Motor control method of vehicle
By dynamically adjusting the current distribution values of the d-axis and q-axis of the motor, the problem of regenerative braking failure when the battery SOC is close to the upper limit in new energy vehicles is solved, achieving stable braking under energy recovery conditions and reducing mechanical brake wear, thus improving the driving experience.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- WEICHAI POWER CO LTD
- Filing Date
- 2026-04-01
- Publication Date
- 2026-05-12
Smart Images
Figure CN122008902A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of vehicle control technology, and more particularly to a method for controlling the motor of a vehicle. Background Technology
[0002] Currently, when the battery SOC of a new energy vehicle approaches its upper limit, the traditional strategy directly limits the motor feed current to zero or an extremely low value. The motor cannot output negative torque through the feed current, which disables the regenerative braking function. As a result, it cannot provide braking torque, and the vehicle braking relies entirely on the mechanical braking system. This leads to accelerated wear of mechanical components, increased maintenance costs, and if the feed current is suddenly limited or cut off, the braking torque will decrease sharply, requiring emergency compensation from the mechanical brakes. The braking force is not linear, which affects driving smoothness. Summary of the Invention
[0003] This invention provides a method for controlling the motor of a vehicle to ensure the braking capability of the entire vehicle, reduce the use of mechanical brakes, and ensure a better driving experience.
[0004] In a first aspect, the present invention provides a method for controlling the motor of a vehicle, comprising: Obtain vehicle operating conditions; When the vehicle is operating under energy recovery conditions, the real-time SOC value of the battery and the motor torque demand value are obtained. First motor current allocation information is obtained based on the real-time SOC value and the motor torque demand value. The first motor current allocation information includes a first d-axis current allocation value and a first q-axis current allocation value. Motor control is performed based on the first motor current distribution information.
[0005] Optionally, obtaining vehicle operating conditions includes: Acquire motor speed, motor torque, real-time d-axis current, and real-time q-axis current; When the motor speed is greater than zero, the motor torque is less than zero, the real-time d-axis current is less than zero, and the real-time q-axis current is less than zero, the vehicle operating condition is determined to be an energy recovery condition.
[0006] Optionally, after obtaining the real-time SOC value of the battery and the motor torque requirement value, the following may also be included: Obtain the preset SOC value; When the real-time SOC value is greater than or equal to the preset SOC value, active degradation operation is initiated. When the real-time SOC value is less than the preset SOC value, the active degradation operation is not initiated.
[0007] Optionally, when active degradation operation is initiated, first motor current allocation information is obtained based on the real-time SOC value and the motor torque demand value. The first motor current allocation information includes a first d-axis current allocation value and a first q-axis current allocation value, which include: The SOC degradation coefficient is obtained based on the real-time SOC value; Obtain the maximum permissible field weakening current value of the motor; The first d-axis current allocation value is determined based on the SOC degradation coefficient and the maximum allowable field weakening current value of the motor. Obtain the permanent magnet flux linkage, d-axis inductance, q-axis inductance, and number of pole pairs of the motor; The first q-axis current allocation value is determined based on the motor torque requirement, the motor permanent magnet flux linkage, the d-axis inductance, the q-axis inductance, and the number of motor pole pairs.
[0008] Optionally, obtaining the SOC degradation coefficient based on the real-time SOC value includes: Get the preset maximum SOC value and the preset minimum SOC value; The SOC degradation coefficient is determined based on the real-time SOC value, the preset maximum SOC value, and the preset minimum SOC value.
[0009] Optionally, based on the first formula, the SOC degradation coefficient is determined according to the real-time SOC value, the preset maximum SOC value, and the preset minimum SOC value. The first formula is: ; Where, k SOC Let k be the SOC degradation coefficient. SOC ∈[0,1]; SOC is the real-time SOC value; SOC max The preset maximum SOC value; SOC min The preset minimum SOC value.
[0010] Optionally, based on the second formula, the first d-axis current allocation value is determined according to the SOC degradation coefficient and the maximum allowable field weakening current value of the motor. The second formula is: i d =-i dmax ×(1-k soc ); Among them, i d Assign values to the first d-axis current; i dmax k is the maximum permissible field weakening current value for the motor. SOC The SOC degradation coefficient is given.
