Electric propulsion system

Abstract

The utility model discloses an electric propulsion system. In one example, a state machine generated by executable instructions may control a maximum power output of an electric propulsion system. The state machine allows for adding states and changing conditions to facilitate transitions between various states without the need to completely reconstruct the maximum power output method. The maximum output power of the electric propulsion system is controlled through the state machine, the technical achievement of creating a power control system can be achieved, expansion and modification of the system are relatively simple, and the system is convenient to upgrade.

Description

[0001] Comparison search of relevant applications

[0002] This application claims priority to U.S. Provisional Application No. 63 / 595,995, filed November 3, 2023, entitled “SYSTEM AND METHOD FOR ELECTRIC MACHINE PEAK POWER MANAGEMENT”. The entire contents of the above application are incorporated herein by reference. Technical Field

[0003] This disclosure relates to managing the peak output power of an electric propulsion system. The electric propulsion system may be part of an electric vehicle or a hybrid vehicle. Background Technology

[0004] Electric vehicles can operate continuously at or below their continuous rated operating conditions. Continuous rated operation may be a function of several operating conditions, which may include, but are not limited to, load (such as driver demand load), component temperature, and cooling system capacity. If components of the electric propulsion system (such as inverters, cables, motors, etc.) operate beyond their continuous rated operating conditions, it may lead to a degradation in electric propulsion performance. However, electric propulsion systems can also operate beyond their continuous operating conditions for a period of time without system degradation. This period may depend on the operating conditions of the propulsion system and the specifications of the electric propulsion system. To improve vehicle drivability and performance, it may be necessary to operate the electric propulsion system for less time than this continuous rated operating time. For example, the electric propulsion system should ideally operate beyond its continuous rated operating time during gear shifts or when passing another vehicle. Individual components of the propulsion system may include hardware or software monitors to enforce the operational limitations of the electric propulsion system, but programming an electric propulsion system can be very complex and difficult to understand when a large number of inputs and conditions need to be considered. Furthermore, updating and diagnosing an electric propulsion system that may involve a large number of input and conditional statements can be both difficult and time-consuming. Utility Model Content

[0005] The inventors recognized the above-mentioned problems and developed an electric propulsion system comprising an electric motor; an inverter electrically coupled to the electric motor; and one or more controllers including executable instructions that cause the controllers to generate a state machine configured to control the maximum power output of the electric propulsion system, wherein the state machine is at any given time in exactly one of a plurality of states, including at least one state that allows the output power of the electric propulsion system to exceed the continuous rated output power of at least one component of the electric propulsion system, and at least one state that allows the output power of at least one component of the electric propulsion system to be limited to less than the continuous rated output power of at least one component.

[0006] By controlling the maximum output power of an electric propulsion system using a state machine, a power control system can be created. This system is relatively simple to expand and modify, facilitating system upgrades. Furthermore, the state machine makes it easier to understand and diagnose the operation of the power control system during the use of the electric propulsion system.

[0007] This specification offers several advantages. In particular, this approach simplifies the design of power control for electric propulsion systems. Furthermore, it allows for system diagnostics in a manner that makes system operation easier for technicians to assess. Additionally, the state machine allows for the addition of other states without requiring significant effort.

[0008] It should be understood that the foregoing summary is intended to present the concepts further described in the detailed description in a simplified form. It is not intended to identify the key features of the claimed subject matter, the scope of which is uniquely determined by the claims following the detailed description. Furthermore, the claimed subject matter is not limited to embodiments that address any of the shortcomings pointed out in the foregoing or any part of this disclosure. Attached Figure Description

[0009] Figure 1 This is a schematic diagram of an example vehicle that includes an electric vehicle propulsion system.

[0010] Figure 2A-2C An example of an electric vehicle configuration is shown.

[0011] Figure 3 An example state machine is shown that controls the maximum output power of an electric propulsion system.

[0012] Figure 4 Display according to Figure 3 state machines and Figure 1-2C An example of the vehicle operation sequence of the system. Detailed Implementation

[0013] This paper describes a method and system for controlling the maximum or peak power output of a vehicle's electric propulsion system. The electric propulsion system can be installed in an electric vehicle or a hybrid vehicle. In one example, the electric propulsion system is installed in... Figure 1 Among the vehicles shown. Figure 2A-2C An example of a drivetrain system for a vehicle with an electric propulsion system is shown. Figure 3 The state machine used to control the maximum output power of the electric propulsion system is shown. Figure 4 Showing according to Figure 3 An example of a state machine-based maximum power output control sequence for an electric propulsion system.

[0014] Figure 1 An example of a vehicle propulsion system 199 for vehicle 10 is shown. Figure 1 In this diagram, mechanical connections between components are represented by solid lines, while electrical connections are represented by dashed lines. 110 represents the front end of the vehicle, and 111 represents the rear end. When the front end 110 moves the vehicle 10, the vehicle 10 moves forward. When the rear end 111 guides the vehicle 10, the vehicle 10 moves in the opposite direction. In this example, the vehicle 10 is a rear-wheel drive vehicle, but in other examples, the vehicle 10 may be a four-wheel drive or front-wheel drive vehicle.

[0015] The vehicle propulsion system 199 includes a propulsion source 105 (e.g., an electric motor), but in other examples, two or more propulsion sources may be provided. In one example, propulsion source 105 may be a synchronous or induction motor, which may operate as a motor or generator. In other examples, propulsion source 105 may be a direct current (DC) machine. The vehicle propulsion system 199 also includes a transmission 135. Propulsion source 105 is mounted on transmission 135, which supplies power from rotor 105a to transmission 135. Transmission 135 may be mechanically connected to differential gear 106. Differential gear 106 may be coupled to two shafts, including a first or right axle 190a and a second or left axle 190b. The vehicle 10 also includes front wheels 102 and rear wheels 103.

[0016] The 135 transmission can be called a stepped ratio transmission, and its configuration can be as follows: Figure 2A-2CAs shown in more detail, different configurations are also possible. The transmission 135 may include one or more clutch actuators (not shown) for shifting gears using one or more clutches. The transmission 135 may include a first speed sensor 119 for sensing the speed of the propulsion source 105 and a second speed sensor 185 for sensing the speed of the transmission output shaft. A power inverter 115 is electrically coupled to the propulsion source 105 for converting direct current (DC) to alternating current (AC) and vice versa. The powertrain controller 116 is electrically connected to sensors 117 and actuators of the vehicle propulsion system 199. For example, sensors 117 may include, but are not limited to, inverter switch temperature sensors, motor winding temperature sensors, bus temperature sensors, etc.

