JP2778709B2 - Interrupter type motor controller - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial application field) The present invention relates to an interrupter-type motor control device that controls the rotation of a motor by interrupting a supplied current.

(Prior Art) Generally, an interrupter-type control device is used as a control device for an actuator such as a motor-operated valve driven by a relatively small motor. In the motor control by this type of control device, the rotation of a motor that normally drives an actuator is controlled by intermittently and inverting the polarity of a current supplied from a power source of the motor by a thyristor switch. The details employed in, for example, motorized valve control will be described with reference to the block diagram of FIG.
The current valve opening signal S2 from the motor-operated valve unit 2 composed of S1, the valve element 2a, and the drive motor 2b is input, and a deviation between the two signals is calculated to output a deviation signal S3 to the interrupter circuit 3.
The interrupter circuit 3 outputs a pulse signal S4 corresponding to the polarity of the input deviation signal S3 to the gate pulse generator 4 with a pulse width and a pulse interval corresponding to the absolute value of the deviation signal S3. Here, the pulse width of the pulse signal S4 is a time during which the current of the drive motor 2b is applied, and the pulse interval is a request for a pause time of the application of the current. Therefore, the interrupter circuit 3 determines the absolute value of the input deviation signal S3. When the absolute value is small, a pulse signal output having a short pulse width and a long pulse interval is generated, and when the absolute value is large, a pulse signal output having a long pulse width and a short pulse interval is generated. The output pulse signal S4 is input to the gate pulse generator 4,
As a result, the gate pulse generator keeps outputting the gate pulse signal S5 for turning on the thyristor switch to the thyristor device 5 for the duration of the pulse width (energization command). In the thyristor device 5, while the gate pulse signal S 5 is being input, the internal thyristor switch is turned “ON”, and conduction between the power supply device 6 and the drive motor 2 b in the motor-operated valve unit 2 is established. The thyristor switch in the thyristor device 5 has two circuits for normal rotation and reverse rotation, and switches the thyristor switch that is turned “ON” according to the polarity of the gate pulse signal S5 to change the rotation direction of the drive motor 2b. The drive motor 2b is connected to the valve body 2a, and the rotational speed and the rotation direction are controlled by the intermittent current from the thyristor device 5 to drive the valve body 2a. The valve opening at that time is output as a valve opening signal S2 from the valve body 2a, and the drive motor 2b is driven until the valve opening signal S2 substantially matches the valve opening setting signal S1.

However, the interrupter circuit 3 continues to output the pulse signal S4 until the valve opening setting signal S1 and the valve opening signal S2 completely match. However, immediately before the settling, the absolute value of the pulse signal S4 becomes small. Repeated movement becomes unstable. Therefore, normally, a dead band is provided in the interrupter circuit 3 so that the pulse signal S4 is not output unless a deviation signal S3 exceeding a set value is input.

The details of this conventional interrupter circuit 20, as shown in the block diagram of FIG. 4, are composed of a dead band circuit 8, an integrator 9 and a pulse generator 10. The dead band circuit 8 is provided with a deviation signal S3.
And outputs only a signal equal to or greater than the dead zone set value to the integrator 9 and the pulse generator 10 as a deviation signal S8. Integrator 9
Receives the deviation signal S8 and outputs the integrated value to the pulse generator 10 as the pulse interval setting signal S9. The integrator 9 receives the pulse signal S20 from the pulse generator 10, is reset by the "ON" signal (energization command) of the pulse signal S20, and makes the internal integral value zero. The pulse generator 10 receives the interval setting signal S9 from the integrator 9 and
When the interval setting signal S9 exceeds the pulse interval set value, the output pulse signal S20 is turned "ON". Also,
The "ON" signal (pulse width) of the pulse signal 20 from the pulse generator 10 is long when the absolute value is large and small when the absolute value is small, according to the deviation signal S8 input from the dead zone circuit 8 by the pulse generator 10. The signal is output short, and is output while distinguishing the up signal and the down signal based on the polarity of the deviation signal S8. The pulse width and pulse interval are determined by the pulse generator 10.
Although it becomes variable in response to the input deviation signal S8, its reference value can be adjusted by a setting unit (not shown) in the pulse generator 10.