[0011] Optionally, based on the third formula, the first q-axis current allocation value is determined according to the motor torque requirement, the motor permanent magnet flux linkage, the d-axis inductance, the q-axis inductance, and the number of motor pole pairs. The third formula is: ; Among them, i q Assigning a value to the first q-axis current, T e This refers to the required motor torque value; L is the permanent magnet flux linkage of the motor; d L is the d-axis inductance; q is the q-axis inductance; p is the number of pole pairs of the motor.
[0012] Optionally, when active degradation is not enabled, the following are also included: Obtain the preset motor current distribution MAP; The second motor current allocation information is determined according to the preset motor current allocation MAP diagram. The second motor current allocation information includes the second d-axis current allocation value and the second q-axis current allocation value. Motor control is performed based on the second motor current distribution information.
[0013] Optionally, before performing motor control based on the first motor current distribution information, the method further includes: Set current safety limits, wherein the current safety limits satisfy i d 2 +i q 2 ≤I max 2 and |i q |<I chargemax , where i d Assign values to the first d-axis current; i q Assign values to the first q-axis current; I max The preset maximum current amplitude; I chargemax Set the maximum battery charging current.
[0014] The technical solution of this invention, through a vehicle motor control method, includes: acquiring the vehicle's operating conditions; when the vehicle is in an energy recovery operating condition, acquiring the real-time SOC value of the battery and the motor torque demand value; acquiring first motor current allocation information based on the real-time SOC value and the motor torque demand value, the first motor current allocation information including a first d-axis current allocation value and a first q-axis current allocation value; and performing motor control based on the first motor current allocation information. In the energy recovery operating condition, ensuring a constant negative torque, the first motor current allocation information is dynamically acquired based on the battery SOC value to ensure the vehicle's braking capability, reduce the use of mechanical brakes, and ensure a better driving experience.
[0015] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description
[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0017] Figure 1 A flowchart illustrating a vehicle motor control method provided in an embodiment of the present invention; Figure 2 A graph showing the relationship between d-axis current and q-axis current values provided in an embodiment of the present invention; Figure 3 A flowchart of another vehicle motor control method provided in an embodiment of the present invention; Figure 4 A flowchart of another vehicle motor control method provided in an embodiment of the present invention; Figure 5 A flowchart of another vehicle motor control method provided in an embodiment of the present invention; Figure 6 A flowchart of another vehicle motor control method provided in an embodiment of the present invention; Figure 7 A flowchart of another vehicle motor control method provided in an embodiment of the present invention; Figure 8 A flowchart of another vehicle motor control method provided in an embodiment of the present invention. Detailed Implementation
[0018] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.
[0019] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.
[0020] Figure 1 This is a flowchart of a vehicle motor control method provided in an embodiment of the present invention. Figure 2 This invention provides a relationship diagram between d-axis and q-axis current values. This embodiment is applicable to vehicle motor control. The method can be executed by the vehicle's motor control device, which can be implemented in hardware and / or software and can be configured within the vehicle. Figure 1 and Figure 2 As shown, the method includes: S101, obtain vehicle operating conditions.
[0021] Among them, vehicle operating conditions include driving conditions, energy recovery conditions, coasting conditions and emergency braking conditions, etc. The vehicle operating conditions can be determined according to the torque direction and energy flow direction.
[0022] S102: When the vehicle is operating in energy recovery mode, obtain the real-time SOC value of the battery and the motor torque demand value.
[0023] When the vehicle is operating in energy recovery mode, the battery management system obtains the real-time SOC value of the battery and determines the maximum allowable charging current of the battery based on the real-time SOC value. The vehicle controller determines the electrode torque requirement value based on the maximum allowable charging current of the battery. This results in a smaller available torque for the motor when the battery has a high SOC value, so the motor current needs to be adjusted to avoid the vehicle braking relying entirely on the mechanical braking system, which would increase maintenance costs.
[0024] S103, obtain the first motor current allocation information based on the real-time SOC value and the motor torque demand value. The first motor current allocation information includes the first d-axis current allocation value and the first q-axis current allocation value.