[0017] The gearbox 135 can transmit mechanical power to or receive mechanical power from the differential gear 106. The differential gear 106 can transmit mechanical power to or receive mechanical power from the rear wheel 103 via the right axle 190a and the left axle 190b. The propulsion source 105 can consume alternating current (AC) power supplied by the power inverter 115. Alternatively, the propulsion source 105 can supply AC power to the power inverter 115. The power inverter 115 can obtain high-voltage direct current (DC) power from the battery 160 (e.g., a traction battery, also referred to as an energy storage device or battery pack). The power inverter 115 can convert the DC power from the battery 160 into AC power for use by the propulsion source 105. Additionally, the power inverter 115 can also supply AC power from the propulsion source 105. The power inverter 115 can convert the AC power from the propulsion source 105 into DC power for storage in the battery 160.

[0018] The propulsion source 105 can transmit mechanical power to or receive mechanical power from the gearbox 135. Therefore, the gearbox 135 can be a multi-speed gear set that can shift gears when commanded by the powertrain controller 116. The powertrain controller 116 includes a processor 116a and a memory 116b. The memory 116b (e.g., a storage medium) may include dedicated read memory, random access memory, and persistent memory. The memory can be programmed with computer-readable data representing processor-executable instructions for performing the methods and control techniques described herein, as well as other contemplated but not specifically listed variations. Therefore, the control techniques, methods, etc., described herein can be stored as instructions in non-transitory memory.

[0019] Battery 160 can periodically receive electrical energy from a power source, such as a stationary power grid 5 located outside the vehicle (e.g., not part of the vehicle). As a non-limiting example, vehicle propulsion system 199 can be configured as a plug-in electric vehicle (EV) to supply electrical energy to battery 160 via stationary power grid 5 and charging station 12. Charge can be delivered to battery 160 via plug socket 100.

[0020] Battery 160 may include BMS controller 139 (e.g., battery management system controller) and power distribution box 162. BMS controller 139 provides charging balancing between energy storage elements (e.g., battery cells) and communication with other vehicle controllers (e.g., vehicle control unit 152). BMS controller 139 includes a core processor 139a and memory 139b (e.g., random access memory, read-only memory, and keep-update memory).

[0021] Vehicle 10 may include a vehicle control unit (VCU) 152, which can communicate via a controller area network (CAN) 120 with a power inverter 115, a powertrain controller 116, a friction or basic brake controller 170, a global positioning system (GPS) 188, a BMS controller 139, and an instrument panel 186 and components therein. VCU 152 includes a memory 114, which may include dedicated read memory (ROM or non-temporary memory) and random access memory (RAM). VCU also includes a digital processor or central processing unit (CPU) 153 and input and output (I / O) 118 (e.g., digital inputs, digital outputs, analog inputs, and analog outputs, including counters, timers, and discrete inputs). VCU may receive signals from sensors 154 and provide control signal outputs to actuators 156. Sensors 154 may include, but are not limited to, lateral acceleration sensors, longitudinal acceleration sensors, yaw rate sensors, tilt sensors, temperature sensors, battery voltage and current sensors, and other sensors described herein. In addition, sensor 154 may also include steering angle sensor 197, driver demand pedal position sensor 141, vehicle distance sensors (including radio detection and ranging (RADAR), light detection and ranging (LIDAR), sound navigation and ranging (SONAR), and brake pedal position sensor 151). Actuators may include, but are not limited to, the inverter, transmission controller, display device, human-machine interface, friction braking system, and battery controller described herein.

[0022] Driver demand pedal position sensor 141 is connected to driver demand pedal 140 and is used to determine the degree to which human 142 depresses driver demand pedal 140. Brake pedal position sensor 151 is connected to brake pedal 150 and is used to determine the degree to which human 142 depresses brake pedal 150. Steering angle sensor 197 is configured to determine the steering angle based on the position of steering wheel 198.

[0023] The vehicle propulsion system 199 includes a global positioning system 188 that receives timing and location data from one or more GPS satellites 189. The global positioning system may also include a geographic map in ROM for determining the location of the vehicle 10 and the characteristics of the roads that the vehicle 10 may travel on.

[0024] The vehicle propulsion system 199 may also include an instrument panel 186 with which the vehicle operator can interact. The instrument panel 186 may include a display system 187 configured to display information to the vehicle operator. As a non-limiting example, the display system 187 may include a touchscreen or human-machine interface (HMI) display, enabling the vehicle operator to view graphical information and input commands. In some examples, the display system 187 may be wirelessly connected to the Internet (not shown) via the VCU 152. Therefore, in some examples, the vehicle operator may communicate with a website or software application (app) and the VCU 152 via the display system 187.

[0025] The dashboard 186 may further include an operator interface 182 through which the vehicle operator adjusts the vehicle's operating status. Specifically, the operator interface 182 may be configured to activate and / or deactivate the operation of the vehicle's drivetrain (e.g., propulsion source 105) based on operator input. Additionally, the operator may request axle modes (e.g., parking, reverse, neutral, drive) through the operator interface. Various examples of the operator interface 182 may include an interface utilizing a physical device (such as a key) that can be inserted into the operator interface 182 to activate the vehicle propulsion system 199, including propulsion source 105, and to turn on the vehicle 10. Removing the device deactivates the transmission 135 and propulsion source 105, thereby turning off the vehicle 10. Propulsion source 105 can be activated by supplying power to propulsion source 105 and / or power inverter 115. Propulsion source 105 can be deactivated by stopping the supply of power to propulsion source 105 and / or power inverter 115. There are also examples where an additional or selective start / stop button may be used, manually pressed by the operator, to start or stop propulsion source 105, thereby turning the vehicle on or off. In other examples, remote electrification of the axles or motors can be initiated via a remote computing device (not shown), such as a cellular phone or a smartphone-based system, where the user's cellular phone sends data to a server, which communicates with the vehicle control unit 152 to activate the inverter 115 and the propulsion source 105. The spatial orientation of the vehicle 10 is indicated by axle 175.

