JP4286607B2 - Electric motor monitoring device - Google Patents

Description

  The present invention relates to a motor monitoring device used in industrial machines such as machine tools and robots.

In a conventional motor monitoring device, as described in Patent Document 1, a control signal or a motor state signal such as the rotation speed and output torque of the motor sampled within a certain time in the control device is displayed on the monitor device. . Therefore, the state of the electric motor can be monitored.
JP-A-6-278173

  However, even if the motor monitoring device is used when the torque generated from the motor exceeds the range of outputable torque, or when the motor is accelerating, the torque becomes insufficient and the motor vibrates for a short time. There was a problem that it was difficult to see immediately.

  The present invention has been made to solve the above-described problems, and can quickly confirm whether or not an electric motor that drives a mechanical load is operating within the range of outputable torque of the electric motor. An object of the present invention is to provide a motor monitoring device.

  The motor monitoring apparatus according to the first invention has a bus and controls the q-axis armature current Iq and the d-axis armature current Id using the speed detection signal ωm detected from the motor driving the mechanical load. A motor monitoring device that displays characteristics of the motor based on an input signal input from a control device, the voltage detecting means for detecting a voltage of the bus and generating a bus voltage signal, and the input First torque calculating means for obtaining a torque τmax (ω) that can be output from the motor with respect to the speed detection signal ωm based on a constant determined by the motor and the bus voltage signal; and the speed detection signal ωm as the input signal Based on a first absolute value means for obtaining an absolute value speed detection signal that is an absolute value of the q-axis, and a q-axis armature current command signal Iqr as the input signal for flowing the q-axis armature current Iq. Second absolute value means for obtaining an absolute value generation torque that is an absolute value of the generated torque τa of the motor, and the absolute value generation torque and the torque τmax (ω) with respect to the absolute speed detection signal on the X and Y axes The first waveform generating means for generating a display signal to be displayed on the display, and the display means for displaying on the screen based on the display signal.

  The motor monitoring apparatus according to the second invention has a bus and controls the q-axis armature current Iq and the d-axis armature current Id using the speed detection signal ωm detected from the motor driving the mechanical load. A motor monitoring device that displays the characteristics of the electric motor based on an input signal input from a control device, wherein the constant is determined by the input electric motor and the bus voltage is determined in advance. Second torque calculating means for obtaining a torque τmax (ω) that can be output from the electric motor with respect to the speed detection signal ωm, and a first value for obtaining an absolute value speed detection signal that is an absolute value of the speed detection signal ωm as the input signal. Absolute value generation means that generates an absolute value of the generated torque τa of the motor based on the q-axis armature current command signal Iqr as the input signal for flowing the q-axis armature current Iq. Second absolute value means for obtaining torque, and first waveform generating means for generating a display signal for displaying the absolute value generation torque with respect to the absolute value speed detection signal and the torque τmax (ω) on the X and Y axes. And display means for displaying on the screen based on the display signal.

  According to a third aspect of the present invention, there is provided an electric motor monitoring apparatus comprising: a storage unit that stores constants corresponding to a plurality of types of electric motors; and a position detector that detects a position of the electric motor and generates a position detection signal. It is the constant of the corresponding electric motor read from the storage means based on the identification information.

  The constant in the motor monitoring device according to the fourth invention is characterized in that the inductance of each phase, the number of poles, and the maximum value of the armature interlinkage magnetic flux.

  The motor monitoring device according to the fifth aspect of the invention is input from a control device that controls the q-axis armature current Iq and the d-axis armature current Id using the speed detection signal ωm detected from the motor driving the mechanical load. A motor monitoring device that displays characteristics of the motor based on the input signal, a table storing torque τmax (ω) that can be output by the motor with respect to the speed detection signal ωm, and the speed as the input signal Based on a first absolute value means for obtaining an absolute speed detection signal that is an absolute value of the detection signal ωm, and the q-axis armature current command signal Iqr as the input signal for flowing the q-axis armature current Iq Second absolute value means for obtaining an absolute value generation torque that is an absolute value of the generated torque τa of the absolute value, the absolute value generation torque for the absolute value speed detection signal, and the absolute value from the table Second waveform creating means for reading out the torque τmax (ω) read in response to the speed detection signal and generating a display signal to be displayed on the X and Y axes, and a display to be displayed on the screen based on the display signal Means.

