Method and system for controlling pole switches in an electric motor

Abstract

Disclosed herein is an electric vehicle comprising: an electric motor switchable between a first mode having a first number of poles and a second mode having a second number of poles smaller than the first number of poles; a plurality of inverters coupled to the electric motor; and a control module coupled to the plurality of inverters. The control module receives current vehicle information, determines based on the current vehicle information that a mode switch is required between a first mode and a second mode of the electric motor, wherein the first mode achieves higher torque than the second mode; and performs the mode switch by controlling the inverter.

Description

Technical Field

[0001] The present disclosure relates generally to electric vehicles and, more particularly, to pole switches for controlling electric motors used in electric vehicles. Background Art

[0002] Electric motors are used in many applications, including electric vehicles that use pole-changing motors to power vehicles. Pole-changing motors (also known as Dahlander motors or two-speed motors) vary the speed of the motor, and thus the torque provided by the motor, by changing the number of poles. With a greater number of poles, the torque is also greater, resulting in a higher output power provided by the motor. Typically, the synchronous speed of a motor is determined by the power supply frequency and the number of poles in the motor windings, with speed being positively correlated with frequency and inversely correlated with the number of poles.

[0003] Pole-changing motors are known for their power efficiency because, compared to other speed control systems (such as variable frequency drives), less power is lost because most of the power is used to drive the motor rather than switching electrical pulses. However, a downside of pole-changing motors is that they experience more rapid wear and tear on mechanical components after frequently changing between different pole numbers. Furthermore, they experience high harmonic distortion during pole changes, which can lead to reduced peak current, heating, radiation, and core losses in the motor.

[0004] In view of the above examples, a need exists for a system that can better control the operation of a pole-changing electric motor so that the motor operates in a manner that optimizes the fuel economy, performance, emissions, and component life of the electric vehicle. Summary of the Invention

[0005] Various embodiments of the present disclosure relate to systems and methods for electric vehicles, including an electric motor switchable between a first mode having a first number of poles and a second mode having a second number of poles smaller than the first number of poles, a plurality of inverters coupled to the electric motor, and a control module coupled to the plurality of inverters. The control module receives current vehicle information, determines based on the current vehicle information that a mode switch is required between a first mode and a second mode of the electric motor, wherein the first mode achieves higher torque than the second mode, and performs the mode switch by controlling the plurality of inverters.

[0006] In one example, the current vehicle information includes one or more of the following: a current motor mode, a current load, and a current vehicle speed. In another example, the control module also receives lookahead information and determines the need for mode switching based on the current vehicle information and the lookahead information. In one aspect of this example, the lookahead information includes predicted route information. Moreover, in another aspect of this example, the predicted route information includes one or more of the following: terrain information, road condition information, and traffic information. In one example, the control module is also configured to receive historical information and determine the need for mode switching based on the historical information. In one aspect of this example, the historical information includes driving mode information.

[0007] This document also discloses a method in an electric vehicle, the electric vehicle having an electric motor that can switch between a first mode having a first number of poles and a second mode having a second number of poles less than the first number of poles, a plurality of inverters connected to the electric motor, and a control module connected to the plurality of inverters. The method includes the following steps: receiving current vehicle information by the control module; determining by the control module based on the current vehicle information that a mode switch is required between a first mode and a second mode of the electric motor, the first mode achieving a higher torque than the second mode; and performing the mode switch by the control module by controlling the plurality of inverters. In one example, the current vehicle information includes one or more of the following items: a current motor mode, a current load, and a current vehicle speed. In one aspect of this example, the method further includes the following steps: receiving forward-looking information by the control module, and the control module determining that a mode switch is required based on the current vehicle information and the forward-looking information. In another aspect of this example, the forward-looking information includes one or more of the following items: terrain information, road condition information, and traffic information. In one example, determining that a mode switch is required includes determining, by a control module, that the motor is currently in a first mode; measuring, by at least one sensor coupled to the motor, a current speed of the vehicle; and determining, by the control module, that a mode switch from the first mode to the second mode is required in response to the current speed increasing to greater than a threshold speed. In one example, determining that a mode switch is required includes determining, by the control module, that the motor is currently in a second mode; measuring, by at least one sensor coupled to the motor, a current speed of the vehicle; and determining, by the control module, that a mode switch from the second mode to the first mode is required in response to the current speed decreasing to less than a threshold speed. In one aspect of this example, the threshold speed may be based on a current vehicle load or mass change. In one example, the method further includes executing, by the control module, a mode switch in response to a user input selecting a towing mode for the vehicle.