[0025] Specifically, the first motor current distribution information can be obtained based on the real-time SOC value and motor torque demand value. This information includes the first d-axis current distribution value and the first q-axis current distribution value. The ratio of the first d-axis and first q-axis current distribution values can be dynamically adjusted. Specifically, the first d-axis current distribution value can be increased, while the first q-axis current distribution value may decrease or increase, depending on the torque curve. Alternatively, the phase angle can be adjusted to reduce the current fed into the battery in real time, maintain negative torque output, ensure the vehicle's braking capability, reduce the use of mechanical brakes, and achieve a better driving experience under energy recovery conditions. Figure 2 As shown, point A is the intersection of the current vector circle, the constant torque curve, and the MTPA curve, while point A1 is the intersection of the zero-efficiency feedback curve and the constant torque curve. Under most vehicle operating conditions, the motor distributes current according to the MTPA curve. However, when the vehicle is operating under energy recovery conditions and the real-time SOC value is greater than or equal to the preset SOC value, it is necessary to actively deviate from the MTPA curve, increasing the first d-axis current distribution value and changing it from point A to point A1. During the increase of the first d-axis current distribution value, due to the limitation of the zero-efficiency feedback curve, the first d-axis current distribution value cannot exceed the horizontal coordinate of point A1.
[0026] S104, motor control is performed based on the current distribution information of the first motor.
[0027] The motor in this vehicle can be a permanent magnet synchronous motor. Motor control is achieved through adjusted first d-axis and first q-axis current distribution values, ensuring constant output torque, increasing current amplitude, reducing the current fed into the battery in real time, guaranteeing the vehicle's braking capability, reducing the use of mechanical brakes, and achieving a better driving experience under energy recovery conditions.
[0028] This invention, in its embodiments, acquires vehicle operating conditions. When the vehicle is operating in energy recovery mode, it acquires the real-time SOC value of the battery and the motor torque demand value. Based on the real-time SOC value and the motor torque demand value, it acquires first motor current allocation information, which includes a first d-axis current allocation value and a first q-axis current allocation value. Motor control is then performed based on this first motor current allocation information. This effectively reduces the current fed into the battery, prevents battery overcharging or thermal runaway, and maintains negative torque output from the motor, ensuring the vehicle's braking capability and driving experience.
[0029] Optional, Figure 3 A flowchart of another vehicle motor control method provided in an embodiment of the present invention is shown below. Figure 3 As shown, the method includes: S201, obtain motor speed value, motor torque value, real-time d-axis current value and real-time q-axis current value.
[0030] The vehicle's motor controller can acquire motor speed, motor torque, real-time d-axis current, and real-time q-axis current. The motor controller senses signals through sensors, performs calculations based on these signals, and issues control commands accordingly.
[0031] S202, when the motor speed is greater than zero, the motor torque is less than zero, the real-time d-axis current is less than zero, and the real-time q-axis current is less than zero, the vehicle operating condition is determined to be energy recovery condition.
[0032] Specifically, when the motor speed is greater than zero and the motor torque is less than zero, the vehicle is considered to be in energy recovery mode. To prevent battery overcharging or thermal runaway, the controller actively deviates from the optimal energy-saving MTPA trajectory, thus entering the field weakening control phase. When the real-time d-axis current value is less than zero, the controller begins injecting a negative d-axis current into the electrodes. This current is a field weakening current, which generates a reverse magnetic field to partially counteract the inherent strong magnetic field of the permanent magnet. When the real-time q-axis current value is less than zero, the motor output torque is negative.
[0033] S203: When the vehicle is operating in energy recovery mode, obtain the real-time SOC value of the battery and the motor torque requirement value.
[0034] S204. Obtain the first motor current allocation information based on the real-time SOC value and the motor torque demand value. The first motor current allocation information includes the first d-axis current allocation value and the first q-axis current allocation value.
[0035] S205, motor control is performed based on the current distribution information of the first motor.
