JP3399396B2 - Motor control system - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor control system for controlling a motor.

[0002]

2. Description of the Related Art In recent years, a motor control system for controlling a motor or the like mounted on an electric vehicle monitors the occurrence of an abnormality in the motor control system during operation of the motor and, when an abnormality occurs, energizes the motor. It is equipped with a fail-safe function that shuts off and shuts down the operation. Further, there is also one having an initial operation check function of whether or not a motor control operation including a fail-safe function is normally performed at the time of starting the motor.

In a conventional motor control system for an on-vehicle motor as shown in FIG. 3, during a normal operation, a torque command value calculation unit (not shown) is used in the main calculation unit 5 in accordance with an accelerator opening degree, a vehicle speed and the like. In order to generate a target torque in the motor based on the calculated torque command value, first, a two-phase excitation current command value Id and a torque current command value Iq are calculated and output to the current control unit 4. .

The current control section 4 improves the output accuracy of the exciting current command value Id and the torque current command value Iq by using the output of a feedback circuit (not shown). The coordinate conversion unit 21 performs coordinate conversion of the excitation current command value Id and the torque current command value Iq based on the rotation angle of the motor 1 detected by the rotation angle sensor 13, and the three-phase current command value I.
u, Iv, and Iw are calculated and output to the inverter 2 connected to the battery 6. The inverter 2 has a current command value I
The motors 1 are controlled by converting u, Iv, and Iw into motor currents Iu ′, Iv ′, and Iw ′.

In order to monitor the occurrence of an abnormality in the motor control system, the sub-calculation unit 7 receives the same torque command value as the main calculation unit 5 and performs the same calculation as the main calculation unit 5 to generate the exciting current command value Id. 'And the torque current command value Iq' are calculated and output to the comparison unit 8. Current sensor 1
In 4, the motor currents Iu ′, Iv ′, Iw ′ are detected,
In the coordinate conversion unit 15, based on the rotation angle of the motor 1 detected by the rotation angle sensor 13, the motor currents Iu ′, Iu.
Coordinate conversion of v'and Iw 'is performed, and the exciting current detection value Id "
Then, the detected torque current value Iq ″ is calculated.

The comparing unit 8 compares the exciting current command value Id 'calculated by the sub-calculating unit 7 with the exciting current detection value Id "converted by the coordinate converting unit 15, and also the torque current command value Iq'. And the detected torque current value Iq ″ are compared. When the motor control system is operating normally, the values of the exciting current command value Id ′ and the exciting current detection value Id ″ are substantially the same, and the values of the torque current command value Iq ′ and the torque current detection value Iq ″ are the same. The values are almost the same. Something went wrong,
When the difference between the command values exceeds a predetermined value, the comparing unit 8 outputs an abnormal signal to the fail safe unit 10. In the fail safe unit 10, when an abnormal signal is input, the motor drive relay (not shown) is cut off. Therefore, it becomes impossible to drive the motor, and the safety of the motor control is ensured.

Immediately after the driver turns on the key switch, an initial operation check is performed to confirm whether the failsafe function is operating normally. When the key operation detection unit 11 detects that the key switch for starting the motor is turned on, first, the initial operation check signal is sent from the initial operation check control unit 22 to the main operation unit 5,
It is output to the sub calculation unit 7 and the comparison unit 8.

When the initial operation check signal is input, the main arithmetic unit 5 outputs a predetermined value as the excitation current command value Id in order to perform an operation check without generating torque in the motor 1, and the torque current Iq = 0 is output as the command value Iq. In the sub-calculation unit 7, when the initial operation check signal is input, Id '= 0 as the excitation current command value Id' and Iq '= as the torque current command value Iq'.
Outputs 0.

In the comparison unit 8, when the initial operation check signal is input, the exciting current command value Id 'and the exciting current detection value I
If the difference in d ″ or the difference between the torque current command value Iq ′ and the detected torque current value Iq ″ is greater than or equal to a predetermined value, an abnormal signal is output to the initial operation check control unit 22. Since the exciting current command value Id and the exciting current command value Id 'having different values are output from the main computing unit 5 and the sub computing unit 7, the comparing unit 8
Outputs an abnormal signal to the initial operation check control unit 22.
By the above operation, the initial operation check control unit 22
You can check whether the fail-safe function is operating normally.