(Problem to be Solved by the Invention) The conventional control device using the interrupter circuit 20 sets the pulse interval setting value in a direction of increasing the pulse interval, and when the input signal changes in a ramp shape, the actual The apparent dead zone becomes wider than the dead zone set value, and the ability of the controlled object to follow an input change becomes poor.

This will be described with reference to FIG. 2 and using the characteristic diagrams of FIG. 4 and FIG. FIG. 5 (A) shows a pulse generator 10
5B is a characteristic diagram showing the dead band width when the set value of the pulse interval is not too long, and FIG. 5B is a characteristic diagram showing the dead band width when the set value of the pulse interval is too long. That is, the straight line a in FIG. 5 (A) is obtained when the valve opening setting signal S1 in FIG. 2 is changed into a ramp shape, and the straight line b is the valve opening signal S2.
Is shown. Note that, here, for ease of understanding, the valve opening signal S2 of the straight line b is not moved.

The deviation signal S3 is represented by a value between the straight line a and the straight line b. When the dead zone set value is c, the deviation signal S3 exceeds the dead zone set value c at the point A, so that the integrator 9 starts the integration operation and At the point B after the lapse of the time T1, the pulse signal S2 is output from the pulse generator 10.
Generates 0 (d). Here, the apparent dead zone width until the pulse actually starts to be output is e, which is slightly larger than the dead zone set value c at the point A. Next, FIG. 5 (B) shows the same valve opening setting signal S1 as FIG. 5 (A).
Shows the case where the pulse interval setting value of the pulse generator 10 is set longer at the rate of change of
S20 (f) starts to appear at a point C at which a time T2 has elapsed from the point A. The apparent dead zone width g before the pulse actually starts to be output is larger between the straight line a and the straight line b than in the case of FIG. When the pulse interval setting value is set so that the pulse interval becomes longer, the apparent dead zone width becomes wider. Thus, conventionally, when the input signal changes in the form of a ramp, the apparent dead zone widens and the followability of the controlled object to the input signal deteriorates, and the plant control system becomes unstable due to the valve opening / closing result. There were disadvantages.

The present invention has been made in view of the above, and an object thereof is to add a function of generating an initial pulse when an input deviation signal exceeds a dead zone to an interrupter circuit in an interrupter-type motor control device, It is an object of the present invention to provide an interrupter-type motor control device that has a certain dead zone even when a small deviation signal is input and that can obtain good tracking of a controlled object.

(Means for Solving the Problems) A deviation calculator between a control set value of a drive motor for controlling a position of a device and a current value, and detecting that a deviation signal as an output exceeds a predetermined set value. An interrupter circuit for generating a first pulse from the pulse generator when the signal continues for a predetermined time and continuously outputting a pulse signal while there is a deviation input equal to or greater than a set value; A thyristor device that continuously outputs power and a gate pulse generator that controls the thyristor device are provided.

(Operation) In an interrupter circuit that provides an output signal to a gate pulse generator that controls a thyristor device for motor control,
By generating the first pulse from the pulse generator when the input deviation signal exceeds a predetermined set value of the dead band circuit, for example, even when the input deviation signal is very small immediately before settling, there is no delay in the generation of the first pulse, and the control accuracy is reduced. Can be improved. In addition, since the pulse output signal is output with a slight time delay from the time of signal input, erroneous output of the first pulse due to signal fluctuation or noise is prevented.

Example An example of the present invention will be described with reference to the drawings. The same components as those described above are denoted by the same reference numerals, and detailed description will be omitted.

