JPS60180486A - Speed controller of motor - Google Patents

Abstract

PURPOSE:To regulate only a gain characteristic in a low frequency band without varying crossing frequency by one operation of a rotary switch. CONSTITUTION:When the setting of a rotary switch 19 is altered at the regulating time, the set value (x) varies from 0 to 15 in response to the set position, but in order to prevent the crossing frequency Wc from varying due to the time constants T1(x), T2(x) in response to the set value (x) and the variation in the time constants T1(x), T2(x), the gain K1(x) in response to the time constants T1(x), T2(x) is stored as arranging data in advance in a ROM10, and controlled and calculated by using the time constants T1(x), T2(x) in response to the set value (x) of the rotary switch 19 and the gain K1(x). Thus, only the gain characteristic of low frequency band can be regulated without varying the frequency Wc by one operation of the switch.

Description

Detailed Description of the Invention [Technical Field of the Invention] The present invention relates to a speed control device for an electric motor that is controlled and calculated using a transfer function including a delay element and a lead + element. Only the band gain characteristic can be adjusted by one adjustment means.

[Prior art]

An example of a conventional speed control device for a stacking motor is shown in FIGS. 1 to 6.

FIG. 1 is a block diagram showing the structure of the control device.

In the same figure, (1) is a three-phase AC' reduction, (2 is a motor, (8) is a load directly connected to this motor (2), and (4 is a motor).
) is a speed detector that detects the rotational speed of the electric motor (2), (4 is a speed detection signal detected by this detector, (5 is
) is a speed command circuit that issues a speed command signal (5a) to rotate the electric motor (2) at an arbitrary speed, and (6) is a speed command circuit that compares the speed command signal (5a) and the speed detection signal (4a) and outputs a speed command signal (5a) to rotate the motor (2) at a desired speed. A control calculation circuit that performs control calculation based on a transfer function, (6a) is a drive command signal output from this calculation circuit, and (γ) is a control calculation circuit that predetermines the drive command signal (6a) to rotate the electric motor (2). This is a drive circuit for converting the drive signal into a drive signal.

Furthermore, FIG. 2 shows the concept of the above-mentioned control arithmetic circuit.
Unit), (8a) is the data bus (Data B
us), (9) is RAM (RandumAcces
s Memory\αO) is ROM (Read 0n
ly Memory) 01) Anti-type (IB) is an interface (4a) Anti-type (6a)
As in FIG. 1, these represent a speed detection signal, a speed command signal, and a drive command signal, respectively.

Furthermore, FIG. 3 shows a block diagram showing the transmission elements of a conventional speed control device for an electric motor, in which (14) is a subtractor, (b)) is a proportional element, (16) is a lead/lag element,
0 indicates a delay element.

In the above figure, when the speed command signal (5a) is now issued from the speed command circuit (5), this speed command signal (5a)
a) is taken into CPU (8)- of the control arithmetic circuit (6) via the interface αη and the data bus (Sa). On the other hand, the speed detection signal (4a) is sent to c via the interface (121, data bus (8a)).
These speed command signals are compared with the speed detection signal (4a), a control calculation is performed based on a predetermined transfer function, and the data bus (8a) and interface (181) are input. Drive command signal (6a) via
is issued, and this command signal is converted into a predetermined drive signal by a drive circuit (7) to rotate the electric motor (2).

Figure 3 above shows the elements of each part of the motor speed control system.

The relationship between signals and the like is shown, and FIG. 4 shows an open loop Bode diagram (broken line approximation).

Here, Kl of the proportional element (15), lead/lag element α6)
time constant TI, 'T2, delay element (time constant T3 of lη is 2 for the gain of the drive circuit (γ), shaft converted moment of the motor (2) considering the load (8)) J% speed detector ( 4) is calculated and set in advance so that the gain characteristic shown in the Bode diagram of FIG. 4 is obtained according to the gain F of FIG.

That is, the open loop gain G1 of this speed control system is expressed by the missing equation (1), where ω is the angular frequency.

2・□・F...(1) Jω Therefore, the gain of 1 can be determined by the deficit equation (2).

O...(2) Also, when the angular frequency is the crossing frequency ωC, the open loop gain G1 is 1 (that is, 0 (dB)), so K1
is determined by the missing equation (8).