[0010]

However, since the rotation angle sensor 13 is composed of a photo encoder attached to the stator side of the motor 1 and a slit provided on the rotor side, and detects the rotation angle, it stops. When detecting the phase angle of the motor 1, the initial detected initial phase angle value has an error of 0 ° to 30 °. An accurate phase angle is detected only when the rotor rotates and moves from one of the six divided areas to another area.

Therefore, as shown in FIG. 4A, the phase angle θr4 of the S pole Sr and the N pole Nr of the rotor is 30 °.
However, the initial phase angle detection value θs4, which is the detection value of the first phase angle by the rotation sensor 13, is 60 °.
May be output. In order to simplify the explanation, the modeled S is used instead of the actual magnetic pole.
A pole and a north pole are used.

At the time of checking the initial operation, first, the coordinate conversion unit 2
In 1, the current command value is calculated so that the torque becomes 0 with reference to the detected initial phase angle value θs4 = 60 °,
It outputs to the inverter 2 and energizes the stator 17 of the motor 1. Therefore, the phase angles of the S pole Ss and the N pole Ns generated in the stator 17 are the initial phase angle detection value θs4 = 60 °.
Is equal to The actual positions of the S pole Sr and the N pole Nr of the rotor 16 and the N poles Ns and S generated in the stator 17
Since the position of the pole Ss is displaced, torque is generated in the rotor 16 and the rotor 16 rotates in the direction of the arrow.

The calculation of the current command value in the coordinate converter 21 is performed every 2 ms, and each time, the current of the rotor 16 of the rotor 16 detected by the rotation angle sensor 13 is newly adjusted so that the torque of the motor 1 becomes zero. Coordinate conversion is performed based on the detected phase angle value to calculate a current command value. The rotation angle sensor 13 can accurately detect the rotation angle from the initial stage of detection, and when the rotor 16 rotates, the detected phase angle value output from the rotation sensor 13 is the initially detected initial phase angle value. It is the value obtained by adding the rotation angle to.

Therefore, 10 ms after the phase angle of the rotor 16 is first detected, the rotor 16 rotates 20 ° and the actual phase angle θr5 of the rotor becomes 50 °, as shown in FIG. 4 (b). If it becomes, the phase angle detection value θs
As for 5, 80 ° is output. Therefore, in the coordinate conversion unit 21, the phase angle detection value θs5 =
The current command value is calculated and the motor is energized so that the torque becomes 0 on the basis of 80 °. Therefore, in the stator 17, the phase angle of the S pole Ss and the N pole Ns is the phase angle detection value θs5 = 80 °.

When the rotor 16 rotates to some extent, the error between the actual phase angle of the rotor 16 and the phase angle detected by the rotation sensor 13 is eliminated. However, for example, when the phase angle error is eliminated when the phase angle of the rotor 16 reaches 60 °, the phase angle θr6 of the rotor 16 becomes 60 ° as shown in (3) of FIG. Until immediately before, the phase angle θs6 of the stator 17 becomes a value larger than the phase angle θr6 of the rotor by 30 °, and the torque for rotating the rotor 16 is continuously generated, so that the rotor 16 or the motor 1 rotates.

As described above, when the detection error of the initial phase angle is large, there is a problem in that the motor 1 rotates and a shock is transmitted to the driver, which may cause discomfort. In view of the above conventional problems, the present invention aims to reduce the rotation of the motor that occurs when the motor is energized while the motor is stopped during the initial operation check or the like, and to reduce the discomfort given to the driver. And

[0017]

In order to solve the above problems, according to the invention of claim 1, a rotation angle sensor for detecting a rotation angle or a phase angle of the motor, and a rotation of the motor detected by the rotation angle sensor. The motor control unit calculates a motor drive signal for driving the motor based on the detected angle value or the detected phase angle, and an inverter that drives the motor according to the motor drive signal calculated by the motor control unit. The motor control system has a motor energization signal output unit that outputs a motor energization signal when energizing the motor in a motor stopped state.When the motor energization signal is input, the motor control unit first uses the rotation angle sensor. The motor drive signal that makes the torque generated in the motor zero is calculated based on the detected initial phase angle value that is the detected phase angle detection value.

