JP2014036480A - Motor driving device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a motor driving device capable of detecting the erroneous setting of the number of pulses between magnetic poles to be uniquely determined from a synchronous motor and a position detector, and automatically setting the number of pulses between the magnetic poles.SOLUTION: A motor driving device for controlling a synchronous motor to which a position detector is attached includes: a torque command generator 1 for outputting a torque command 12 in accordance with a start signal 11; a magnetic pole position setter 2 for outputting a magnetic pole position command 13 in accordance with the start signal 11; a current controller 4 for outputting a UVW command voltage 14 in accordance with the torque command 12 and the magnetic pole position command 13; and an erroneous setting detector 3 for outputting an erroneous setting detection signal 16 in accordance with position information 15 from the position detector and the magnetic pole position command 13. The erroneous setting detector 3 detects the erroneous setting of the number of pulses per electric angle in accordance with the amount of change of the position information 15 with respect to the change of the magnetic pole position command 13, and outputs an erroneous setting detection signal 16.

Description

  The present invention relates to a vector control method for a synchronous motor, and more particularly to detection of an erroneous setting of the number of pulses per magnetic pole and an automatic setting method.

  Conventionally, vector control of a synchronous motor detects the magnetic pole position by an absolute position detector (resolver or absolute encoder), and performs electromagnetic force control while controlling the amplitude and phase of a sine wave current having a phase synchronized with the magnetic pole position. Is.

  Basically, the current phase γmax at which the generated torque is maximum is obtained by shifting the current phase γmin at which the generated electromagnetic force becomes zero regardless of the applied current by 90 °. As a method of obtaining the current phase, there is a method of updating the current phase γ according to the polarity of the generated torque (see, for example, Patent Document 1).

  In this method, a current is applied to a phase obtained by dividing the electrical angle half cycle by N with reference to the temporary magnetic pole position, and the moving direction D (+, 0, −) at that time is determined in step 1; A current is applied to a phase obtained by dividing the electrical angle region where the sign is inverted into two, and a step 2 for determining the moving direction D1 at that time, and two electrical angle regions in which the moving direction changes from + to 0 and from 0 to −, respectively. Step 3 for applying a current to the divided phase and determining the moving direction D2 at that time, and Step 4 for determining an intermediate point of the electrical angle region where the moving direction is zero as a phase where the generated electromagnetic force is zero. The current phase is determined based on the zero position P in step 4.

JP 2006-296027 A

  However, the above-described technique needs to update the phase in which the current is applied in accordance with the amount of movement of the motor, and the number of position detector pulses between the magnetic poles of the motor (between N poles or between S poles) (Referred to as the number of pulses per magnetic pole), and set the number of pulses per magnetic pole directly with parameters, etc., or set the number of magnetic poles per rotation and the resolution of the position detector with parameters etc. Based on this, it is necessary to derive the number of pulses per magnetic pole. For this reason, there is a problem in that the magnetic pole position cannot be detected correctly if the parameters are set incorrectly.

  In addition, even when the correct magnetic pole position is known using a Hall sensor or the like, only rough magnetic pole position information can be obtained, so it is necessary to refine the magnetic pole position information using the number of pulses per previous magnetic pole, If the setting is wrong, there is a problem that the motor cannot be driven normally.

  The present invention solves the above-described conventional problems, and provides a motor driving device that can detect an erroneous setting of the number of pulses between magnetic poles, and a motor driving device that can automatically set the number of pulses per magnetic pole. With the goal.

In a motor drive device that controls a synchronous motor to which a position detector is attached,
A torque command generator that outputs a torque command in response to a start signal;
A magnetic pole position setter that outputs a magnetic pole position command in response to the start signal;
A current controller that outputs a UVW command voltage according to the torque command and the magnetic pole position command;
An erroneous setting detector that outputs an erroneous setting detection signal from position information from the position detector and the magnetic pole position command;
The erroneous setting detector detects an erroneous setting of the number of pulses per electrical angle from the amount of change in the position information with respect to a change in the magnetic pole position command, and outputs an erroneous setting detection signal.

  According to the motor drive device of the first aspect, it is possible to detect an erroneous setting of the number of pulses between the magnetic poles from the change amount of the position information with respect to the change amount of the magnetic pole position command. According to the motor drive device of the second aspect, it is possible to automatically set the number of pulses between the magnetic poles based on the change amount of the position information with respect to the change amount of the magnetic pole position command.

