JPS62164119A - Automatic voltage adjuster - Google Patents

Abstract

PURPOSE:To stabilize a large-capacity three-phase power source with a high precision by attaching a servomotor to a voltage adjuster which can be adjusted only manually and comparing a feedback signal of the output voltage to perform the control. CONSTITUTION:A CPU 7 reads the output voltage feedback signal from an input circuit 14 by a routine, which is executed with interrupt at intervals of a certain time, and stores it as a current output voltage (v). This output voltage (v) is compared with a set voltage V; and if the latter is higher than the former, a servomotor 10 is reversed to reduce the current value by DELTAv unless a lower limit switch 12 is turned on because the current value is larger than a target value. If the voltage (v) becomes higher than the voltage V, the servomotor 10 is rotated forward to increase the current value by DELTAv unless an upper limit switch 13 is turned on because the current value does not reach the target value. This operation is repeated at intervals of a certain time to change the current value toward the target value.

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to automatic voltage control for setting and stabilizing the output of AC voltage, and in particular automatic voltage adjustment for controlling the voltage of a large-capacity drive power supply. It is related to vessels.

BACKGROUND OF THE INVENTION Traditionally, Stydac or inductance digitizers have been widely used to adjust the voltage of alternating current. Sliduc is used for relatively small capacity, and induction regulator is used for consciously large capacity, but both are configured to adjust the output voltage manually with a dial or handle. Recently, frequency converters using semiconductors have been used for this purpose. This method will be briefly explained using FIG. In FIG. 3, 1 is an AC/DC converter, 2 is an amplifier, 3 is a sine wave signal generator,
4 is a CPU, and 5 is an interface for communicating with a personal computer, etc., and GPiB is usually used. CPU that receives voltage and frequency commands from the interface 5
5 interprets it and instructs the sine wave signal generator 3 to generate a sine wave signal according to the commanded frequency and voltage. The sine wave signal generator 3 provides a reference signal to the amplifier 2, and the amplifier 2 amplifies the power of this reference signal to obtain a predetermined output. Further, the sine wave signal generator 3 compares the command input 32 and the output voltage feedback signal 31, controls the reference signal 33 so that the two always match, and maintains a stable ratio of the output voltage. As a power source for the amplifier 2, a full-wave rectified single-phase or three-phase alternating current is used.

Problems to be Solved by the Invention However, in the case of voltage regulators such as Sliduc, the output voltage is set as a ratio of the input voltage, and in terms of operation, it is considered to be the same as voltage division using a resistor. Therefore, if the input voltage or load changes, the output voltage will also change accordingly. In order to keep the output voltage constant, it is necessary to readjust it according to fluctuations in the input voltage or load, but these fluctuations are rarely predictable, and as a result, the stability of the output voltage becomes extremely poor. Also, when applying voltage to a motor, etc., it is necessary to take the starting current into account and raise it slowly. A frequency converter is used when automatic control is not available, such as from a computer, but as mentioned above, since it uses a semiconductor amplifier, its capacity is relatively small, and in principle it cannot be used for single-phase use. If you want to make it three-phase, you will need three of these units and a three-phase adapter to control the phase.This method is fine for small capacity cases, but for large capacity cases, it is necessary to use this method. Also three phases are 3
When current is required, it is not practical in terms of space and price.

The present invention was made in view of the above problems, and is a controller that automatically sets and stabilizes the output voltage of a voltage regulator that can only be adjusted manually by commands from a computer, etc., and also allows the user to specify the rise time of the output voltage. It provides:

Means for Solving the Problems In order to solve the above problems, the automatic voltage regulator of the present invention has the following features:
An interface that communicates with the host computer (hereinafter referred to as the host), a servo motor that drives the adjustment axis of the voltage regulator, an input circuit that feeds back the output voltage, and a limit switch that indicates the upper and lower limits of the voltage regulator. , and a CPU that centrally controls them.

Operation The present invention has the above-described configuration, and by comparing the command voltage given by the host with the feedback signal of the output voltage, the output voltage is controlled by the servo motor so that the difference is always 1:0. It is something to do. As a result, the output voltage is automatically adjusted to the command value of a personal computer, etc., and is stabilized by the feedback signal.