  As described above, according to the first aspect of the invention, the motor can be operated at a torque higher than the output possible torque, or the motor can be driven by the control device having a reduced bus voltage to reduce the output possible torque of the motor. In addition, since the output torque τmax (ω) and the generated torque based on the q-axis armature current are simultaneously displayed on the display means on the X and Y axes, the use state of the motor based on the torque can be confirmed by visually checking the display. There is an effect that the right or wrong of can be easily confirmed.

  According to the second aspect of the invention, the output torque τmax (ω) and the generated torque based on the q-axis armature current can be displayed on the X and Y axes at the same time, even when the motor is operated to a torque higher than the outputtable torque. Therefore, it is possible to easily confirm whether or not the motor is in use based on the torque by visually recognizing the display.

  According to the third aspect of the invention, there is an effect that a plurality of types of motor monitors can be realized with a simple configuration.

  According to the fourth aspect of the invention, the torque that can be output can be obtained from constants of several types of electric motors.

  According to the fifth invention, by using a table of torque that can be output by the motor with respect to the speed detection signal measured in advance, the output possible torque τmax (ω) and the generated torque based on the q-axis armature current are X, Since it is displayed on the display means on the Y-axis, there is an effect that it is possible to easily confirm whether or not the motor is in use based on the torque by visually recognizing the display.

Embodiment 1
An embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a block diagram of a motor control system including a monitor device according to an embodiment, FIG. 2 is a constant table diagram of the motor used in the motor monitor device shown in FIG. 1, and FIG. 3 is a generation with respect to the rotation speed of the motor. FIG. 4 is a characteristic diagram showing a CRT screen of the monitor device shown in FIG. 1, and FIG. 4 is a characteristic diagram showing a curve of q-axis armature current (torque component current) Iq corresponding to the maximum torque that can be generated.
In FIG. 1, a motor control system 1 controls a three-phase synchronous motor 3 as a motor and a three-phase synchronous motor 3 from a three-phase AC power source 5 by dividing it into a q-axis armature current Iq and a d-axis armature current Id. At the same time, the control device 100 having the AC and DC buses, the rotational position of the motor 3 and the position detection signal are output, and the model name information MID of the three-phase synchronous motor 3 is controlled when the power is turned on. And a mechanical load 300 including a position detector 200 having transmission means capable of transmitting to 100, a ball screw 301 as a load driven by the three-phase synchronous motor 3, and a movable base 303 screwed to the ball 301. Yes. And the monitor apparatus 500 which displays the characteristic of the electric motor 3 based on the input signal input from the control apparatus 100 is provided.

  The control device 100 includes a main circuit unit and a control circuit unit. The main circuit unit smoothes and smoothes the converter 103 that converts the three-phase AC power supply 5 into a DC voltage, and the output voltage of the converter 103. A capacitor 105 that obtains a DC voltage, an inverter 107 that converts the DC voltage to a three-phase AC voltage, a current detector 109 that detects a current flowing through the three-phase synchronous motor 3 and generates a current detection signal, and a DC bus The voltage detector 111 detects a voltage, filters it with an arbitrary time constant, and generates a bus voltage signal Vdc.

  The control circuit unit obtains a difference between the position command signal and the position detection signal and generates a position deviation signal, a position controller 153 that inputs the position deviation signal and generates a speed command signal, and position detection A differentiator 155 for differentiating the signal to generate a speed detection signal ωm, a subtractor 157 for determining a difference between the speed command signal and the speed detection signal and generating a speed deviation signal, and a current command by inputting the speed deviation signal A speed controller 159 that generates a signal, and a current controller 161 that controls the inverter 107 based on a current deviation signal that is a difference between the current command signal and the current detection signal, and generates a q-axis armature current command signal Iqr. When the power is turned on, the switch 170 is turned on when the three-phase synchronous motor 3 is driven. When the power is turned on, the switch 170 is turned on, the q-axis armature current command signal Iqr, the speed detection signal ωm, and the model name. Information MID, mother And an output interface 172 for outputting a line voltage signal Vdc.

