JPS6152183A - Motor control device - Google Patents

Abstract

PURPOSE:To effectively control a motor by logically calculating on the basis of a rotor position detection signal to output a malfunction discrimination signal, thereby discriminating the malfunction of a position detector or the like. CONSTITUTION:The outputs of position detectors 4a-4c for detecting the positions of a rotor 2a of a motor 2 are waveform-shaped by a waveform shapers 5a-5c, respectively, and the logic sum of the outputs is obtained by an OR circuit 12C, and the logic sum of the inverted outputs is obtained by an OR circuit 12Y. The output of malfunction detecting means 12 having the OR circuits 12X, 12Y is input to malfunction discriminating means 13 to output a malfunction signal Z.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a motor control device, and particularly to abnormality determination of a position detection element.

(Prior Art) Fig. 1 is a block diagram of a motor control device according to the prior art, and Fig. 2 is a diagram showing a part of the circuit of Fig. 1.
This is an inverter that converts direct current output DC into alternating current and supplies it to stator winding terminals 2U, 2V, and 2W of permanent magnet type brushless motor 2.

3 is a current control circuit that controls the input current of this inverter 1. 4a, 4b, 4c are rotor 2a of motor 2
This is a position detection element such as a Hall element that detects the position of.

5a, 5b, 5c are respective position detection elements 4a, 4b, 4c
This is a waveform shaping circuit consisting of a comparator that sequentially shapes the pulse waveforms of the outputs a-"-c from the output a-"-c and outputs pulses Ha to Hc whose rising edges overlap the pulses output earlier. 6 is an inverter control means, which is a waveform shaping circuit 5a.

The inverter 1 is controlled based on the outputs Ha, Hb, ) 4c of 5b and 5c. 7 is each waveform shaping circuit 5a, 5
This is an AND circuit that detects the AND of the outputs of two waveform shaping circuits 5a to 5c among the waveform shaping circuits 5a to 5c. 8 is a conversion means for converting the number of pulses from the AND circuit 7 into voltage;
is a comparison circuit that compares and calculates the output of the conversion means 8 and the output of the speed command means 10. 11 is the AND circuit 7° conversion means 8. The rotation speed control means is comprised of a comparator circuit 9 and controls the current control circuit 3 based on the output of the comparator circuit 9. Note that the inverter 1 includes power transistors IR to IW and the like. The inverter control means 6 includes inverting circuits 6a to 6C and AND circuits 6L to 6.
Q. It consists of base amplifier circuits 6R to 6W, and the outputs R-W of the base amplifier circuits 6R to 6W are manually powered corresponding to the power transistors IR to IW, respectively. The AND circuit 7 consists of AND circuits 7a to 7C1OR circuits 7d.

The operation of the conventional device configured as described above is shown in FIG.
l~(C1 will be used in conjunction with the explanation below. In addition, Fig. 3 (
al~(C) shows the waveforms of each part in FIGS. 1 and 2.

First, the outputs a of the position detection elements 4a, 4b, and 4c.

b and c are waveform shaping circuits 5a consisting of comparators.

The signals Ha and Hb are waveform-shaped by 5b and 5c.

Hc, and this signal Ha w Hc is distributed and input to the inverter control means 6 and the AND circuit 7 .

