JPS6337596B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automatic inverter switching device when controlling a plurality of electric motors used in a spinning machine line or the like using run-up and running inverters.

As is well known, in a spinning machine line, a plurality of electric motors are operated at the same speed. In recent years, these electric motors have come to be operated by inverters, but if multiple electric motors are controlled from the start with one inverter, the capacity of the inverter must be increased due to inrush current of the electric motors, etc. . For this reason, it has become common practice to use a run-up inverter to start the electric motor, and after a predetermined period of time, switch to the operating inverter to control the operation of the electric motor. Note that the above-mentioned run-up inverter is a device that starts the electric motor at a low frequency. After starting, this inverter uses a cushion to increase the speed, and when synchronized with the operating inverter (frequency voltage and phase match), the operation control of the motor is switched from the run-up inverter to the operating inverter.

The operating inverter is also used in the traverse of the spinning machine line. Here, traverse refers to winding the thread uniformly on a winding machine to improve the winding appearance. For this purpose, it is necessary to operate the inverter that performs traverse operation by changing the operating frequency of the inverter in a pattern as shown in FIG. For this reason,
The operating frequency of the operating inverter is constantly changing, so when switching the selected motor from the run-up inverter to the operating inverter, the frequency of the operating inverter changes from moment to moment according to a predetermined pattern, so in such a situation It was extremely difficult to achieve synchronization and phase matching.

This invention was made in view of the above-mentioned circumstances, and aims to simplify the circuit, and visually monitors the frequency of both inverters, especially a signal called a traverse synchronization signal, which corresponds to the frequency of the traverse start-up position of the operating inverter. It is an object of the present invention to provide an automatic inverter switching device which can easily and accurately switch inverters by regarding the coincidence as a synchronous coincidence.

An embodiment of the present invention will be described below with reference to the drawings. In Fig. 2, 1 is an operating inverter;
This operating inverter 1 is formed from a converter section 1a, a capacitor 1b, and an inverter section 1c. 2 is a motor group, which includes motors 2a, 2b, and 2c.
are connected to the operating inverter 1 via first contacts 3a, 3b, and 3c that are sequentially controlled by the output of an operation sequence section, which will be described later. 4 is a run-up inverter, and this run-up inverter 4 is a converter section 4.
a, a capacitor 4b, and an inverter section 4c. The output of this run-up inverter is transmitted to the electric motors 2a, 2 via second contacts 5a, 5b, 5c which are sequentially controlled by the output of an operation sequence section which will be described later.
b, 2c.

6a are the first and second contacts 3a, 3b, 3c,
This circuit 6a is a casing circuit into which information for controlling 5a, 5b, 5c, etc. is input, and this circuit 6a exchanges signals with the I/O port 7a of the microcomputer 7. Reference numeral 6b is an operation input section, and an operation input signal is supplied to the I/O port 7a via the sequence circuit 6a. The I/O port 7a is connected to ROM7c, ROM7b, interrupt control circuit 7e and CPU7f by bus 7b, respectively.
The output of the microcomputer 7 is supplied to a frequency setting input terminal and a voltage setting input terminal v of a PWM control signal generation section 8a in a drive control section 8. this
The PWM control signal generating section 8a generates a signal to control the inverter section 4c of the run-up inverter 4, and the signal generated by the generating section 8a is given to the control element constituting the inverter section 4c via the drive circuit 8b. . 9 is a drive control section, and 9a in this control section 9 is a PWM control signal generation section 9a that generates a signal to control the inverter section 1c of the operating inverter 1, and the signal generated by this generation section 9a is sent to the drive circuit 9b. Inverter section 1c via
is given to the control elements constituting the.

Reference numeral 10 denotes an AND circuit forming a coincidence circuit, and a first input terminal of this AND circuit 10 is supplied with the traverse synchronization signal ₀ from the output terminal of the PWM control signal generating section 9a. Also, the second
An output signal (INTE) from the interrupt control circuit 7e is supplied to the output terminal. The AND circuit 10 outputs an output signal when the AND condition of the signal is satisfied, and this signal is supplied to the CPU 7f as an interrupt request signal. The AND circuit 10 detects coincidence between the traverse synchronization signal ₀ of the running inverter 1 and the frequency signal ₁ of the run-up inverter 4 based on the interrupt control signal output from the microcomputer 7.

