JPH08308241A - Inverter - Google Patents

Abstract

PURPOSE: To save a useless labor of separately connecting an input terminal to a PC by effectively utilizing the input terminal of an inverter controller. CONSTITUTION: A temperature sensor and a limit switch are connected to the input terminals 12a, 12b of a terminal block 12. When an indication motor 9 is operated by the control command from a PC24, an inverter controller 11 communicates the input data from the block 12 to the PC24. Then, the PC24 calculates the command on the basis of the communicated data, and transmits it to an inverter controller 11. Accordingly, a useless labor of connecting the sensor and the switch to the PC24 is saved, so that the terminals 12a, 12b of the block 12 are effectively utilized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inverter device for performing variable speed control of an electric motor, which has a structure for controlling an inverter circuit by using an external control means.

[0002]

2. Description of the Related Art An inverter device is equipped with a terminal block having an analog input terminal, a digital input terminal, an analog output terminal and a digital output terminal. And
When a control command such as a frequency command value or an operation stop command output from an external controller is supplied to the control means from the input terminal of the terminal block, the control means is configured to control the inverter circuit based on this control command. ing.

In this configuration, a communication terminal block is provided, and in a small-scale system, an external control means composed of a PC (programmable controller) is connected to this communication terminal block, and a temperature sensor and a flow rate are connected to the PC. The sensor and limit switch detection data are input. When the PC is selected, the terminal block is invalidated, and the control command created by the PC based on the detection data is communicated from the communication terminal block to the control means.

[0004]

However, in the above-mentioned conventional configuration, the terminal block is invalidated when the PC is selected.
For this reason, the detection data from the temperature sensor, the limit switch, etc. must be input to the PC, resulting in the waste of separately connecting the input terminal to the PC.

The present invention has been made in view of the above circumstances, and an object thereof is to effectively utilize the input terminals of the terminal block,
An object of the present invention is to provide an inverter device capable of eliminating waste of separately connecting an input terminal to an external control means.

[0006]

According to another aspect of the present invention, there is provided an inverter device for controlling an inverter circuit based on a control command, and an analog input terminal, a digital input terminal and an analog output terminal connected to the control means. A terminal block having a digital output terminal and data supplied from the input terminal of the terminal block through the control means,
It is characterized by including an external control means for calculating a control command and outputting it to the control means.

The inverter device according to a second aspect is characterized in that the control means outputs the data supplied from the external control means from the output terminal of the terminal block. An inverter device according to a third aspect is characterized in that one of the data given from the external control means to the control means is data for an analog output terminal of the terminal block. The inverter device according to a fourth aspect is characterized in that one of the data given from the control means to the external control means is a digital conversion result of an analog signal inputted from the analog input terminal of the terminal block to the control means.

[0008]

According to the means described in claim 1, when data is supplied from the input terminal of the terminal block to the control means, the data is supplied from the control means to the external control means. Then, the external control means calculates a control command based on the data and outputs it to the control means. According to the means described in claim 2, when the data is supplied from the external control means to the control means, the data is output through the output terminal of the terminal block.

According to the third aspect, when data is supplied from the external control means to the control means, the data is output from the analog output terminal of the terminal block. According to the means described in claim 4, when data is given to the analog input terminal of the terminal block, the data is digitally converted and the conversion result is supplied to the external control means.

[0010]

An embodiment of the present invention will be described below with reference to the drawings. First, in FIG. 1, the inverter circuit 1 includes power source side terminals 2a to 2c, load side terminals 3a to 3c, a DC power source circuit 4, an inverter main circuit 5, a base drive circuit 6,
It is composed of a control power supply circuit 7. A three-phase AC power supply 8 is connected to the power supply side terminals 2a to 2c, and a three-phase induction motor 9 corresponding to an electric motor is connected to the load side terminals 3a to 3c. There is.

The DC power supply circuit 4 is composed of a full-wave rectifier circuit 4a and a smoothing capacitor 4b. Converted to power supply, smoothing capacitor 4b
Is smoothed by.