The rising edge of the signal Ha-Hc overlaps with the pulse output earlier as shown in FIG. This signal Ha-Hc and the signal ha-h inverted by the inverting circuits 6a to 6C.
By combining the AND circuits 6L to 6Q as shown in FIG. 2, signals L to Q are obtained. This signal L-
Q is input to each base amplifier circuit 6R to 6W,
The base amplifier outputs R to W are used to switch the power transistors IR to IW, respectively, and drive the rotor 2a. On the other hand, the signal Ha input to the AND circuit 7
-= Hc is determined by AND circuits 7a to 7C between Ha and H.
bSHb and Hc, and Hc and Ha are ANDed and become a pulse signal F via an OR circuit 7d. This pulse signal F
The pulse frequency increases in proportion to the rotational speed of the rotor 2a, and is output by the next converting means 8 as an analog voltage in proportion to the rotational speed. The voltage signal from the converting means 8 is input to a comparator circuit 9, where it is compared with the signal from the speed command means 10, and the difference is amplified and output to the current control circuit 3. In the current control circuit 3, the comparison circuit 9
The supply current of the inverter 1 is controlled according to the signal from the inverter 1. For example, the signal from the converting means 8 is transmitted to the speed command means 10.
When the signal is larger than the signal from the inverter 1, that is, when the rotational speed of the rotor 2a becomes faster, the current supplied to the inverter 1 is reduced to slow down the rotational speed. In this way, in the conventional device, the rotor 2a
The rotation speed is maintained at the set value of the speed command means 10.

However, since the position detection elements 4a to 4C are usually incorporated in the motor 2, the position detection elements 4a to 4C
There is a possibility that the connecting wires may be disconnected, or the position detection elements 4a to 4C themselves may fail due to short circuit or open state. Therefore, among the waveform-shaped output Ha=Hc, the output corresponding to the failed element (for example, output Ha) remains at "L" level as shown in FIG.
As shown in C1, it is maintained at the "H" level. The output signal F of the AND circuit 7 is the output) (when a becomes "L", the number of pulses decreases, and when it becomes rHJ, it becomes an output with a wide Nockles width. Therefore, when the output 1 (a becomes rLJ), the number of pulses decreases. In this case, it is determined that the rotational speed of the rotor 2a has become slow, and the rotational speed is increased beyond the set value.Output) (a
If it becomes rHJ, the rotational speed of the rotor 2a will be reduced.

On the other hand, since the outputs of the position detecting elements 4a to 4C are also input to the inverter control means 6, the current flowing through each stator winding is affected by a fault in the position detecting elements 4a to 4c or their connection lines. For example, when the output Ha becomes "L",
Signal R- input to each power transistor IR~IW
W changes, and the current flowing through each stator winding becomes unbalanced.

As a result, the morph torque becomes abnormal, so even if the current is increased by the current control circuit 3 to increase the rotation speed as described above, the accelerating force of the rotor 2a is weak, but in the case of a light load such as a high-speed flywheel load. The acceleration force increases and the rotational speed becomes dangerous. As described above, the conventional device has the disadvantage that control of the rotational speed of the rotor 2a may become unstable due to failure of the position detection elements 4a to 4c or disconnection of their connection lines, which may lead to a dangerous situation. was.

C. Summary of the Invention] The present invention has been made in view of the drawbacks of the conventional examples as described above, and includes a first OR circuit for detecting the logical sum of the outputs of the respective waveform shaping circuits, and a an abnormality determining means comprising a second logical sum circuit for detecting the logical sum of the signals whose outputs are inverted; By providing an abnormality determining means for outputting an abnormality determination signal based on the output of the second OR circuit, the drawbacks of the conventional device described above are eliminated. This will be explained in detail below using examples.

[Embodiments of the invention]

FIG. 4 is a configuration diagram of a motor control device according to the present invention,
FIG. 5 is a diagram showing a part of the circuit shown in FIG. 4. The same reference numerals are used for the same components as in FIGS. 1 and 2 of the conventional example, and the explanation thereof will be omitted. In the figure, 12X is a first OR circuit that detects the OR of the outputs Ha-Hc of the respective waveform shaping circuits 5a to 5C. 12Y is a second OR circuit that detects the OR of the signals obtained by inverting the outputs Ha - Hc of the respective waveform shaping circuits 5a to 5C.