[0008] Also disclosed herein is an electric vehicle system including an electric vehicle. The electric vehicle includes: an electric motor that can switch between a first mode having a first number of poles and a second mode having a second number of poles less than the first number of poles, a plurality of inverters connected to the electric motor, and a control module connected to the plurality of inverters, the control module being configured to perform mode switching by controlling the plurality of inverters. The electric vehicle system also includes a transportation management system that is connected to the control module of the electric vehicle. The transportation management system receives current vehicle information and forward-looking information; determines based on the current vehicle information and forward-looking information that a mode switch is required between a first mode and a second mode of the electric motor, the first mode achieving a higher torque than the second mode; and instructs the control module to perform the mode switch. In one example, the transportation management system includes a mapping application and an optimization module.

[0009] While multiple embodiments are disclosed, other embodiments of the present disclosure will become apparent to those skilled in the art from the following detailed description, which shows and describes illustrative embodiments of the present disclosure. Accordingly, the drawings and detailed description are to be regarded as illustrative in nature and not restrictive. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The embodiments will be more readily understood in view of the following description taken in conjunction with the following drawings, wherein like numerals represent like elements. These depicted embodiments are to be understood as illustrative of the present disclosure and not limiting in any way.

[0011] Figure 1 is a block diagram of an electric vehicle according to one embodiment;

[0012] Figure 2 According to one embodiment Figure 1 A block diagram of a pole switch controller in an electric vehicle;

[0013] Figure 3 According to one embodiment Figure 1 Schematic diagram of an AC motor in an electric vehicle;

[0014] Figure 4A and Figure 4B According to one embodiment Figure 1 An illustration of possible pole positions in an AC motor in an electric vehicle;

[0015] Figure 5 is a block diagram of an electric vehicle control system according to one embodiment;

[0016] Figure 6 is a flowchart of a method of determining whether to switch from a mode with a smaller number of poles to a mode with a larger number of poles according to one embodiment;

[0017] Figure 7 is a flowchart of a method of determining whether to switch from a mode with a smaller number of poles to a mode with a larger number of poles according to one embodiment;

[0018] Figure 8 is a flowchart of a method of determining whether to switch from a mode with a greater number of poles to a mode with a smaller number of poles according to one embodiment;

[0019] Figure 9 is a graph showing the relationship between speed and torque / power of a vehicle according to one embodiment;

[0020] Figure 10 is a block diagram of an electric vehicle control system using a cloud network according to one embodiment.

[0021] While the present disclosure is susceptible to various modifications and alternatives, specific embodiments have been illustrated by way of example in the accompanying drawings and are described in detail below. However, it is not intended to limit the present disclosure to the particular embodiments described. On the contrary, the present disclosure is intended to cover all modifications, equivalents, and alternatives falling within the scope of the present disclosure as defined by the appended claims. DETAILED DESCRIPTION

[0022] In the following detailed description, reference is made to the accompanying drawings, which form a part of this detailed description and in which are shown, by way of illustration, specific embodiments in which the present disclosure may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and it is understood that other embodiments may be utilized and structural changes may be made without departing from the scope of the present disclosure. Therefore, the following detailed description is not to be read in a limiting sense, and the scope of the present disclosure is limited only by the appended claims and their equivalents.

[0023] References throughout this specification to "one embodiment," "an embodiment," or similar language are intended to mean that a particular feature, structure, or characteristic described in conjunction with that embodiment is included in at least one embodiment of the present disclosure. The phrases "in one embodiment," "in an embodiment," and similar language that appear throughout this specification may, but need not, all refer to the same embodiment. Similarly, use of the term "implementation" is intended to mean an implementation having a particular feature, structure, or characteristic described in conjunction with one or more embodiments of the present disclosure, although an implementation may be associated with one or more embodiments in the absence of a clear correlation to indicate otherwise. Furthermore, the features, structures, or characteristics of the subject matter described herein may be combined in any suitable manner in one or more embodiments.