Embodiment FIG. 1 shows a main configuration diagram in an embodiment of the present invention. In Fig. 1, 6 is a syntax interface for communicating with the host, and it is commonly used as GP-IB or R3232.
Possible examples include C centronics. 7 is CPU, 8 is N
C device, 9 is a servo amplifier, 10 is a servo motor, the shaft of which is connected to the adjustment shaft of a voltage regulator 11. 12 is a limit switch that indicates the lower limit of the adjustment range of the adjustment axis of the voltage regulator 11, and 13 is a limit switch that indicates the upper limit. 14 is an input circuit for feeding back the output voltage, and 15 is an A/D converter circuit for converting the input voltage into digital data.

Regarding the automatic voltage regulator configured as above, the second
The operation will be explained using figures. Figure 2 is the CP of Figure 1.
It is a flowchart which shows the processing procedure of U7. (a)
(b) shows a main routine, and (b) shows a driving routine executed by an interrupt. First, in FIG. 2(a), after turning on the power,
Initialization is performed in step 16, and in step 17 a command from the host is awaited via the interface 6 in FIG.

When a command is given from the host, if the command is to set a rising time in step 18, the voltage ΔU to be raised for each interrupt processing routine is calculated in one step. If not, it is determined in step 20 whether or not there is an output voltage setting command, and if so, the target voltage V is set in step 21. If not, it is determined in step 22 whether there is a status output, and if so, in step 23, a host status signal is outputted through the interface 6 in FIG. This status outputs a servo motor driving signal, an output voltage setting completion signal, a current target voltage, an increased voltage Δ0, and the like. When the above steps are completed, the process returns to step 17 and the above operations are repeated. Next, in FIG. 2(b), this is a routine that is executed by an interrupt every certain fixed time (for example, 10+w), and in step 24, the output voltage feedback signal is read from the input circuit 14 of FIG. , this is stored as 0 as the current output voltage. In step 25, this 0 is compared with V set in step 21 of Fig. 2 (a), and if U>■, the current value exceeds the target value, so in step 26, the lower limit is set. Make a judgment and lower limit switch 1
If 2 is not on, the current value is set to 2 in step 27.
The servo motor 10 in FIG. 1 is reversed so as to decrease the amount of ΔU set in one step in FIG. 1(a).

Further, when the result of step 21 is U<V, the current value has not reached the target value, so the upper limit is determined in step 28, and if the upper limit switch 13 is not on, the process proceeds to step 29. The current value is shown in Figure 2 (a).
The servo motor 10 in FIG. 1 is rotated in the normal direction so as to raise the amount by ΔU set in step 19. By repeating the above operations at regular intervals, the current value changes toward the target value. For example, if the current value is OV and the output voltage is set to 100v, V=1
If it is set to 00, the voltage will increase O by the amount of voltage commensurate with the rising time every fixed time, for example every 100 m5, and it will take a predetermined time to reach 100V. If the output voltage changes due to input voltage fluctuations or load fluctuations in this state, it will be adjusted to the target value V in the interrupt processing shown in Figure 2 (b), so the output voltage will be extremely responsive. The properties will be well stabilized.

Effects of the Invention As described above, the present invention attaches a servo motor to a voltage regulator that could only be adjusted manually in the past, and controls it by comparing it with a feedback signal of the output voltage. In addition to stabilizing the power supply accurately, it can also be set automatically by commands from a computer, etc.

[Brief explanation of drawings]

FIG. 1 is a main configuration diagram of an embodiment of the present invention, FIG. 2 is a flowchart showing the operation of FIG. 1, and FIG. 3 is a block diagram of a conventional frequency converter. 6...Interface, 7...C'
PU, 8...NC device, 9...Servo amplifier, 10...Servo motor, 11...
...Manual voltage regulator, 12...Lower limit switch, 13...Upper limit switch, 14
...Input circuit, 15...A/D converter. Name of agent: Patent attorney Toshio Nakao (1 person) Figure 1 L--1--=--, - Limited to 12 Minoto Figure 2 (a)

Claims (1)

[Claims] A servo motor that drives an adjustment axis of a voltage regulator, a servo amplifier that drives the servo motor, an NC device that gives commands to the servo amplifier, a CPU that controls the NC device, and receives commands from a host computer. an interface, a limit switch indicating the lower limit and an upper limit of the adjustment range of the voltage regulator, an input circuit feeding back the current voltage output, and an A/D converter converting the input into digital; An automatic voltage regulator that controls the servo motor with a rising time specified by the interface until the feedback input becomes equal to the command according to a command from the interface, and obtains a predetermined voltage output.