The inverter main circuit 5 is constructed by connecting six switching elements 5a composed of transistors in a three-phase bridge connection, and the emitter of each switching element 5a is connected to the load side terminals 3a to 3c. . Then, the inverter main circuit 5 is the power supply bus bar 4 of the DC power supply circuit 4.
connected between c and 4d, and smoothing capacitor 4b
Is supplied to the induction motor 9 through the inverter main circuit 5.

The base drive circuit 6 is connected to the base of each switching element 5a and controls switching of each switching element 5a based on a switching pattern. The control power supply circuit 7 is connected between the power supply buses 4c and 4d, and the smoothing capacitor 4
A control power supply Vcc having a DC constant voltage is created from the output of b.
In addition, E shows earth potential.

The control power supply generated by the control power supply circuit 7 is supplied to the inverter control section 11 corresponding to the control means through the power supply monitoring circuit 10. The inverter control unit 11 is composed of a microcomputer, and the power supply monitoring circuit 10 puts the inverter control unit 11 in a reset state (power-on reset state) until the output voltage of the control power supply circuit 7 reaches the set level Vcc. Hold. The inverter control unit 11 has a built-in RAM 11a.
Various processing operations are performed using M11a as a work area.

The terminal block 12 has eight digital input terminals 1
2a is provided. These digital input terminals 12a
A limit switch (not shown) or an external operating device (not shown) is connected to the ON / OFF data output from the limit switch or an external operating device (for example, a remote monitoring device). The operation stop command is input from the digital input terminal 12a to the input port of the inverter control unit 11 through the buffer 13.

The terminal block 12 has two analog input terminals 1
2b is provided. These analog input terminals 12b
Sensors such as a temperature sensor and a flow rate sensor (neither shown) or an external operating device are connected to the temperature sensor. Temperature data detected by the temperature sensor, flow rate data detected by the flow rate sensor, or The frequency command value output from the operation unit is input from the analog input terminal 12b through the A / D converter 14 to the input port of the inverter control unit 11.

The terminal block 12 has two analog output terminals 1
2c is provided, and the two analog output terminals 12c are connected to the inverter control unit 11 via the low-pass filter circuit 15.
Connected to the output port of. An external operation device is connected to these analog output terminals 12c, and the inverter control unit 11 operates the low-pass filter circuit 1
5 outputs analog data such as a frequency command value to the external operating device through the analog output terminal 12c.

The terminal block 12 has four digital output terminals 1
2d is provided, and the four digital output terminals 12d are connected to the output port of the inverter control unit 11 via the buffer 16. An external controller is connected to these digital output terminals 12d, and the inverter control unit 11 operates from the buffer 16 to the digital output terminals 12d.
The digital data such as the operation stop command is output to the external controller through d.

A nonvolatile memory 17 is connected to the data bus and address bus of the inverter control unit 11. The non-volatile memory 17 is composed of a rewritable memory such as an EEPROM, and the non-volatile memory 17 stores an operation mode and a large number of control data (for example, 350 control condition data).

A volatile memory 18 is connected to the data bus and address bus of the inverter control unit 11.
The volatile memory 18 is composed of a memory that can be read and written in both directions.
The data bus and address bus of the communication control unit 19 are connected. The communication control unit 19 is composed of a microcomputer, and the serial port of the communication control unit 19 is connected to the communication terminal block 2 via the transmission / reception circuit 20.
1 is connected.

A PC 24 corresponding to an external control means is connected to the terminal of the communication terminal block 21. This PC24
Corresponds to a host controller of the inverter control unit 11, and the inverter control unit 11 and the PC 24 are
Data is transmitted and received via the communication control unit 19. still,
The control circuit unit 22 includes a power supply monitoring circuit 10, an inverter control unit 11, a terminal block 12, a buffer 13, and an A / D converter 1.
4, a low-pass filter 15, a buffer 16, a non-volatile memory 17, a volatile memory 18, a communication control unit 19, a transmission / reception circuit 20, and a terminal block 21, and the inverter control unit 11 is a non-volatile memory 17. Control based on data.