According to the second aspect of the present invention, the motor energization signal output section outputs the motor energization signal when the initial operation check is performed while the motor is stopped.

[0019]

According to the first aspect of the present invention, when the motor is energized while the motor is stopped, the motor is driven based on the initial phase angle detection value which is the phase angle detection value first detected by the rotation angle sensor. Calculate the signal. Therefore, even if there is an error in the detected initial phase angle value, the phase angle of the magnetic pole generated in the stator of the motor does not change. Until the phase angle of the motor rotor becomes equal to the initial phase angle detection value of the rotation angle sensor, the phase angle of the magnetic poles generated in the stator becomes larger than the phase angle of the rotor. Occurs and the rotor rotates.

However, since the phase angle of the magnetic pole in the stator does not change from the initial detected initial phase angle value, the torque for rotating the rotor decreases as the phase angle of the rotor approaches the phase angle of the magnetic pole of the stator. Therefore,
Since the total amount of torque generated in the motor is reduced, the amount of rotation of the motor is reduced and the shock generated is also reduced, so that the driver's discomfort is reduced.

According to the second aspect of the present invention, when the initial operation check is performed and the motor is stopped, the phase angle fixed to the initial phase angle detection value first detected by the rotation angle sensor. Since the motor drive signal is calculated based on the detected value, the total amount of motor torque generated during the initial operation check can be reduced, and discomfort given to the driver is reduced.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described with reference to examples. FIG. 1 is a block diagram showing the configuration of the embodiment. The motor 1 is a running motor mounted on an electric vehicle and is an AC synchronous motor. A transaxle (not shown) is connected to the motor 1, and the driving force from this transaxle is transmitted to both front wheels (not shown) via the left and right front wheel shafts.

The motor 1 is connected to the main arithmetic unit 5 via an inverter 2, a coordinate conversion unit 3 and a current control unit 4. The main calculation unit 5 is connected to the sub calculation unit 7, the comparison unit 8, and the initial operation check control unit 9, and is also connected to a torque command value calculation unit (not shown). The initial operation check control unit 9 is connected to a key operation detection unit 11 that detects an operation of a key switch for starting the motor 1 and a shift position detection unit 12 that detects a travel range from the position of a shift lever, and the main operation detection control unit 9 is also connected. Arithmetic unit 5,
It is also connected to the sub calculation unit 7, the coordinate conversion unit 3, and the comparison unit 8.

When the key operation detector 11 detects that the key switch for starting the motor is operated, the initial operation check controller 9 sends an initial operation check signal to the main controller 5, the sub controller 7, and the comparison controller. Output to the unit 8. In addition, the travel range when the key operation is performed is read from the shift position detection unit 12, and if it is parking, the motor energization signal is output to the coordinate conversion unit 3. That is, when the position of the shift lever is in the parking state and the motor is stopped, the motor energization signal is output to the coordinate conversion unit 3.

In the coordinate conversion unit 3, when the motor energization signal is not input from the initial operation check control unit 9,
The excitation current command value Id and the torque current command value Iq are coordinate-converted based on the rotation angle detection value or the phase angle detection value of the motor 1 sequentially detected by the rotation angle sensor 13, and the three-phase current command is used as a motor drive signal. The values Iu, Iv, and Iw are calculated and output to the inverter 2.

When the motor energization signal is input, the exciting current command value Id and the torque current command value Iq are the initial phase angle detection values which are the phase angle detection values of the motor 1 which are first detected by the rotation angle sensor 13. Perform coordinate conversion based on the value 3
The phase current command values Iu, Iv, Iw are calculated and output to the inverter 2. Other configurations are similar to those of the conventional example shown in FIG. The initial operation check control unit 9 constitutes the motor energization signal output unit of the invention, and the main calculation unit 5 and the coordinate conversion unit 3 constitute the motor control unit.

