Main and auxiliary motor switching control method and system for dual-motor power system of new energy commercial vehicle

Abstract

The invention provides a main and auxiliary motor switching control method and system for a dual-motor power system of a new energy commercial vehicle, and the method comprises the steps: S1, collecting the initial operation parameters of two motors when the vehicle is started; s2, respectively calculating initial weight coefficients of the two motors according to the initial operation parameters; s3, the initial weight coefficients of the two motors are compared, the motor with the large initial weight coefficient is selected as a main motor, and the other motor is selected as an auxiliary motor; s4, in the running process of the vehicle, real-time running parameters of the two motors are collected in real time, and real-time weight coefficients of the two motors are calculated according to the real-time running parameters; and S5, when the absolute value of the torque requested by the driver is smaller than a set threshold value or the actual torque distribution coefficient meets a preset relation, switching of the main motor and the auxiliary motor is triggered. According to the method, the key operation parameters are collected, the weight coefficient is calculated according to the key operation parameters, accurate control over the switching time of the main motor and the auxiliary motor is achieved, power distribution of the double motors is optimized, and it is ensured that the motors operate in the optimal load state.

Description

Technical Field

[0001] This invention belongs to the field of dual-motor control technology for commercial vehicles, and in particular relates to a method and system for switching between main and auxiliary motors in a dual-motor power system for new energy commercial vehicles. Background Technology

[0002] Currently, dual-motor power systems in new energy commercial vehicles typically include a main motor and an auxiliary motor. The main motor provides the primary power output, while the auxiliary motor provides supplementary power when needed. This configuration improves vehicle power performance and energy efficiency. However, existing dual-motor power systems suffer from imbalances in motor load distribution and lifespan. Traditional main-auxiliary motor switching control methods usually rely on a single parameter, such as motor temperature, to switch between the two motors. This fails to adequately adapt to varying operating conditions, resulting in low motor efficiency and impacting overall vehicle performance and lifespan. Summary of the Invention

[0003] To address the problems existing in the prior art, this invention aims to propose a main and auxiliary motor switching control method and system for a dual-motor power system of new energy commercial vehicles. It comprehensively considers the influence of multiple parameters and dynamically adjusts the switching timing of the main and auxiliary motors to optimize the working performance of the dual-motor power system and improve the operating efficiency and reliability of commercial vehicles.

[0004] To achieve the above objectives, the technical solution of the present invention is implemented as follows: A method for controlling the switching between main and auxiliary motors in a dual-motor power system for a new energy commercial vehicle, comprising: S1. When the vehicle starts, the initial operating parameters of the two motors are collected. The initial operating parameters include the motor body temperature, the motor controller temperature, the motor fault level, and the motor work load. S2. Calculate the initial weighting coefficients of the two motors according to the initial operating parameters. The initial weighting coefficients are obtained by multiplying the weighting coefficients corresponding to each initial operating parameter. S3. Compare the initial weighting coefficients of the two motors, select the motor with the larger initial weighting coefficient as the main motor, and the other motor as the auxiliary motor. S4. During vehicle operation, real-time operating parameters of the two motors are collected, and real-time weighting coefficients of the two motors are calculated based on the real-time operating parameters. S5. When the absolute value of the torque requested by the driver is less than the set threshold, or the actual torque distribution coefficient meets the preset relationship, the switching between the main and auxiliary motors is triggered.

[0005] Furthermore, in S5, the actual torque distribution coefficient satisfies the preset relationship that the result of multiplying the actual torque distribution coefficient by 2 and then subtracting 1 is less than the weight coefficient corresponding to the real-time weight coefficient.

[0006] Furthermore, when the torque distribution coefficient is 0.5, it is an average distribution; when it is 0 or 1, it is a single motor drive.

[0007] Furthermore, in S5, the set threshold is 50 Nm.

[0008] Furthermore, in S3, if the initial weighting coefficients of the two motors are equal, then the other motor is selected as the main motor based on the main motor at the end of the previous driving cycle.

[0009] Furthermore, in S2, the weighting coefficient corresponding to the motor body temperature gradually decreases as the temperature increases; the weighting coefficient corresponding to the motor controller temperature gradually decreases as the temperature increases; and the weighting coefficient corresponding to the motor fault level gradually decreases as the fault level increases.

[0010] Furthermore, in S2, the calculation process of the weighting coefficient corresponding to the motor's work load is as follows: the current and voltage of the two motors are collected, the power of each motor is calculated, and the power is integrated to obtain the work done by each motor in the current driving cycle; the difference in work done by the two motors is calculated, and the weighting coefficient corresponding to the difference is the weighting coefficient corresponding to the motor's work load.