[0026] The figure also shows a base or friction brake controller 170 for vehicle 10. The friction brake controller 170 can selectively apply and release the friction brakes (e.g., 172a and 172b) by allowing hydraulic fluid flow to the friction brakes. The application and release of the friction brakes prevents the friction brakes from locking the front wheels 102 and rear wheels 103. Wheel position or vehicle speed sensors 161 provide wheel speed data to the friction brake controller 170. A vehicle propulsion system 199 provides torque to the rear wheels 103 to propel vehicle 10.

[0027] A human or autonomous driver can request wheel torque or power from the driver by pressing the driver request pedal 140 or by sending a driver request wheel torque / power request to the vehicle control unit 152. The vehicle control unit 152 can then instruct the powertrain controller 116 to request torque or power from the propulsion source 105. The powertrain controller 116 can command the power inverter 115 to provide the driver-requested wheel torque / power via the electrified axle 190 and the propulsion source 105. The power inverter 115 converts the direct current (DC) from the battery 160 to alternating current (AC) and supplies the AC to the propulsion source 105. The propulsion source 105 rotates and transmits torque / power to the transmission 135. The transmission 135 transmits the torque from the propulsion source 105 to the differential gear 106, which transmits the torque from the propulsion source 105 to the rear wheels 103 via shafts 190a and 190b.

[0028] When the driver requests the pedal to be fully released, and the vehicle 10's speed exceeds a threshold speed, the vehicle control unit 152 may request a small amount of negative braking power or regenerative braking power to gradually slow down the vehicle 10. The requested regenerative braking force can be a function of the driver's requested pedal position, battery state of charge (SOC), vehicle speed, and other conditions. If the driver requests the pedal 140 to be fully released and the vehicle speed is below a threshold speed, the vehicle control unit 152 may request the propulsion source 105 to provide a small amount of positive torque / power (e.g., propulsion torque), which may be referred to as climbing torque or climbing power. Creep torque or power can keep the vehicle 10 stationary when traveling on a gentle incline.

[0029] A human or autonomous driver can also request negative or regenerative braking torque, or driver-required braking force, by pressing the brake pedal 150 or by issuing a driver-required braking force request to the vehicle control unit 152. The vehicle control unit 152 can instruct the powertrain controller 116 to request the generation of a first portion of the driver-required braking force via the propulsion source 105. Furthermore, the vehicle control unit 152 can also request a portion of the driver-required braking force to be provided via the friction brake controller 170 and the friction brake 172, to provide a second portion of the driver-required braking force.

[0030] After the vehicle control unit 152 determines the braking power request, it can command the powertrain controller 116 to allocate a portion of the braking power requested by the driver to the propulsion source 105. The propulsion source 105 can convert the vehicle's kinetic energy into alternating current.

[0031] The powertrain controller 116 includes a predetermined transmission shift schedule, according to which the fixed-ratio gears of the transmission 135 can be selectively engaged and disengaged. The shift schedule stored in the powertrain controller 116 can select shift points or events based on the wheel torque and vehicle speed requested by the driver.

[0032] Looking at it now Figure 2A , Figure 2A A first example of a vehicle propulsion system 199 is shown. For example, vehicle 10 can be a passenger car, commercial vehicle, or off-highway vehicle such as a wheel loader, excavator, dump truck, material handling vehicle, tractor, harvester, mining truck, etc. Off-highway vehicles are those whose size, weight, and / or maximum speed make them unsuitable for use on highways and other roads under certain circumstances. Vehicle propulsion system 199 includes a propulsion source 105 and a gearbox 135. In the illustrated example, propulsion source 105 is electrically coupled to inverter 115 via electrical connection 209 (e.g., multiphase wires, busbars, combinations thereof, etc.). Therefore, in the illustrated example, propulsion source 105 is an alternating current (AC) motor. More specifically, the traction motor can be a multiphase (e.g., three-phase or multi-phase) AC motor. In one specific use case, the propulsion source can be a three-phase AC motor. However, in other examples, vehicle propulsion system 199 can use a direct current (DC) propulsion source.

[0033] Inverter 115 can be electrically connected to battery 160. Therefore, when propulsion source 105 is operating as a motor, electrical energy can flow between inverter 115 and battery 160 during drive operation and regenerative operation.

[0034] The vehicle propulsion system 199 may further include one or more drive axle assemblies 212 mechanically coupled to an output interface 214, which may be included in a transmission 135. In one example, the drive axle assembly may be a rear drive axle assembly. The drive axle assembly may include a differential, axles (e.g., half-shafts) coupled to the associated differential, drive wheels coupled to the axles, etc. The drive wheels may be mounted on hubs and may contact driving surfaces during vehicle operation.

[0035] The propulsion source 105 may include components such as a rotor and a stator, which generate power through electromagnetic interactions during operation. Additionally, in one example, the motor may be a generator designed to generate electrical energy during regenerative operation.

[0036] The transmission 135 may include an input shaft 213 that is mechanically connected (e.g., a direct mechanical connection) to the rotor shaft in the propulsion source 105. Splines, bolts, and flanges, combinations thereof, and / or the like may be used to form the mechanical connection between the rotor shaft and the input shaft 213. The inputs and outputs of the transmission 135 generally represent the power flow that occurs when the vehicle is in a driven state, in which mechanical power is transmitted from the traction motor to the drive wheels to propel the vehicle in a desired direction (e.g., forward or reverse drive direction). However, it is understood that during regenerative operation, the direction of the mechanical power flow is reversed (e.g., from the drive wheels to the traction motor).

[0037] In the illustration, input shaft 213 is fixedly connected to gear 218. This fixed coupling allows both components to rotate together. Furthermore, as shown, gear 218 meshes with gear 220 on shaft 222 (e.g., an idler shaft). Gear 220 is fixedly connected to shaft 222. However, in other examples, other gear arrangements and / or other mechanical connections may be established between the input shaft and the idler shaft.