FIG. 1 is a block diagram of the interrupter circuit 3 in the interrupter-type electric motor control device shown in FIG. 2 and includes a dead zone circuit 11, an integrator 9, a pulse generator 12, and a filter circuit 13. The dead band circuit 11 receives the deviation signal S3 from the deviation calculator 1, and outputs only a signal having a predetermined dead band or more as a deviation signal S8. The dead zone circuit 11 detects when the deviation signal S3 exceeds the dead zone set value, and outputs the first pulse request signal S10 to the filter circuit 13. The integrator 9 receives the deviation signal S8 from the dead zone circuit 11, and outputs the integrated value as a pulse interval setting signal S9. Further, the pulse signal S4 from the pulse generator 12 is input to the integrator 9, and the pulse signal S4 is reset by an "ON" signal (energization command) of the pulse signal S4 to set the internal integrated value to zero. The filter circuit 13 receives the first pulse request signal S10 from the dead zone circuit 11, and outputs the first pulse output signal S11 to the pulse generator 12 only once after a predetermined time has elapsed. The pulse generator 12 receives the interval setting signal S9 from the integrator 9, and turns on the pulse signal S4 when the interval setting signal S9 exceeds the pulse interval set value. Further, the pulse signal S4 “ON” signal (pulse width) from the pulse generator 12 is long when the absolute value of the deviation signal S8 is large in accordance with the deviation signal S8 input from the dead zone circuit 11 by the pulse generator 12,
When the absolute value is small, the signal is output shortly, and the signal is output while distinguishing the up signal and the down signal based on the polarity of the deviation signal S8. The pulse generator 12 outputs a pulse signal having a constant pulse width according to the first pulse output signal S11 from the filter circuit 13.
Parts other than the interrupter circuit 3 are configured in the same manner as in FIG.

Next, the operation of the above configuration will be described. The deviation calculator 1 receives the valve opening setting signal S1 and the valve opening signal S2 from the motor-operated valve unit 2, calculates a deviation between the two signals, and outputs a deviation signal S3 to the interrupter circuit 3 shown in FIG. I do. In this interrupter circuit 3, the case where the valve opening degree setting signal S1 changes in a ramp shape will be described.
Increases and exceeds the dead band set value of the dead band circuit 11, the first pulse request signal S10 is output to the filter circuit 13. After confirming that the initial pulse request signal S10 has continued for a certain time, the filter circuit 13 outputs the initial pulse output signal S11 to the pulse generator 12 only once. The predetermined time delay at this time is to prevent the generation of erroneous pulses due to a sudden change in the signal or noise. The pulse generator 12 that has received the first pulse output signal S11 outputs a first pulse signal having a constant pulse width once. The integrator 9 uses this first pulse signal.
Is reset, thereby starting a new integration operation. If the interval setting signal S9, which is the integration value, exceeds the pulse interval setting value, the pulse generator 12 outputs the second pulse signal h2, and then outputs the deviation signal. Continue to emit pulses until S3 falls below the dead zone set value. This will be described with reference to FIG.
FIG. 3 is a characteristic diagram showing the dead band width when the input signal is changed into a ramp shape in a state where the pulse interval setting of the pulse generator 12 is set long as in FIG. 5 (B) of the conventional example. A straight line a indicates the movement of the signal when the valve opening setting signal S1 is changed into a ramp shape, and a straight line b indicates the movement of the valve opening setting signal S2. The deviation signal S3 is indicated by a value between the straight line a and the straight line b.
Exceeds the dead zone set value, the first pulse request signal S10 is output from the dead zone circuit 11 to the filter circuit 13, and after the lapse of the signal noise determination time T3, the first pulse output signal S11 is output, and the pulse generator 12 outputs the pulse signal S4. The first pulse (h1) of (h) is output. The integrator 9 is reset by the first pulse (h1), starts integration after the first pulse (h1) ends, and outputs a second pulse (h2) after a lapse of time T4. Here, the apparent dead zone width until the pulse (h2) actually starts to be emitted is the point D of the first pulse (h1).
I, which is almost the same as the dead zone set value c, and the difference is extremely small.