Next, the operation of the above embodiment will be described using FIGS. 3A to 3K.
It is assumed that the vehicle has already been operated before the operation of the vehicle. Here, the functions of the sequence circuit 6a and the microcomputer 7 will be described. The sequence circuit 6a sequentially selects the motor group 2 and transfers the selected motor from the run-up inverter 4 to the running inverter 1 after the run-up inverter 4 completes synchronization of traverse operation and on condition that the frequencies of the run-up inverter and the run inverter 1 match. This is to perform predetermined switching.

Further, the microcomputer 7 has the following functions. That is, the sequence circuit 6a
a starting means for starting the selected motor to a predetermined speed N and maintaining the speed N for a predetermined time, and a frequency signal ₁ corresponding to the speed N (traverse of the operating inverter), on the condition that the motor is selected in When the frequency rises, hold the same frequency as the frequency command at the cushion start position.
on the condition that the traverse synchronization signal ₀ of the operating inverter 1 (signal output at the rising cushion start position of the traverse frequency of the operating inverter) taken in from the operation control signal generating section and the frequency signal ₁ match; A traverse driving means controls the run-up inverter 4 to perform traverse operation based on a predetermined pattern to follow the run-up inverter 1, and the traverse synchronization signal ₀ of the run-up inverter 1 and the frequency signal ₁ of the run-up inverter 4 match during this traverse operation. It is determined that there is a synchronization match on the condition that the synchronization match signal is sent to the sequence circuit 6a.
and a means for outputting a low speed command to the run-up control signal generating section 8a on the condition that the run-up inverter 4 is switched to the running inverter 1 in this circuit.

FIG. 3A is a characteristic diagram showing the operation pattern of the run-up inverter. First, at time _t0 , the operation command signal b
(FIG. 3B) is input to the microcomputer 7 from the operation input section 6a. This command signal b is input from the microcomputer 7 to the PWM control signal section 8a. The PWA control signal generator 8a has a frequency setting input and a voltage setting input, and an output signal obtained from a signal from the computer 7 supplied to both input terminals is supplied to the drive circuit 8b. That is, the run-up inverter 4 is started by the operation command signal b shown in FIG. 3B. After starting, the third
At time _t1 shown in FIG. C, a low speed command signal _c1 is sent from the sequence circuit 6a. Along with this signal _c1 , a low speed relay contact signal d shown in FIG. 3D is sent out from the sequence circuit 6a. This signal d
2, the first contact 5a in FIG. 2 is closed, and the electric motor 2a is started. After the electric motor 2a is started, the electric motor 2a waits for the inrush current to decrease and maintains a low speed state until a high speed finger signal arrives. FIG. 3E shows the operating waveform of the electric motor 2a. Here, when the high-speed command signal arrives from the sequence circuit 6a at time _t2 (FIG. 3F), the operating frequency of the run-up inverter 4 increases, and the speed of the electric motor 2a increases from time _t2 to _t3 . .

At time _t3 , the operating frequency of the run-up inverter 4 is held at the frequency at the cushion start position when the traverse frequency of the operating inverter rises, and the increase in frequency is stopped. On the other hand, time t ₃
When this happens, an interrupt enable signal (INTE) is sent from the interrupt control circuit 7e of the microcomputer 7, as shown in FIG. 3G. At time _t4 , the traverse synchronization signal of operation enable 1 (signal ( ₀ ) output at the frequency of the traverse start position of the operation inverter and the cushion start position) is activated.
The signal is input to the AND circuit 10 from the PWA control signal generator 9a. Since the enable signal (INTE) shown in FIG. 3G is input to this AND circuit 10, the first interrupt request signal (INTR) shown in FIG. 3H is sent from the AND circuit 10. This signal (INTR) causes the microcomputer 7 to
An interrupt is applied to the CPU 7f. This action starts the traverse operation of the run-up inverter 4, and continues the traverse operation until the next synchronization signal arrives. The operating frequency of the run-up inverter 4 during this traverse operation is stored in advance in the ROM 7c in the microcomputer as shown in _{FIG .} is the third
It will look like Figure A. As the run-up inverter 4 performs the traverse operation, it follows the operating frequency of the operating inverter 1. Here, the second interrupt request signal (INTR ₂ ) (Fig. 3 I)
(The traverse of the inverter starts for the second time,
When the friction start position) is applied to the CPU 7f, if the running frequency of the run-up inverter 4 matches the traverse start frequency of the running inverter, it is assumed that frequency tracking to the running inverter 1 has been completed, and the time At _t6 , the synchronization completion signal (FIG. 3J) is sent to the sequence circuit 6a (the synchronization completion signal is output with a time delay from _t5 to _t6 due to the matching confirmation processing time).
When this completion signal is input, the changeover switch in the changeover section 3 is switched from the run-up inverter 4 side to the running inverter 1 side.
The electric motor 2a is thereafter controlled by the output of the operating inverter 1. When the operation switching is completed, the run-up inverter 4 is switched to the third mode at time _t7 .
A frequency lowering command signal shown in FIG. K is sent out. Time _t8 becomes the next motor starting low speed frequency set value. In addition, FIG. 4 is a pattern characteristic diagram showing the traverse operation frequency change of the run-up inverter 4 and the running inverter 1 operated by the above-mentioned FIG. 3 A to K, and in FIG. 4, h ₀ to h ₃ correspond to the actions at times t ₃ , t ₄ , and t ₅ in FIG. 3, respectively.
That is, h ₁ is the hold frequency (the frequency at the traverse rise cushion start position of the operating inverter), h ₂ is the time when the traverse operation starts, and h ₃ is the time when frequency tracking is completed when the traverse synchronization signal matches.

