TWI809461B - Motor control method and motor control system - Google Patents

Abstract

A motor control method and a motor control system are provided. The motor control method includes: during a demarcating period, demarcating a vehicle motor by a dynamometer to obtain a first current command table and a second current command table; during a driving period, providing a rotation speed command and a torque command, generating a first current command corresponding to the rotation speed command and the torque command by the first current command table, and generating a second current command corresponding to the rotation speed command and the torque command by the second current command table; and during the driving period, generating an operating current command according to a current battery voltage value, the first current command, and the second current command.

Description

Motor control method and motor control system

The present invention relates to the field of motor control, and in particular to a motor control method and a motor control system.

Existing automotive motors are calibrated with a single calibrated voltage value to generate a current command table before use. After the calibration is completed, the vehicle motor is mounted on a vehicle (such as a locomotive, a car, an electric bicycle, etc.). Operation commands are provided while the vehicle is in motion. The current command table generates a current command according to the operation command and the electric power of the vehicle battery, so that the vehicle motor can be driven according to the current command.

However, the voltage value of a car battery varies. When the voltage value of the vehicle battery does not conform to or is different from the calibrated voltage value, the current command meter will not be applicable, resulting in unstable or out-of-control operation of the vehicle motor. Therefore, how to improve the running stability of the vehicle motor is one of the research directions for those skilled in the art.

The invention provides a motor control method and a motor control system capable of improving the running stability of a vehicle motor.

The motor control method of the present invention is suitable for vehicle motors. Vehicle motors operate within the range of battery voltage values. The motor control method includes: during calibration, using a dynamometer to calibrate the vehicle motor to obtain a first current command table and a second current command table, wherein the first current command table and the second current command table correspond to the battery voltage Different battery voltage values in the value range; during driving, provide a speed command and a torque command, use the first current command table to generate a first current command corresponding to the speed command and torque command, and use the second current command table to generate A second current command corresponding to the rotational speed command and the torque command; and during driving, receiving a current battery voltage value from the vehicle battery, and generating an operating current according to the current battery voltage value, the first current command, and the second current command Order. The vehicle motor operates in response to an operating current command.

The motor control system of the present invention is suitable for vehicle motors. Vehicle motors operate within the range of battery voltage values. A motor control system includes a dynamometer, a vehicle battery, and a controller. During the calibration period, the dynamometer calibrates the vehicle motor to obtain the first current command table and the second current command table. The first current command table and the second current command table correspond to different battery voltage values in the battery voltage value range. The car battery provides the current battery voltage value during driving. The controller is coupled to the vehicle motor. The controller receives the first current command table and the second current command table during calibration. The controller provides a speed command and a torque command during driving, uses a first current command table to generate a first current command corresponding to the speed command and a torque command, and uses a second current command table to generate a corresponding speed command and a torque command the second current command, and generate an operating current command according to the current battery voltage value, the first current command and the second current command. The vehicle motor operates in response to an operating current command.

Based on the above, during the calibration period, the present invention uses different battery voltage values in the battery voltage range to calibrate the vehicle motor to generate the first current command table and the second current command table. During running, the present invention uses the first current command table to generate the first current command, and uses the second current command table to generate the second current command. In addition, during driving, the present invention generates an operating current command according to the current battery voltage value of the vehicle battery, the first current command, and the second current command. The first current command and the second current command of the present invention are generated based on the battery voltage range. Therefore, the applicable range established by the first current command and the second current command can be applied to any current battery voltage value in the battery voltage value range. In this way, even if the current battery voltage value changes, the vehicle motor can run stably according to the operating current command. The present invention also utilizes the current battery voltage value to perform calculations on the first current value and the second current value to generate an operating current value corresponding to the operating current command. In this way, the length of execution time during calibration can be significantly reduced. In addition, the memory space for storing the first current command table and the second current command table can also be reduced.

In order to make the above-mentioned features and advantages of the present invention more comprehensible, the following specific embodiments are described in detail together with the accompanying drawings.

Parts of the embodiments of the present invention will be described in detail with reference to the accompanying drawings. For the referenced reference symbols in the following description, when the same reference symbols appear in different drawings, they will be regarded as the same or similar components. These embodiments are only a part of the present invention, and do not reveal all possible implementation modes of the present invention. Rather, these embodiments are only examples within the scope of the patent application of the present invention.