[0036] This invention acquires motor speed, motor torque, real-time d-axis current, and real-time q-axis current. When the motor speed is greater than zero, the motor torque is less than zero, the real-time d-axis current is less than zero, and the real-time q-axis current is less than zero, the vehicle's operating condition is determined to be energy recovery mode. In energy recovery mode, the real-time SOC value of the battery and the required motor torque are acquired. First motor current allocation information, including first d-axis current allocation and first q-axis current allocation, is obtained based on the real-time SOC value and the required motor torque. Motor control is then performed based on this first motor current allocation information. In energy recovery mode, the negative torque remains constant. The first motor current allocation information is dynamically acquired based on the battery SOC value to ensure the vehicle's braking capability, reduce the use of mechanical brakes, and ensure a better driving experience. By dynamically adjusting the real-time SOC value and acquiring the first motor current allocation information, a function related to the SOC value can be set. When the SOC value increases, the current amplitude is actively increased, thereby increasing copper losses, reducing the motor's output feed current, and ensuring constant output torque.
[0037] Optional, Figure 4 A flowchart of another vehicle motor control method provided in an embodiment of the present invention is shown below. Figure 4 As shown, the method includes: S301, obtain motor speed value, motor torque value, real-time d-axis current value and real-time q-axis current value.
[0038] S302, when the motor speed is greater than zero, the motor torque is less than zero, the real-time d-axis current is less than zero, and the real-time q-axis current is less than zero, the vehicle operating condition is determined to be energy recovery condition.
[0039] S303: When the vehicle is operating in energy recovery mode, it obtains the real-time SOC value of the battery and the motor torque requirement value.
[0040] S304, Get the preset SOC value.
[0041] The preset SOC value can be set according to actual design requirements, and the embodiments of the present invention do not impose specific limitations.
[0042] S305: When the real-time SOC value is greater than or equal to the preset SOC value, the active degradation operation is started.
[0043] When the real-time SOC value is greater than or equal to the preset SOC value, continuing to charge may cause the battery to overcharge or thermal runaway. Therefore, it is necessary to activate the active degradation operation to prevent damage to the battery.
[0044] S306: When the real-time SOC value is less than the preset SOC value, the active degradation operation will not be enabled.
[0045] When the real-time SOC value is less than the preset SOC value, the battery still has enough capacity to store the current fed into the motor. Therefore, there is no need to activate the active degradation operation, and the battery can continue to be charged.
[0046] S307, obtain the first motor current allocation information based on the real-time SOC value and the motor torque demand value. The first motor current allocation information includes the first d-axis current allocation value and the first q-axis current allocation value.
[0047] S308 controls the motor based on the current distribution information of the first motor.
[0048] This invention, in its embodiments, acquires the real-time SOC value of the battery and the motor torque requirement value when the vehicle is operating in energy recovery mode; acquires a preset SOC value; when the real-time SOC value is greater than or equal to the preset SOC value, active degradation operation is initiated; when the real-time SOC value is less than the preset SOC value, active degradation operation is not initiated. This achieves precise control of the motor, ensuring the vehicle's braking capability and thus guaranteeing the driving experience.
[0049] Optional, Figure 5 A flowchart of another vehicle motor control method provided in an embodiment of the present invention is shown below. Figure 5 As shown, the method includes: S401, obtain motor speed value, motor torque value, real-time d-axis current value and real-time q-axis current value.
[0050] S402, when the motor speed is greater than zero, the motor torque is less than zero, the real-time d-axis current is less than zero, and the real-time q-axis current is less than zero, the vehicle operating condition is determined to be energy recovery condition.
[0051] S403: When the vehicle is operating in energy recovery mode, it obtains the real-time SOC value of the battery and the motor torque requirement value.
[0052] S404, Get the preset SOC value.
[0053] S405: When the real-time SOC value is greater than or equal to the preset SOC value, the active degradation operation is started.
[0054] S406: When the real-time SOC value is less than the preset SOC value, the active degradation operation is not enabled.
[0055] S407, obtain the SOC degradation coefficient based on the real-time SOC value.
[0056] The SOC degradation coefficient can be calculated based on the real-time SOC value obtained in real time.
[0057] S408, obtain the maximum allowable field weakening current value of the motor.
[0058] The maximum allowable field weakening current value of the motor can be determined by the motor type and the reverse d-axis current that the motor controller can withstand. Alternatively, it can be set according to actual design requirements in practical applications; this embodiment of the invention does not impose specific limitations.
[0059] S409, determine the first d-axis current allocation value based on the SOC degradation coefficient and the maximum allowable field weakening current value of the motor.
