JP5331523B2 - Control device for three-phase synchronous motor with erroneous wiring detection function - Google Patents

Abstract

The present invention provides a control device of a three-phase synchronous motor with a wiring error detection function which can correctly detect the wiring error of the three-phase synchronous motor. If two-phase wiring error or three-phase wiring error exist, a wiring error detection part (8) detects the wiring error of a three-phase power line between an armature current supplying device (3) and the three-phase synchronous motor M with the following states: (1) the q-axis current instruction Iqc becomes a saturation state, (2) the q-axis current feedback signal IqF becomes a value larger than a preset value, and (3) the q-axis current feedback signal IqF and the feedback speed signal VcF become opposite polarities.

Description

  The present invention relates to a control device for a three-phase synchronous motor having a function capable of detecting erroneous wiring of power lines.

  In the erroneous wiring detection function disclosed in Japanese Patent No. 2797882 (Patent Document 1), it is assumed from an on / off pattern that generates means for sequentially turning on any two of the power transistors of a power converter that drives an electric motor. It is determined whether the servo motor and the servo motor control device are connected by means for comparing the current feedback signal to the output current of the three-phase or multi-phase output of the servo motor control device. In addition, as a protection method when the power line of the conventional three-phase synchronous motor is miswired, there is a method of detecting a miswiring by giving a current command and looking at q-axis current feedback and speed vibration. In addition, there is a case in which DC excitation is performed and an incorrect wiring is detected when the position where the motor stops is not the correct position. In addition, there is one that detects a phase current during dynamic brake operation, and detects it as an incorrect wiring if the order of the phase current is different.

Japanese Patent No. 2797882

  5 to 7 show waveforms of respective commands when the power line of the three-phase synchronous motor is normally wired in the general synchronous motor control device, when the two-phase miswiring is performed, and when the three-phase miswiring is performed. It is. From FIG. 5 to FIG. 7, it can be seen that when two phases are miswired, vibration occurs in the q-axis current feedback for a while, but when three phases are miswired, there is no vibration in the q-axis current feedback. From this, it can be seen that the miswiring cannot be detected depending on the miswiring situation by the method of detecting the miswiring by looking at the q-axis current feedback and the vibration of the speed. Further, in the method using DC excitation, it is necessary to provide a special miswiring detection mode to detect DC wiring and detect miswiring, and the motor moves due to DC excitation. Depending on the machine, there is a machine that cannot take a long moving distance, and it is required that extra movement does not occur. Further, in the method using the dynamic brake, it is necessary to operate the dynamic brake after rotating the motor, and it is difficult to assume the rotation of the motor even though the motor does not move well due to incorrect wiring. In addition, since a three-phase dynamic brake is required, there is a problem that it cannot be applied to a device using a single-phase dynamic brake. In this way, the conventional miswiring detection technology has several problems, such as when three-phase miswiring cannot be detected correctly, when it cannot be detected without a dedicated detection mode, or when it cannot be applied depending on circuit conditions. It was. In addition, if there is an incorrect wiring in the motor power line, the motor will rotate or vibrate in the opposite direction to the command and will not move correctly as the original command, so it is necessary to correct the wiring as soon as possible. However, the conventional miswiring detection technique cannot be detected correctly, so that there is a problem that the identification of the cause is delayed and it takes time to start up the system.

  An object of the present invention is to detect a three-phase miswiring as a miswiring, and without using a special operation such as direct current excitation or a special circuit such as a three-phase dynamic brake. It is an object of the present invention to provide a control device for a three-phase synchronous motor having a miswiring detection function capable of correctly detecting miswiring.

  A three-phase synchronous motor having an erroneous wiring detection function of the present invention includes a position detection unit, a feedback speed signal generation unit, a torque command generation unit, a current command generation unit, a current detector, and an orthogonal biaxial conversion unit. And an armature current supply device and a miswiring detector.