[0024] like Figure 1 As shown, according to one embodiment, an electric vehicle 100 includes at least one energy storage device, a set of inverters 104, an alternating current (AC) motor 106, a retarder or braking system 108, and a set of wheels 110. In the illustrated example, the energy storage device is a battery 102, but in other examples, different types of energy storage devices can also be implemented, such as a fuel cell, a capacitor, or a flywheel. The inverters 104 are controlled using a pole switching controller 112, which controls whether the inverters 104 operate synchronously with each other or whether there is a delay between the inverters 104, as will be further described below. The battery 102 can be any suitable battery, including but not limited to lead-acid batteries, nickel-metal hydride batteries, and lithium-ion batteries. The AC motor 106 is an induction motor, also known as an asynchronous motor. The retarder 108 can be a friction braking system that uses brake pads to generate friction with the brake rotor to slow or stop the vehicle, or it can be a regenerative braking system that recovers the vehicle's kinetic energy and converts it into electricity to recharge the battery 102.

[0025] Figure 2An example of components within the pole switching controller 112 is shown, according to one embodiment. The controller 112 includes a processing unit 200 coupled to both a memory unit 202 and a receiver / transmitter 204. The processing unit 200 is also coupled to the inverter 104 and essentially provides electrical signals to the inverter 104, instructing the inverter 104 to function in a certain manner. In some examples, the processing unit 200 can be any suitable processor (such as a system on a chip, a central processing unit (CPU), etc.) and includes a control module that makes decisions regarding whether to switch poles in the motor 106. The memory unit 202 can be any suitable memory, such as static or dynamic random access memory (SRAM or DRAM), flash memory, etc. The receiver / transmitter 204 can be any suitable digital communication module that enables access to external devices. In some examples, the receiver / transmitter 204 can wirelessly receive and transmit data to and from external devices via the Internet and / or an intranet, etc. Moreover, in some examples, digital communication is performed using the Internet, a local area network (LAN), a controller area network (CAN) bus, a cloud network, or any other suitable means known in the art. The transmitter can send instructions to the external device to send data back to the controller 112, and the receiver can receive the transmitted data from the external device and send the data to the processing unit 200. The received data is then used by the processing unit 200 to analyze whether the motor 106 should operate with more poles or fewer poles based on the preferred performance level of the vehicle 100. In some examples, the inverter 104 includes two inverters 206 and 208, wherein the operation of each inverter is controlled by the processing unit 200. Specifically, the processing unit 200 can control the delay between the first inverter 206 and the second inverter 208 to change the number of poles of the motor 106, as explained below.

[0026] Figure 3 1 shows an example of the wiring of the AC motor 106 according to an embodiment. The motor 106 includes a stator 300, which is a stationary electrical component, and a rotor 302, which is a rotating component located inside the stator 300. The stator 300 defines a set of electromagnets 304 ( Figure 3 In the example shown, the electromagnets are numbered 1 to 12 in positions similar to numbers on a clock. The electromagnets are formed by winding wires 306 or 308 around segments of the stator 300 and are activated in the presence of a rotating magnetic field. Electromagnets 1, 2, 5, 6, 9, and 10 are connected to each other by first wires 306. Electromagnets 3, 4, 7, 8, 11, and 12 are connected to each other by second wires 308 (in FIG. Figure 3206 are connected to each other (shown as a thick line in FIG. 1 to distinguish them from the first wire 306). One end of the first wire 306 is connected to the first inverter 206, and the other end is connected to the neutral position 310. And one end of the second wire 308 is connected to the second inverter 208, and the other end is connected to the neutral position 312. In this way, each electromagnet is coupled to the adjacent electromagnet.

[0027] Figure 4A shows the polarity of each electromagnet 1 to 12 in one state according to an embodiment, and Figure 4B The polarity of the same electromagnet in another state according to the same embodiment is shown. Figure 4A The state in occurs when the first inverter 206 is operating in synchronization with the second inverter 208, so the two inverters are controlled so that the polarity of each electromagnet is opposite to the polarity of its neighbor. In this way, the alternating polarity (NSNS...) allows each electromagnet to act as a separate pole providing either a north pole or a south pole to the motor 106. Figure 4A In the example shown, twelve physical poles provide a total of twelve (12) magnetic poles.