[0060] The first d-axis current allocation value can be calculated by combining the SOC degradation coefficient and the maximum allowable field weakening current value of the motor. Specifically, it can be based on the second formula i d =-i dmax ×(1-k soc This determines the first d-axis current allocation value under the current real-time SOC. Where i d Assign values to the first d-axis current; i dmax k is the maximum permissible field weakening current value for the motor. SOC This is the SOC degradation coefficient.
[0061] S410 retrieves the permanent magnet flux linkage, d-axis inductance, q-axis inductance, and number of pole pairs of the motor.
[0062] Among them, the permanent magnet flux linkage, d-axis inductance, q-axis inductance, and number of pole pairs of the motor can be obtained from the motor controller to obtain the basic parameters of the motor.
[0063] S411, determine the first q-axis current distribution value based on the motor torque requirement, the motor permanent magnet flux linkage, the d-axis inductance, the q-axis inductance, and the number of motor pole pairs.
[0064] The first q-axis current allocation value can be calculated by combining the motor torque requirement, the motor permanent magnet flux linkage, the d-axis inductance, the q-axis inductance, and the number of motor pole pairs. Specifically, it can be based on the third formula. The first q-axis current distribution value is calculated, where i q Assigning a value to the first q-axis current, T e This represents the required motor torque value. For permanent magnet flux linkage in motors; L d For d-axis inductance; L q is the q-axis inductance; p is the number of pole pairs of the motor.
[0065] S412 controls the motor based on the current distribution information of the first motor.
[0066] Specifically, when the real-time SOC value exceeds the preset SOC value, an active degradation operation can be initiated. Furthermore, by calculating the SOC degradation coefficient, the first d-axis current allocation value and the first q-axis current allocation value can be redistributed. The smaller the SOC degradation coefficient, the larger the absolute value of the first d-axis current allocation value, leading to increased copper losses, reduced motor efficiency, and a smaller feed current to the battery, thus preventing battery overcharging or thermal runaway.
[0067] This invention provides an embodiment that obtains a SOC degradation coefficient based on real-time SOC values; obtains the maximum permissible field weakening current value of the motor; determines a first d-axis current allocation value based on the SOC degradation coefficient and the maximum permissible field weakening current value; obtains the motor permanent magnet flux linkage, d-axis inductance, q-axis inductance, and number of motor pole pairs; determines a first q-axis current allocation value based on the motor torque requirement value, the motor permanent magnet flux linkage, d-axis inductance, q-axis inductance, and number of motor pole pairs; and performs motor control based on the first motor current allocation information. By obtaining the first d-axis current allocation value based on the real-time SOC value and the first q-axis current allocation value based on the motor torque requirement value, the overall vehicle braking capability can be effectively guaranteed, reducing the use of mechanical brakes and ensuring a better driving experience.
[0068] Optional, Figure 6A flowchart of another vehicle motor control method provided in an embodiment of the present invention is shown below. Figure 6 As shown, the method includes: S501, obtains motor speed value, motor torque value, real-time d-axis current value and real-time q-axis current value.
[0069] S502, when the motor speed is greater than zero, the motor torque is less than zero, the real-time d-axis current is less than zero, and the real-time q-axis current is less than zero, the vehicle operating condition is determined to be energy recovery condition.
[0070] S503, when the vehicle is operating in energy recovery mode, obtains the real-time SOC value of the battery and the motor torque requirement value.
[0071] S504, obtain the preset SOC value.
[0072] S505: When the real-time SOC value is greater than or equal to the preset SOC value, the active degradation operation is started.
[0073] S506: When the real-time SOC value is less than the preset SOC value, the active degradation operation is not enabled.
[0074] S507, obtain the preset maximum SOC value and the preset minimum SOC value.
[0075] The preset maximum SOC value and preset minimum SOC value can be set according to actual design requirements, and the embodiments of the present invention can be set according to actual design requirements. For example, the preset maximum SOC value can be 100%, and the preset minimum SOC value can be 20%.
[0076] S508 determines the SOC degradation coefficient based on the real-time SOC value, the preset maximum SOC value, and the preset minimum SOC value.
[0077] The SOC degradation coefficient can be calculated by combining the real-time SOC value, the preset maximum SOC value, and the preset minimum SOC value. Specifically, it can be based on the first formula. The SOC degradation coefficient is calculated; where k SOC k is the SOC degradation coefficient. SOC ∈[0,1]; SOC is the real-time SOC value; SOC max The preset maximum SOC value; SOC min This is the preset minimum SOC value.
