JPH02266892A - Common power supplying method for general purpose inverter by converter with regenerating function - Google Patents

Abstract

PURPOSE:To simplify a facility by regenerating power to a common AC power source from first inverters of a transistor inverter through a second inverter when motors are regeneratively braked. CONSTITUTION:AC voltage is converted to DC voltage by first converters 31 for converting AC voltage into DC voltage for a plurality of motors 4a, 4b respectively. The DC voltage is reversely converted by first inverters 32 to arbitrary AC voltage to drive the motors 4a, 4b. When the motors 4a, 4b are regeneratively braked, power is regenerated to a common power source 1 from the inverter 32 of transistor inverters 3a-3e through a converter 2 with a regenerating function. Accordingly, the second inverter can be of necessary minimum regenerative capacity, and since the drives of the motors 4a, 4b are performed by the inverters 32, it can be achieved sufficiently by the motor capacity.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a transistor having an irreversible converter section.
The present invention relates to a common power supply method in which a converter with a regeneration function is applied to an inverter.

[Conventional technology]

FIG. 2 shows a block diagram showing a circuit configuration using such a conventional common power supply method.

An electric motor 4a is driven from an AC power source 1 via a converter 2 with a regeneration function and a transistor inverter 3a.

The driving of the electric motor 4b is also carried out through the transistor inverter 3b using the regenerative converter 2 in common.

As shown in the figure, the converter 2 with regeneration function has, for example, a diode converter section and a transistor inverter section connected in parallel to the AC power supply 1 and transistor inverters 3a and 3b at the output stage, respectively, and a diode converter section 31. The output stage of the converter section 31 . ... and the inverter section 32, and the smoothing capacitor section 33 on the DC side of...
．． ... to smooth the DC current.

[Problem to be solved by the invention]

By the way, electric motors 4a and 4b using the conventional common power supply method
In the drive of each transistor inverter 3a
, 3b, their respective respective diode converter sections 31. ...is not used.

Furthermore, when looking at the electric power and the regenerative power in the converter with regeneration function 2, depending on such conventional systems, the regenerative side capacity [that is, the transistor inverters 3a, 3b and the transistor inverter section 32. ...
However, due to the original purpose of a common power supply method, it is rare for the electric motors 4a and 4b to perform regenerative operation at the same time]. The converter 2 converts the DC current to a transistor inverter 3a.

3b smoothing capacitor section 33. . . and smoothed by the transistor/inverter section 32. ...and electric motor 4a.

Since the current capacity to drive 4b is borne by the diode converter section of converter 2 with regeneration function,
There may be a shortage.

SUMMARY OF THE INVENTION An object of the present invention is to provide a common power supply method using a converter with a regeneration function of a general-purpose inverter, which is a simple means for solving the problems of the conventional method.

[Means to solve the problem]

In order to achieve the above object, the present invention includes a first converter unit that converts an AC voltage into a DC voltage for each of a plurality of driven motors, and a first converter unit that converts the DC voltage back into an arbitrary AC voltage. Each transistor/inverter is provided with an inverter section, and the first
A second converter section converts the AC voltage into a DC voltage by connecting each electric motor to the output side of the inverter section and connecting a common AC power source to the input side of the first converter section of each transistor inverter. A converter with a regeneration function is provided with a second inverter section that reversely converts a DC voltage into an arbitrary AC voltage, and the AC side of the second converter section of this o-generating machine finger converter is connected to a common AC power source, In addition, the AC side of the second inverter section is connected to a common AC power supply, and the DC side of the second converter section and the DC side of the second inverter section are connected to the first converter section of each transistor inverter. ◆The first converter section in the inverter converts the AC voltage into a DC voltage, and converts this DC voltage into an arbitrary AC voltage. The inverter section performs reverse conversion to operate each motor electrically, and when each motor is regeneratively braked, the power is transferred from the first inverter section of each transistor inverter to the second inverter section of the converter with regenerative LA function. This is a common power supply method using a converter with a regeneration function of a general-purpose inverter, which is characterized by regenerating power to a common AC power supply.

[For production]

Since the present invention uses the method described above, it is rare for each electric motor to be regeneratively braked at the same time.
The second inverter section of the converter with regeneration function requires only the minimum necessary regeneration capacity, and the electric drive of each motor is
Since the first converter section in each transistor inverter converts the AC voltage into a DC voltage, and the first inverter section converts the DC voltage back to an arbitrary AC voltage, the electric capacity can be used sufficiently.

〔Example〕

FIG. 1 shows a block diagram showing a circuit configuration in an embodiment of the present invention.

The same reference numerals in all drawings indicate the same parts.