[0011] Furthermore, the weighting coefficient corresponding to the motor's work load gradually decreases as the work difference increases.

[0012] Furthermore, in S4, the real-time operating parameters include the motor body temperature, the motor controller temperature, the motor fault level, and the motor work load; the real-time weighting coefficient is obtained by multiplying the weighting coefficients corresponding to each real-time operating parameter.

[0013] A main-auxiliary motor switching control system for a dual-motor power system of a new energy commercial vehicle includes: The data acquisition module collects the initial and real-time operating parameters of the two motors. The weight coefficient calculation module calculates the initial weight coefficient using the initial running parameters and the real-time weight coefficient using the real-time running parameters. The logic switching module compares the initial weighting coefficients of the two motors when the vehicle starts, selects the motor with the larger initial weighting coefficient as the main motor, and the other motor as the auxiliary motor; during vehicle operation, when the absolute value of the torque requested by the driver is less than a set threshold, or the actual torque distribution coefficient meets the preset relationship, the switching between the main and auxiliary motors is triggered.

[0014] Compared with existing technologies, the main and auxiliary motor switching control method for the dual-motor power system of new energy commercial vehicles described in this invention has the following advantages: The present invention provides a method and system for controlling the switching of main and auxiliary motors in a dual-motor power system for new energy commercial vehicles. By collecting key operating parameters, including motor body temperature, controller temperature, fault level, and work load, and calculating weighting coefficients accordingly, the method achieves precise control over the timing of switching between the main and auxiliary motors, optimizes the power distribution of the dual motors, ensures that the motors operate under optimal load conditions, thereby extending the service life of the motors and improving the energy efficiency of new energy commercial vehicles.

[0015] Furthermore, this invention uses the driver's requested torque and the actual torque distribution coefficient as switching conditions, allowing flexible switching between the main and auxiliary motors when the torque demand is low or the torque distribution meets a specific relationship. It comprehensively considers the continuity of torque during motor switching to ensure a balanced distribution of motor workload under different operating conditions, thereby guaranteeing the smoothness and safety of vehicle operation. Attached Figure Description

[0016] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings: Figure 1 The control flowchart provided for embodiments of the present invention; Figure 2 This is a block diagram of a control system provided in an embodiment of the present invention. Detailed Implementation

[0017] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0018] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are used only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0019] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0020] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0021] like Figure 1 As shown, a method for switching control between the main and auxiliary motors in a dual-motor power system for new energy commercial vehicles includes: S1. When the vehicle starts, the initial operating parameters of the two motors are collected. The initial operating parameters include the motor body temperature, the motor controller temperature, the motor fault level, and the motor work load. S2. Calculate the initial weighting coefficients of the two motors according to the initial operating parameters. The initial weighting coefficients are obtained by multiplying the weighting coefficients corresponding to each initial operating parameter. S3. Compare the initial weighting coefficients of the two motors, select the motor with the larger initial weighting coefficient as the main motor, and the other motor as the auxiliary motor. S4. During vehicle operation, real-time operating parameters of the two motors are collected, and real-time weighting coefficients of the two motors are calculated based on the real-time operating parameters. S5. When the absolute value of the torque requested by the driver is less than the set threshold, or the actual torque distribution coefficient meets the preset relationship, the switching between the main and auxiliary motors is triggered.

[0022] This invention intelligently selects the primary and auxiliary motors by collecting key initial operating parameters during vehicle startup, including motor body temperature, controller temperature, fault level, and work load, and calculating initial weighting coefficients accordingly. During vehicle operation, the method continuously collects real-time operating parameters and dynamically calculates real-time weighting coefficients to ensure optimal motor operation. Furthermore, this method introduces the driver's requested torque and the actual torque distribution coefficient as switching conditions, allowing flexible switching between primary and auxiliary motors when torque demand is low or when torque distribution meets specific relationships. The advantages of this method are balanced motor load distribution, improved energy efficiency, extended motor lifespan, and reduced maintenance costs.

[0023] In a preferred embodiment of the present invention, in S3, if the initial weight coefficients of the two motors are equal, then the other motor is selected as the main motor based on the main motor at the end of the previous driving cycle.

[0024] Specifically, when the initial weighting coefficients of the two motors are equal, the other motor is selected as the new master motor by referring to the master motor state at the end of the previous driving cycle. This avoids the system always tending to select the same motor as the master motor. By rotating the master motors, the workload of the two motors can be distributed more evenly, reducing overuse of individual motors. This helps prevent motor overload and premature wear, thus extending their service life.