Please refer to FIG. 1 . FIG. 1 is a flow chart of a motor control method according to a first embodiment of the present invention. In this embodiment, the motor control method is applicable to a vehicle motor. Vehicle motors can be applied to vehicles (such as locomotives, automobiles, electric bicycles, etc.) or other electric mobile vehicles. Vehicle motors are capable of operating within a range of battery voltage values. That is to say, the vehicle motor is designed to operate normally under the battery voltage range. Taking a car as an example, the battery voltage ranges from 550 to 600 volts (the present invention is not limited thereto). In this embodiment, the motor control method includes steps S110-S130. In step S110 , during the calibration period, a dynamometer is used to calibrate the vehicle motor to obtain a first current command table and a second current command table. For example, the first current command table is generated based on the first battery voltage value in the battery voltage value range. The second current command table is generated based on a second battery voltage value in the range of battery voltage values. The second battery voltage value is different than the first battery voltage value. For another example, the first current command table is generated based on the highest battery voltage value in the battery voltage value range. The second current command table is generated based on the lowest battery voltage value in the range of battery voltage values. In this embodiment, step S110 may be performed before delivery or at the quality assurance stage.

After step S110 is completed, the vehicle motor will be mounted on the vehicle. In step S120, a rotational speed command and a torque command are provided during driving. The first current command table generates a first current command corresponding to the rotational speed command and the torque command. The second current command table generates a second current command corresponding to the rotational speed command and the torque command. In step S130, during driving, the current battery voltage value from the vehicle battery is received. The operating current command is generated according to the current battery voltage, the first current command and the second current command. Therefore, the vehicle motor operates in response to the operating current command. After the step S130 is completed, the motor control method returns to the step S120.

It is worth mentioning here that the first current command table and the second current command table are generated by calibrating the vehicle motor according to different battery voltage values in the battery voltage value range. During travel, the first current command table generates a first current command. The second current command table generates a second current command. In addition, the operating current command is generated according to the current battery voltage value of the vehicle battery, the first current command and the second current command during driving. It can be known that the first current command and the second current command are generated based on the battery voltage range. Therefore, the applicable range established by the first current command and the second current command can be applied to any current battery voltage value in the battery voltage value range. In this way, even if the current battery voltage value changes, the vehicle motor can run stably according to the operating current command. In this embodiment, the first current value and the second current value are calculated by using the current battery voltage value to generate an operating current value corresponding to the operating current command. In this way, the length of execution time during calibration can be significantly reduced. In addition, the memory space for storing the first current command table and the second current command table can also be reduced.

Specifically, please refer to FIG. 2A and FIG. 2B at the same time. FIG. 2A is a schematic diagram illustrating the operation of the motor control system during calibration according to an embodiment of the present invention. FIG. 2B is a schematic diagram illustrating the operation of the motor control system during driving according to an embodiment of the present invention. In this embodiment, the motor control system includes a dynamometer 110 , a controller 120 and a vehicle battery 130 . During calibration (eg step S110 of FIG. 1 ), the vehicle motor M is coupled to the dynamometer 110 and the controller 120 . The controller 120 receives different input voltage values P1 and P2 to provide corresponding operating current commands, and uses the operating current commands to drive the motor M of the vehicle. Accordingly, the vehicle motor M operates based on the operation current command to drive the load L in the dynamometer 110 . During calibration, the dynamometer 110 calibrates the vehicle motor M to obtain a first current command table T1 and a second current command table T2 .

In this embodiment, the input voltage value P1 is provided during a time interval during calibration. The controller 120 receives an input voltage value P1 to provide a plurality of operating current commands corresponding to the input voltage value P1. Accordingly, the vehicle motor M operates to drive the load L in the dynamometer 110 based on the plurality of operating current commands corresponding to the input voltage value P1.

In this embodiment, the dynamometer 110 includes a torque sensor 111 and a rotational speed sensor 112 . During calibration, the torque sensor 111 senses the torque value applied to the load L by the motor M of the vehicle. During the calibration period, the rotational speed sensor 112 senses the rotational speed value generated by the load L being driven by the motor M of the vehicle. Therefore, the dynamometer 110 generates the first current command table T1.

The input voltage value P2 is provided at another time interval during the calibration. The controller 120 receives the input voltage value P2 to provide a plurality of operating current commands corresponding to the input voltage value P2. Accordingly, the vehicle motor M operates to drive the load L in the dynamometer 110 based on the plurality of operating current commands corresponding to the input voltage value P2. During the calibration period, the dynamometer 110 uses the torque sensor 111 to sense the torque value applied by the vehicle motor M to the load L, and uses the rotational speed sensor 112 to sense that the load L is driven by the vehicle motor M during the calibration period. The resulting speed value. Therefore, the dynamometer 110 generates the second current command table T2. In this embodiment, the input voltages P1 and P2 can be provided by the same or different power supplies. The input voltage value P1 is different from the input voltage value P2.