Block diagram of main parts of motor drive apparatus according to Embodiment 1 of the present invention Detailed explanatory drawing of the rotation method of the motor in Embodiment 1 of this invention Detailed explanatory drawing of the operation method of the linear motor in Embodiment 1 of this invention Main part block diagram of motor drive apparatus in Embodiment 2 of the present invention

(Embodiment 1)
FIG. 1 is a block diagram of a motor drive device according to claim 1, wherein a torque command generator 1 that outputs a torque command 12 from a start signal 11 and a magnetic pole position setting that outputs a magnetic pole position command 13 from a start signal 11. 2, an erroneous setting detector 3 that outputs an erroneous setting detection signal 16 from the magnetic pole position command 13 and position information 15, and a current controller 4 that outputs a UVW command voltage 14 from the torque command 12 and the magnetic pole position command 13. ing.

  First, a method for rotating the motor using the torque command 12 and the magnetic pole position command 13 will be described. Here, a motor using an electromagnet (armature) on the stator side and a permanent magnet on the rotor side will be described. A torque command 12 and a magnetic pole position command 13 are output by the start signal 11, and current control is performed by the current controller 4. When controlling a normally synchronous motor, the magnetic pole position of the motor is detected via the position information 15, a command voltage is applied in a sine wave shape according to the position, and a rotating magnetic field is generated on the stator side, thereby generating a rotor. Rotate. However, in this method, the magnetic pole position is not detected, and when the torque command 12 is applied in a state where the magnetic pole position command 13 is set to a fixed value, as shown in FIGS. Generates a magnetic field 19 having a certain magnetic pole direction, so that the rotor 20 moves to a position coinciding with the magnetic pole direction and stops (locked state). When the magnetic pole position command 13 is changed little by little from that state, the magnetic field 19 generated on the stator 18 side gradually moves as shown in FIG. Rotate together. That is, by applying the torque command 12 and changing the magnetic pole position command 13, the motor can be rotated without using the position information 15. Thereby, the rotation amount of the motor can be controlled only by the change amount of the magnetic pole position command 13 and the position information 15 without depending on the position information 15.

Next, a method for detecting an erroneous setting of the number of pulses per magnetic pole of the motor from the magnetic pole position command 13 and the position information 15 in the erroneous setting detector 3 will be described. Normally, when the motor moves corresponding to one magnetic pole, the amount of change in the position information 15 is equal to the set number of pulses per magnetic pole. As described above, since the rotation amount of the motor can be controlled by changing the magnetic pole position command 13, for example, the change amount of the position information 15 when the magnetic pole position command 13 is changed between one magnetic pole is set in advance. If the number of pulses between the magnetic poles is far from the set value (for example, more than twice or less than half), it is determined that the number of pulses between the magnetic poles is not set correctly, and an erroneous setting detection signal 16 is generated. . Since the feedback control using the position information 15 is not performed, an accurate motor rotation amount according to the change amount of the magnetic pole position command 13 is not necessarily obtained due to the influence of the frictional force or the like, but it is generally used. The resolution of a position detector is mainly 2 N per revolution (N is a positive integer), and it is considered that an error in the set value is more than twice or less than half. There is no problem in detection accuracy as follows. Further, by increasing the change amount of the magnetic pole position command 13, the error of the change amount of the position information 15 with respect to the change amount of the magnetic pole position command 13 is reduced, and the detection accuracy of the set value abnormality can be improved.

  Specifically, a rotary motor having two magnetic poles as shown in FIG. 2 will be described as an example.

  The magnetic pole position command 13 is fixed to the initial value, and the torque command 12 is applied. As a result, the motor rotates and stops where the magnetic poles of the rotor 20 and the magnetic field 19 generated on the stator 18 side coincide. Whether or not the motor is stopped can be determined by determining whether or not the amount of change per unit time of the position information 15 is within a certain threshold. This initial operation can be performed in both the positive and negative directions with a maximum electrical angle of 180 degrees. After completion of the initial operation, the rotor 20 rotates according to the changing direction of the magnetic pole position command 13 by changing the magnetic pole position command 13 by a constant change amount. Therefore, if the magnetic pole position command 13 is changed by 360 degrees of the electrical angle between one magnetic pole, the motor will make one rotation. Therefore, by measuring the amount of change in the position information 15 before and after the magnetic pole position command 13 is changed by 360 degrees in electrical angle, it is possible to determine whether the preset number of pulses per magnetic pole is correct as described above. By generating the erroneous setting detection signal 16, detection of a set value abnormality can be realized in a host controller or the like.

  Also, by giving a certain inclination when the torque command 12 is applied in the initial operation, the impact of the initial operation can be reduced.