  The position detection unit detects the rotor position θm of the rotor with respect to the stator of the three-phase synchronous motor, and outputs a rotor position detection signal indicating the rotor position. The feedback speed signal generator generates a feedback speed signal indicating the speed of the three-phase synchronous motor. The torque command generation unit generates a torque command based on the speed command and the feedback speed signal. The current command generation unit outputs a d-axis current command and a q-axis current command based on the torque command. The current detector detects a current of at least two phases flowing through the armature winding and outputs a current signal indicating the current of the two phases. The orthogonal biaxial converter calculates and outputs a d-axis current feedback signal and a q-axis current feedback signal by orthogonal biaxial conversion based on the current signal and the rotor position signal output from the current detector. The armature current supply device supplies an armature current to the armature winding based on the d-axis current command, the q-axis current command, the d-axis current feedback signal, and the q-axis current feedback signal. The armature current supply device is configured to determine the phase of the armature current based on the rotor position θm detected by the position detector.

  The miswiring detector detects that the q-axis current command is saturated when there is an incorrect wiring of the three-phase power line based on the q-axis current feedback signal, the feedback speed signal, and the q-axis current command. The three-phase between the armature current supply device and the three-phase synchronous motor by utilizing the situation that the signal becomes a predetermined value or more and the situation where the q-axis current feedback signal and the feedback speed signal are reversed in polarity occurs. When an incorrect wiring of the power line is detected, an alarm signal is output. That is, the miswiring detection unit pays attention to the fact that when two-phase miswiring and three-phase miswiring occur, phenomena peculiar to the q-axis current feedback signal, the feedback speed signal, and the q-axis current command appear. Detects miswiring of three-phase power lines based on the phenomenon. As a result, according to the present invention, it is possible to correctly detect miswiring of a three-phase synchronous motor without using a special operation such as direct current excitation or a special circuit such as a three-phase dynamic brake as in the prior art. it can.

More specifically, the miswiring detection unit can be composed of a saturation state determination unit, a q-axis current feedback signal determination unit, an integration unit, and a determination unit. The saturation state determination unit determines whether or not the q-axis current command is in a saturated state. The q-axis current feedback signal determination unit determines whether the magnitude of the q-axis current feedback signal is equal to or greater than a predetermined value. The integrating unit integrates the time during which the polarity of the feedback speed signal and the polarity of the q-axis current feedback signal are opposite to output an integrated value. The determination unit determines that the wiring is incorrect and outputs an alarm signal when the integrated value exceeds a predetermined accumulated time. The q-axis current command is saturated in both cases of two-phase miswiring and three-phase miswiring. However, it is not possible to determine whether or not the saturation is caused only by the saturation state because of the incorrect wiring. In addition, the q-axis current feedback signal does not become smaller than a predetermined value in any of the two-phase miswiring and the three-phase miswiring. That is, the q-axis current feedback signal does not show such a large fluctuation that the polarity changes. When two-phase miswiring occurs, the feedback speed signal changes from one polarity to the other. When three-phase miswiring occurs, the polarity of the feedback speed signal alternately repeats one polarity and the other polarity. If erroneous wiring is determined on the condition that the polarity of the feedback speed signal changes, it is erroneously determined in consideration of noise generation. Therefore, the integration unit integrates the time during which the polarity of the feedback speed signal and the polarity of the q-axis current feedback signal are opposite to output an integrated value. Here, “accumulating time” means adding each period as t1 + t2 + t3... When a reverse polarity relationship is established between certain periods t1, t2, t3. Means. When the polarity is always reversed, the elapsed time from the start of integration becomes the integrated value as it is. In this way, since the change in the polarity of the q-axis current feedback signal is seen using the feedback speed signal whose polarity does not change as a criterion, it is possible to reliably determine the interval in which the polarity changes.

  When the integrated value exceeds a predetermined cumulative time, the determination unit determines that the wiring is incorrect and outputs an alarm signal, so that the predetermined cumulative time is set to an appropriate length and thus is affected by noise. Incorrect wiring can be reliably determined.