Next, the operation of this embodiment will be described. The normal operation is the same as the conventional example. The details of the operation when the initial operation check is performed at the time of starting the motor will be described. First, when the key switch for starting the motor 1 is turned on,
The operation when the shift lever positioning is parking will be described. When the key switch is operated and the shift lever positioning is detected as parking, the initial operation check control unit 9 outputs an initial operation check signal to the main calculation unit 5, the sub calculation unit 7, and the comparison unit 8. , And outputs a motor energization signal to the coordinate conversion unit 3.

In the main arithmetic unit 5, a predetermined value is output as the excitation current command value Id and Iq = 0 is output to the current control unit 4 as the torque current command value Iq so that the motor 1 does not generate torque. . The sub-calculation unit 7 outputs Id ′ = 0 as the excitation current command value Id ′ and Iq ′ = 0 as the torque current command value Iq ′ to the comparison unit 8.

The coordinate conversion unit 3 is based on an initial phase angle detection value, which is a detection value when the rotation angle sensor 13 first detects the phase angle of the rotor 1, and the excitation input via the current control unit 4 is performed. The current command value Id and the torque current command value Iq are coordinate-converted to calculate three-phase current command values Iu, Iv, and Iw, which are output to the inverter 2. In the inverter 2, the current command values Iu, Iv, Iw are converted into motor currents Iu ′, Iv ′,
It is converted into Iw ′ and the motor 1 is controlled.

The current sensor 14 controls the motor currents Iu ', Iu.
Detecting v ′ and Iw ′, the coordinate conversion unit 15 performs coordinate conversion of the motor currents Iu ′, Iv ′, and Iw ′ based on the phase angle of the rotor 1, and detects the excitation current detection value Id ″ and the torque current detection value Iq. Is calculated and output to the comparison unit 8. In the comparison unit 8, the exciting current command value Id ′ input from the sub calculation unit 7 is input.
Since the difference between (Id ′ = 0) and the exciting current detection value Id ″ (predetermined value when operating normally) input from the coordinate conversion unit 15 is greater than or equal to a predetermined value, an abnormal signal is output as the initial operation check control unit 9 By the above operation, the initial operation check control unit 9 can confirm that the fail-safe function is operating normally.

The torque generated in the motor 1 when the coordinate conversion unit 3 performs the coordinate conversion based on the initial phase angle detection value as described above will be described. For simplification of explanation, modeled S poles and N poles are used instead of actual magnetic poles. When the phase angle of the motor 1 is detected by the rotation angle sensor 13, there is an error of 0 to 30 ° between the actual phase angle of the motor 1 and the detected value of the phase angle of the rotation angle sensor 13 due to the detection error of the rotation angle sensor 13. May occur.

For example, as shown in FIG. 2A, although the actual phase angle θr1 is 30 °, the initial phase angle detection value θs1 which is the first detection value by the rotation sensor 13 is detected.
May be output as being 60 °. At this time, the coordinate conversion unit 3 detects the initial phase angle detection value θs1 = 60.
The current command value is calculated so that the torque becomes 0 on the basis of °, and output to the inverter 2 and the stator 1 of the motor 1
Energize 7.

Therefore, the S pole S generated in the stator 17
The initial phase angle detection value θs1 =
It is equal to 60 °. Actual S poles Sr and N of the rotor
Since the position of the pole Nr and the positions of the N pole Ns and the S pole Ss generated in the stator 17 are displaced, torque is generated in the rotor 16 and the rotor 16 rotates in the direction of the arrow.

In the coordinate conversion unit 3, the calculation of the current command value is 2
Although it is performed every ms, since the motor energization signal is input, the torque of the motor 1 is set to 0 based on the initial phase angle detection value θs1 which is the detection value when the phase angle is first detected each time. Calculate the current command value. 10 ms after the first detection of the phase angle, for example, the rotor 16 moves 20 °
When rotated, the actual phase angle θr2 of the rotor 16 becomes 50 °, as shown in FIG.