...(8) Furthermore, the time constants TI, T2. T3 is determined so that the reciprocals of each become the angular frequencies of corner points a, b, and C on the Bode diagram.

However, the above calculation results are only theoretical values, and the Bode diagram shown in FIG. 4 is not necessarily optimal in practice. Therefore, each constant was made variable within a predetermined range using a rotary switch (not shown), and the actual electric motor (2)
It is conceivable to adjust it so that it can be optimally controlled.

In this adjustment, the time constant T1 is changed.

That is, if the time constant is increased, for example, the open loop gain G1 decreases as the time constant moves to a lower range from the corner point a as shown in FIG. 5 for Al as shown in equation (1) above.

On the other hand, if the time constant T1 is made smaller, the corner point a moves to a higher frequency range and the open loop gain G1 becomes larger, as shown in FIG. 5A2. Further, when T1 (T2) is set, the open loop gain Gl becomes so large that the turning point a becomes a turning point as shown in FIG. 5A3.

Next, the time constant T2 is adjusted to vary in the same manner as described above.

That is, if the time constant T2 is made small, as shown by Bl in FIG. 6, if the time constant T2 is made large, as shown by B2 in FIG.
The break point and open loop gain change as shown in .

However, as can be seen from FIGS. 5 and 6 above, when trying to adjust the low-frequency open-loop gain characteristic rather than reaching the corner without changing the crossover frequency ωC, the time constants Tl and T2
It is necessary to change three constants, ie, gain Kl and gain Kl, and the adjustment work is extremely complicated and takes a lot of time.

[Summary of the invention]

The present invention has been made based on the above-mentioned circumstances, and in a device that controls an electric motor using a transfer function having a delay element and a lead element, the present invention has been developed to control a motor using a transfer function having a delay element and a lead element. A speed control device for an electric motor is provided with a variable number setting means consisting of the following, and only the gain characteristics of a specific band can be changed using this one adjustment means without changing the crossover frequency, thereby making it possible to adjust the speed simply and quickly. The purpose is to provide.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIG. 7 and FIG. 10. In these figures, (18) is an interface, (1
One is a rotary switch that outputs a value X of 0 and 15 depending on the set position.

In these figures, the same parts as in Figure 1 and Figure 6 are given the same reference numerals, and Figure 8 and
x 1(x), T lx), T 2(x
) indicates that it is array data with set value X as an argument. Therefore, if you change the setting of rotary switch α during adjustment, set value Time constant T1(X) according to set value X
, T 2 (x) and these time constants T l (x),
In order to prevent the crossover frequency ωC from changing due to changes in T 2 (X), the time constants T 1 (X), T
The gain corresponding to 2(X) and 1(x) are stored in advance in the ROM'(10) as array data as shown in FIG. (x).

T20: ), control calculation is performed using xl(x).Here, the possible values of the time constants T1(X) and T2(X) are tn)tn-10, that is, In the range where the set value X is smaller than 8, the time constant T1(X) is set to t. and set the time constant T2(x) from a large value t8 to a small value t according to the set value X. Here, unless T1(X)≦T2(x), the break point of the advance element will be on the low frequency side, and the Bode diagram in Figure 9 will change from S1 to S.
It changes like 2→S3. Note that S3 is Tl(X).

=' T 2(X), that is, a Bode diagram when the set value X is 8.

Next, in a range where the set value χ is greater than 8, T2(X) is set to t. , and the time constant T1(x) is set to a small value t. to a large value t according to the set value -+ 0 where the Bode diagram changes as shown in 85. In this case, the gain Kl(X) is determined by the missing equation (4).

-・ ・(Accordingly, even if the time constants T I (x) and T 2 (x) change, the crossing frequency ωC does not change as shown in the Bode diagram of SO and anti-type 5 in Figure 9. Also, the setting When the value
When is large, the time constant T l (
Since x) is a large value, the gain Kl(X) is large (O), that is, the value k of the gain Kl(X) in FIG. The anti-type k 15 is kn)kn-1, which is 0 or more, so that with respect to the theoretical Bode diagram SO, only the low-frequency gain characteristics can be changed by operating a single rotary switch without changing the crossover frequency 00. key Sψ becomes possible.

In the above embodiment, a rotary switch was used as a means for setting the set value The value is not particularly limited to 16 points. Furthermore, the adjustment range of each time constant of the lead element and the delay element does not have to be equal, and the adjustment step width of each time constant may be different from each other. ,.