  The “predetermined value” of the q-axis current feedback signal is preferably 10% or more of the rated current. If this value is exceeded, false detection can be prevented.

  In the case of three-phase miswiring and two-phase miswiring, three-phase miswiring is performed earlier than the case of two-phase miswiring, and the accumulated value increases at a constant rate and the accumulated value is faster. Tends to reach a predetermined cumulative time. Therefore, it is preferable that the above-mentioned predetermined accumulated time is determined in consideration of the change state of the integrated value in the case of two-phase erroneous wiring. Incidentally, if the predetermined cumulative time is 30 msec, both two-phase miswiring and three-phase miswiring can be detected.

It is a block diagram which shows the structure of an example of embodiment of the control apparatus of the three-phase synchronous motor provided with the erroneous wiring detection function of this invention. It is a figure which shows an example of the specific example of an incorrect wiring detection part. (A) thru | or (D) is a wave form diagram used in order to demonstrate the state when a three-phase miswiring generate | occur | produces and the operation | movement of the miswiring detection part of FIG. (A) thru | or (D) is a wave form diagram used in order to demonstrate the state when two-phase miswiring generate | occur | produces and the operation | movement of the miswiring detection part of FIG. (A) And (B) is a wave form diagram used in order to explain the state at the time of normal wiring. (A) And (B) is a wave form diagram used in order to explain a state when two phase incorrect wiring has occurred. (A) And (B) is a wave form diagram used in order to explain a state when three-phase miswiring has occurred.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram showing a configuration of an example of an embodiment of a control device for a three-phase synchronous motor having an erroneous wiring detection function according to the present invention. A control device for a three-phase synchronous motor having this erroneous wiring detection function includes a torque command generator 1, a current command generator 2, an armature current supply device 3, a current detector 4, and an orthogonal biaxial converter. 5, a position detection unit 6, a feedback speed signal generation unit 7, and an erroneous wiring detection unit 8.

The torque command generator 1 generates a torque command TCMD based on the speed command Vc and the feedback speed signal VcF. The current command generator 2 outputs a d-axis current command IdC and a q-axis current command IqC based on the torque command TCMD. The armature current supply device 3 includes an armature winding of the three-phase synchronous motor M based on a d-axis current command IdC and a q-axis current command IqC and a d-axis current feedback signal IdF and a q-axis current feedback signal IqF described later. To supply armature current. The armature current supply device 3 includes two current controllers 31 and 32, a coordinate converter 33, a PWM controller 34, and a power converter 35. The two current controllers 31 and 32 are configured to determine a current deviation between the d-axis current command IdC, the q-axis current command IqC, the d-axis current feedback signal IdF, and the q-axis current feedback signal IqF as a d-axis voltage command VdC and a q-axis voltage command. Convert to VqC. The coordinate converter 33 generates a d-axis voltage command VdC and q based on a signal from the signal generation means OSC that generates a sin signal and a cos signal corresponding to the rotor position (θm) of the encoder constituting the position detector 6. The shaft voltage command VqC is subjected to orthogonal coordinate transformation and two-phase three-phase transformation to output three-phase voltage commands VUC, VVC, and VWC. The PWM controller 34 performs PWM control on the power converter 35 including the three-phase inverter circuit based on the PWM control commands VUC, VVC, and VWC. The power converter 35 converts DC power into three-phase AC power and supplies a three-phase armature current to the three-phase synchronous motor M. The armature current supply device 3 determines the phase of the armature current based on the rotor position signal θm detected by the encoder constituting the position detector 6.

  The current detector 4 detects a current for at least two phases flowing through the armature winding of the three-phase synchronous motor M, and outputs current signals IU and IV indicating the current for the two phases. The orthogonal biaxial conversion unit 5 including a coordinate conversion unit uses the current signals IU and IV output from the current detector 4 based on sin and cos signals generated by the signal generation means OSC based on the rotor position signal θm. The coordinates are converted to output a d-axis current feedback signal IdF and a q-axis current feedback signal IqF.

