. The hybrid electric powertrain system according to claim 9, wherein: A motor control unit is integrated into a controller for the inverter, and wherein the controller for the inverter is communicatively coupled to a vehicle control unit and is configured to: determining a desired speed of the motor; and The desired speed of the motor is achieved via frequency variation to update the speed and torque of the motor.

12. The hybrid electric powertrain system according to claim 9, wherein: The one or more inverters are coupled in parallel to the AC power bus.

13. The hybrid electric powertrain system according to claim 9, wherein: A motor control unit is communicatively coupled to the cycloconverter and is configured to drive one or more control outputs to the cycloconverter to adjust speed and torque of the motor.

14. The hybrid electric powertrain system according to claim 9, wherein: The cycloconverter comprises one or more processing circuits, the one or more processing circuits comprising one or more memory devices coupled to one or more processors, the one or more memory devices being configured to store instructions on the one or more memory devices that, when executed by the one or more processors, cause the one or more processors to: receiving voltage measurements from the inverter; One or more control inputs for the motor are determined using a motor control algorithm, the one or more control inputs being determined based on: the voltage measurement result; and one or more operating conditions of the vehicle; as well as Operation of the motor is controlled to achieve the one or more control inputs.

15. The hybrid electric powertrain system according to claim 9, wherein: The transformer is configured to step up a voltage output of the AC power bus from a lower voltage to a higher voltage, wherein the lower voltage is between 270 volts AC and 800 volts AC and the higher voltage is at least 1300 volts AC.

16. The hybrid electric powertrain system of claim 9, wherein: The battery generates an output voltage between 270 volts DC and 600 volts DC, wherein the fuel cell generates an output voltage between 600 volts DC and 800 volts DC.

17. The hybrid electric powertrain system of claim 9, wherein: The motor is a variable speed traction motor that receives a voltage output of the AC power bus, including a frequency of the voltage output converted by the cycloconverter.

18. A method for operating a hybrid electric powertrain in a vehicle, the method comprising: generating a first DC power output from one or more fuel cells; generating a second DC power output from one or more batteries; converting the first DC power output and the second DC power output to produce one or more AC power outputs; and The one or more AC power outputs are combined to provide a combined AC power output to the motor.

19. The method according to claim 18, wherein: The method further comprises: receiving voltage measurements from one or more inverters; determining one or more control inputs for the motor based on the voltage measurements and one or more operating conditions of the vehicle using a motor control algorithm; and Operation of the motor is controlled to achieve the one or more control inputs.

20. The method according to claim 19, wherein: The one or more control inputs include at least one of a frequency of the motor, a voltage of the motor, a frequency of an AC power bus, or a voltage of the AC power bus, and wherein the method further comprises: determining, using the motor control algorithm and based on the voltage measurements and the one or more operating conditions of the vehicle, at least one of a frequency of the motor, a voltage of the motor, a frequency of the AC power bus, or a voltage of the AC power bus; and Operation of the motor is controlled to achieve a determined at least one of a frequency of the motor, a voltage of the motor, a frequency of the AC power bus, or a voltage of the AC power bus.

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