12 is the first logic circuit 12X and the second logic circuit 12Y.
This is an abnormality determination means consisting of: 3 is an abnormality determining means that outputs an abnormality signal 2 based on the output from the abnormality determining means 12. The first OR circuit 12X is made up of an OR circuit 12x, as shown in FIG. 5, and the second OR circuit 12Y is made up of inversion circuits 12a to 12c and an OR circuit 12y. Further, the outputs x and y of the first OR circuit 12X and the second OR circuit 12Y are input to the inverting OR circuit 12Z, and become the output of the abnormality determining means 12.

Next, the operation of this embodiment configured as described above will be explained with reference to FIGS. 6(al) and (b). Waveform shaping circuit 5
The outputs Ha - Hc from a to 5c are input to the OR circuit 12x of the 18th @ Riwa concave 1st path 12X, and the normal output
This is H.J.

However, at the time tzO in FIG. 6 (71), the output Ha becomes r.
If the signal Ha = H'c remains at LJ, there will be a section in which neither signal Ha = H'c becomes rHJ, and in that section the signal X becomes rLJ. On the other hand, since the signals Ha to Hc are each inverted by the inverting circuits 12a to 12c and input to the OR circuit 12y, the normal output Y is rHJ.

If the output Ha remains rHJ at the time tz shown in Fig. 6 (bl), both of the signals Ha - Hc will become rL.
There is a section where the signal Y does not become J, and in that section the signal Y becomes rLJ. These signals X and Y are input to the inverting OR circuit 12Z, and when either of the outputs X and Y becomes rLJ, an interval is created in which the output 2 of the inverting circuit 12Z becomes rHJ,
An abnormality signal Z is output, so that it can be known that a problem has occurred. Thereby, even if a problem occurs in the position detection elements 43 to 40, etc., it can be dealt with immediately, and abnormal rotation of the motor 2 can be prevented.

Note that the abnormality signal Z output from the abnormality determination means 13
Accordingly, it is also possible to cut off the input terminal of the inverter 1 and automatically stop the rotation of the motor 2. Further, although the above embodiment has been described with respect to a three-phase motor, it can be similarly applied to a two-phase or four-phase or more-phase motor.

〔Effect of the invention〕

As explained above, according to the motor control device according to the present invention, the first OR circuit detects the logical sum of the outputs of the respective waveform shaping circuits, and the logical sum of the signals obtained by inverting the outputs of the respective waveform shaping circuits. an abnormality determining means comprising a second OR circuit for detecting; and the first. By including the abnormality determination means that outputs an abnormality determination signal based on the output of the second OR circuit, it is possible to determine an abnormality in the position detection element, etc., and to ensure reliable motor control.

[Brief explanation of the drawing]