[0028] Figure 4B The state in occurs when the second inverter 206 has a 180 degree delay relative to the first inverter 204 (or when the first inverter has a 180 degree delay relative to the second inverter, which will result in the same relative delay between the two inverters 204 and 206), thereby causing the electromagnets 3, 4, 7, 8, 11 and 12 associated with the second inverter 206 to reverse their polarity so that each electromagnet includes one adjacent electromagnet with the same polarity and another adjacent electromagnet with a different polarity. In this way, each pair of adjacent physical poles with the same polarity (e.g., Figure 4B The electromagnet pairs 2-3, 4-5, 6-7, 8-9, 10-11 and 12-1 in FIG operate as a single magnetic pole (e.g., poles I, II, III, IV, V and VI, respectively), so that Figure 4B In the example shown, twelve physical poles are used to provide a total of six (6) magnetic poles. Therefore, the motor 106 is Figure 4A The mode of operation has twelve magnetic poles, but when Figure 4B The mode of operation has only six magnetic poles, even though both modes use twelve physical poles to operate. The difference in the number of poles affects the torque of the electric vehicle 100. Figure 4B The number of poles is halved, the pole pitch and synchronous speed are doubled, but the torque is halved, while the shaft power at standstill is almost the same.

[0029] Figure 51 shows an example of various components that processing unit 200 may access, according to one embodiment. For example, processing unit 200 accesses one or more sensors 500 associated with various components within electric vehicle 100 to determine whether a 180-degree delay is induced in one of inverters 204 or 206, as shown above, by receiving measurement data from sensor 500. In some examples, sensor 500 measures vehicle load or mass, such as the number of passengers or the total weight of the loads on the vehicle. In some examples, the transmission gear ratio is recorded, and sensor 500 senses which transmission gear is currently in use, such as high gear or short gear. In some examples, sensor 500 is a speedometer that measures the speed or velocity of electric vehicle 100. In some examples, sensor 500 is an ammeter that measures ground fault current or leakage current in the event of unintentional contact between an energized conductor and ground or the vehicle frame. In some examples, sensor 500 is a thermistor that measures the temperature of vehicle 100, or more specifically, battery 102 of vehicle 100. In some examples, sensor 500 is a gyroscope that measures the angular velocity of vehicle 100 to maintain the vehicle's orientation, thereby conserving momentum. Other types of sensors are commonly found in electric vehicles, such as position sensors including but not limited to rotational position sensors and angular position sensors, battery monitoring sensors that measure the health and state of charge of battery 102, tire pressure sensors, and other MEMS (micro-electromechanical system) based sensors.

[0030] In some examples, processing unit 200 is coupled to user interface 502 to receive specific instructions from a user regarding the state of electric vehicle 100. For example, a user may need to use vehicle 100 to tow another vehicle from one location to another. In this case, the user can select "Towing Mode" on user interface 502, which sends an instruction to processing unit 200 that vehicle 100 requires more torque to perform towing. Thus, in response to this user input, processing unit 200 observes the number of poles currently in motor 106 and, if twelve poles are present, processing unit 200 takes no action. However, if only six poles are present (i.e., there is a 180-degree delay in one of inverters 206, 208 relative to the other), processing unit 200 eliminates the 180-degree delay, for example by applying an additional 180-degree delay to the already delayed inverter, to synchronize inverters 204 and 206 relative to each other. Furthermore, the user may deactivate "traction mode" after completing the traction, in which case the processing unit 200 may then determine whether to maintain the twelve-pole mode or revert to the six-pole mode based on other factors further described below.

[0031] Another component accessible to processing unit 200 is Intelligent Transportation System (ITS) 504, a transportation management system that provides information to optimize the user's driving experience. For example, ITS 504 includes a mapping application, based on user input or historical data from previous trips, that contains data regarding the grade (also known as "slope" or "incline") of roads and highways within a certain distance from the vehicle's current location or within the area or terrain surrounding the predicted route that vehicle 100 is estimated to take. The mapping application may also include speed limit information and traffic information for the roads and highways that the user is predicted to travel. In some examples, the mapping application also includes the potential rolling resistance that vehicle 100's wheels 110 may experience. Rolling resistance, which depends on the surface's rolling friction coefficient, is the reaction force that vehicle 100 must overcome due to the rolling motion between wheels 110 and the surface on which vehicle 100 is moving. Different road surfaces and road conditions (e.g., concrete, asphalt, gravel, snow, dirt, mud, grass, sand, etc.) have different values ​​for this coefficient. Even with the same contact surface, this coefficient can vary significantly depending on how well-maintained the road is (poorly maintained roads will naturally have higher coefficients than well-maintained roads) or the thickness and softness of the layer of material covering the surface (e.g., snow, dirt, mud, sand). Thus, assuming vehicle 100 is traveling on a road covered with snow or sand, for example, requires more torque than assuming vehicle 100 is traveling on a well-maintained concrete road. In any of these examples, the mapping application is configured to find the best route that takes the shortest time, shortest distance, or any other parameter based on user preferences and current transportation and road condition information.

