An automotive-grade power module output evaluation method and device, and a motor controller

Abstract

The application provides a kind of vehicle gauge power module output evaluation method, device and motor controller, it is related to motor control technical field, comprising: determine vehicle operating mode, simulation is run, determine motor operating state curve;Wherein, the motor operating state curve is the variation curve of motor torque relative speed;According to the change of the motor operating state curve determines motor operating evaluation point;At motor operating evaluation point, calculate real-time current to carry out power module output evaluation;Solve the problem that the output evaluation workload of existing vehicle under all operating conditions is large and the operation is complex, or the result accuracy is not enough due to the evaluation based on only limit operating condition.

Description

Technical Field

[0001] This invention relates to the field of motor control technology, and in particular to a method, apparatus and motor controller for evaluating the output of automotive-grade power modules. Background Technology

[0002] As a core sub-component of the motor controller, the power capability of the automotive-grade power module determines the overall vehicle performance. To meet the system-level requirements of the vehicle, design requirements are often added layer by layer at each stage, starting from the OEM's specifications. This results in overly stringent evaluation conditions for the module's power capability, leading to over-design of the power module. Even if the same automotive-grade power module is used in different vehicle models, such as P1+P3 dual-motor architecture models or P2+P4 dual-motor architecture models, the final output limit of the power module may differ due to the different operating modes of the vehicles. Therefore, the module's capability should be evaluated in conjunction with the application.

[0003] Existing automotive-grade power module output evaluation methods assess the motor power output of a vehicle under certain extreme conditions and calculate the output capability under extreme conditions. However, they lack consideration of the actual operating conditions of the entire vehicle, resulting in low accuracy. Alternatively, they may take the lowest value among the actual working outputs of the vehicle under all operating conditions, which is labor-intensive and complex to operate. Summary of the Invention

[0004] In order to overcome the above-mentioned technical defects, the present invention aims to provide an automotive-grade power module output evaluation method, device and motor controller to solve the problems of large workload and complicated operation of output evaluation under all vehicle operating conditions, or insufficient accuracy of results due to evaluation based only on extreme operating conditions.

[0005] This invention discloses a method for evaluating the output of automotive-grade power modules, comprising:

[0006] The vehicle's operating mode is determined, and simulation operation is conducted to determine the motor's operating state curve; wherein, the motor's operating state curve is the curve of the change in motor torque relative to speed;

[0007] The motor operation evaluation point is determined based on the changes in the motor operation status curve.

[0008] Real-time current is calculated at the motor operating evaluation point to evaluate the power module output.

[0009] Preferably, the motor operation evaluation points include the high torque low speed point, the turning speed point, and the maximum speed point in the motor operation state curve.

[0010] Preferably, the power module output evaluation includes:

[0011] Based on whether the real-time current reaches the preset reference current;

[0012] And / or, determine the peak output current of the power module based on the real-time current at each motor operating evaluation point.

[0013] Preferably, the simulation operation conditions are determined based on the vehicle's output requirements.

[0014] Preferably, it further includes:

[0015] Adjust the operating motor status so that the vehicle operating mode can be applied to different working conditions, including preset vehicle speed, acceleration, and deceleration.

[0016] Preferably, it also includes selecting a power module configuration or output strategy based on the results of the power module output evaluation.

[0017] The present invention also provides an automotive-grade power module output evaluation device, comprising:

[0018] The calculation module is used to determine the vehicle's operating mode, perform simulation operation, and determine the motor operating state curve; wherein, the motor operating state curve is the curve of the change of motor torque relative to speed.

[0019] The determination module is used to determine the motor operation evaluation point based on the motor operation status curve;

[0020] The output module is used to calculate the real-time current at the motor operating evaluation point for power module output evaluation.

[0021] The present invention also provides a motor controller that applies the power module output evaluation device described above.

[0022] Compared with existing technologies, the above technical solution has the following advantages:

[0023] The automotive-grade power module output evaluation method provided in this application analyzes the vehicle's operating conditions based on the overall vehicle architecture, performs simulation operation under various vehicle operating modes, and obtains the motor operating state curve. Based on the changes in the motor operating state curve, multiple motor operating evaluation points are determined. The power module output is evaluated based on the current at each motor operating evaluation point, such as evaluating the output capability based on a preset reference current or determining the output peak evaluation point. This solves the problems of existing methods that involve large workload and complex operation for output evaluation under all vehicle operating conditions, or insufficient accuracy of results due to evaluation based only on extreme operating conditions. Attached Figure Description

[0024] Figure 1 This is a flowchart of an embodiment of the automotive-grade power module output evaluation method, device, and motor controller described in this invention;

[0025] Figure 2This is a reference diagram of the motor operating status curves of motors P1 and P3 in Example 1 of the automotive-grade power module output evaluation method, device and motor controller of the present invention.