That is, in the present invention, the electric drive of each electric motor is performed by transistor inverters 3a and 3b of each general-purpose inverter.
, 3c, 3d, 3e, -----
-- converts AC voltage into DC voltage at each first converter section, and inversely converts DC voltage into arbitrary AC voltage. In addition, the regenerative braking that is performed individually is a common power supply method performed by the converter 2 with regeneration function,
The regeneration side capacity of the converter with regeneration function 2 may be configured with an appropriate and extremely small number of components.

Each electric motor 4a, 4b, 4c, 4d is driven.

4e, ----[However, electric motors 4c, 4d, 4
e.

. . . Below, each first converter section 31 that converts an AC voltage into a DC voltage, which is not shown in the drawings.
. . . and respective first inverter sections 32 . Each transistor inverter 3a, 3b provided with...

3c, 3d, 3e, . . . are provided. However, a smoothing capacitor 33 for smoothing the DC current is provided on the DC side to which the first converter sections 31, . . . and the first inverter sections 32, . . . are connected. ... are connected in parallel.

Each of these transistor inverters 3a, 3b.

Each electric motor 4a, 4b, . . . is connected to the output side of the first inverter section 32, .
Connect...

and each of these transistor inverters 3a.

3b, 3c, 3d, 3e, . . . first converter sections 31. A common AC power supply 1 is connected to the input side of...

Moreover, the converter 2 with regeneration function is provided, which includes a second converter section that converts an alternating current voltage into a direct current voltage, and a second inverter section that converts the direct current voltage back into an arbitrary alternating current voltage.

The AC side of the second converter section of this converter with regeneration function 2 is connected to a common AC power source, and the AC side of the second inverter section is connected to the common AC power source 1, and the AC side of the second converter section is connected to the common AC power source 1. The DC side and the DC side of the second inverter section are connected to each transistor inverter 3a, 3b, 3c,
3d, 3e.

. . . the first converter section 31. ...and the first
Inverter section 32. Commonly connected to each connected DC side.

In such a circuit configuration, each electric motor 4a.

When 4b, . . . are in electric operation, each transistor/inverter 3a, 3b, 3c, 3d, 3e, -=-
The first converter section 31. . . converts the AC voltage from the AC power supply 1 into a DC voltage, and converts this DC voltage back into an arbitrary AC voltage at the first inverter section 32°, so that each motor 4a, 4b.

The rotation of . . . is arbitrarily controlled and electrically driven.

When each electric motor 4a, 4b, . . . is regeneratively braked, each transistor inverter 3a.

3b, 3c, 3d, 3e, . . . the first inverter sections 32. By regenerating power from ... to the common AC power supply 1 via the second inverter section of the converter with regeneration function 2, each electric motor 4a, 4b.

...decelerates to a stop.

Therefore, in electric operation, each transistor/inverter 3a
, 3b, the first converter section 31., which has not been used in the past.
... supplies sufficient power, and in regenerative braking, power is regenerated to the AC type R1 via the second inverter section of the converter with regeneration function 2, and this regeneration function is used for this rare power regeneration that occurs simultaneously. The attached converter 2 may have a minimum capacity. For example, it is most suitable for controlling the rotation of a centrifugal separator group consisting of three or more electric motors.

〔Effect of the invention〕

Thus, according to the present invention, when a general-purpose inverter is applied to control the electric/regenerative operation of a large number of electric motors, the capacity of the converter with regeneration function is drastically reduced, resulting in a significant cost reduction, equipment is simplified, and an ideal A common power supply method using a converter with regeneration function of a general-purpose inverter is achieved.

4a.

4b.

Claims (1)

[Claims] 1. A first converter unit that converts an AC voltage into a DC voltage and a first inverter unit that converts the DC voltage back into an arbitrary AC voltage are provided for each of the plurality of motors to be driven. Each motor is connected to the inverter output side of each transistor inverter, and a common AC power source is connected to the converter input side of each transistor inverter, and the AC voltage is converted to a DC voltage. A converter with a regeneration function is equipped with a second converter section that converts the DC voltage into an arbitrary AC voltage, and a second inverter section that reversely converts the DC voltage into an arbitrary AC voltage. is connected to a common AC power source, and the AC side of the second inverter section is connected to a common AC power source, and the DC side of the second converter section and the DC side of the second inverter section are connected to each other. The first converter section of the transistor inverter and the first inverter section are commonly connected to each connected DC side, and the first converter section in each transistor inverter converts the alternating current voltage into a direct current voltage. The voltage is inversely converted to an arbitrary AC voltage in the first inverter section to operate each motor electrically, and when each motor is regeneratively braked, the first inverter section in each transistor inverter is connected to a converter with regeneration function. A common power supply method using a converter with a regeneration function of a general-purpose inverter, characterized in that electric power is regenerated to a common AC power supply via a second inverter section of the general-purpose inverter.