In this manner, when the valve opening degree setting signal S1 which is an input signal changes in a ramp shape, even when the pulse interval is set to be longer as the pulse interval setting value T4, the apparent dead zone is hardly widened. . Therefore, even if the input signal fluctuates irregularly or the absolute value becomes small immediately before the control position is settled, the followability is good and the control system does not become unstable. Further, the output pulse signal S4 is input to the gate pulse generator 4, whereby the gate pulse generator 4 instructs the time thyristor device 5 having a pulse width (energization command) to turn the thyristor switch "ON". Continue to output the pulse signal S5. In the thyristor device 5, the internal thyristor switch is turned “ON” while the gate pulse signal S 5 is input, and the thyristor device 5 is electrically connected to the drive electric machine 2 b in the motor-operated valve unit 2. The thyristor switch in the thyristor device 5 includes two circuits for normal rotation and reverse rotation, and switches the thyristor switch that is turned “ON” according to the polarity of the gate pulse signal S5 to change the drive motor.
Change the rotation direction of 2b. The drive motor 2b is connected to the valve body 2a, and drives the valve body 2a by controlling the rotation speed and the rotation direction by an intermittent current from the thyristor device 5. In addition, the valve opening is output from the valve body 2a as a valve opening signal S2, and the drive motor 2b is driven until the valve opening signal S2 substantially coincides with the valve opening setting signal S1 to bring the valve body 2a to a predetermined opening. Although the adjustment is performed, control can be performed without decreasing the followability even near the set value.

〔The invention's effect〕

As described above, according to the present invention, by the function of the adopted interrupter circuit, even when the deviation signal is very small, the predetermined insensitive body is maintained substantially constant, and good follow-up characteristics of the controlled body such as a motor-operated valve can be obtained. In addition, since the generated pulse has a certain time delay in the filter circuit, stable control can be performed without irregular and short-term disturbance, and the control system is stabilized to improve the stability of plant operation. Has the effect of doing

[Brief description of the drawings]

FIG. 1 is a block diagram of an interrupter circuit of the present invention, FIG. 2 is a block diagram of an interrupter-type motor control device of one embodiment of the present invention, and FIG. 3 is a long pulse interval for an input signal ramp-like change of the present invention. FIG. 4 is a configuration diagram of a conventional interrupter circuit, FIG. 5 (A) is a characteristic diagram at a short pulse interval with respect to an input signal-ramp change by the conventional interrupter circuit, FIG. FIG. 5B is a characteristic diagram at a long pulse interval in FIG. 5A. DESCRIPTION OF SYMBOLS 1 ... Deviation calculator, 2 ... Electric valve unit, 2a ... Valve element, 2b ... Driving motor, 3 ... Interrupter circuit, 4 ... Gate pulse generator, 5 ... Thyristor device, 6 ... Power supply , 9 ... integrator, 11 ... dead zone circuit, 12 ... pulse generator, 13 ... filter circuit.

Claims (1)

(57) [Claims] A control device for controlling the rotation of a motor by intermittently supplying a supplied current, a deviation calculator for inputting a control set value and a current value and outputting a deviation signal thereof, wherein the deviation value is set to a predetermined value. A dead band circuit that outputs only a signal that exceeds the value, an integrator that receives a deviation signal from the dead band circuit and outputs an integrated value thereof as a pulse interval setting signal, A pulse generator that receives a deviation signal from a dead band circuit and generates a pulse having a width proportional to the absolute value of the deviation signal when the pulse interval setting signal exceeds a predetermined value, and an integrator and a pulse generator The pulse request signal which is connected to the dead band circuit in another system and is output when the deviation signal input to the dead band circuit exceeds a predetermined set value has a time delay with respect to the pulse request signal. And a filter circuit for outputting a pulse output signal to the pulse generator, and an interrupter circuit for interrupting a current for driving the motor by an output pulse from the pulse generator. apparatus.