JPS5899292A - Motor speed control device - Google Patents

Abstract

PURPOSE:To operate a rolling system within the shortest acceleration time and to enhance the function of the system intended for the latest high productivity, by providing a thyristor power source device, a control part, a current detecting device, and a computing device. CONSTITUTION:The computing device 8 makes a thyristor Ward Leonard device 2 control the speed at a speed reference. Meanwhile, to the computing device 8, the signals from detectors 5-7, which impart the signals of starting, acceleration, deceleration, and stop, and the signal from the current detecting device 23, which detects the current of the motor 3, are inputted. The thyristor power source device 21 and the control part 22 constitute the thyristor Ward Leonard device 2 together with the current detector device 23. In this constitution, the rolling system can be operated within the shortest acceleration and deceleration time at all times, and the function of the system can be enhanced with the intention for achieving the latest high productivity.

Description

DETAILED DESCRIPTION OF THE INVENTION (A) Description of the Technical Field The present invention relates to an electric motor speed control device for controlling the speed of an electric motor used on two sides of a rolling equipment (rolling auxiliary machine, etc.).

(b) Description of Prior Art Conventionally, this type of control device operates linearly at a predetermined constant acceleration/deceleration rate! = A speed standard was given that would cause acceleration and deceleration.

In this conventional method, the thermal effective value BM1j of the electric motor and thyristor power supply is not checked, and a motor with a margin greater than the actual load pattern is selected and used.
However, recently, from the perspective of energy conservation, it has become increasingly common to select the minimum motor rating.
, the conventional method had the disadvantage that it could not provide sufficient protection when HM & was used in excess of 1. When used with high-frequency, rapid acceleration/deceleration loads such as rolling auxiliary machinery, etc., the motor and thyristor power supply device should be used within the thermal base; in order to obtain high productivity. C2. It is an object of the present invention to provide a magnetic motor speed control device that provides commands that can automatically shorten the operating cycle.

(d) Structure and operation of the invention Next 4: The content of the invention will be specifically explained with reference to FIG. FIG. 1 shows an embodiment of the present invention, and 8 is a calculation device, which controls the speed of the thyristor Leonard device 2 (given a DC motor 3 and 9 standards passed) from this device. It is something. On the other hand, the arithmetic unit 84=
is a detector 5 that gives signals for starting, accelerating, decelerating, and stopping;
6.7 and a signal from a current detection device 23 that detects the current of the electric motor 3 are input. Reference numeral 21 denotes a thyristor power supply device, which together with a control section 22 and a current detection device 23 constitutes a thyristor Leonard device 2.

Next, the operation of the arithmetic unit 8 will be explained with reference to FIG. Figure 2 shows the speed and @flow pattern during acceleration of the electric motor. (For example, 50 m@) every ζ;, Internal memory 4: Store it and calculate the effective value BM8 for each cycle.One cycle refers to To in the #I2 diagram, and 1 when the same operation is repeated 9 times. It says period.

As is well known, the effective value RM & is obtained by a quadratic formula.
re: f7 First class value for each pulling time t: Sampling time To: l Cycle time 10,000 lI! From Figure 2, the effective value version 8 is expressed by the formula (2).

Therefore, in order to get closer to the effective value RM8 by one cage, the next total St-
and calculate the next acceleration/deceleration time.

Normally, the acceleration time and deceleration time are the same, so I: XT, 3
I,”X(T,+T,) ,, then (2) formula U
, To and device x (T number + T number) of the Sarashi secondary (b) do not change -r, the only variables are the current I during acceleration and the acceleration time T), 2r, , if there are two people, (3)
From the formula, A =: 8M8" x Tg -I," x
(T, +T,) When 8M8 is set to 1 in equation (4), A':=TO-C...(5) On the other hand, the current during acceleration and the acceleration time are inversely proportional (; because there is (7 ) by converting the equation (6) (if two people are involved, then (8) - (61 aQ equation) to create the speed pattern shown in Figure 2 using the /, and give it as the speed standard for the next cycle.9 Normal ζ: It is possible to operate with the effective value RM8 close to 1.

A processor (J'U or controller) may be used as this arithmetic unit, and recently a microprocessor CPυ
A Leonard device (= a built-in microcomputer Leonard) has also been developed, so it is possible to incorporate the functions of one of the four microprocessors.

(e) Effects of the Invention As described above, the present invention I: According to the present invention, equipment can always be operated with the shortest acceleration/deceleration time, and the drive device allows the functions of modern equipment aimed at high productivity. @shi can be demonstrated.

Conversely, even if the acceleration/deceleration time is set unnecessarily short, the effective value &
Since M& is actually measured and corrected in the next cycle, the motor can be used within its rating and a thermal film can be maintained.

[Brief explanation of the drawing]

FIG. 1 is a system configuration diagram showing an embodiment of the present invention, 82
The figure is a diagram showing the relationship between speed and 11EIL during acceleration and deceleration. l... AC power supply 2... Siris Leonard device 3... direct ft@motor 4... speed detector 5 ... Detector for start command 6 ... Detector for deceleration command 7 ... Detector for stop command 8 ... Arithmetic device 21
... Thyristor power supply device 22 ... Control section 23.
・・Current detection device (7317) Representative Patent Attorney Kensuke Chika (1 person) Fig. 2 - 11 shouts M

Claims (1)

[Scope of Claims] Electric motor 1 that drives rollers etc. that convey rolled material = thyristor power supply device that supplies electric power, a control section that controls the firing angle of the thyristor of this power supply device, and this control section C Two speed standards and a current detection device for detecting a load current of the motor. The rated torque, rated current, and flywheel effect GD of the electric motor are memorized in advance, and when the stored material and the actual rolled material are conveyed (= the current detected by the current detection device 12 and the flow time) The effective value BM&
Accordingly, the motor speed side # device is characterized in that it is equipped with the control unit C;