[0038] In the illustrated embodiment, the gearbox 135 also includes: a first friction clutch 228 that may be mounted on shaft 222; and a second friction clutch 226 that may be mounted on output shaft 224. The second friction clutch 226 may be associated with a second operating gear ratio formed between gears 230 and 232. Gear 232 may be secured to output shaft 224 via bearing 233. Therefore, when the second friction clutch 226 is disengaged, gear 232 and output shaft 224 can rotate independently. Similarly, the first friction clutch 228 may be associated with a first operating gear ratio formed between gears 234 and 236. The second operating gear ratio may be greater than the first operating gear ratio. Therefore, the first operating gear ratio can be used during vehicle start-up and low-speed maneuvering. Conversely, the second operating gear ratio can be used during higher-speed maneuvering. However, in other examples, the first operating gear ratio may be greater than the second operating gear ratio.

[0039] The first friction clutch 228 may include an inner plate bracket 238 (e.g., a hub) fixedly connected to a shaft 222 and an outer plate bracket 240 (e.g., a drum) fixedly connected to a gear 234. Each plate bracket may include several sets of plates 241 designed to engage and disengage frictionally during clutch disengagement and engagement, respectively. More specifically, these plates (e.g., friction discs and spacers) may be staggered to selectively transmit torque. For example, friction plates may be splined to a carrier. However, other plate and carrier connection techniques may also be considered. The gear 234 may be statically mounted on the shaft 222. For example, the gear 234 may be secured to the shaft 222 using a bearing 242. The bearing described herein may include an outer raceway, an inner raceway, or rolling elements (e.g., balls, cylinders, tapered cylinders, etc.). Free-running mounting refers to connecting the gear to the shaft so that the gear and shaft can rotate independently. In the illustration, gear 234 meshes with gear 236 fixedly connected to the output shaft 224.

[0040] The second friction clutch 226 may include an outer plate bracket 244 fixedly connected to the gear 232, an inner plate bracket 246 fixedly connected to the output shaft 224, and a plate 248 in the two brackets. Therefore, the second friction clutch 226 may have a structure similar to that of the first friction clutch 228.

[0041] Friction clutches 226 and 228 can be wet friction clutches to reduce clutch temperature during gear shifting and decrease the likelihood of overheating. Therefore, in such an example, friction clutches 226 and 228 can receive lubricant (e.g., natural and / or synthetic oil) from lubrication system 250. Lubrication system 250 may include oil sump, pump, lines, conduits, valves, etc., for collecting lubricating oil and delivering it to the clutch and other components requiring lubrication, such as bearings and gears. Furthermore, in one example, lubrication system 250 may also be designed as a hydraulic drive circuit, enabling the friction clutch to be hydraulically actuated. For example, the friction clutch may include a hydraulically driven piston in fluid communication with the drive circuit. However, in other examples, the hydraulic actuation circuit may be formed in a separate system independent of the lubrication system, or the friction clutch may be electrically and / or pneumatically actuated.

[0042] Friction clutches 226 and 228 are located on different shafts of the transmission, which allows for greater space efficiency and load distribution. However, in other examples, the clutches can be coaxially mounted on the same shaft.

[0043] Output interface 214 (such as a spline, flange, yoke, etc.) can be used to connect output shaft 224 to downstream components. Specifically, as shown by arrow 252, a mechanical connection can be established between the output interface and drive axle assembly 212. Shafts, joints, gears, chains, and combinations thereof can be used to establish the mechanical connection between the output interface and the drive axle assembly.

[0044] Understandably, in other examples, gearbox 135 may include additional shafts, gears, and / or clutches, which may have different layouts. For example, gearbox 135 may include a second idler shaft on which another clutch is mounted, and / or an additional shaft as an output shaft. Therefore, in other examples, gearbox 135 may have three or more speeds. However, increasing the number of available working gears in the gearbox increases its size and complexity. Therefore, a two-speed gearbox may be particularly suitable to reduce its size, complexity, and the likelihood of component degradation. Using a two-speed gearbox may be particularly suitable for traction motors because the power band of an electric motor is wider than that of an internal combustion engine, etc.

[0045] The storage medium can be programmed with computer-readable data representing processor-executable instructions for carrying out the methods and control techniques described herein, as well as other anticipated but not specifically listed variations. Therefore, the control techniques, methods, etc., described herein can be stored as instructions in non-transitory memory.

[0046] Figure 2A as well as Figure 2B and 2C The system of axes provided is for reference. In one example, the z-axis may be a vertical axis (e.g., parallel to the gravity axis), the x-axis may be a transverse axis (e.g., a horizontal axis), and / or the y-axis may be a longitudinal axis. However, in other examples, these axes may have other orientations.

[0047] The propulsion source 105 can be configured to rotate the rotor shaft in opposite directions, which corresponds to forward and reverse drive. Therefore, in such an example, the gearbox 135 can be designed with the same number of forward and reverse drive gears. However, in other examples, the gearbox can have an asymmetrical number of forward and reverse gear ratios.

[0048] Figure 2B and 2C The mechanical power paths 270 and 280 of the transmission 135 of the vehicle propulsion system 199 are shown respectively in the first and second operating gears. Figure 2B and 2CIn this configuration, inverter 115 transmits electrical energy to propulsion source 105, which generates mechanical power and inputs that power into transmission 135. However, as mentioned earlier, in other embodiments, inverter 115 may be omitted from the powertrain system.

[0049] In mechanical power paths 270 and 280, power is transmitted from propulsion source 105 to input shaft 213, from input shaft to gear 218, from gear 218 to gear 220, and from gear 222 to shaft 222.

[0050] exist Figure 2B In the power path 270 shown, power is transmitted from shaft 222 to gear 234 via first friction clutch 228, from gear 234 to gear 236, from gear 236 to output shaft 224, and from output shaft 224 to drive axle assembly 212.

[0051] On the other hand, Figure 2C In the power path 280 shown, power flows through the first friction clutch 228, then from the shaft 222 to the gear 230, from the gear 230 to the gear 232, through the second friction clutch 226 from the gear 232 to the output shaft 224, and then from the output shaft 224 to the drive axle assembly 212.