[0025] In a preferred embodiment of the present invention, in S4, the real-time operating parameters include the motor body temperature, the motor controller temperature, the motor fault level, and the motor work load, and the real-time weighting coefficient is obtained by multiplying the weighting coefficients corresponding to each real-time operating parameter.

[0026] Specifically, by multiplying the weighting coefficients of multiple key operating parameters, a comprehensive real-time weighting coefficient can be obtained. This coefficient reflects the overall performance and reliability of the motor under the current operating conditions. By considering all key parameters, the real-time weighting coefficient helps to select the motor with the best performance under the current conditions as the main motor, thereby improving the efficiency and response speed of the entire power system.

[0027] In a preferred embodiment of the present invention, in S5, the set threshold is 50 Nm.

[0028] Specifically, this threshold is used to assess the magnitude of the torque requested by the driver. "Driver-requested torque" refers to the torque demand signal sent by the driver to the vehicle's powertrain via the accelerator pedal. When the absolute value of the requested torque is less than 50 Nm, the system considers the current acceleration demand of the vehicle to be low, thus allowing switching between the main and auxiliary motors. By switching motors under low torque requests, the impact of the switching action on the vehicle's power output can be reduced, thereby providing a smoother driving experience and avoiding potential power interruptions or unevenness that may occur when switching under high torque demands.

[0029] In a preferred embodiment of the present invention, in S5, the actual torque distribution coefficient satisfies a preset relationship: the result of multiplying the actual torque distribution coefficient by 2 and then subtracting 1 is less than the weight coefficient corresponding to the real-time weight coefficient. The correspondence between the real-time weight coefficient and the weight coefficient is shown in Table 1.

[0030] When the torque distribution coefficient is 0.5, it is an average distribution; when it is 0 or 1, it is a single motor drive; otherwise, it is an over-rotation state.

[0031] Specifically, the smaller the real-time weighting coefficient, the larger the corresponding weighting coefficient, and the easier it is to meet the conditions for switching between the main and auxiliary motors. For example, when the real-time weighting coefficient is 12, the corresponding weighting coefficient is 0.5. When the two motors distribute torque in a 3:7 ratio, 0.7×2-1=0.4<0.5, so the main and auxiliary motors can be switched. When the two motors distribute torque in a 1:9 ratio, 0.9×2-1=0.8>0.5, so the main and auxiliary motors cannot be switched. The larger the torque difference between the two motors, the more likely driving problems will occur when switching between the main and auxiliary motors.

[0032] Table 1 Correspondence between Motor Body Temperature and Weighting Coefficient

[0033] In a preferred embodiment of the present invention, in S2, the weighting coefficient corresponding to the motor body temperature, as shown in Table 2, gradually decreases as the temperature increases. Reducing the weighting coefficient when the motor temperature is high helps to transfer more power load to the motor with a lower temperature, thereby achieving better power distribution and cooling effect.

[0034] Table 2 Correspondence between Motor Body Temperature and Weighting Coefficient

[0035] In a preferred embodiment of the present invention, in S2, the weighting coefficient corresponding to the motor controller temperature, as shown in Table 3, gradually decreases as the temperature increases. Reducing the weighting coefficient as the motor controller temperature rises can decrease its involvement under high-load conditions, thereby avoiding damage caused by overheating and achieving effective thermal protection for the motor controller.

[0036] Table 3 Correspondence between Motor Controller Temperature and Weighting Coefficient

[0037] In a preferred embodiment of the present invention, in S2, the weighting coefficient corresponding to the motor fault level, as shown in Table 4, gradually decreases as the fault level increases. As the fault level increases, the decrease in the weighting coefficient encourages the system to use motors in better health, which facilitates preventative maintenance and reduces the need for unexpected downtime and emergency repairs.

[0038] Table 4 Correspondence between Motor Fault Levels and Weighting Coefficients

[0039] In a preferred embodiment of the present invention, in S2, the calculation process of the weighting coefficient corresponding to the motor work load is as follows: the current and voltage of the two motors are collected, the power of each motor is calculated, and the power is integrated to obtain the work done by each motor in the current driving cycle; the difference in work done by the two motors is calculated, and the weighting coefficient corresponding to the difference is the weighting coefficient corresponding to the motor work load, as shown in Table 5. The weighting coefficient gradually decreases as the difference in work increases. The weighting coefficient is dynamically adjusted according to the difference in work done by the two motors so that the weighting coefficient can reflect the degree of imbalance of the load of the two motors in the current driving cycle.

[0040] Table 5. Correspondence between the difference in work done by the two motors and the weighting coefficient.