[0032] By combining this information, processing unit 200 can determine the optimal operating mode for motor 106. In some examples, information transfer between processing unit 200 and any of components 500, 502, and 504 is bidirectional. That is, processing unit 200 can send a request signal to component 500, 502, or 504 to request that the component provide information data to processing unit 200. In some embodiments, information transfer is unidirectional, that is, information is transferred from component 500, 502, or 504 to processing unit 200 with predetermined time intervals between each individual transfer. As described below, this transfer can be performed via wired or wireless communication, as appropriate.

[0033] Figure 6 FIG. 6 shows an example of a method 600 for determining whether a change in the number of poles is required by the processing unit 200 according to an embodiment. In the method 600 , at the start of the method, the motor 106 is in a mode with a smaller number of poles (e.g., Figure 4B), and the processing unit 200 determines whether to maintain a lower number of poles or switch to a higher number of poles. Specifically, in box 602, the processing unit 200 determines whether the speed of the electric vehicle 100 is less than a threshold speed. In some examples, the threshold speed may be less than 20 mph to 30 mph. In some examples, the threshold speed changes based on the vehicle load or mass and whether a traction mode is selected for the vehicle via user input. If the answer to box 602 is "yes," the method proceeds to box 604, where the processing unit determines whether there is an estimated increase in the required torque of the vehicle 100. In some examples, the estimated increase in required torque is caused by an increased load or mass of the vehicle 100, a predicted slope on the road, the need for the vehicle 100 to tow another vehicle, or other suitable conditions in which high torque is desired. If the answer to box 604 is "yes," the method proceeds to box 606, where the processing unit 200 determines to switch the mode of the motor 106 to a higher number of poles. Alternatively, if the answer to box 602 is "no", i.e., the vehicle speed is greater than the threshold, or if the answer to box 604 is "no", i.e., the required torque of the vehicle 100 has not increased as estimated, then in both cases, a smaller number of poles is maintained so that the motor 106 can provide less torque but can provide a faster speed for the vehicle 100 to travel.

[0034] Figure 7 is an example of another method 700 for determining whether a change in pole count is required, according to an embodiment. In block 702, processing unit 200 determines whether the torque demand is greater than a predetermined threshold. If the answer to block 702 is "no," switching to a mode with a higher pole count is not required, so the method proceeds to block 608, where the lower pole count is maintained. If the answer to block 702 is "yes," the method proceeds to block 704, where processing unit 200 determines whether the vehicle speed is greater than a threshold speed, which, as previously described, may be less than 20 mph to 30 mph, according to some examples. If the answer to block 704 is "no," processing unit 200 may switch to a mode with a higher pole count, as in block 606. If the answer to block 704 is "yes," the method proceeds to block 706, where processing unit 200 determines whether the vehicle speed is decreasing, such that the speed of vehicle 100 will eventually reach the threshold speed. If the answer to block 706 is "no," processing unit 200 may proceed to block 710 and decrease the vehicle speed toward the threshold speed.

[0035] In one example, processing unit 200 automatically reduces vehicle speed and notifies the user via user interface 502 that the vehicle speed is being reduced to enable high torque mode. In another example, processing unit 200 uses user interface 502 to display a notification to the user to reduce vehicle speed in consideration of the predicted torque demand. In this example, the user has discretion over when to switch modes, which may be beneficial if the user is reluctant to slow vehicle 100 for various reasons, such as time constraints. In either case, processing unit 200 waits until the vehicle speed decreases to a threshold speed before switching to a mode with a higher number of poles (as indicated by block 708), which will then provide vehicle 100 with higher torque but lower speed.

[0036] Figure 8 Another example of a method 800 for determining whether a pole number change is required according to an embodiment is shown. Method 800 differs from the previously mentioned methods in that, in methods 600 and 700, vehicle 100 is initially in a mode with a smaller number of poles, whereas in method 800, vehicle 100 is initially in a mode with a larger number of poles. That is, methods 600 and 700 are applicable when vehicle 100 is in a mode with a smaller number of poles, whereas method 800 is applicable when vehicle 100 is in a mode with a larger number of poles.