  The position detector 6 comprising an encoder detects the rotor position θm of the rotor relative to the stator and outputs a rotor position detection signal θm indicating the rotor position. The feedback speed signal generator 7 generates a feedback speed signal VcF indicating the speed of the moving element of the three-phase synchronous motor M based on the rotor position detection signal θm.

  The erroneous wiring detection unit 8 is a three-phase power that electrically connects the power converter 35 and the three-phase synchronous motor M based on the q-axis current feedback signal IqF, the feedback speed signal VcF, and the q-axis current command IqC. Detects miswiring of wires. When there is a two-phase miswiring or a three-phase miswiring, the miswiring detection unit 8 (1) the q-axis current command IqC becomes saturated, and (2) the q-axis current feedback signal IqF exceeds a predetermined value. (3) Utilizing the fact that the q-axis current feedback signal IqF and the feedback speed signal VcF have opposite polarities, the three-phase between the armature current supply device 3 and the three-phase synchronous motor M An erroneous wiring of the power line is detected and an alarm signal AS is output. How to use the alarm signal AS is arbitrary. For example, an alarm may be generated by the alarm signal AS, or power supply to the motor may be stopped by interrupting the operation of the power converter.

  FIG. 2 shows an example of a specific configuration of the erroneous wiring detection unit 8. 3A to 3D show the relationship between the speed command Vc and the speed (feedback speed signal VcF) when three-phase miswiring (UVW → WUV) occurs; q-axis current command IqC , The relationship between the d-axis current command IdC, the q-axis current feedback signal IqF, and the d-axis current feedback signal IdF; the integrated value IV integrated by the integrating unit 83; and the alarm signal AS. 4A to 4D show the relationship between the speed command Vc and the speed (feedback speed signal VcF) when the two-phase miswiring (UVW → UWV) occurs; q-axis current command IqC , The relationship between the d-axis current command IdC, the q-axis current feedback signal IqF, and the d-axis current feedback signal IdF; the integrated value IV integrated by the integrating unit 83; and the alarm signal AS.

  2 includes a saturation state determination unit 81, a q-axis current feedback signal determination unit 82, an integration unit 83, and a determination unit 84. As shown in FIGS. 3B and 4B, the saturation state determination unit 81 determines whether or not the q-axis current command IqC is saturated. This is because the q-axis current command IqC does not saturate when there is no erroneous wiring (see FIG. 5). The q-axis current feedback signal determination unit 82 determines whether the magnitude of the q-axis current feedback signal IqF is greater than or equal to a predetermined value. This is to correctly determine the polarity of the q-axis current feedback signal IqF. Therefore, such a condition is added for the purpose of preventing a determination malfunction. Preferably, if the magnitude of the q-axis current feedback signal is 10% or more of the rated current, a determination error can be prevented.

  The integrating unit 83 integrates the time during which the polarity of the feedback speed signal VcF and the polarity of the q-axis current feedback signal IqF are opposite to output an integrated value IV. The accumulating unit 83 includes an internal clock or a timer for accumulating time. In the case of three-phase miswiring, as shown in FIG. 3B, the feedback speed signal VcF has a negative polarity from the beginning, and the q-axis current feedback signal IqF always has a positive polarity. ing. Therefore, after the q-axis current feedback signal determination unit 82 determines that the magnitude of the q-axis current feedback signal IqF is equal to or greater than a predetermined value, the integration unit 8 integrates the time of reverse polarity and integrates the integrated value. Is output. In this case, since the reverse polarity relationship continues continuously, the integrated value coincides with the elapsed time after determining that the magnitude of the q-axis current feedback signal IqF is equal to or greater than a predetermined value. In the case of two-phase miswiring, as shown in FIG. 4B, the feedback speed signal VcF oscillates around a zero value, and thus has a negative polarity and a positive polarity. On the other hand, the polarity of the q-axis current feedback signal IqF always shows a positive polarity. Therefore, after the q-axis current feedback signal determination unit 82 determines that the magnitude of the q-axis current feedback signal IqF is equal to or greater than a predetermined value, the integration unit 8 determines the time during which the feedback speed signal VcF has a negative polarity. Is accumulated.