  The monitor device 500 includes an input interface 502, a first absolute value unit 504 as first absolute value means for obtaining a speed absolute value signal of the speed detection signal ωm, and three-phase synchronization based on the q-axis armature current Iq. Based on the second absolute value unit 506 as a second absolute value means for obtaining the absolute value generation torque | τa | of the generated torque τa of the electric motor 3, the constant determined by the three-phase synchronous motor 3, and the bus voltage signal Vdc. The first torque calculation means 510 for obtaining the torque τmax (ω) that can be output from the three-phase synchronous motor 3 with respect to the speed detection signal ωm, and a constant corresponding to the model name of the three-phase synchronous motor 3 as shown in FIG. A table 512, first waveform creation means 514, and a CRT screen 520 as display means.

Torque calculation means 510 is configured to execute the following calculation. First, the terminal voltage Va of the three-phase synchronous motor 3 is expressed by the following equation of the IEEJ Technical Report No. 614 “From the 3.5 equation on page 16 described in the drive system of the electromagnetic actuator for control”.
Va = {(RaId−ωLqIq) ² + (RaIq + ωφa + ωLdId) ² } ^1/2
... (1)
Where Ra: armature resistance, ω: electrical angular velocity
Lq, Ld: d, q axis inductance
Φa: Maximum armature flux linkage converted to dq axis (3/2) ^1/2 · Φf
φf: Maximum value of armature interlinkage magnetic flux generated by a permanent magnet The relational expression between the terminal voltage Va and the detected bus voltage (bus voltage detection signal) Vdc is as follows.
Vdc = (2) ^1/2・ Va (2)
When the d-axis armature current Id is controlled to 0 and the q-axis armature current Iq is determined as RaIq << ωφa, the following equation is obtained.
Iq = {Vdc ² / 2- (ωφa) ² } ^1/2 / ωL (3)
Here, the following formula (4) of the relationship between the electrical angular velocity ω and the rotational angular velocity (speed detection signal) ωm is substituted into the formula (3), and arranged as La = Lb = L, the following formula (5) is obtained.
ω = p ・ ωm (4)
Here, p: number of pole pairs Iq = p {Vdc ² / 2- (p · ωm · φa) ² } ^1/2 / ωmL (5)
The equation (5) is the q-axis armature current (torque component current) Iq, which is proportional to the torque τa generated by the three-phase synchronous motor 3, so that the maximum torque τmax of the three-phase synchronous motor 3 is set to the q-axis armature. It can be shown by the current Iq. The q-axis armature current Iq required to generate the maximum torque τmax is a characteristic approximately inversely proportional to the rotational speed (speed detection signal) ωm as shown in FIG. Due to the limitation on the maximum current 107, the maximum torque τmax is set to a constant value.

  The table unit 512 has an internal constant of the three-phase synchronous motor 3 according to the above formula (5) for each type of the three-phase synchronous motor 3, that is, as shown in FIG. B, C,... Have a constant table of maximum armature flux linkage φf by permanent magnet, each phase inductance L, and the number of pole pairs p, based on the motor type name information MID from the position detector 200 Any one of the constant tables is selected.

  The waveform generation means 514 converts the signal transmitted as real time or buffering data into an absolute value speed detection signal | ωm | on the horizontal axis, an absolute value generation torque | τa | on the vertical axis, and a torque τmax that can be output. A display signal to be displayed on the CRT screen 520 as a waveform is generated, and the display signal is input to the CRT screen 520.

The operation of the motor monitoring apparatus configured as described above will be described with reference to the drawings. First, when a position command signal is generated, a DC voltage is obtained from the three-phase AC power source 5 via the converter 103, and the three-phase synchronous motor 3 is driven by the inverter 107 to drive the ball screw 301 and the movable base 303.
The control device 100 obtains a position deviation signal by the subtractor 151 based on the position command signal and the position detection signal, the position controller 153 generates a speed command signal based on the position deviation signal, and the differentiator 155 outputs the position detection signal. The speed detection signal ωm is obtained by differentiation. The subtractor 157 obtains a speed deviation signal that is the difference between the speed command signal and the speed detection signal ωm and inputs it to the speed controller 159, and the speed controller 159 inputs the current command signal to the current controller 161. On the other hand, the voltage detector 111 detects the bus voltage and generates a bus voltage signal Vdc.