[0078] S509, obtain the maximum allowable field weakening current value of the motor.
[0079] S510 determines the first d-axis current distribution value based on the SOC degradation coefficient and the maximum allowable field weakening current value of the motor.
[0080] S511, obtain the permanent magnet flux linkage of the motor, the d-axis inductance, the q-axis inductance, and the number of pole pairs of the motor.
[0081] S512 determines the first q-axis current distribution value based on the motor torque requirement, the motor permanent magnet flux linkage, the d-axis inductance, the q-axis inductance, and the number of motor pole pairs.
[0082] S513 controls the motor based on the current distribution information of the first motor.
[0083] This invention embodiment obtains a preset maximum SOC value and a preset minimum SOC value; determines a SOC degradation coefficient based on the real-time SOC value, the preset maximum SOC value, and the preset minimum SOC value; obtains the maximum allowable field weakening current value of the motor; determines a first d-axis current allocation value based on the SOC degradation coefficient and the maximum allowable field weakening current value of the motor; obtains the permanent magnet flux linkage, d-axis inductance, q-axis inductance, and number of pole pairs of the motor; determines a first q-axis current allocation value based on the motor torque requirement value, the permanent magnet flux linkage, d-axis inductance, q-axis inductance, and number of pole pairs of the motor; and performs motor control based on the first motor current allocation information. The ability to obtain the first d-axis current allocation value based on the real-time SOC value and the first q-axis current allocation value based on the motor torque requirement value effectively ensures the vehicle's braking capability, reduces the use of mechanical brakes, and guarantees a better driving experience.
[0084] Optional, Figure 7 A flowchart of another vehicle motor control method provided in an embodiment of the present invention is shown below. Figure 7 As shown, the method includes: S601, obtains motor speed value, motor torque value, real-time d-axis current value and real-time q-axis current value.
[0085] S602, when the motor speed is greater than zero, the motor torque is less than zero, the real-time d-axis current is less than zero, and the real-time q-axis current is less than zero, the vehicle operating condition is determined to be energy recovery condition.
[0086] S603, when the vehicle is operating in energy recovery mode, obtains the real-time SOC value of the battery and the motor torque requirement value.
[0087] S604, Get the preset SOC value.
[0088] S605: When the real-time SOC value is greater than or equal to the preset SOC value, the active degradation operation is started.
[0089] S606, obtain the preset maximum SOC value and the preset minimum SOC value.
[0090] S607 determines the SOC degradation coefficient based on the real-time SOC value, the preset maximum SOC value, and the preset minimum SOC value.
[0091] S608, obtains the maximum allowable field weakening current value of the motor.
[0092] S609, determine the first d-axis current allocation value based on the SOC degradation coefficient and the maximum allowable field weakening current value of the motor.
[0093] S610, obtains the permanent magnet flux linkage of the motor, the d-axis inductance, the q-axis inductance, and the number of pole pairs of the motor.
[0094] S611, determine the first q-axis current distribution value based on the motor torque requirement, the motor permanent magnet flux linkage, the d-axis inductance, the q-axis inductance, and the number of motor pole pairs.
[0095] S612 controls the motor based on the current distribution information of the first motor.
[0096] S613: When the real-time SOC value is less than the preset SOC value, the active degradation operation is not enabled.
[0097] S614, obtain the preset motor current distribution MAP.
[0098] The preset motor current distribution MAP can include the correspondence between the real-time SOC value, the second d-axis current distribution value, and the second q-axis current distribution value. The preset motor current distribution MAP can be set and stored in advance so that the second d-axis current distribution value and the second q-axis current distribution value can be obtained according to the real-time SOC value under the current operating conditions.
[0099] S615, determine the second motor current distribution information according to the preset motor current distribution MAP diagram. The second motor current distribution information includes the second d-axis current distribution value and the second q-axis current distribution value.
[0100] The second motor current distribution information, namely the second d-axis current distribution value and the second q-axis current distribution value, can be determined based on the real-time SOC value and the preset motor current distribution MAP to ensure motor control.
[0101] S616 controls the motor based on the current distribution information of the second motor.
