JPH06261599A - Approach-run operation control system of inverter - Google Patents

Abstract

PURPOSE:To prevent a shock in the changeover from an inverter for an approach run to an inverter for an operation when the drive of a load motor is changed over from the inverter for the approach run to the inverter for the operation. CONSTITUTION:The number of revolutions of load motors 1M to NM is increased by an inverter 8 for an approach run. When the output frequency of 'the inverter 8 for the approach run coincides with a set value, a set-attainment detection circuit 13 generates an output, and the output-voltage phase of the inverter 8 for the approach run and the output-voltage phase of an inverter 2 for an operation are controlled by a phase control circuit 15 so as to coincide with each other. When a synchronization detection circuit 16 detects the completion of the synchronization of both inverters, a sequence circuit 14 changes over first make-and-break means 88M1 to 88MN and second make-and-break means 88S1 to 88SN. At this time, the sequence circuit turns on the first and second make-and-break means simultaneously and for a short time, and the inverter 2 for the operation is operated in parallel with the inverter 8 for the approach run. As a result, the driving inverter of a load motor can be changed over smoothly and without any instantaneous interruption.

Description

Detailed Description of the Invention

[0001]

[Field of Industrial Application] Among textile machines, a permanent motor (hereinafter abbreviated as PM motor) is used as a drive motor for a godet roller in a spinning system.
A multi-drive system in which a single PWM inverter drives a plurality of PM motors is widely used.

In the above system, when the operation is started, the inverter is operated at a low frequency, the PM motors are sequentially put in one by one by directly inserting them, and after threading the roll, the frequency of the inverter is changed. It has started up to the operating frequency and has started production operation. By the way, in the case of the above operating method, the production efficiency cannot be obtained because the yarn cannot be put into the production operation until all the yarns are wound on the rolls.

For this reason, in recent years, there have been an inverter for operation that operates at the production operating frequency from the beginning, and an inverter for running that starts the PM motor that drives the roll that has been threaded in advance from the stopped state to the production operating frequency. Has been provided, and an approach drive system is being adopted in which the PM motor is switched from the approach inverter to the drive motor when the approach inverter reaches the operating frequency.

If the approaching driving system as described above is adopted, the operating efficiency of the system can be improved. The present invention relates to the above-described inverter running control system, and more particularly, the present invention relates to an inverter running control system capable of smoothly switching from the running inverter to the running inverter.

[0005]

2. Description of the Related Art FIG. 3 is a block diagram of a conventional running control system for an inverter, in which 1 is a three-phase AC power source, 2 is an operating inverter, and 3 is various constants of the operating inverter. Setting device, 4 is an acceleration / deceleration limiting circuit, and 5 is P for PWM control of the driving inverter 2.
A WM control circuit 6 is a base drive circuit for driving the driving inverter 2. The control circuit for the driving inverter 2 is composed of 3 to 6.

Further, 7 is a three-phase AC power supply, 8 is a running inverter, 9 is a setting device for setting various constants of the running inverter 8, 10 is an acceleration / deceleration limiting circuit, 11 is PWM control of the running inverter 8. A PWM control circuit 12 for driving the drive inverter 8 is a base drive circuit for driving the inverter 8 for running, and a control circuit for the inverter 8 for running is constituted by 9 to 12.

Reference numeral 13 is a set value arrival detection circuit for detecting that the output frequency of the running inverter has reached the set frequency.
Reference numeral 14 is a sequence circuit for switching the inverter that drives the motor, 88M1 to 88MN are driven by the sequence circuit 14, and a contactor that connects the load motor and the operating inverter 2 is used. 88S1 to 88SN are driven by the sequence circuit 14 and the load is Contactors for connecting the motor and the run-up inverter 8 are load motors 1M to NM.

FIG. 4 is a diagram showing an operation time chart of the above-described system. In FIG. 4, A is the output frequency of the driving inverter 2, B is the output frequency of the running inverter, and C is the set value arrival detection circuit 13. Output signal, D is contactor 88S
1 operation, E operation of contactor 88M1, F operation of contactor 88
The operation of S2 and the operation G of the contactor 88M2 are shown.

Next, the operation of the system shown in FIG. 3 will be described with reference to the time chart of FIG. First, the output frequency of the driving inverter 2 is raised to a predetermined frequency (see A in FIG. 4), and then the output frequency of the running inverter 8 is raised (see B in FIG. 4). At this point, the contactor 88S1 is in the ON state (see D in FIG. 4), and when the output frequency of the running inverter 8 rises, the load motor 1M is driven accordingly.

When the output frequency of the approaching inverter reaches the preset value set in the preset value arrival detection circuit 13,
The set value arrival detection circuit 13 generates an output signal (see C in FIG. 4).
The sequence circuit 14 turns off the contactor 88S1 at time T1 (see D in FIG. 4), and subsequently at time T2.
Then, the contactor 88M1 is turned on (see E in FIG. 4). As a result, the load motor 1M is driven by the driving inverter 2.