Further, in the above embodiments, the explanation has been given of the case where the low-frequency gain characteristics are changed, but the present invention can also be easily applied to the case where the high-frequency gain characteristics are changed.

Furthermore, it can be configured to adjust each of the low and high frequencies, and by multiplying the gain Kl(x) by another adjustment coefficient, the overall gain can be adjusted without changing the shape of the Bode diagram. It is also possible to do so.

〔Effect of the invention〕

As described above, according to the present invention, in a device that controls an electric motor using a transfer function having a delay element and a lead element, a single adjustment means that performs a control calculation based on the transfer function allows a specified Since only the band gain characteristics can be changed, adjustments can be made easily and quickly.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a speed control device for an electric motor, FIG. 2 is a schematic configuration diagram of a control calculation circuit in a conventional speed control device for an electric motor, FIG. 3 is a block diagram showing transmission elements of the device, and FIG. Fig. 6 is a Bode diagram of Fig. 3 above, Fig. 7 is a schematic configuration diagram of a control calculation circuit in a speed control device for an electric motor showing an embodiment of the present invention, and Fig. 8 is a transmission diagram of the above device. A block diagram showing the elements, FIG. 9 is a Bode diagram of FIG. 8, and FIG. 10 is an array data table. (2)・Electric motor (4)・Φ speed detector (4a)・・
Speed detection signal (5) Speed command circuit (5a) Speed command signal (6) Control calculation circuit (6a) Drive command signal (7) Drive circuit (8) CPU (9 )...RA
M (10)...ROM01) anti-mold (1B) and (1
8)...Intern Eighth α... Rotary Switch Agent Masuo Oiwa Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Procedural Amendment (r-fake) Dear Commissioner of the Japan Patent Office 1;' J+: Showing items, y Asama 59-0355
84 Li2. Name of the invention: Electric motor speed control device 3. Relationship with the case of the person making the amendment. Patent applicant address: Chiyo, Tokyo [2-chome, 90-nai, 11-ku [12-3 W.
Name (ωl) Mitsubishi Electric Co., Ltd. Representative Katayama 1-Claw 4, Agent 5, Detailed description of the invention in the statement of subject matter of amendment, 6 Brief description of the drawings
, Supplementary contents (1) Akira M Haru, page 3, line 8 (r), rc: enter
The description aN is corrected to rc:central J. (2) Details, L: rRandumJ on page 3, line 9
The description ``r RandomJ'' is supplemented with Supplement 1. (3) l! The description "These speed command signals" in the 4th line of page 4 of the Q table has been changed to "These speed command signals (5a)"
And capture [1 mi. (4) Complement 1 on page 5, line 7 of the specification. (5) Complement 1F for the description r angular frequency J on page 5, line 9 of the specification as "angular frequency ω." (6) The statement "theoretically" on page 56, line 1 of the specification is amended to "theoretically." (7) The statement "switch" on page 7, line 14 of the specification is amended to "switch, J." (8) The statement "does it change?" on page 8, line 13 of the specification is amended to "does it change?" (10) The statement "interface" on page 12 of the specification, line 18 of tfj, is amended to "interface." (11) Figures 5, 6, and 9 of the drawings will be corrected as shown in the attached sheet. 7. At least 1 copy of drawings after amendment of catalog of attached documents Figure 5, Figure 61. cloudy

Claims (1)

[Claims] A speed command circuit that issues a rotational speed command signal for an electric motor; and a control calculation based on a predetermined transfer function having a proportional element, a delay element, and an advance element in accordance with the speed command signal from this circuit, and generates a control signal. - a control calculation circuit for
A speed control device for an electric motor, comprising a drive circuit that converts the control signal output from the arithmetic circuit into a drive signal for rotating the electric motor, wherein the control arithmetic circuit is provided with a variable number setting means, and the control arithmetic circuit is provided with a variable number setting means. When the set value set by the means is equal to a predetermined value, the time constants of the delay element and the advance element are made equal, and the set value is on either side larger or smaller than the predetermined value. , the time constant of the delay element or the time constant of the lead element is changed respectively, and the proportional ratio is adjusted so that the crossing frequency does not change in accordance with the change in the time constant of the delay element, the lead element, and the time constant of the nine elements. Speed control device 0 for an electric motor characterized by changing the values of elements