The current controller 161 generates a q-axis armature current command signal Iqr and a d-axis armature current command signal Idr = 0 based on the DC bus voltage signal Vdc and the speed deviation signal, and supplies them to the inverter 107. The three-phase synchronous motor 3 is driven by controlling so that the q-axis armature current Iq flows. The speed detection signal ωm, the q-axis armature current command signal Iqr, and the bus voltage signal Vdc are input to the input interface 502 of the monitor device 500 via the output interface 172.
The first absolute value detector 504 obtains the absolute value | Iq | of the q-axis armature current Iq, and the second absolute value detector 506 obtains the absolute value | ωm | of the speed detection signal ωm to generate a waveform. Input to means 514.
The torque calculation means 510 includes a q-axis armature current Iq, a DC bus voltage Vdc, the number of pole pairs as an internal constant of the three-phase synchronous motor 3, the maximum armature flux linkage value φf, each phase inductance L, and the speed detection signal ωm. The q-axis armature current (torque current) Iq is obtained from the above equation (5) and input to the waveform creating means 512. The waveform creating means 514 displays the speed detection signal ωm on the X axis of the CRT screen 520, and the generated torque τa and the maximum torque τmax on the Y axis as shown in FIG.

That is, it is an operation state in which it is desirable that the waveform of the generated torque τa is within the output possible torque region. Here, when a torque command exceeding the capacity of the three-phase synchronous motor 3 is given, for example, at the point of crossing the maximum torque τmax line, such as point A during power running (acceleration) in FIG. The generated torque τa of the three-phase synchronous motor 3 may vibrate to cause residual vibration.
Also, during regeneration side operation (during deceleration), the bus voltage value Vdc filtered with a time constant sufficiently longer than the deceleration time rises, so the maximum torque τmax obtained based on the DC bus voltage according to the torque command The phenomenon that the three-phase synchronous motor 3 generates the generated torque τa is not preferable.

  As described above, when the three-phase synchronous motor 3 is driving the mechanical load 300, a curve based on the output possible torque τmax (ω) with respect to the speed detection signal (rotational speed) ωm along the average bus voltage is drawn. . Therefore, the operation of the electric motor can be checked based on the outputtable torque τmax (ω) in consideration of the voltage fluctuation of the three-phase AC power supply 5 or the like. In the above embodiment, the bus voltage is a DC bus voltage, but may be a bus voltage on the three-phase AC power supply 5 side.

Embodiment 2. FIG.
Another embodiment will be described with reference to FIGS. FIG. 5 is a block diagram of an electric motor control system including a monitor device, and FIG. 6 is an actual measurement table of the monitor device shown in FIG. In FIG. 5, the same reference numerals as those in FIG.
In the first embodiment, a curve of possible output torque τmax (ω) of the three-phase synchronous motor 3 is obtained from the internal constant of the three-phase synchronous motor 3 and the bus voltage and displayed on the X and Y axes of the CRT screen 520. However, a table may be provided by actually measuring the torque τmax (ω) curve that can be output from the three-phase synchronous motor 3.

  5, the monitor device 500 can output the motor 3 corresponding to the speed detection signals ω1, ω2,..., Ω5 shown in FIG. 3 corresponding to the model names A, B, C,. Measurement table 522 as a second table that is generated and stored with a specific torque τmax (ω), the absolute value generation torque, and the torque read from the measurement table 522 corresponding to the absolute value speed detection signal | ωm | τmax (ω) is read out, and second waveform generating means 524 for generating a display signal to be displayed superimposed on the X and Y axes is provided.

In the monitoring apparatus 500, the second waveform creating means 524 reads out the absolute value generation torque | τa | with respect to the absolute value speed detection signal | ωm | and the absolute value speed detection signal | ωm | from the actual measurement table 522. Torque τmax (ω) is read out and a display signal to be displayed superimposed on the X and Y axes is generated and input to the CRT screen 520. Based on the display signal, torque τmax (ω) and absolute value are generated on the CRT screen 520. According to such a monitoring apparatus 500 that displays the torque | τa |, the torque calculation means 510 shown in FIG. 1 is not necessary.

  As described above, the present invention can be applied to an application for monitoring the comparison between the possible output torque of the electric motor in which the electric motor and the mechanical load are combined with the torque in the actual use state.