(Embodiment 2)
FIG. 4 is a block diagram of the motor drive device according to claim 2, wherein the torque command generator 1 that outputs the torque command 12 from the start signal 11, and the magnetic pole from the start signal 11 and the pulse number correction value 17 between the magnetic poles. A magnetic pole position setting device 2 that outputs a position command 13; an erroneous setting detector 3 that outputs an erroneous setting detection signal 16 and a pulse number correction value 17 between magnetic poles from the magnetic pole position command 13 and position information 15; A current controller 4 that outputs a UVW command voltage 14 from the magnetic pole position command 13 is provided.

  The basic operation is the same as in the first embodiment, and only the differences will be described here. The difference from the first embodiment is that not only the erroneous setting detector 3 detects the erroneous setting of the number of pulses per magnetic pole and generates the erroneous setting detection signal 16, but also derives the correct number of pulses per magnetic pole. This is a point that is output as a pulse number correction value 17 between the magnetic poles.

Specifically, the amount of change in the position information 15 before and after changing the magnetic pole position command 13 is measured, the number of pulses corresponding to the amount of change in the magnetic pole position command 13 per magnetic pole is derived, and the number of pulses per magnetic pole The correction value 17 is output to the magnetic pole position setting device 2. Thereafter, the magnetic pole position setting device 2 can correctly generate the magnetic pole position command 13 according to the amount of change in the position information 15 by using the pulse number correction value 17 between the magnetic poles. Since feedback control using the position information 15 is not performed, an accurate motor rotation amount is not necessarily obtained according to the change amount of the magnetic pole position command 13 due to the influence of frictional force or the like. By increasing the amount, the error of the change amount of the position information 15 with respect to the change amount of the magnetic pole position command 13 is reduced, and the number of pulses per magnetic pole can be set with higher accuracy. Further, the resolution of position detectors that are generally used is mainly 2 N per rotation (N is a positive integer), and the combination of the number of magnetic poles per rotation and the resolution of the position detector is the mainstream. Since the setting value of the number of pulses per magnetic pole is limited, the number of pulses per magnetic pole can be set without error by selecting the closest setting value as the number of pulses corresponding to the change amount of the magnetic pole position command 13. .

  In addition, although this description is described with a rotary motor for convenience, as shown in FIG. 3, detection of an abnormal setting value of the number of pulses per magnetic pole can be similarly performed with a linear motor such as a linear motor. And the correct number of pulses per magnetic pole can be set. The operation method in the case of the linear motor in FIG. 3 is the same as that in FIG. 2 except that the rotary motion of the rotor 20 of the motor in FIG. 2 is changed to the linear motion of the mover 21 in FIG. .

  In addition, for the sake of convenience, this description is given for the case where the stator side is an electromagnet and the rotor side is a permanent magnet. It is possible to detect an abnormal set value and set the correct number of pulses per magnetic pole.

  The motor driving device of the present invention is also useful for detecting abnormal combinations of a synchronous motor and a position detector.

1: Torque command generator 2: Magnetic pole position setting device 3: Incorrect setting detector 4: Current controller 11: Start signal 12: Torque command 13: Magnetic pole position command 14: UVW command voltage 15: Position information 16: Incorrect setting detection Signal 17: Pulse number correction value between magnetic poles 18: Stator 19: Magnetic field 20: Rotor 21: Movable element

Claims (2)

In a motor drive device that controls a synchronous motor to which a position detector is attached,
A torque command generator that outputs a torque command in response to a start signal;
A magnetic pole position setter that outputs a magnetic pole position command in response to the start signal;
A current controller that outputs a UVW command voltage according to the torque command and the magnetic pole position command;
An erroneous setting detector that outputs an erroneous setting detection signal from position information from the position detector and the magnetic pole position command;
The motor drive device characterized in that the erroneous setting detector detects an erroneous setting of the number of pulses per electrical angle from the amount of change in the position information with respect to a change in the magnetic pole position command and outputs an erroneous setting detection signal. In a motor drive device that controls a synchronous motor to which a position detector is attached,
A torque command generator that outputs a torque command in response to a start signal;
A magnetic pole position setting device that outputs a magnetic pole position command based on the start signal and a pulse number correction value between the magnetic poles;
A current controller that outputs a UVW command voltage according to the torque command and the magnetic pole position command;
An erroneous setting detector for outputting an erroneous setting detection signal and a pulse number correction value between magnetic poles from position information from the position detector and the magnetic pole position command,
The motor setting device according to claim 1, wherein the erroneous setting detector derives a correct pulse number between magnetic poles from a change amount of the position information with respect to a change in the magnetic pole position command to obtain a pulse number correction value between magnetic poles.

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