[0102] Specifically, the motor is controlled based on the second d-axis current distribution value and the second q-axis current distribution value in the second motor current distribution information to ensure the braking effect of the whole vehicle.
[0103] This invention embodiment does not initiate active degradation operation when the real-time SOC value is less than a preset SOC value; obtains a preset motor current distribution MAP; determines second motor current distribution information based on the preset motor current distribution MAP, the second motor current distribution information including the second d-axis current distribution value and the second q-axis current distribution value; and performs motor control based on the second motor current distribution information to achieve precise control of the motor and ensure the braking effect of the entire vehicle.
[0104] Optional, Figure 8 A flowchart of another vehicle motor control method provided in an embodiment of the present invention is shown below. Figure 8 As shown, the method includes: S701, obtains motor speed value, motor torque value, real-time d-axis current value and real-time q-axis current value.
[0105] S702, when the motor speed is greater than zero, the motor torque is less than zero, the real-time d-axis current is less than zero, and the real-time q-axis current is less than zero, the vehicle operating condition is determined to be energy recovery condition.
[0106] S703, when the vehicle is operating in energy recovery mode, obtains the real-time SOC value of the battery and the motor torque demand value.
[0107] S704, obtain the preset SOC value.
[0108] S705: When the real-time SOC value is greater than or equal to the preset SOC value, the active degradation operation is started.
[0109] S706, obtain the preset maximum SOC value and the preset minimum SOC value.
[0110] S707 determines the SOC degradation coefficient based on the real-time SOC value, the preset maximum SOC value, and the preset minimum SOC value.
[0111] S708, obtains the maximum allowable field weakening current value of the motor.
[0112] S709 determines the first d-axis current allocation value based on the SOC degradation coefficient and the maximum allowable field weakening current value of the motor.
[0113] S710 retrieves the permanent magnet flux linkage, d-axis inductance, q-axis inductance, and number of pole pairs of the motor.
[0114] S711 determines the first q-axis current distribution value based on the motor torque requirement, the motor permanent magnet flux linkage, the d-axis inductance, the q-axis inductance, and the number of motor pole pairs.
[0115] S712, sets the current safety limit condition, the current safety limit condition satisfies i d 2 +i q2 ≤I max 2 and |i q |<I chargemax , where i d Assign values to the first d-axis current; i q Assign values to the first q-axis current; I max The preset maximum current amplitude; I chargemax Set the maximum battery charging current.
[0116] Among them, the current safety limit condition can limit the current output of the motor and the charging current of the battery, which can ensure the vehicle's automatic capability and the driving experience under energy recovery conditions.
[0117] S713 controls the motor based on the current distribution information of the first motor.
[0118] S714: When the real-time SOC value is less than the preset SOC value, the active degradation operation is not enabled.
[0119] S715, obtain the preset motor current distribution MAP.
[0120] S716, determine the second motor current distribution information according to the preset motor current distribution MAP diagram. The second motor current distribution information includes the second d-axis current distribution value and the second q-axis current distribution value.
[0121] S717 controls the motor based on the current distribution information of the second motor.
[0122] This invention embodiment sets current safety limits, and the current safety limits satisfy i d 2 +i q 2 ≤I max 2 and |i q |<I chargemax , where i d Assign values to the first d-axis current; i q Assign values to the first q-axis current; I max The preset maximum current amplitude; I chargemax The maximum battery charging current is preset. When the current safety limit conditions are met, the motor is controlled based on the first motor current distribution information to ensure the braking effect of the entire vehicle.
[0123] Based on the same inventive concept, this embodiment of the invention also provides a vehicle, which includes at least a motor and a control unit. The control unit is used to execute the motor control method of the vehicle provided in any embodiment of the invention. Therefore, the vehicle provided in this embodiment of the invention includes the technical features of the motor control method of the vehicle provided in any embodiment of the invention, and can achieve the beneficial effects of the motor control method of the vehicle provided in any embodiment of the invention. The similarities can be referred to the above description of the motor control method of the vehicle provided in this embodiment of the invention, and will not be repeated here.
[0124] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.