[0052] Figure 1-2CThe system provides an electric propulsion system, including an electric motor, an inverter electrically coupled to the motor, and one or more controllers, including executable instructions that cause the controllers to generate a state machine configured to control the maximum power output of the electric propulsion system. The state machine is in one of a plurality of states at any given time, and the plurality of states includes at least one state that allows the output power of the electric propulsion system to exceed the rated output power of at least one component of the electric propulsion system, and at least one state that allows the output power of at least one component of the electric propulsion system to be limited to less than the rated output power of at least one component. In a first example, the electric propulsion system includes a plurality of states, wherein the transitions between the plurality of states depend on the operating conditions of the electric propulsion system. In a second example that may include the first example, the electric propulsion system includes operating conditions including a first threshold temperature. In a third example that may include one or both of the first and second examples, the electric propulsion system includes operating conditions including a second threshold temperature. In a fourth example that may include one or more of the first to third examples, the electric propulsion system includes operating conditions including enhanced conditions. In a fifth example that may include one or more of the first to fourth examples, the electric propulsion system includes a plurality of states, wherein the plurality of states includes a minimum performance state. In a sixth example, which may include one or more of the first to fifth examples, the electric propulsion system includes multiple states, including an inverter derating state. In a seventh example, which may include one or more of the first to sixth examples, the electric propulsion system includes multiple states, including two enhancement-type states.

[0053] Now for reference Figure 3 The figure shows a graphical view of an example state machine 300 used to manage the maximum or peak power output of an electric vehicle propulsion system. State machine 300 is a representation of a mathematical model that can be implemented using executable controller instructions stored in non-transitory memory, variable values ​​stored in transient memory, and the operating states of devices and / or actuators. State machine 300 can receive inputs indicating vehicle operating conditions (e.g., motor winding temperature, inverter switch temperature, bus temperature, vehicle position, positions of other vehicles around the vehicle, vehicle speed, driver demand, ambient temperature, vehicle route data, engaged transmission gear, etc.). State machine 300 can be viewed as a method for controlling the maximum output torque or power of the vehicle propulsion system.

[0054] In this example, state machine 300 includes five states: 302, 308, 314, 318, and 330. However, in other examples, more or fewer states may be provided. State machine 300 operates in a manner where it can be in only one state at a time. Before transitioning to or entering a state, state machine 300 may perform entry actions (e.g., changing the operating state of an actuator, changing the value of a variable stored in memory, reading the value of a variable stored in memory, determining the operating state of an actuator, etc.). Exit actions (e.g., changing the operating state of an actuator, changing the value of a variable stored in memory, reading the value of a variable stored in memory, determining the operating state of an actuator, etc.) may be performed by state machine 300 when transitioning from or exiting a state. State machine 300 may move from one state (e.g., rated performance state 302) to a second state (e.g., enhancement type 1 state) via transitions (e.g., transition 332). State machine 300 also includes a state group 340, which in this example consists of three states (such as 302, 308, and 330), but in other examples, the state group may include more or fewer groups. State group 340 is a way of indicating that a state entering a state group can enter any state within that group. State group 340 provides a way to minimize the actual total number of transition lines from one state to another, while still indicating that a state can be entered or be entered from any state within the state group.

[0055] State machine 300 can operate in conjunction with other control routines to manage the maximum or peak power output of vehicle propulsion system 199. For example, another control routine can determine the driver-demanded torque or power required by vehicle propulsion system 199. The driver-demanded torque or power can be a function of the driver-demanded pedal position and vehicle speed. The driver-demanded torque or power can be provided to state machine 300, which can output the final driver-demanded torque or power for vehicle propulsion system, which may be a limited version of the driver-demanded torque or power determined based on the driver-demanded pedal position and vehicle speed. For example, if the driver-demanded torque is 350 Nm based on the driver-demanded pedal position and vehicle speed, state machine 300 can command vehicle propulsion system to provide 340 Nm of torque, or provide other constraint values ​​based on vehicle operating conditions when state machine 300 constrains vehicle propulsion system 199. Additionally, state machine 300 can also output a driver-demanded torque or power value that cannot be exceeded in any state of state machine 300, and the driver-demanded torque or power value can be different in each state. Another control routine outside state machine 300 can receive a driver's required torque or power value that is not allowed to be exceeded from state machine 300. The external control routine can adjust the driver's required torque or power so that the final driver's required torque or power of the vehicle propulsion system is equal to or less than the driver's required torque or power value that is not allowed to be exceeded. For example, if the driver's required torque is determined to be 350 Nm based on the driver's required pedal position and vehicle speed, and if the final driver's required torque of the vehicle propulsion system does not exceed 330 Nm, then the control routine that receives the final driver's required torque of the vehicle propulsion system can command the vehicle propulsion system to provide 330 Nm of torque.

[0056] In one example, rated performance state 302 is a state in which the driver's required torque or power may be limited to a first threshold level less than or equal to the driver's required torque or power. The first threshold level for the driver's required torque or power may be based on the maximum torque or power that the vehicle propulsion system can continuously output (e.g., for a threshold time, such as 10 minutes) without causing the vehicle propulsion system components to exceed their respective threshold temperatures and / or return to lower output. When state machine 300 is in rated performance state, state machine 300 limits the commanded torque or power and / or output torque or power of the vehicle propulsion system to less than or equal to the first threshold driver's required torque or power. The commanded torque or power or output torque or power of the vehicle propulsion system can be achieved by limiting the magnitude of the current supplied to propulsion source 105 and / or inverter 115. When transitioning from another state to rated performance state 302, the commanded torque or power or output torque or power of the vehicle propulsion system can be limited to less than or equal to the first threshold level by increasing or decreasing the commanded torque or power, or increasing or decreasing the output torque or power.

[0057] The vehicle propulsion system can operate in a minimum performance state 308 by limiting the driver's required torque or power to a second threshold level, where the second threshold level is lower than a first threshold level. The second threshold level can be based on the driver's required torque or power output when the heat generated by the vehicle propulsion system within a specified time (e.g., 5 minutes) is less than a threshold. When state machine 300 is in the minimum performance state 308, it limits the commanded torque or power and / or output torque or power of the vehicle propulsion system to less than or equal to the second threshold driver's required torque or power. The commanded torque or power, or output torque or power, of the vehicle propulsion system can be limited to less than or equal to the first threshold level by reducing the commanded torque or output torque or power of the vehicle propulsion system when transitioning from another state to the minimum performance state 308.