In addition, the traverse synchronization signal of the operating inverter _{is 0.}
is a signal output at the frequency of the traverse rise cushion start position. However, the signal ₀ for synchronization between the driving inverter and the run-up inverter
The same operation can be performed at the center frequency _c of the traverse or at the falling cushion start position _D of the traverse.

As described above, according to the present invention, since the run-up inverter is started and then switched to the running inverter after the synchronization of the traverse operation is completed, the same accuracy of synchronization of both inverters can be achieved with a simple circuit. can.

[Brief explanation of the drawing]

Fig. 1 is an operating frequency pattern characteristic diagram of the inverter during traverse operation, Fig. 2 is a configuration explanatory diagram showing an embodiment of the present invention, Fig. 3 A to K is a time chart of the approach inverter, and Fig. 4 is an operational frequency pattern diagram of the inverter during traverse operation. FIG. 3 is a traverse operation frequency pattern characteristic diagram of an inverter and a run-up inverter. DESCRIPTION OF SYMBOLS 1... Driving inverter, 2... Electric motor group, 3... Switching section, 4... Run-up inverter, 6... Operation sequence section, 7... Microcomputer, 8, 9... Drive control section, 10... AND circuit.

Claims (1)

[Claims] 1. A plurality of electric motors are driven by an operation inverter controlled by a first drive control unit and a run-up inverter controlled by a second drive control unit, and are switched under control of an operation sequence unit when starting the electric motors. When the changeover switch inside the section is selected and connected to the run-up inverter side, the run-up inverter will drive from the time of startup until the speed and frequency synchronize with the operating pattern of the inverter, and after the synchronization matches, the switch will be switched by a command from within the operation sequence section. In an inverter automatic switching device, which switches a changeover switch in the section to the operating inverter side to enter steady operation, then sequentially starts the electric motor with a run-up inverter and switches to the operating inverter, the electric motor is selected in the operation sequence section. starting means for starting the selected electric motor to a predetermined speed with a run-up inverter and holding the speed N for a predetermined time under the condition; Frequency signal ₁ corresponding to traverse synchronization signal ₀ output from the drive control unit of the inverter after accelerating the selected motor to high-speed operation by outputting it to the drive control unit of the inverter
traverse operation means for holding the traverse synchronization signal ₀ of the running inverter and frequency signal ₁ of the running inverter to perform traverse operation based on a predetermined pattern on the condition that the traverse synchronization signal 0 of the running inverter matches the frequency signal 1 of the running inverter, and controlling the running inverter to follow. During this traverse operation, on the condition that the traverse synchronization signal ₀ of the running inverter and the frequency signal ₁ of the run-up inverter match, it is determined that the synchronization matches, and a synchronization match signal is sent to the operation sequence section, and this operation sequence is executed. a microcomputer comprising means for outputting a switching signal from a run-up inverter to a running inverter by a changeover switch in the switching part, and outputting a low speed command to a drive control part of the run-up inverter on condition that the switching has been made; Based on the interrupt control signal output from the computer, a traverse synchronization signal ₀ from the drive control section of the driving inverter and a frequency signal of the run-up inverter.
1. An automatic switching device for an inverter, comprising a matching circuit that detects matching with ₁ .