Next, after stopping the run-up inverter 8, the sequence circuit 14 turns on the contactor 88S2 (see F in FIG. 4) to raise the output frequency of the run-up inverter 8 to drive the load motor 2M. To do. Then, similar to the above, when the output frequency of the approach inverter 8 reaches the set value preset in the set value arrival detection circuit 13, the contactor 88S2 is turned off, the contactor 88M2 is subsequently turned on, and the load motor 2M Is driven by the driving inverter 2.

Similarly, the load motors 3M to NM
Sequentially from the run-up inverter 8 to the drive inverter 2
Switch to drive.

[0013]

By the way, in the above-mentioned conventional method, when switching from the running inverter 8 to the driving inverter 2, the phases of the output voltages of the running inverter 8 and the driving inverter 2 are matched, that is, Synchronous control is not performed. Further, when switching the inverters driving the load motors 1M to NM from the running inverter 8 to the driving inverter 2, as shown in FIG. 4, contactors 88S1 to 8S1 to prevent cross-flow of both inverters.
Time to switch between 8SN and contactors 88M1-MN (T1
The drive of the load motors 1M to NM is momentarily cut off by taking the time difference of -T2).

Therefore, when the drive of the load motors 1M to NM is switched from the running inverter 8 to the running inverter 2, a shock may be generated, which may adversely affect the yarn of the product. Furthermore, since the phases of the output voltages of the driving inverter 2 and the run-up inverter 8 do not match, driving of the load motors 1M to NM is performed by the driving inverter 2
A large current was supposed to flow when switching to.

The present invention has been made in order to improve the above-mentioned drawbacks of the prior art, and it is possible to switch from the run-up inverter to the drive inverter without any interruption, and the shock at the time of switching can be obtained. It is an object of the present invention to provide an approach drive control system for an inverter that can prevent this.

[0016]

In order to solve the above problems, the present invention relates to a load motor for driving a load, an approaching inverter for starting the load motor from a stopped state to a rotation speed during operation, and during production, A driving inverter for driving the load motor, a first opening / closing means for connecting the output of the running inverter and the load motor at the time of starting the load motor, and a first opening / closing means for connecting the output of the driving inverter and the load motor during production. 2 opening / closing means, setting arrival detecting means for producing an output when the output frequency of the running inverter matches the set frequency, and turning off the first opening / closing means when the setting reaching detection means produces an output. In the inverter running control system including the sequence circuit for turning on the second opening / closing means, the inverter for running and the output side of the inverter for running are connected to each other. Provided with a flow reactor,
A phase control circuit that controls the output voltage phase of the running inverter so that the output voltage phases of the running inverter and the running inverter match when the setting arrival detection means generates an output, the driving inverter and the running inverter. A synchronization detection circuit that detects that the output voltage phase matches the inverter is provided, and when the synchronization detection circuit generates an output, the sequence circuit turns on both the first and second contactors, After operating the driving inverter and the running inverter in parallel for a short time, turn off the second contactor,
The load inverter is configured to be driven by the driving inverter.

[0017]

[Operation] When the load motor is started by the running inverter and the output frequency of the running inverter matches the set value, the phase control circuit takes in the phase signal of the output voltage of the running inverter and outputs the output of the running inverter. Control is performed so that the voltage phase matches the output voltage of the inverter for operation.

When the synchronization detection circuit detects that the phase signals of the driving inverter and the running inverter match each other, that is, when the completion of synchronization is detected, the sequence circuit detects the first and second sequence circuits.
Switch the opening and closing means. At that time, the sequence circuit simultaneously turns on the first and second opening / closing means for a short time to operate the operation inverter and the running inverter in parallel for a short time.

Therefore, the driving inverter and the running inverter can be operated synchronously, and the inverter for driving the load motor can be smoothly switched without interruption. Also,
Since the AC reactors are connected to the output sides of the driving inverter and the running inverter, the cross current flowing between the driving and running inverters can be reduced.
Further, since the output voltages of the driving inverter and the running inverter are the same, the cross current flowing between both inverters is essentially small, and the value of the AC reactor can be reduced.

[0020]

FIG. 1 is a block diagram showing an embodiment of the present invention. In FIG. 1, the same components as those shown in FIG. 3 are designated by the same reference numerals, and in this embodiment, , P
Three-phase phase signal generation circuit 5'in the WM control circuits 5 and 11,
11 'is shown, and in addition to the one shown in FIG. 3, the phase control circuit 15 for controlling the output voltage phase of the driving inverter 2 and the running inverter 8 and the driving inverter 2 and the running inverter 8 are shown. A synchronization detection circuit 16 that detects that the phases of the output voltages match, and a phase control circuit 15
Contact 17 and AC reactor 18,1
9 is added.

FIG. 2 is a time chart showing the operation of this embodiment. In FIGS. 2A to 2G, A is the output frequency of the driving inverter 2 and B is the output frequency of the running inverter, as in FIG. C is the output signal of the set value arrival detection circuit 13, D is the operation of the contactor 88S1, E is the operation of the contactor 88M1, F is the operation of the contactor 88S2, and G is the contactor 88M2.
In addition, H indicates the ON / OFF operation of the synchronization signal of the contact 17, and I indicates the output signal of the synchronization detection circuit 16.