In this embodiment, the input voltage value P1 may be the highest battery voltage value in the range of battery voltage values. The input voltage value P2 may be the lowest battery voltage value in the range of battery voltage values. Therefore, the first current command table T1 records a plurality of first current commands corresponding to the highest battery voltage value, a plurality of rotational speed commands and a plurality of torque commands. The second current command table T2 records a plurality of second current commands corresponding to the highest battery voltage value, a plurality of rotational speed commands, and a plurality of torque commands.

In this embodiment, the motor control system further includes a memory STR. The memory STR is coupled to the controller 120 . The memory STR stores the first current command table T1 and the second current command table T2. In this embodiment, the memory STR can be set in the controller 120 .

In this embodiment, the vehicle motor M, the controller 120 and the memory STR are provided on the vehicle before the running period. A vehicle battery 130 on the vehicle is coupled to the controller 120 . Furthermore, a vehicle motor M is coupled to a vehicle load LD. The vehicle load LD may be the transmission of the vehicle. During running (as shown in step S120 of FIG. 1 ), the rotational speed command CMD1 and the torque command CMD2 are provided. For example, when the vehicle is operated to accelerate, decelerate or shift gears, the speed command CMD1 and the torque command CMD2 are provided. The controller 120 receives the rotational speed command CMD1 and the torque command CMD2. The controller 120 utilizes the first current command table T1 to generate a first current command corresponding to the rotational speed command CMD1 and the torque command CMD2 . The controller 120 uses the second current command table T2 to generate a second current command corresponding to the rotation speed command CMD1 and the torque command CMD2 . In this embodiment, the first current command corresponds to the first current value. The second current command corresponds to the second current value. The first current value is smaller than the second current value.

It should be noted that the input voltage value P1 may be the highest battery voltage value in the range of battery voltage values. The input voltage value P2 may be the lowest battery voltage value in the range of battery voltage values. The first current value is smaller than the second current value. That is to say, the first current value and the second current value are negatively correlated with the input voltage values P1 and P2 respectively.

During driving (eg step S130 of FIG. 1 ), the controller 120 receives the current battery voltage V from the vehicle battery 130 . In addition, the controller 120 also generates the operating current command OPCMD according to the current battery voltage V, the first current command and the second current command. The vehicle motor M operates in response to the operation current command OPCMD, thereby driving the vehicle load LD.

Further, the controller 120 uses the current battery voltage V to perform calculations on the first current value and the second current value to generate an operating current value corresponding to the operating current command OPCMD. In this embodiment, the operating current value is negatively correlated with the current battery voltage V. That is to say, when the current battery voltage V of the vehicle battery 130 drops, the operating current value of the operating current command OPCMD will increase. Therefore, the rotational speed and torque provided by the vehicle motor M will increase. On the other hand, when the current battery voltage V of the vehicle battery 130 increases, the operating current value of the operating current command OPCMD decreases. Therefore, the rotational speed and torque provided by the vehicle motor M will decrease.

Based on the above, when the current battery voltage V of the vehicle battery 130 changes, the rotational speed and torque provided by the vehicle motor M can be compensated or corrected in response to the control of the controller 120 . In this way, even if the current battery voltage V changes, the vehicle motor M can run stably according to the operating current command OPCMD.

Please refer to FIG. 2A , FIG. 2B and FIG. 3 at the same time. FIG. 3 is a flow chart of a motor control method according to a second embodiment of the present invention. In this embodiment, the motor control method includes steps S210-S240. In step S210, the highest battery voltage value and the lowest battery voltage value in the range of battery voltage values are defined. For example, the battery voltage ranges from 550 to 600 volts. The maximum battery voltage value is 600 volts. The minimum battery voltage value is 550 volts.

In step S220, the dynamometer 110 calibrates the vehicle motor M during the calibration period. In this embodiment, the input voltage value P1 may be the highest battery voltage value in the range of battery voltage values. The input voltage value P2 may be the lowest battery voltage value in the range of battery voltage values. Therefore, the dynamometer 110 will obtain the first current command table T1 corresponding to the highest battery voltage value and the second current command table T2 corresponding to the lowest battery voltage value. The dynamometer 110 provides the first current command table T1 and the second current command table T2 to the controller 120 .

