JP2883643B2 - Inverter group operation method - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a group operation method in which electric motors are individually operated by a plurality of inverters.

[Conventional technology]

Conventionally, as a group operation of a plurality of electric motors by a plurality of inverters, for example, as shown in FIG. 3, a special control device such as a master controller is installed, and the tuning operation, the ratio operation, the operation / stop are controlled by the control. What is achieved is known. In the drawing, reference numerals 1 (1A to 1N) denote inverters (INV), 4 denotes a frequency setting device, 5 denotes a start / stop command device, and 8 denotes a master controller.

[Problems to be Solved by the Invention] As described above, when a plurality of motors are group-operated by a plurality of inverters, a special control device is used for tuning operation and ratio operation, and from there, via an individual signal line. Since the signal is transmitted, there is a problem that the cost for the device or the wiring increases.

Therefore, an object of the present invention is to realize a group operation of inverters easily and inexpensively.

[Means for solving the problem]

In arranging a plurality of inverters each having a communication function and operable as either a master unit or a slave unit and individually operating the electric motors, the inverters are connected to each other via a serial communication line, and among them, Is set as a master unit and the remaining units are set as slave units, and an operation frequency command is given to the master unit, so that a common operation frequency command is given to all of the slave units via the communication line to perform the tuning operation. In addition, ratio operation is possible by setting the operation frequency ratio for the master unit to the slave unit in advance, and it is also possible to operate / stop commonly by giving a start / stop command to the slave unit from the master unit. Can also.

[Action]

A communication function is provided for each inverter and connected to each other via a communication line to transmit the information necessary for inverter tuning operation, ratio operation, etc. from the master unit to the slave unit, enabling simple and inexpensive group operation. To

〔Example〕

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

First, one of the inverter groups can be set as a master unit. This is a function that is normally provided in the inverter. Since it is included as one of the setting functions of various operating conditions, there is no special hardware to be added. The remaining inverters can be set as slave units, but this is also the same as above and does not require any special hardware. The setting for this is performed by the operating condition setting unit 7, which is specifically constituted by a man-machine interface 71 having an input function and a display function, a memory 72, a CPU 73 and the like as shown in FIG. Have been. Further, each inverter has a communication interface 6 (6A to 6N), through which the master unit transmits data serially, while the slave unit receives serial data via this. The serial data is, for example, a digital signal and includes various information for realizing the inverter group operation.

Here, if the inverter 1A is a master unit and 1B to 1N are slave units, and an operation frequency command is given to the master unit 1A by the frequency setting unit 4, the master unit 1A converts this signal into serial data, and the communication interface The operating frequency information is transmitted to the slave units 1B to 1N via 6A and the serial communication line 3. Each slave unit
1B-1N receives this information via the communication interfaces 6B-6N, determines its own operation frequency from this information or the ratio operation information which each person has in advance, and performs the tuning operation or the ratio operation. Since the transmission of this information is performed in a short time, no trouble occurs in the tuning operation or the ratio operation of the inverter group.

In this case, the operation / stop command device 5 is installed only in the master unit 1A, and the operation / stop information is also given from the master unit to the slave unit via the communication interface 6A and the serial communication line 3, thereby providing a plurality of inverters. Synchronize (simultaneously)
It can be started or stopped.

〔The invention's effect〕

According to the present invention, a communication function is provided for each of the inverters, and the inverters are connected to each other via a communication line to transmit information required for tuning operation, ratio operation, and the like of the inverter from the master unit to the slave unit. A group operation using a plurality of inverters and motors can be performed without adding a special control device. That is, if the cost for wiring, the ease of maintenance, the simplification of the system, and the like are given, the effect can be said to be extremely large.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an embodiment of the present invention, FIG. 2 is a block diagram showing a specific example of an operation condition setting unit, and FIG. 3 is a schematic diagram showing a conventional example of a group operation system. Description of symbols 1 (1A to 1N) ... inverter, 2 (2A to 2N) ... electric motor, 3 ... communication line, 4 ... frequency setting device, 5 ... run / stop command device, 6 (6A to 6N) …… communication interface,
7: Operating condition setting section, 8: Master controller, 71
…… Man-machine interface, 72 …… Memory, 73 ……
CPU.

Claims (1)

(57) [Claims] A plurality of inverters having a communication interface and a plurality of inverters having a communication interface and a memory, a CPU, and an operating condition setting unit comprising a man-machine interface are connected to each other by a serial communication line via the communication interface; One unit is set as the master unit and the other unit is set as the slave unit, and the operating frequency ratio for the master unit is stored in each slave unit in advance, and the operating frequency command value given to the master unit is set via the serial communication line to each slave unit. Each slave unit determines its own operating frequency from the pre-stored operating frequency ratio, and performs the tuning operation or ratio operation by sending it to the master unit. A group operation method for inverters, characterized in that each slave unit is started and stopped in common by sending it to each slave unit via a line.