[0037] Thus, at block 802, vehicle 100 is operating in the mode that provides the highest torque, during which time processing unit 200 determines whether the predicted torque demand is less than the threshold torque demand. If the answer to block 802 is "yes," the method proceeds to block 804, where processing unit 200 determines whether vehicle speed is increasing. If the answer to either block 802 or 804 is "no," there is no need to switch the vehicle's mode, so processing unit 200 maintains a higher pole count, as in block 808. If the answer to block 804 is "yes," the method proceeds to block 806, where processing unit 200 switches the vehicle's mode to a mode with a lower pole count, because no more torque is needed and vehicle 100 requires the speed that can be achieved by reducing the number of poles in electric motor 106. In some examples, there may be additional steps in the method shown above to incorporate hysteresis into the system before making the decision to avoid or minimize switching back and forth between modes. For example, there may be a step where processing unit 200 identifies when the last mode change took effect so that processing unit 200 can avoid changing modes too quickly to reduce the risk of a fault in motor 106. In some examples, processing unit 200 may also decide not to switch between modes when such a fault is detected in any component of motor 106.

[0038] Figure 9A graph depicting the relationship between power and torque relative to the speed of the electric vehicle 100 is shown. When the vehicle 100 is initially stationary, i.e., having zero speed and zero power, speed and power can be increased by providing a constant high torque until a point when the vehicle 100 reaches a base speed, because it is desirable for an electric vehicle to have high torque at low speeds to start and accelerate the motor. However, because high torque cannot be maintained at high speeds, the torque gradually decreases as speed increases, while the power remains constant after reaching the base speed. In some examples, the base speed is the same as the threshold speed, which may be less than 20 mph to 30 mph. Therefore, the graph is generally divided into two regions: (a) a constant high torque region and (b) a constant high power region. Generally, the region of constant high torque corresponds to a mode with a greater number of poles, while the region of constant high power corresponds to a mode with a lesser number of poles.

[0039] Figure 10 An example of an electric vehicle network system 1000 according to an embodiment is shown. Network system 1000 includes an electric vehicle 100 wirelessly connected to a cloud network 1002, which in turn allows access to a remote ITS 504. The ITS 504 in this example includes multiple terminals 1004, 1006, and 1008 that provide different services within the ITS 504. For example, the first terminal 1004 can be a mapping application running on a remote computing device as previously described, which provides raw data regarding road conditions and road grades, among other information. The raw data from the first terminal 1004 can be transmitted via the cloud network 1002 to a second terminal 1006, which is another remote computing device that performs calculations and makes determinations regarding whether to switch between modes within the vehicle 100. In this example, the processing unit 200 within the vehicle 100 does not perform methods 600, 700, and 800 as previously described, but rather the second terminal 1006 performs these methods. In some examples, the second terminal 1006 includes an optimization module that runs one or more optimization algorithms, such as look-ahead techniques and predictive modeling, based on information provided by the mapping application from the first terminal 1004 to assist in the decision-making process. The third terminal 1008 is a remote server or database that stores data about previous trips made by the vehicle 100, allowing the second terminal 1006 to make decisions based not only on current data and look-ahead data, but also on past historical data provided by the third terminal 1008.

[0040] The present subject matter may be specifically implemented in other specific forms without departing from the scope of the present disclosure. The embodiments are to be considered in all aspects as shown and without restriction. Those skilled in the art will recognize that other implementations consistent with the disclosed embodiments are possible. The above detailed description and examples described herein have been presented for the purposes of illustration and description only and not for limitation. For example, the described operations may be performed in any suitable manner. These methods may be performed in any suitable order while still providing the described operations and results. Therefore, it is contemplated that the present embodiment covers any and all modifications, variations or equivalents that fall within the scope of the basic principles disclosed above and claimed herein. Moreover, although the above description describes hardware in the form of a processor executing code, hardware in the form of a state machine, or dedicated logic that can produce the same effect, other structures may also be considered.