[0041] A main-auxiliary motor switching control system for a dual-motor power system of a new energy commercial vehicle includes: The data acquisition module collects the initial and real-time operating parameters of the two motors. The weight coefficient calculation module calculates the initial weight coefficient using the initial running parameters and the real-time weight coefficient using the real-time running parameters. The logic switching module compares the initial weighting coefficients of the two motors when the vehicle starts, selects the motor with the larger initial weighting coefficient as the main motor, and the other motor as the auxiliary motor; during vehicle operation, when the absolute value of the torque requested by the driver is less than a set threshold, or the actual torque distribution coefficient meets the preset relationship, the switching between the main and auxiliary motors is triggered.

[0042] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for switching control between main and auxiliary motors in a dual-motor power system for new energy commercial vehicles, characterized in that, include: S1. When the vehicle starts, the initial operating parameters of the two motors are collected. The initial operating parameters include the motor body temperature, the motor controller temperature, the motor fault level, and the motor work load. S2. Calculate the initial weighting coefficients of the two motors according to the initial operating parameters. The initial weighting coefficients are obtained by multiplying the weighting coefficients corresponding to each initial operating parameter. S3. Compare the initial weighting coefficients of the two motors, select the motor with the larger initial weighting coefficient as the main motor, and the other motor as the auxiliary motor. S4. During vehicle operation, real-time operating parameters of the two motors are collected, and real-time weighting coefficients of the two motors are calculated based on the real-time operating parameters. S5. When the absolute value of the torque requested by the driver is less than the set threshold, or the actual torque distribution coefficient meets the preset relationship, the switching between the main and auxiliary motors is triggered.

2. The main and auxiliary motor switching control method for a dual-motor power system of a new energy commercial vehicle according to claim 1, characterized in that: In S5, the actual torque distribution coefficient satisfies the preset relationship that the result of multiplying the actual torque distribution coefficient by 2 and then subtracting 1 is less than the weight coefficient corresponding to the real-time weight coefficient.

3. The main and auxiliary motor switching control method for a dual-motor power system of a new energy commercial vehicle according to claim 2, characterized in that: When the actual torque distribution coefficient is 0.5, it is an average distribution; when it is 0 or 1, it is a single motor drive.

4. The main and auxiliary motor switching control method for a dual-motor power system of a new energy commercial vehicle according to claim 1, characterized in that: In S5, the set threshold is 50 Nm.

5. The main and auxiliary motor switching control method for a dual-motor power system of a new energy commercial vehicle according to claim 1, characterized in that: In S3, if the initial weight coefficients of the two motors are equal, the other motor is selected as the main motor based on the main motor at the end of the previous driving cycle.

6. The main and auxiliary motor switching control method for a dual-motor power system of a new energy commercial vehicle according to claim 1, characterized in that: In S2, the weighting coefficient corresponding to the motor body temperature gradually decreases as the temperature increases; the weighting coefficient corresponding to the motor controller temperature gradually decreases as the temperature increases; and the weighting coefficient corresponding to the motor fault level gradually decreases as the fault level increases.

7. The main and auxiliary motor switching control method for a dual-motor power system of a new energy commercial vehicle according to claim 1, characterized in that: In S2, the calculation process of the weighting coefficient corresponding to the work load of the motor is as follows: the current and voltage of the two motors are collected, the power of each motor is calculated, and the power is integrated to obtain the work done by each motor in the current driving cycle. Calculate the difference in work done by the two motors, and the weighting coefficient corresponding to the difference is the weighting coefficient corresponding to the work load of the motor.

8. The main and auxiliary motor switching control method for a dual-motor power system of a new energy commercial vehicle according to claim 7, characterized in that: The weighting coefficient corresponding to the motor's work load gradually decreases as the work difference increases.

9. The main and auxiliary motor switching control method for a dual-motor power system of a new energy commercial vehicle according to claim 1, characterized in that: In S4, the real-time operating parameters include the motor body temperature, the motor controller temperature, the motor fault level, and the motor work load. The real-time weighting coefficient is obtained by multiplying the weighting coefficients corresponding to each real-time operating parameter.

10. A main and auxiliary motor switching control system for a dual-motor power system of a new energy commercial vehicle, characterized in that, include: The data acquisition module collects the initial and real-time operating parameters of the two motors. The weight coefficient calculation module calculates the initial weight coefficient using the initial running parameters and the real-time weight coefficient using the real-time running parameters. The logic switching module compares the initial weighting coefficients of the two motors when the vehicle starts, selects the motor with the larger initial weighting coefficient as the main motor, and the other motor as the auxiliary motor. During vehicle operation, when the absolute value of the torque requested by the driver is less than the set threshold, or when the actual torque distribution coefficient meets the preset relationship, the switching between the main and auxiliary motors is triggered.

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