[0058] The vehicle propulsion system can operate in Enhancement Type 1 state 330 by limiting the driver's required torque or power to a third threshold level (where the third threshold level is greater than the first threshold level). The third threshold level for the driver's required torque or power can be based on the maximum torque or power that the vehicle propulsion system can output, the duration of which is longer than the first threshold time but less than the duration of the first threshold time (e.g., longer than 1 minute but less than 10 minutes). The third threshold level for the driver's required torque or power is greater than the first level of the driver's required torque or power. When state machine 300 is in Enhancement Type 1 state 330, state machine 300 limits the commanded torque or power and / or output torque or power of the vehicle propulsion system to be less than or equal to the third threshold level for the driver's required torque or power. When transitioning from another state to Enhancement Type 1 state 330, the commanded torque or power or output torque or power of the vehicle propulsion system can be limited to less than or equal to the third threshold level by increasing or decreasing the commanded torque or power or output torque or power of the vehicle propulsion system.

[0059] The vehicle propulsion system can operate in Enhancement Type 2 state 318 by limiting the driver's required torque or power to a fourth threshold level (where the fourth threshold level is greater than the third threshold level). The fourth threshold level for driver-required torque or power can be based on the maximum torque or power that the vehicle propulsion system can output within a time period exceeding a second threshold but less than a third threshold (e.g., exceeding 3 seconds but less than 2 minutes). The fourth threshold level for driver-required torque or power is greater than the third threshold level. When state machine 300 is in Enhancement Type 2 state 318, state machine 300 limits the commanded torque or power and / or output torque or power of the vehicle propulsion system to be less than or equal to the fourth threshold driver-required torque or power.

[0060] In this example, the final state that state machine 300 might occupy is inverter derating state 314. In one example, inverter derating state 314 is a state where the output current of inverter 115 is limited to a first threshold current level. The first threshold current level can be based on the specifications of the devices within the inverter and other vehicle operating conditions. State machine 300 can limit the inverter's current output by adjusting the on and / or off times of the inverter switch that generates AC power from the DC power supply. The commanded motor current can be limited by limiting the magnitude of the inverter commanded current. When transitioning from another state to inverter derating state 314, the inverter commanded current can be limited to a level less than or equal to the first threshold current level by reducing the maximum inverter current threshold.

[0061] To determine the conditions for transitions between various states, vehicle operation can be monitored under selected conditions. Specifically, during vehicle calibration, it can be determined that enhancements are needed under selected vehicle operating conditions. Furthermore, the selected vehicle operating conditions can be determined based on variable values. Therefore, variable values ​​can be used to control the transitions between enhancement performance types 1 and 2, as well as other states. For example, during vehicle calibration, it can be determined that enhancement performance type 1 or enhancement performance type 2 is desirable when the current vehicle passes a second vehicle, during vehicle startup (e.g., acceleration from zero speed), during gearbox shifting, when vehicle speed increases, when the vehicle travels in an unexpected direction, during a specific vehicle speed range or window, when the road gradient exceeds a threshold, and under other vehicle operating conditions. The outputs of various vehicle sensors can be used as a basis to determine whether the vehicle operating conditions indicate a request or desire to exit a first specific state and enter a second specific state. The transitions between the various states of state machine 300 may also include pre-lowering at least a portion of the vehicle propulsion system 199 based on one or more temperatures within the vehicle propulsion system 199.

[0062] Transitions between various states may be as described herein, but it is understood that, based on the description herein, transitions between various states are not limited. The transition from rated performance state 302 to minimum performance state 308 may be performed as indicated by arrow 304 in response to the temperature of the vehicle propulsion system 199 being equal to or greater than a first threshold temperature. By transitioning from rated performance state 302 to minimum performance state 308, the vehicle propulsion system 199 may be pre-cooled in the event that the vehicle propulsion system 199 returns to rated performance state 302 and then enters enhanced type 1 state 330 or enhanced type 2 state 318, in order to reserve thermal headroom for operation of the vehicle propulsion system 199 in enhanced type 1 state 330 or enhanced type 2 state 318. The operation from rated performance state 302 to minimum performance state 308 may include gradually reducing the required driver-demanded torque or power by progressively limiting the driver-demanded torque or power to below a threshold, or by progressively reducing the value not exceeding the driver-demanded torque or power. The driver-demanded torque or power, or the instruction to the driver-demanded torque or power, may be limited to a fixed value or a value that varies according to vehicle operating conditions. The state machine 300 can transition from a minimum performance state 308 to a rated performance state 302, as indicated by arrow 306, in response to the temperature of the vehicle propulsion system 199 falling below a first threshold temperature.

[0063] State machine 300 can exit rated performance state 302 and enter enhanced performance type 1 state, as indicated by arrow 332, in response to the satisfaction of conditions for entering enhanced performance type 1 state. These conditions may include, but are not limited to, the vehicle performing a gear shift, the vehicle overtaking a second vehicle, the vehicle moving in an unexpected direction (e.g., the vehicle rolling in the opposite direction after parking on a hillside while the vehicle's transmission is in drive), the vehicle traveling on a road with a gradient greater than a threshold gradient, and an increase in vehicle speed. Enhanced type 1 state may have lower priority than enhanced type 2 state. Enhanced type 1 state 330 can be entered from rated performance state 302 when enhanced type 1 state 330 is needed but its urgency is lower than enhanced type 2 state 318. State machine 300 can enter rated performance state 302 from enhanced type 1 state 330 (as indicated by arrow 334) in response to at least one condition in enhanced type 1 state 330 not being satisfied. The transition from rated performance state 302 to enhanced type 1 state 330 may include gradually reducing the limitation on the driver's required torque or power by increasing a threshold, or gradually increasing the required driver's required torque or power by gradually increasing a value not exceeding the driver's required torque or power. State machine 300 may also transition from enhanced type 1 state 330 to minimum performance state 308 in response to a temperature of the vehicle propulsion system 199 equal to or greater than a first threshold temperature, as indicated by arrow 336. By transitioning from enhanced type 1 state 330 to minimum performance state 308, the vehicle propulsion system 199 can be pre-cooled when it enters enhanced type 2 state 318, thus preserving thermal headroom for continued operation in enhanced type 2 state 318. Compared to operation in rated performance state 302, enhanced type 1 state 330 allows the vehicle propulsion system 199 to generate greater torque and power.