In step S230, during running, the rotational speed command CMD1 and the torque command CMD2 are provided. The controller 120 uses the first current command table T1 to generate a first current command corresponding to the rotation speed command CMD1 and the torque command CMD2 . The controller 120 uses the second current command table T2 to generate a second current command corresponding to the rotation speed command CMD1 and the torque command CMD2 .

In step S240 , also during driving, the controller 120 receives the current battery voltage V from the vehicle battery 130 . In addition, the controller 120 also performs an interpolation operation according to the current battery voltage V, the first current command, and the second current command to generate the operating current command OPCMD. The vehicle motor M thus operates in response to the operating current command OPCMD, thereby driving the vehicle load LD. After step S240 is completed, the motor control method returns to step S230.

In this embodiment, the controller 120 uses the current battery voltage value V to perform an interpolation operation on the first current value and the second current value to generate an operating current value corresponding to the operating current command OPCMD.

An example is used to illustrate how the operating current value is generated. In this embodiment, the controller 120 generates the operating current value based on the formula (1), for example. ………..…………..(1)

Wherein, In is the operating current value of the operating current command OPCMD, I1 is the first current value of the first current command, I2 is the first current value of the second current command, Vmax is the highest battery voltage value, and Vmin is the lowest battery voltage value .

Based on the formula (1), the controller 120 will subtract the lowest battery voltage value in the range of battery voltage values from the current battery voltage value V to obtain the first difference (ie, V−Vmin), and divide the first difference by the battery range of voltage values (i.e., Vmax-Vmin) to obtain the quotient, subtract the second current value from the first current value to obtain a second difference (i.e., I1-I2), and multiply the second difference by the quotient to get the compensation value. The battery voltage value range may be a difference obtained by subtracting the lowest battery voltage value from the highest battery voltage value. Next, the controller 120 obtains the operating current value according to the compensation value and the second current value. Since the first current value is smaller than the second current value, the second difference is a negative number. That is, if the current battery voltage value V increases, the operating current value will decrease. If the current battery voltage value V drops, the operating current value will rise. In this embodiment, the operating current value is negatively correlated with the current battery voltage value. The speed and torque provided by the vehicle motor M can be compensated or corrected in response to the control of the controller 120 . In this way, even if the current battery voltage V changes, the vehicle motor M can run stably according to the operating current command OPCMD.

Incidentally, the controller 120 uses the current battery voltage value V to perform an interpolation operation on the first current value and the second current value to generate an operating current value corresponding to the operating current command OPCMD. Therefore, the length of execution time during calibration can be significantly shortened. In addition, the memory space for storing the first current command table T1 and the second current command table T2 can also be reduced.

To sum up, during the calibration period, the present invention uses different battery voltage values in the battery voltage range to calibrate the vehicle motor to generate the first current command table and the second current command table. During running, the present invention uses the first current command table to generate the first current command, and uses the second current command table to generate the second current command. During running, the present invention generates an operating current command according to the current battery voltage value of the vehicle battery, the first current command and the second current command. The first current command and the second current command of the present invention are generated based on the battery voltage range. Therefore, the applicable range established by the first current command and the second current command can be applied to any current battery voltage value in the battery voltage value range. In this way, even if the current battery voltage value changes, the vehicle motor can run stably according to the operating current command. In addition, the controller uses the current battery voltage value to perform calculations on the first current value and the second current value to generate an operating current value corresponding to the operating current command. In this way, the length of execution time during calibration can be significantly reduced. In addition, the memory space for storing the first current command table and the second current command table can also be reduced.

Although the present invention has been disclosed above with the embodiments, it is not intended to limit the present invention. Anyone with ordinary knowledge in the technical field may make some changes and modifications without departing from the spirit and scope of the present invention. The scope of protection of the present invention should be defined by the scope of the appended patent application.

110: Dynamometer 111: Torque sensor 112: Speed sensor 120: Controller 130: car battery CMD1: speed command CMD2: torque command L: load LD: vehicle load M: car motor OPCMD: Operating Current Command P1, P2: input voltage value T1: the first current command table T2: second current command table S110~S130: steps S210~S240: steps STR: memory V: current battery voltage value

FIG. 1 is a flow chart of a motor control method according to a first embodiment of the present invention. FIG. 2A is a schematic diagram illustrating the operation of the motor control system during calibration according to an embodiment of the present invention. FIG. 2B is a schematic diagram illustrating the operation of the motor control system during driving according to an embodiment of the present invention. FIG. 3 is a flow chart of a motor control method according to a second embodiment of the present invention.