[0026] Figure 3 This is a schematic diagram of a second embodiment of the automotive-grade power module output evaluation method, device, and motor controller described in this invention.

[0027] Figure label:

[0028] 4-Automotive-grade power module output evaluation device; 41-Calculation module; 42-Judgment module; 43-Output module. Detailed Implementation

[0029] The advantages of the present invention will be further illustrated below with reference to the accompanying drawings and specific embodiments.

[0030] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numerals in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this disclosure. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this disclosure as detailed in the appended claims.

[0031] The terminology used in this disclosure is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. The singular forms “a,” “the,” and “the” as used in this disclosure and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any and all possible combinations of one or more of the associated listed items.

[0032] It should be understood that although the terms first, second, third, etc., may be used in this disclosure to describe various information, such information should not be limited to these terms. These terms are used only to distinguish information of the same type from one another. For example, without departing from the scope of this disclosure, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Depending on the context, the word "if" as used herein may be interpreted as "when," "when," or "in response to determination."

[0033] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this 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. Therefore, they should not be construed as limitations on this invention.

[0034] In the description of this invention, unless otherwise specified and limited, it should be noted that the terms "installation", "connection" and "linking" should be interpreted broadly. For example, they can refer to mechanical or electrical connections, or internal connections between two components. They can be direct connections or indirect connections through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.

[0035] In the following description, suffixes such as "module," "part," or "unit" used to denote elements are used only for the convenience of the description of the invention and have no specific meaning in themselves. Therefore, "module" and "part" can be used interchangeably.

[0036] Example 1: This invention discloses an output evaluation method for automotive-grade power modules. This embodiment is used to evaluate the output capability of automotive-grade power modules in specific vehicle applications. In this embodiment, the possible operating modes of the entire vehicle are fully analyzed, the corresponding motor operating curves are calculated, and extreme operating points are selected to evaluate the module's power capability at specific points. Based on the actual operating characteristics of the vehicle, the true peak output capability of the power module in this application is obtained through as few evaluation points as possible, avoiding under- or over-design, saving evaluation time, and accelerating module product definition or design. For details, please refer to [link / reference]. Figure 1 This includes the following steps:

[0037] S10: Determine the vehicle's operating mode, conduct simulation operation, and determine the motor operating state curve; wherein, the motor operating state curve is the curve of change in motor torque relative to speed (e.g., Figure 2 (Example of a curve);

[0038] In the above steps, the vehicle operating mode refers to the actual possible operating modes of the entire vehicle. Specifically, it also includes adjusting the state of the operating motors so that the vehicle operating mode can be applied to different operating conditions, including preset vehicle speed, acceleration, and deceleration. In this embodiment, taking a P1+P3 architecture hybrid vehicle as an example, its vehicle operating modes include, but are not limited to, pure electric drive, internal combustion engine direct drive, regenerative braking, range extender drive, parallel drive, and engine start. In pure electric drive, the clutch is disengaged, the P1 motor does not operate, and the P3 motor is driven by a positive power factor. This corresponds to low-speed (below the preset speed, such as below 80 km / h) cruising / low-speed slow acceleration, etc. In internal combustion engine direct drive, the P1 and P3 motors do not operate, and the clutch is engaged. This corresponds to medium-to-high-speed cruising, slow acceleration, etc. In regenerative braking, the clutch is disengaged, and the P1 and P3 motors are not engaged. When motor 1 is not working, motor P3 generates electricity with a negative power factor, corresponding to deceleration and other operating conditions. When using range extender drive, the clutch is disengaged, motor P1 generates electricity with a negative power factor, and motor P3 generates electricity with a positive power factor, corresponding to low SOC, medium-speed cruising, low-speed rapid acceleration, or overtaking conditions. When using parallel drive, the clutch is engaged, motor P1 is not working, and motor P3 drives with a positive power factor, corresponding to medium-high speed full-load acceleration and other operating conditions. When using generator drive, the clutch is disengaged, motor P1 drives the engine with a positive power factor, and motor P2 drives the wheels with a positive power factor, corresponding to switching from low-speed cruising to medium-high speed and other operating conditions.

[0039] Based on the above, controlling the different operating states of the motor and clutch enables the switching and operation of the vehicle's working mode. The vehicle working mode described above is an example under a P1+P3 architecture hybrid vehicle. Other vehicles can also be selected to implement all or some of the above working modes for simulation. It should be noted that the simulation operating conditions can be determined according to the vehicle's output requirements to improve the consistency between the vehicle simulation and the actual application scenario. For example, the simulation operating conditions could be set as follows: Vdc = 450V, switching frequency f... sw =10kHz, coolant flow rate 8L / min, coolant temperature 65℃, power factor PF = -1 to 1. Where the power factor is close to 1, the heating is mainly caused by IGBT devices; where the power factor is close to -1, the heating is mainly caused by diode devices. Simulation was conducted to place the vehicle in the above operating modes to determine the motor's operating state curve.