[0064] As indicated by arrow 320, in particularly urgent situations, such as when passing another vehicle or turning onto a busy road, state machine 300 can transition from rated performance state 302, minimum performance state 308, or enhanced type 1 state 330 to enhanced type 2 state 318. State machine 300 can exit enhanced type 2 state 318 and, as indicated by arrow 322, transition from enhanced type 2 state 318 to rated performance state 302, minimum performance state 308, or enhanced type 1 state 330 in response to at least one condition for entering enhanced type 2 state 330 not being met. Furthermore, state machine 300 can exit enhanced type 2 state 318 and enter inverter derating state 312 in response to the temperature of the vehicle propulsion system 199 exceeding a second threshold temperature (where the second threshold temperature is greater than the first threshold temperature), as indicated by arrow 316. The transition from rated performance state 302, enhanced type 1 state 330, or minimum performance state 308 to enhanced type 2 state 318 may include gradually reducing the limitation on the driver's required torque or power by increasing a threshold, or gradually increasing the required driver's required torque or power by gradually increasing the threshold by no more than the value of the driver's required torque or power. Compared to operation in enhanced type 1 state 330, enhanced type 2 state 318 allows the vehicle propulsion system 199 to generate greater torque and power.

[0065] State machine 300 can enter inverter derating state 314 from minimum enhanced state 308 or enhanced performance type 2 state 318, as indicated by arrows 316 and 310, in response to the temperature of vehicle propulsion system 199 exceeding a second threshold temperature, wherein the second threshold temperature is greater than a first threshold temperature. When the temperature of vehicle propulsion system 199 falls below the second threshold temperature, state machine 300 can exit inverter derating state 314, as indicated by arrow 312. The operation of entering inverter derating state 314 from minimum performance state 308 or enhanced performance type 2 state 318 may include gradually reducing the maximum inverter output current.

[0066] Therefore, state machine 300 allows the vehicle propulsion system to move between several states to control the maximum or peak power output of the electric propulsion system. The state machine states may include two boost states, where the torque or power output of the electric propulsion system can exceed its rated power output, and two depress the output of the electric propulsion system to reduce the likelihood of system degradation.

[0067] State machine 300 provides a method for operating a vehicle, including: moving between states of the state machine to control the maximum power output of an electric propulsion system, wherein the state machine includes multiple states and allows the state machine to enter exactly one state at a time, and the electric propulsion system to enter exactly one state at a time. In a first example, the method further includes adjusting one or more control parameters to transition from a first state to a second state among the multiple states. In a second example that may include the first example, the method further includes receiving input and moving between states based on the input. In a third example that may include one or both of the first and second examples, the method includes states comprising a set of states, wherein each state within the state set can be entered from a state outside the state set based on vehicle operating conditions. In a fourth example that may include one or more of the first to third examples, the method includes states comprising a minimum performance state and an inverter derating state. In a fifth example that may include one or more of the first to fourth examples, the method includes states that also include two enhancement-type states. In a sixth example that may include one or more of the first to fifth examples, the method includes the maximum power output being increased to be greater than the rated power output when the state machine is in either of the two enhancement-type states.

[0068] The state machine 300 also provides a method for operating a vehicle, the method comprising: responding to movement between states of the state machine, constraining the driver-demanded torque or power of the vehicle propulsion system to control the maximum torque or power output of the electric propulsion system, wherein the state machine includes multiple states and allows entering exactly one state of the state machine and one electric propulsion system state at a time, constraining the driver-demanded torque or power including adjusting the maximum commanded driver-demanded torque or power. In a first example, the method includes multiple states, including an enhanced performance type 1 state and an enhanced performance type 2 state. In a second example that may include the first example, the method includes: when the state machine is in the enhanced performance type 1 state, limiting the driver-demanded torque according to a first temperature threshold; and when the state machine is in the enhanced performance type 2 state, limiting the driver-demanded torque according to a second temperature threshold. In a third example that may include one or both of the first and second examples, the method includes the enhanced performance type 2 state allowing the maximum torque or power output of the electric propulsion system to be greater than that of the enhanced performance type 1 state. In a fourth example that may include one or more of the first to third examples, the method includes the enhanced performance type 2 state and the enhanced performance type 1 state based on vehicle operating conditions indicating the urgency of vehicle movement.

[0069] Figure 4 Showing according to Figure 1-2C System and Figure 3 The maximum power output control sequence of the state machine. Figure 4 The sequence of Figure 1-2C The system and through Figure 3 The state machine representation method is used in conjunction with generation. Figure 4 The graphs in the image are arranged chronologically, with vertical lines representing relevant times within the sequence.

[0070] Figure 4 The first graph at the top shows the relationship between the requested driver torque demand and time. The vertical axis represents the driver torque demand, which increases along the direction of the arrow. The horizontal axis represents time, which increases from left to right on the graph. Trajectory 402 represents the requested driver torque demand.

[0071] Figure 4 The second graph at the top is a graph showing the relationship between the driver's required torque (e.g., the torque generated by the electric propulsion system under command) and time. The vertical axis represents the driver's required torque, which increases along the direction of the arrow on the vertical axis. The horizontal axis represents time, which increases from the left to the right of the graph. Trajectory 404 represents the driver's required torque under command.

[0072] Figure 4 The third image at the top shows the relationship between the power management status of an electric propulsion system and time. The vertical axis represents the power management status of the electric propulsion system, and the numbers on the vertical axis are used for identification. Figure 3 The status identifiers for the shown states are as follows. The horizontal axis represents time, increasing from the left side of the graph to the right. Trajectory 406 indicates the currently active power management state.

[0073] Figure 4 The fourth graph at the top is a graph showing the relationship between enhancement conditions (e.g., conditions where the power output of the electric propulsion system may be higher than the maximum power output of the electric propulsion system under rated operating conditions) and time. The vertical axis represents the enhancement conditions, which are marked along the vertical axis. The horizontal axis represents time, which increases from the left to the right of the graph. Trajectory 408 represents the current enhancement state.