However, since the coordinate conversion unit 3 calculates the current command value so that the torque becomes 0 with the initial phase angle detection value θs1 = 60 ° as a reference, the stator 17 is different from the beginning of energization. Without S pole Ss and N pole N
The phase angle of s is 60 °. That is, during the initial operation check, the current command value output from the coordinate conversion unit 3 does not change from the value calculated first, and therefore the position of the magnetic pole generated in the stator 17 also does not change.

Until the actual phase angle of the rotor 16 reaches the initial phase angle detection value of 60 °, torque for rotating the rotor 16 is continuously generated and the rotor 16 rotates. However, since the positions of the S pole and the N pole in the stator 17 do not change from the beginning, the rotor 16 is rotated as the positions of the N pole and the S pole of the rotor 16 approach the positions of the S pole and the N pole in the stator 17. The torque to be applied is reduced, and as shown in FIG.
When the actual phase angle θr3 and the initial phase angle detection value θs1 match, the generated torque becomes zero. Therefore,
At the time of checking the initial operation, the total amount of torque generated in the motor is reduced, the rotation of the motor is reduced, and the shock generated is also reduced, so that the driver's discomfort is reduced.

Further, when the key switch for starting the motor 1 is turned on and the positioning of the shift lever is other than parking, the motor activation signal is not output from the initial operation check control unit 9, so that the conventional example is used. Similar to the operation at the time of initial operation check in, coordinate conversion is performed based on the phase angle detection value of the rotation sensor 13 that is sequentially detected. That is, in order to maintain safety when the motor is started on a slope or the like, the detected value of the phase angle of the motor 1 by the rotation sensor 13 is used for motor control.

In this embodiment, the shift position detector 12 is provided in order to detect the stop of the motor from the position of the shift lever. However, the present invention is not limited to this. It is also possible to provide a means for directly monitoring whether or not it is stopped. That is, it is possible to determine whether or not the motor is stopped.

Further, in the present embodiment, the motor control system of the present invention is applied to the system for checking the initial operation, but the present invention is not limited to this, and it is a system in which it is necessary to energize the motor in the motor stopped state. If so, the present invention can be applied. For example, it can be applied to a case where the capacitor is discharged at the time of key-off, other than at the time of initial operation check.

Usually, a large-capacity capacitor is connected in parallel to a battery for driving a motor of an electric vehicle, and the capacitor is charged by the battery during key-on and traveling. When the electric vehicle is stopped and keyed off, it is necessary to discharge the charged capacitor. The capacitor can be discharged by passing a current through the motor so that no torque is generated in the motor. By applying the present invention to the above-described capacitor discharging system, it is possible to reduce the torque of the motor generated when the capacitor is discharged.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an exemplary embodiment of the present invention.

FIG. 2 is a diagram illustrating a phase angle of a motor and a detected value of the phase angle in the embodiment.

FIG. 3 is a block diagram showing a configuration of a conventional example.

FIG. 4 is a diagram illustrating a phase angle of a motor and a phase angle detection value in a conventional example.

[Explanation of symbols]

1 motor 2 inverter 3,15,21 Coordinate converter 4 Current control section 5 Main computing section 6 battery 7 Sub calculation unit 8 comparison section 9, 22 Initial operation check control unit 10 Fail-safe section 11 Key operation detector 12 Shift position detector 13 Rotation sensor 14 Current sensor 16 rotor 17 Stator

Claims (2)

(57) [Claims] 1. A rotation angle sensor for detecting a rotation angle or a phase angle of the motor, and a motor for driving the motor based on the rotation angle detection value or the phase angle detection value of the motor detected by the rotation angle sensor. In a motor control system including a motor control unit that calculates a drive signal and an inverter that drives the motor according to the motor drive signal calculated by the motor control unit, a motor energization signal when energizing the motor in a motor stopped state The motor control unit outputs a motor energization signal output unit, when the motor energization signal is input, to the initial phase angle detection value which is the phase angle detection value first detected by the rotation angle sensor. A motor control system that calculates a motor drive signal that reduces the torque generated in the motor to 0 based on the above. 2. The motor control system according to claim 1, wherein the motor energization signal output unit outputs a motor energization signal when an initial operation check is performed while the motor is stopped. .