Claims
1. A method for controlling the motor of a vehicle, characterized in that, include: Obtain vehicle operating conditions; When the vehicle is operating under energy recovery conditions, the real-time SOC value of the battery and the motor torque demand value are obtained. First motor current allocation information is obtained based on the real-time SOC value and the motor torque demand value. The first motor current allocation information includes a first d-axis current allocation value and a first q-axis current allocation value. Motor control is performed based on the first motor current distribution information.
2. The vehicle motor control method according to claim 1, characterized in that, Obtaining vehicle operating conditions includes: Acquire motor speed, motor torque, real-time d-axis current, and real-time q-axis current; When the motor speed is greater than zero, the motor torque is less than zero, the real-time d-axis current is less than zero, and the real-time q-axis current is less than zero, the vehicle operating condition is determined to be an energy recovery condition.
3. The vehicle motor control method according to claim 1, characterized in that, After obtaining the real-time SOC value of the battery and the motor torque requirement value, it also includes: Obtain the preset SOC value; When the real-time SOC value is greater than or equal to the preset SOC value, active degradation operation is initiated. When the real-time SOC value is less than the preset SOC value, the active degradation operation is not initiated.
4. The vehicle motor control method according to claim 3, characterized in that, When active degradation operation is initiated, first motor current allocation information is obtained based on the real-time SOC value and the motor torque demand value. The first motor current allocation information includes a first d-axis current allocation value and a first q-axis current allocation value, which include: The SOC degradation coefficient is obtained based on the real-time SOC value; Obtain the maximum permissible field weakening current value of the motor; The first d-axis current allocation value is determined based on the SOC degradation coefficient and the maximum allowable field weakening current value of the motor. Obtain the permanent magnet flux linkage, d-axis inductance, q-axis inductance, and number of pole pairs of the motor; The first q-axis current allocation value is determined based on the motor torque requirement value, the motor permanent magnet flux linkage, the d-axis inductance, the q-axis inductance, and the number of motor pole pairs.
5. The vehicle motor control method according to claim 4, characterized in that, The SOC degradation coefficient is obtained based on the real-time SOC value, including: Get the preset maximum SOC value and the preset minimum SOC value; The SOC degradation coefficient is determined based on the real-time SOC value, the preset maximum SOC value, and the preset minimum SOC value.
6. The vehicle motor control method according to claim 5, characterized in that, Based on the first formula, the SOC degradation coefficient is determined according to the real-time SOC value, the preset maximum SOC value, and the preset minimum SOC value. The first formula is: ； Where, k SOC Let k be the SOC degradation coefficient. SOC ∈[0,1]; SOC is the real-time SOC value; SOC max The preset maximum SOC value; SOC min The preset minimum SOC value.
7. The vehicle motor control method according to claim 4, characterized in that, Based on the second formula, the first d-axis current allocation value is determined according to the SOC degradation coefficient and the maximum allowable field weakening current value of the motor. The second formula is: i d =-i dmax ×(1-k soc ); Among them, i d Assign values to the first d-axis current; i dmax k is the maximum permissible field weakening current value for the motor. SOC The SOC degradation coefficient is given.
8. The vehicle motor control method according to claim 4, characterized in that, Based on the third formula, the first q-axis current allocation value is determined according to the motor torque requirement, the motor permanent magnet flux linkage, the d-axis inductance, the q-axis inductance, and the number of motor pole pairs. The third formula is: ； Among them, i q Assigning a value to the first q-axis current, T e This refers to the required motor torque value; L is the permanent magnet flux linkage of the motor; d L is the d-axis inductance; q is the q-axis inductance; p is the number of pole pairs of the motor.
9. The vehicle motor control method according to claim 3, characterized in that, When active degradation is not enabled, it also includes: Obtain the preset motor current distribution MAP; The second motor current allocation information is determined according to the preset motor current allocation MAP diagram. The second motor current allocation information includes the second d-axis current allocation value and the second q-axis current allocation value. Motor control is performed based on the second motor current distribution information.
10. The vehicle motor control method according to claim 1, characterized in that, Before controlling the motor based on the first motor current distribution information, the method further includes: Set current safety limits, wherein the current safety limits satisfy i d 2 +i q 2 ≤I max 2 and |i q |<I chargemax , where i d Assign values to the first d-axis current; i q Assign values to the first q-axis current; I max The preset maximum current amplitude; I chargemax Set the maximum battery charging current.