[0074] Figure 4 The fifth graph at the top shows the relationship between vehicle propulsion system temperature (such as motor winding temperature, inverter switch temperature, inverter power bus temperature, etc.) and time. The vertical axis represents vehicle propulsion system temperature, which increases along the direction of the arrows on the vertical axis. The horizontal axis represents time, which increases from the left to the right of the curve. Trajectory 410 represents the vehicle propulsion system temperature. The horizontal dashed line 450 represents the first threshold temperature, and the horizontal dashed line 452 represents the second threshold temperature.

[0075] At time t0, the requested driver torque demand and the commanded driver torque demand are equal. The power management state is at rated performance. The enhancement state is zero, and the vehicle propulsion system temperature is below the first and second threshold temperatures.

[0076] At time t1, both the requested driver torque demand and the commanded driver torque demand decrease to zero. All other operating conditions remain essentially unchanged.

[0077] At time t2, both the requested and instructed driver torque requirements increase to initiate vehicle start-up from zero speed. The power management state changes from rated performance to Enhanced Type 1 to support vehicle start-up. Enhanced state indicates start-up, and the vehicle propulsion system temperature begins to rise. Between time t2 and time t3, the vehicle shifts gears once, and the vehicle propulsion system temperature continues to rise.

[0078] At time t3, the vehicle propulsion system temperature exceeds a first threshold. Therefore, the power management system switches to a minimum performance state, reducing the instruction of driver demand even if the requested driver demand remains essentially unchanged. This may cause the vehicle propulsion system temperature to begin cooling. The enhanced state remains active. At time t4, both the requested and instruction of driver demand decrease.

[0079] At time t5, the vehicle propulsion system temperature drops below the first temperature threshold of 450°C. Therefore, the power management state changes from minimum performance to rated performance. Both the requested driver torque demand and the commanded driver torque demand are zero, and the enhancement state is zero.

[0080] At time t6, the vehicle's driver (not shown) increased both the requested driver torque demand and the commanded driver torque demand. The enhancement condition changed to pass, and the power management state changed to Enhanced Performance Type 2. The vehicle's propulsion system temperature began to rise.

[0081] At time t7, the vehicle propulsion system temperature exceeds the second threshold temperature, therefore the power management state changes to inverter derating state to cool the inverter. The requested driver torque demand remains unchanged, while the commanded driver torque demand decreases. The enhanced state remains in effect.

[0082] At time t8, both the requested driver torque demand and the commanded driver torque demand decrease. As the vehicle propulsion system temperature drops below the second threshold temperature, the enhancement state switches to none, and the power management state switches to the lowest performance state.

[0083] At time t9, the vehicle propulsion system temperature falls below a first threshold temperature, therefore the power management state transitions to rated performance state. Shortly after time t9, the requested driver torque demand equals the commanded driver torque demand. The enhanced state remains unchanged.

[0084] Please note that the control and estimation routine examples contained herein can be used in various powertrain and / or vehicle system configurations. The control methods and routines disclosed herein can be stored as executable instructions in non-transitory memory and can be executed by a control system, including controllers, in conjunction with various sensors, actuators, and other transmission and / or vehicle hardware. Furthermore, some methods may be physical operations performed in the real world to change the state of equipment. Therefore, the described actions, operations, and / or functions can be graphically represented as code programmed into the non-transitory memory of a computer-readable storage medium in the vehicle and / or transmission control system. The specific routines described herein may represent one or more of any number of processing strategies, such as event-driven, interrupt-driven, multitasking, multithreading, etc. Therefore, the various operations, runs, and / or functions illustrated may be executed in the illustrated order, in parallel, or in some cases omitted. Similarly, the processing order is not necessarily necessary to achieve the features and advantages of the examples described herein, but is merely for ease of illustration and description. Depending on the specific strategy used, one or more of the illustrated actions, operations, and / or functions may be repeated. One or more method steps described herein may be omitted if necessary.

[0085] Although various embodiments have been described above, it should be understood that these embodiments are merely examples and not limitations. It will be apparent to those skilled in the art that the disclosed subject matter can be embodied in other specific forms without departing from the spirit of the subject matter. Therefore, the embodiments described above should be considered illustrative rather than restrictive in all respects. Consequently, the configurations and routines disclosed herein are exemplary in nature, and these specific examples should not be considered limiting, as many variations are possible. For example, the above-described techniques can be applied to electric vehicles and hybrid vehicles, including induction and synchronous motors. The subject matter of this disclosure includes all novel and non-obvious combinations and sub-combinations of various systems and configurations, as well as other features, functions, and / or characteristics disclosed herein.

[0086] The following claims specifically point to certain combinations and sub-combinations considered novel and non-obvious. These claims may refer to an element or a "first" element or an equivalent element. These claims are to be understood as including one or more such elements, neither requiring nor excluding two or more such elements. Other combinations and sub-combinations of the disclosed features, functions, elements, and / or characteristics may be claimed by amending these claims or by filing new claims in this application or related applications. These claims, whether broader or narrower in scope, identical or different from the original claims, are also considered to be included in the subject matter of this disclosure.

Claims

1. An electric propulsion system, comprising: a motor; an inverter electrically connected to the motor; and one or more controllers comprising executable instructions that cause the one or more controllers to generate a state machine that controls a maximum power output of the electric propulsion system, wherein the state machine is at exactly one of a plurality of states at a time, the plurality of states including at least one state that allows an output power of the electric propulsion system to exceed a rated output power of at least one component in the electric propulsion system, and at least one state that allows an output power of at least one component in the electric propulsion system to be limited to less than a rated output power of the at least one component. Transition between the plurality of states is dependent on operating conditions of the electric propulsion system.

2. The electric propulsion system of claim 1, characterized in that, The operating conditions of the electric propulsion system include a first threshold temperature.

3. The electric propulsion system of claim 2, wherein, The operating conditions of the electric propulsion system include a second threshold temperature.

4. An electric propulsion system according to claim 3, characterised in that, The operating conditions of the electric propulsion system include an augmentation condition.

5. An electric propulsion system according to claim 4, characterized in that The plurality of states includes a minimum performance state.

6. The electric propulsion system of claim 1, wherein, The plurality of states includes an inverter derated state.

7. The electric propulsion system of claim 1, wherein, The plurality of states includes two augmentation type states.

8. The electric propulsion system of claim 7, wherein, ​

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