It is a block diagram of the control system of the electric motor containing the monitor apparatus which shows one embodiment. It is a constant table figure of the electric motor used for the monitoring apparatus of the electric motor shown in FIG. It is a characteristic view which shows the characteristic of the rotational speed of a motor with respect to q-axis armature current (torque current) Iq. It is a characteristic view which shows the CRT screen of the monitor apparatus shown in FIG. It is a block diagram of the control system of the electric motor containing the monitor apparatus which shows other embodiment. FIG. 6 is an actual measurement table of the monitor device shown in FIG. 5.

Explanation of symbols

  3 three-phase synchronous motor, 111 voltage detection circuit, 200 position detector, 300 load machine, 504 first absolute value device, 506 second absolute value device, 510 torque calculation means, 512, 524 waveform creation means, 520 CRT Display screen.

Claims (5)

Based on an input signal input from a control device that controls the q-axis armature current Iq and the d-axis armature current Id using the speed detection signal ωm detected from the electric motor that drives the mechanical load while having a bus. A motor monitoring device that displays the characteristics of the motor,
Voltage detecting means for detecting a voltage of the bus and generating a bus voltage signal;
First torque calculating means for obtaining a torque τmax (ω) that can be output from the motor with respect to the speed detection signal ωm based on the constant determined by the input motor and the bus voltage signal;
First absolute value means for obtaining an absolute value speed detection signal which is an absolute value of the speed detection signal ωm as the input signal;
Second absolute value means for obtaining an absolute value generation torque that is an absolute value of the generated torque τa of the electric motor based on a q-axis armature current command signal Iqr as the input signal for flowing the q-axis armature current Iq;
First waveform generating means for generating a display signal for displaying the absolute value generation torque with respect to the absolute value speed detection signal and the torque τmax (ω) on the X and Y axes;
Display means for displaying on the screen based on the display signal;
An electric motor monitoring device comprising: Based on an input signal input from a control device that controls the q-axis armature current Iq and the d-axis armature current Id using the speed detection signal ωm detected from the electric motor that drives the mechanical load while having a bus. A motor monitoring device that displays the characteristics of the motor,
Second torque calculating means for obtaining a torque τmax (ω) that can be output from the motor with respect to the speed detection signal ωm based on a constant determined by the input motor and a predetermined voltage of the bus;
First absolute value means for obtaining an absolute value speed detection signal which is an absolute value of the speed detection signal ωm as the input signal;
Second absolute value means for obtaining an absolute value generation torque that is an absolute value of the generated torque τa of the motor based on the q-axis armature current command signal Iqr as the input signal for flowing the q-axis armature current Iq;
First waveform generating means for generating a display signal for displaying the absolute value generation torque with respect to the absolute value speed detection signal and the torque τmax (ω) on the X and Y axes;
Display means for displaying on the screen based on the display signal;
An electric motor monitoring device comprising: Storage means for storing constants corresponding to a plurality of types of electric motors;
The constant of the corresponding motor read from the storage means based on the identification information of the motor from a position detector that detects the position of the motor and generates a position detection signal.
The motor monitoring device according to claim 1, wherein the motor monitoring device is a motor monitoring device. The motor monitoring device according to claim 3, wherein the constant is an inductance of each phase, the number of poles, and a maximum value of an armature interlinkage magnetic flux. Using the speed detection signal ωm detected from the motor that drives the mechanical load, the characteristics of the motor are displayed based on the input signal input from the control device that controls the q-axis armature current Iq and the d-axis armature current Id. An electric motor monitoring device,
A table storing torque τmax (ω) that can be output by the motor with respect to the speed detection signal ωm;
First absolute value means for obtaining an absolute value speed detection signal which is an absolute value of the speed detection signal ωm as the input signal;
Second absolute value means for obtaining an absolute value generation torque that is an absolute value of the generated torque τa of the electric motor based on a q-axis armature current command signal Iqr as the input signal for flowing the q-axis armature current Iq;
The absolute value generation torque for the absolute value speed detection signal and the torque τmax (ω) read corresponding to the absolute value speed detection signal from the table are read and displayed on the X and Y axes. Second waveform creating means for
Display means for displaying on the screen based on the display signal;
An electric motor monitoring device comprising:

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