Next, the operation of the embodiment shown in FIG. 1 will be described with reference to FIG. Similar to the conventional example shown in FIG. 3, after raising the output frequency of the driving inverter 2 to a predetermined frequency (see A in FIG. 2), the output frequency of the running inverter 8 is raised (see B in FIG. 2). ). at this point,
The contactor 88S1 is in the ON state (see D in FIG. 2), and when the output frequency of the running inverter 8 rises, the load motor 1M is driven accordingly.

At T1 in FIG. 2, when the output frequency of the approach inverter reaches a preset value preset in the preset value reaching detection circuit 13, the preset value reaching detection circuit 13 generates an output signal (C in FIG. 2). 2), the contact 17 is operated by the sequence circuit 14, and a synchronization command signal (see H in FIG. 2) is given to the phase control circuit 15. When the phase control circuit 15 receives the synchronization command signal, the PWM control circuit 1 of the running inverter 8
A control signal is output to 1 to control the output voltage phase of the running inverter 8 so that the output voltage phase of the running inverter 2 matches the output voltage phase of the running inverter 8.

When the synchronization detection circuit 16 detects that the output voltage phases of the two inverters 2 and 8 coincide with each other at time T2 in FIG. 2, a synchronization completion signal is generated (see I in FIG. 2), and the sequence circuit is generated by this signal. 14 contactor 88M
1 is turned on to connect the driving inverter 2 and the load motor 1M (see E in FIG. 2). Subsequently, the contactor 88S1 connecting the load motor 1M and the running inverter 8 is turned off at time T3 (see D in FIG. 2).

As a result, the load motor 1M is operated at the time (T1
After a short period of synchronous operation during −T2), the drive inverter 8 is switched to drive the drive inverter.
Next, as in the conventional example of FIG. 3, after stopping the running inverter 8, the contactor 88S2 is turned on (see F in FIG. 2), the output frequency of the running inverter 8 is raised, and the load motor 2M is turned on. To drive. Then, similarly to the above, the drive of the load motor 2M is switched from the running inverter 8 to the driving inverter 2, and similarly, the load motors 3M to NM are sequentially switched from the running inverter 8 to the driving inverter 2 to be driven. To do.

Further, when the approaching inverter 8 and the driving inverter 2 are operating in parallel for a short time, both inverters 8,
The cross current flowing between the two is suppressed to a value not more than the value allowed by the AC reactors 18 and 19 connected to the output sides of the inverters 2 and 8.

[0027]

As described above, according to the present invention, when the drive of the load motor is switched from the running inverter to the operating inverter, the output voltage phases of both inverters are made to coincide with each other to perform short-time parallel synchronous operation. Since switching is performed after that, there is no interruption in switching, and it is possible to prevent shock when switching. Therefore, when switching, for example, the yarn of the product is not adversely affected.

Further, as described above, since the output voltage phases of both inverters are matched and the parallel synchronous operation is performed for a short time and then switched, the cross current between both inverters can be reduced and the output of the inverters can be reduced. It is possible to reduce the value of the lateral flow suppressing reactor provided on the side.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention.

FIG. 2 is a time chart showing the operation of the embodiment.

FIG. 3 is a diagram showing a conventional example.

FIG. 4 is a time chart showing an operation of a conventional example.

[Explanation of symbols]

1,7 3-phase AC power supply 2 Inverter for operation 3,9 Setting device 4,10 Acceleration / deceleration limit circuit 5,11 PWM control circuit 6,12 Base
Drive circuit 8 Inverter for running 13 Set value arrival detection circuit 14 Sequence circuit 88M1 to 88MN, 88S1 to 88SN Contactor 1M to NM Load motor 5 ', 11' Three phase phase signal generation circuit 15 Phase control circuit 16 Sync detection circuit 17 contacts 18,19 AC reactor

Claims (1)

[Claims] 1. A load motor for driving a load, an approach inverter for starting the load motor from a stopped state to a rotation speed during operation, an inverter for operation for driving the load motor during production, and a time for starting the load motor. , The first opening / closing means for connecting the output of the running inverter and the load motor, the second opening / closing means for connecting the output of the running inverter and the load motor during production, and the output frequency of the running inverter were set. A set arrival detecting means for producing an output when the frequency matches, and a sequence circuit for turning off the first opening / closing means and turning on the second opening / closing means when the set arrival detecting means produces an output. In the inverter running control system equipped with the inverter, an AC reactor was installed on the output side of the running inverter and the running inverter, and the setting arrival detection When the stage generates an output, the phase control circuit that controls the output voltage phase of the running inverter and the running inverter and the running inverter so that the output voltage phase of the running inverter matches the output voltage phase of the running inverter A synchronization detection circuit for detecting that the output voltage phases match is provided, and when the synchronization detection circuit generates an output, the sequence circuit turns on both the first and second contactors,
Inverter running control for the inverter, characterized in that after the driving inverter and the running inverter are operated in parallel for a short time, the second contactor is turned off and the load motor is driven by the driving inverter. system.