Claims

1. An electric vehicle, comprising: an electric motor switchable between a first mode having a first number of poles and a second mode having a second number of poles, the second number of poles being smaller than the first number of poles; a plurality of inverters coupled to the electric motor; a control module coupled to the plurality of inverters, the control module being configured to: Receive current vehicle information and forward-looking information; determining a need for a mode switch between the first mode and the second mode of the electric motor based on the current vehicle information and the look-ahead information, wherein the first mode achieves a higher torque than the second mode; and Based on determining that the mode switching is required, the mode switching is performed by controlling operations of the plurality of inverters, wherein: (a) in the first mode, each physical pole associated with the plurality of inverters is configured to operate as a single magnetic pole, and (b) In the second mode, each pair of adjacent physical poles having the same polarity associated with the plurality of inverters is configured to operate as the single magnetic pole.

2. The electric vehicle according to claim 1, wherein: The current vehicle information includes one or more of the following: a current motor mode, a current load, and a current vehicle speed.

3. The electric vehicle according to claim 1, wherein: The forward-looking information includes predicted route information.

4. The electric vehicle according to claim 3, wherein: The predicted route information includes one or more of the following items: terrain information, road condition information, and traffic information.

5. The electric vehicle according to any one of claims 1 to 4, wherein: The control module is further configured to receive historical information and determine that the mode switch is required based on the historical information.

6. The electric vehicle according to claim 5, wherein: The historical information includes driving pattern information.

7. A method in an electric vehicle having an electric motor switchable between a first mode having a first number of poles and a second mode having a second number of poles less than the first number of poles, a plurality of inverters coupled to the electric motor, and a control module coupled to the plurality of inverters, the method comprising the steps of: The control module receives current vehicle information and forward-looking information; determining, by the control module based on the current vehicle information and the look-ahead information, that a mode switch is required between the first mode and the second mode of the electric motor, wherein the first mode achieves a higher torque than the second mode; and Based on determining that the mode switching is required, the control module performs the mode switching by controlling the operations of the plurality of inverters, wherein: (a) in the first mode, each physical pole associated with the plurality of inverters is configured to operate as a single magnetic pole, and (b) In the second mode, each pair of adjacent physical poles having the same polarity associated with the plurality of inverters is configured to operate as the single magnetic pole.

8. The method according to claim 7, wherein: The current vehicle information includes one or more of the following: a current motor mode, a current load, and a current vehicle speed.

9. The method according to claim 7, wherein: The forward-looking information includes one or more of the following items: terrain information, road condition information, and traffic information.

10. The method according to any one of claims 7 to 9, wherein The step of determining that the mode switching is required includes: determining, by the control module, that the electric motor is currently in the first mode; measuring a current speed of the vehicle by at least one sensor coupled to the electric motor; and In response to the current speed increasing to greater than a threshold speed, it is determined by the control module that the mode switch from the first mode to the second mode is required.

11. The method according to claim 10, wherein: The threshold speed can vary based on the current vehicle load or mass.

12. The method according to any one of claims 7 to 9, wherein The step of determining that the mode switching is required includes: determining, by the control module, that the electric motor is currently in the second mode; measuring a current speed of the vehicle by at least one sensor coupled to the electric motor; and In response to the current speed decreasing to less than a threshold speed, determining, by the control module, that the mode switch from the second mode to the first mode is required.

13. The method according to claim 12, wherein: The threshold speed can vary based on the current vehicle load or mass.

14. The method according to any one of claims 7 to 9, further comprising the following steps: The mode switch is performed by the control module in response to user input selecting a traction mode of the vehicle.

15. An electric vehicle system, comprising: An electric vehicle, comprising: an electric motor switchable between a first mode having a first number of poles and a second mode having a second number of poles, the second number of poles being smaller than the first number of poles, a plurality of inverters coupled to the electric motor, and a control module coupled to the plurality of inverters, the control module configured to perform mode switching by controlling operations of the plurality of inverters; and a transportation management system coupled to the control module of the electric vehicle, the transportation management system being configured to: Receive current vehicle information and forward-looking information; determining, based on the current vehicle information and the look-ahead information, that a mode switch is required between the first mode and a second mode of the electric motor, wherein the first mode achieves a higher torque than the second mode; and Based on determining that the mode switch is required, instructing the control module to perform the mode switch, wherein: (a) in the first mode, each physical pole associated with the plurality of inverters is configured to operate as a single magnetic pole, and (b) In the second mode, each pair of adjacent physical poles having the same polarity associated with the plurality of inverters is configured to operate as the single magnetic pole.

16. The electric vehicle system according to claim 15, wherein: The transportation management system includes a mapping application and an optimization module.

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