Fig. 1 is a configuration diagram as an example of a motor control device according to the prior art, Fig. 2 is a circuit diagram showing a part of Fig. 1, and Fig. 3 is a circuit diagram showing a part of Fig. 1.
2, FIG. 4 is a configuration diagram as an example of a motor control device according to the present invention, FIG. 5 is a circuit diagram showing a part of FIG. 4, and FIG. , is a waveform diagram of each part in Fig. 5. DC... Direct current input, 1... Inverter, 2... Motor, 2U, 2V, 2W... Stator winding, 2a...
Rotor, 3... Current control circuit, 4... Position detection element, 5... Waveform shaping circuit, 6... Inverter control means, 7... AND circuit, 8... Conversion means, 9 ... Comparison circuit, 10 ... Speed command means, 11 ... Rotation speed control means, 12 ... Abnormality determination means, 12X ... First logic/abnormality determination means. Note that the same reference numerals are used for the same or corresponding parts in the figures. Agent: Masuo Oiwa (2 persons) Procedural amendments were distributed on May 8, 1960 1, Indication of the case: Patent Application No. 173729, 1982, 2,
Name of the invention Motor control device 3, Person making the amendment<\5, Container for claims to be amended, detailed description of the invention, and brief description of the drawings. 6. Contents of amendment (1) The claims are amended as shown in the attached sheet. (2) In the 9th line of page 3 of the specification, the phrase ``of 2111i1'' is corrected to ``of each of 2''. (3) On page 3, lines 10 and 11 of the same book, the phrase ``It is an AND circuit.'' was replaced with ``It consists of an AND circuit and an OR circuit that detects the OR of these three AND outputs.'' It is a logic circuit.'' (4) Same book, page 3, line 11, line 14, page 4, line 3
Lines 4 to 4, line 13, page 5, line 5, page 6, line 11 to 12, "i!Logic circuit 7" is replaced with "logic circuit 7". and correct it. (5) Same book, page 6, lines 12 to 18 “Output”
1a results in rLJ. '' is replaced by ``output) (a remains rLJ or rHJ, the number of output pulses becomes small. Therefore, the output becomes rLJ or ``
If it remains at "H", the comparator circuit 9 determines that the rotational speed of the rotor 2a has become slow and attempts to increase the rotational speed above the set value. ” he corrected. (6) In the same book, page 7, line 10, the phrase "acceleration force increases" is corrected to "even if acceleration force is small." (7) Page 9, lines 12 and 13 of the same book: “Signal H
The phrase ``There is an interval in which neither a-Hc becomes rHJ'' is corrected to ``There is an interval in which the logical sum of signals Ha-Hc does not become rHJ.'' (8) Page 9 of the same book, lines 19 and 20, “Signal H
``There is an interval in which neither a-Ha becomes rLJ'' is replaced by ``signal) (the logical sum of the inverted signals of a-HC is rH
This will be corrected as "There will be an interval that does not become J." (9) Ibid., page 10, lines 12 to 14 F. Also, it can be applied in the same way as the above embodiments. ” will be deleted. αO) Same book, page 11, lines 17 to 18, “7.
. . . logical product circuit" is corrected to ``7 . . . logical circuit." Above 2, claims include an inverter that converts direct current into alternating current and supplies it to the stator winding of a motor, a current control circuit that controls the input current of this inverter, and a plurality of positions that detect the position of the motor rotor. The detection element, a waveform shaping circuit that sequentially shapes the pulse waveform of the output from each position detection element and outputs a pulse whose rising edge overlaps the pulse outputted first, and the inverter according to the output of each waveform shaping circuit. and an AND circuit that detects the AND of the outputs between two of the waveform shaping circuits.
It consists of a conversion means for converting the number of pulses from the rotation into voltage, and a comparison circuit that compares and calculates the output of this conversion means and the output of the speed command means.The rotation control circuit controls the current control circuit based on the output of this comparison circuit. a first logical sum circuit for detecting the logical sum of the outputs of the respective waveform shaping circuits; and a logical imposition of signals obtained by inverting the outputs of the respective waveform shaping circuits. an abnormality determining means comprising a second logical sum circuit; A motor control device comprising: abnormality determination means for outputting an abnormality determination signal based on the output of the second OR circuit.

Claims (1)

[Claims] An inverter that converts direct current to alternating current and supplies it to the stator winding of the motor, a current control circuit that controls the input current of this inverter, multiple position detection elements that detect the position of the motor rotor, and each position detection element. a waveform shaping circuit that sequentially shapes the pulse waveform of the output from the element and outputs a pulse whose rising edge overlaps a pulse that is output first; and an inverter control means that controls the inverter based on the output of each waveform shaping circuit. , an AND circuit for detecting the AND of the outputs between each two of the waveform shaping circuits, a conversion means for converting the number of pulses from the AND circuit into a voltage, and an output of the conversion means. A motor control device comprising: a comparison circuit for comparing and calculating the output of the speed command means; and rotation speed control means for controlling the current control circuit based on the output of the comparison circuit; abnormality detection means comprising a first OR circuit for detecting the OR of the outputs of the respective waveform shaping circuits; and a second OR circuit for detecting the OR of the inverted signals of the outputs of the respective waveform shaping circuits; A motor control device comprising: abnormality determination means for outputting an abnormality determination signal based on the output of the OR circuit.