S110~S130: steps

Claims (8)

A motor control method suitable for a vehicle motor, wherein the vehicle motor operates under a range of battery voltage values, wherein the motor control method includes: using a dynamometer to calibrate the vehicle motor during a calibration period , to obtain a first current command table and a second current command table, wherein the first current command table and the second current command table correspond to different battery voltage values in the battery voltage value range; during a driving period, providing a speed command and a torque command, using the first current command table to generate a first current command corresponding to the speed command and the torque command, and using the second current command table to generate a current command corresponding to the speed command and A second current command of the torque command; and during the driving, receiving a current battery voltage value from a vehicle battery, and according to the current battery voltage value, the first current command and the second current command Generate an operating current command, wherein the vehicle motor responds to the operating current command to run and compensate and correct the rotational speed and torque provided by the vehicle motor; wherein the first current command table records the torque corresponding to the torque command A plurality of first current commands, and the second current command table records a plurality of second current commands corresponding to the torque command; wherein the first current command corresponds to a first current value, wherein the second current command corresponds to a The second current value, wherein the first current value is smaller than the second current value, wherein the step of generating the operating current command according to the current battery voltage value, the first current command and the second current command includes: subtracting a minimum battery voltage value in the battery voltage range from the current battery voltage value to obtain a first difference; dividing the first difference by the battery voltage range to obtain a quotient; subtracting the second current value from a current value to obtain a second difference; multiplying the second difference by the quotient to obtain a compensation value; and obtaining the operation according to the compensation value and the second current value current value. The motor control method as claimed in claim 1, wherein an operating current value corresponding to the operating current command has a negative correlation with the current battery voltage value. The motor control method as claimed in item 1, wherein: the first current command table records the first current commands corresponding to a highest battery voltage value in the battery voltage value range, the rotational speed command and the torque command , and the second current command table records the second current commands corresponding to a lowest battery voltage value in the battery voltage value range, the rotational speed command and the torque command. A motor control system adapted for use with a vehicle motor, wherein the vehicle motor operates at a range of battery voltage values, wherein the motor control system includes: a dynamometer configured to monitor the vehicle motor during a calibration period calibration to obtain a first current command table and a second current command table, wherein the first current command table and the second current command table correspond to different battery voltage values in the battery voltage value range; a vehicle battery , configured to provide a current battery voltage value during a drive; and a controller, coupled to the vehicle motor, configured to: receive the first current command table and the second current command table during the calibration period, and provide a speed command and a torque command during the running period, Using the first current command table to generate a first current command corresponding to the speed command and the torque command, and using the second current command table to generate a second current command corresponding to the speed command and the torque command , and generate an operating current command according to the current battery voltage value, the first current command and the second current command, wherein the vehicle motor operates in response to the operating current command and compensates and corrects the current provided by the vehicle motor speed and torque; wherein the first current command table records a plurality of first current commands corresponding to the torque command, and the second current command table records a plurality of second current commands corresponding to the torque command; wherein The first current command corresponds to a first current value, the second current command corresponds to a second current value, the first current value is less than the second current value, wherein the controller is further configured to utilize the current battery voltage value performing an interpolation operation on the first current value and the second current value to generate an operating current value corresponding to the operating current command; wherein the controller is further configured to: subtract the current battery voltage value from the battery a highest battery voltage value in the range of voltage values to obtain a first difference; divide the first difference by the range of battery voltage values to obtain a quotient; subtracting the second current value from the first current value to obtain a second difference; multiplying the second difference by the quotient to obtain a compensation value; and according to the compensation value and the second current value to obtain the operating current value. The motor control system as claimed in claim 4, wherein an operating current value corresponding to the operating current command has a negative correlation with the current battery voltage value. The motor control system as claimed in claim 4, further comprising: a memory, coupled to the controller, configured to store the first current command table and the second current command table. The motor control system as described in claim 4, further comprising: wherein the first current command table records the first values corresponding to a highest battery voltage value in the battery voltage value range, the rotational speed command and the torque command current command, and the second current command table records the second current commands corresponding to a lowest battery voltage value in the battery voltage value range, the rotational speed command and the torque command. The motor control system as recited in claim 4, wherein the dynamometer includes: a torque sensor configured to sense a torque value of a load applied to the dynamometer by the vehicle motor during the calibration period and a rotational speed sensor configured to sense a rotational speed value generated by the load driven by the vehicle motor during the calibration period.

Images