  When the integrated value is equal to or greater than a predetermined cumulative time RT, the determination unit determines that the wiring is incorrect and outputs an alarm signal. The q-axis current command is saturated in both cases of two-phase miswiring and three-phase miswiring. By setting the predetermined accumulated time to an appropriate length, it is possible to reliably determine erroneous wiring without being affected by noise. In the case of three-phase miswiring and two-phase miswiring, the three-phase miswiring is performed earlier than the case of two-phase miswiring, and the integration rate increases at a constant rate. There is a tendency for the value to reach a predetermined cumulative time RT. Therefore, it is preferable to determine the above-mentioned predetermined accumulated time RT in consideration of the change state of the integrated value in the case of two-phase erroneous wiring. Incidentally, if the predetermined cumulative time RT is 30 msec, both two-phase miswiring and three-phase miswiring can be detected.

  According to the present invention, according to the present invention, a conventional three-phase synchronous motor miswiring can be performed without using a special operation such as direct current excitation or a special circuit such as a three-phase dynamic brake. Can be detected correctly.

DESCRIPTION OF SYMBOLS 1 Torque command generation part 2 Current command generation part 3 Armature current supply apparatus 4 Current detector 5 Orthogonal biaxial conversion part 6 Position detection part 7 Feedback speed signal generation part 8 Incorrect wiring detection part

Claims (3)

A position detector for detecting the rotor position θm of the rotor relative to the stator of the three-phase synchronous motor and outputting a rotor position detection signal;
A feedback speed signal generator for generating a feedback speed signal indicating the speed of the three-phase synchronous motor;
A torque command generator for generating a torque command based on the speed command and the feedback speed signal;
A current command generator that outputs a d-axis current command and a q-axis current command based on the torque command;
A current detector for detecting a current for at least two phases flowing through the armature winding of the three-phase synchronous motor and outputting a current signal indicating the current for the two phases;
An orthogonal biaxial converter that calculates and outputs a d-axis current feedback signal and a q-axis current feedback signal by orthogonal biaxial conversion based on the current signal output from the current detector and the rotor position signal;
An armature current supply device for supplying an armature current to the armature winding based on the d-axis current command, the q-axis current command, the d-axis current feedback signal, and the q-axis current feedback signal;
In the control device for a three-phase synchronous motor, wherein the armature current supply device is configured to determine a phase of the armature current based on the rotor position θm detected by the position detector.
Based on the q-axis current feedback signal, the feedback speed signal, and the q-axis current command, if there is a miswiring of a three-phase power line, the q-axis current command becomes saturated, and the q-axis current feedback signal third between but be more than a predetermined value, and the q-axis current feedback signal and the feedback speed signal by utilizing the fact that situation is reversed polarity occurs the armature current supply device and the three-phase synchronous motor A control device for a three-phase synchronous motor having an erroneous wiring detection function, further comprising an erroneous wiring detection unit that outputs an alarm signal when an erroneous wiring of a phase power line is detected. The erroneous wiring detection unit is
A saturation state determination unit that determines whether or not the q-axis current command is saturated;
A q-axis current feedback signal determination unit that determines whether or not the magnitude of the q-axis current feedback signal is equal to or greater than a predetermined value;
An integration unit that integrates the time in which the polarity of the feedback speed signal and the polarity of the q-axis current feedback signal are opposite to each other, and outputs an integrated value, and miswiring when the integrated value exceeds a predetermined accumulated time The control device for a three-phase synchronous motor having a miswiring detection function according to claim 1, further comprising: a determination unit that determines that the alarm signal is output.   The control device for a three-phase synchronous motor having an erroneous wiring detection function according to claim 2, wherein the predetermined value is a value of 10% or more of a rated current.