[0040] S20: Determine the motor operation evaluation point based on the changes in the motor operation state curve;

[0041] As explained, in this embodiment, the motor operating state curve, i.e., the change in torque relative to speed, is used to determine the motor operating evaluation point by identifying the points in the motor operating state curve where changes occur. For example... Figure 2In the example shown (points 1-6), specifically, the motor operation evaluation points include, but are not limited to: high torque low speed points, turning point speed points, and maximum speed points in the motor operation state curve. The aforementioned high torque low speed points represent operating conditions that may occur when starting the motor at low ambient temperatures (which need to be limited). Each of the evaluation points identified above represents a region in the motor operation state curve where the curve changes. Using curve changes as evaluation points differs from existing methods that evaluate under extreme or full operating conditions. By using as few evaluation points as possible with varying characteristics, the true peak output capability of the power module in this application can be quickly and accurately obtained. Figure 2 In the present invention, the motor is controlled by reducing the frequency by 5kHz at 225-300rpm and by reducing the frequency by 2.5kHz below 225rpm. However, in actual operation below 2000rpm, the frequency reduction strategy of 5kHz may be used. Based on this, the motor operation evaluation point is determined in the region where the curve changes, and the output capability of the power module is evaluated so as to implement the frequency reduction strategy control of the motor in the future.

[0042] S30: Calculates real-time current at the motor operating evaluation point to evaluate the power module output.

[0043] In this embodiment, the power module output evaluation specifically assesses whether the motor operating current at each motor operation evaluation point reaches a preset reference current. This reference current can be calculated using a preset (existing) torque formula. Therefore, the power module output evaluation includes: determining whether the real-time current reaches the preset reference current; if yes, the power module output capability is better; otherwise, the power module output capability is worse. And / or, determining the peak output current of the power module based on the real-time current at each motor operation evaluation point, used to determine the system boundary conditions for the motor controller's operation, such as determining the minimum and maximum values ​​of the output current capability.

[0044] This embodiment also includes selecting the power module configuration or output strategy based on the power module output evaluation results. Specifically, as an example, when multiple different types of power modules (multiple IGBTs + multiple FRDs) are configured, the output current in drive mode is limited by the IGBT junction temperature, and the output current in power generation mode is limited by the diode junction temperature. Based on the above evaluation points, the minimum output current may occur under both low-speed, high-torque and high-speed, high-power-factor conditions. At low speeds, a frequency reduction strategy can be adopted. At high speeds, after entering the weak magnetic field region, the torque demand will decrease. When only IGBTs + 2 FRDs are configured, the output current is limited by the IGBTs for both power generation and drive. The power limitation point is the IGBT junction temperature. The closer the power factor is to -1, the more the FRDs become the main operating devices, reducing heat dissipation pressure and increasing output current. In this case, using the motor's turning speed point as the peak output evaluation point is more reasonable.

[0045] In this embodiment, the vehicle's operating conditions are analyzed based on the overall vehicle architecture. In conjunction with the motor calibration results, the system boundary conditions for the motor controller's operation are selected, and the output capability of the power module is evaluated. Specifically, simulations are performed under various vehicle operating modes to obtain the motor's operating state curves. Based on the changes in these curves, motor operating evaluation points are determined. The power module output is evaluated based on the current at each motor operating evaluation point. For example, the output capability can be evaluated based on a preset reference current, or any one of the high torque low speed point, the turning point speed point, or the maximum speed point can be determined as the output peak evaluation point. Based on this, vehicle motor output optimization and power module configuration optimization are performed.

[0046] Example 2: This example provides an automotive-grade power module output evaluation device 4 to perform the power module output evaluation method described in Example 1 above. For details, please refer to... Figure 3 ,include:

[0047] The calculation module 41 is used to determine the vehicle's working mode, perform simulation operation, and determine the motor's operating state curve; wherein, the motor's operating state curve is the curve of the change in motor torque relative to speed.

[0048] Specifically, the above-mentioned vehicle operating modes correspond to different operating conditions. Examples include, but are not limited to, pure electric drive, internal combustion engine direct drive, brake energy recovery, range extender drive, parallel drive, and engine start, in order to achieve operating conditions including, but not limited to, low-speed cruise, high-speed cruise, acceleration, and deceleration. By controlling the different operating states of the motor and clutch, the vehicle operating modes can be changed and operated. The simulation operating conditions can be determined according to the vehicle's output requirements, so that the vehicle is in the above-mentioned operating modes, thereby determining the motor operating state curve.

[0049] The determination module 42 is used to determine the motor operation evaluation point based on the motor operation status curve;

[0050] In the above module, the motor operation evaluation points are determined by the points in the motor operation state curve that show changes. Specifically, the motor operation evaluation points include, but are not limited to: high torque low speed points, turning point speed points, and maximum speed points in the motor operation state curve, all of which correspond to different operating conditions / state changes.

[0051] Output module 43 is used to calculate the real-time current at the motor operating evaluation point for power module output evaluation.

[0052] In the aforementioned module, based on the determined motor operating evaluation point, the real-time current is calculated using preset / existing torque formulas. The power module's output is evaluated based on whether this real-time current reaches the preset reference current or can be used as peak output. Based on this output evaluation, the power module configuration or output strategy is selected. Specifically, for example, with a 2IGBT+2FRD power module configuration, the output current in drive mode is limited by the IGBT junction temperature, while the output current in power generation mode is limited by the diode junction temperature. The minimum output current may occur under both low-speed, high-torque and high-speed, high-power conditions. At low speeds, a frequency reduction strategy can be adopted. At high speeds, the torque demand decreases as the field weakens. When only IGBT+2FRD is configured, the power limitation point is the IGBT junction temperature. The closer the power factor is to -1, the more the FRD becomes the primary operating device, reducing heat dissipation pressure and increasing output current. In this case, the operating state at the motor's turning speed point is used as the peak output evaluation point. Based on the analysis of the vehicle architecture and the vehicle operating conditions, the same module can be evaluated and applied more reasonably in different vehicle models. Only the system operating boundary conditions need to be set according to the motor operation evaluation points determined above, reducing the module evaluation conditions.

[0053] Example 3: This invention also provides a motor controller that uses the aforementioned power module output evaluation device to execute the evaluation method described in Example 1. It may also include other modules or components for controlling motor operation. For automotive-grade power modules, it evaluates their output capability under specific vehicle models. Specifically, it fully analyzes the possible operating modes of the vehicle, obtains the corresponding motor operating curves, and selects extreme operating points (i.e., the aforementioned motor operation evaluation points) to evaluate the module's power capability at specific points. This allows the motor controller to determine system boundary conditions and perform reasonable motor control. This differs from existing technologies that only calculate output capability under extreme conditions, lacking consideration of the actual operating conditions of the vehicle, or calculate module output capability under all operating conditions and take the lowest value, increasing the evaluation workload. This invention provides a simple, fast, and highly accurate evaluation method for automotive-grade power module output.

[0054] It should be noted that the embodiments of the present invention have better implementability and are not intended to limit the present invention in any way. Any person skilled in the art may use the above-disclosed technical content to change or modify it into equivalent effective embodiments. However, any modifications or equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. A method for evaluating the output of an automotive-grade power module, characterized in that, include: The vehicle's operating mode is determined, and simulation operation is conducted to determine the motor's operating state curve; wherein, the motor's operating state curve is the curve of the change in motor torque relative to speed; The motor operation evaluation point is determined based on the changes in the motor operation status curve. Calculate the real-time current at the motor operating evaluation point to evaluate the power module output; The motor operation evaluation points include the high torque low speed point, the turning speed point, and the maximum speed point in the motor operation state curve. The power module output evaluation includes: Based on whether the real-time current reaches the preset reference current; And / or, determine the peak output current of the power module based on the real-time current at each motor operating evaluation point.

2. The evaluation method according to claim 1, characterized in that: The simulation operation conditions are determined based on the vehicle's output requirements.

3. The evaluation method according to claim 1, characterized in that, Also includes: Adjust the operating motor status so that the vehicle operating mode can be applied to different working conditions, including preset vehicle speed, acceleration, and deceleration.

4. The evaluation method according to claim 1, characterized in that, Also includes: Select the power module configuration or output strategy based on the results of the power module output evaluation.

5. An automotive-grade power module output evaluation device, characterized in that, include: The calculation module is used to determine the vehicle's operating mode, perform simulation operation, and determine the motor operating state curve; wherein, the motor operating state curve is the curve of the change of motor torque relative to speed. The determination module is used to determine the motor operation evaluation point based on the motor operation status curve; The output module is used to calculate the real-time current at the motor operating evaluation point for power module output evaluation. The motor operation evaluation points include the high torque low speed point, the turning speed point, and the maximum speed point in the motor operation state curve. The power module output evaluation includes: Based on whether the real-time current reaches the preset reference current; And / or, determine the peak output current of the power module based on the real-time current at each motor operating evaluation point.

6. A motor controller, characterized in that: The power module output evaluation device described in claim 5 above is applied.

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