The setting operation section 23 is composed of a key matrix circuit 23a for setting operation, a display section 23b for displaying data and operating status, and drivers 23c, 23d. The key matrix circuit 23a corresponds to function selecting means and control command setting means such as a frequency command value and an operation stop command, and its input / output terminal is connected to the input / output port of the inverter control unit 11. Then, when the parameters are set by the key matrix circuit 23a, the inverter control unit 11 selects the functions (a) to (c) below.

(A) The inverter circuit 1 is controlled based on the set value by the key matrix circuit 23a. (B) The inverter circuit 1 is controlled based on the control command from the external operating device. (C) The inverter circuit 1 is controlled based on the control command from the PC 24. The display unit 23b is composed of a plurality of LEDs, and is connected to the output port of the inverter control unit 11 via the drivers 23c and 23d. Then, the inverter control unit 11 outputs the control command set by the key matrix circuit 23a, the signal selection status by the key matrix circuit 23a, the operating status of the induction motor 9, and the like to the driver 2
3c and 23d, and drivers 23c and 23
It is displayed on the display unit 23b by d.

Next, the operation of the above configuration will be described. When the three-phase AC power supply 8 is turned on and the DC power supply Vcc is supplied from the control power supply circuit 7 to the power supply monitoring circuit 10, the inverter control unit 11 starts its operation and clears the data in the RAM 11a for initialization. Along with this, the communication control unit 19
Turn on the signal for resetting. Then, after the volatile memory 18 is checked and initialized while the communication control unit 19 is being reset, the reset is released and the communication control unit 19 is activated.

When the above-mentioned operation is completed, the inverter control unit 11 reads out the control condition data stored in the non-volatile memory 17 and writes it in the RAM 11a. A to E below
Is an example of control condition data read from the nonvolatile memory 17 by the inverter control unit 11.

A. The frequency command value is 1 of the volatile memory 18.
Use the street address data. B. Use the data at address 2 of the volatile memory 18 for the operation stop command. C. As the data output from the analog output terminal 12c, use the data at address 3 of the volatile memory 18.

D. The A / D converted value (temperature data, flow rate data) input from the analog input terminal 12b through the A / D converter 14 should be written to the volatile memory 18 at address 4. E. FIG. The data (on / off data) input from the digital input terminal 12a should be written into the volatile memory 18 at address 5.

When the control condition data is written in the RAM 11a, the inverter control unit 11 performs a preset logical operation from the control condition data and the states of the input terminals 12a and 12b, and the result is assigned to the assigned function. State, execute the operation according to the signal, and output terminals 12c, 12d
Outputs the status of the function assigned to.

For example, “(a) Key matrix circuit 23
When the function of controlling the inverter circuit 1 based on the set value of a ”is selected, the inverter control unit 11 creates a switching pattern based on the frequency command value and the operation stop command output from the key matrix circuit 23a. Output to the base drive circuit 6. Then, the base drive circuit 6 performs switching control of the inverter main circuit 5 based on the given switching pattern,
The induction motor 9 is operated according to the set control command.

When the function "(b) control the inverter circuit 1 based on a control command from an external operating device" is selected, the inverter control unit 11 causes the input terminal 12 to operate.
A switching pattern is created based on the frequency command value and the operation stop command input through a and 12b, and is output to the base drive circuit 6. Then, the base drive circuit 6 performs switching control of the inverter main circuit 5 based on the given switching pattern, and operates the induction motor 9 according to a control command from an external operating device.

When the functions (a) and (b) are selected, the inverter control section 11 sends data such as a frequency command and an operation stop command from the analog output terminal 12c and the digital output terminal 12d to the external operating device. Output.

When the "(c) control the inverter circuit 1 based on a control command from the PC 24" function is selected, the inverter control unit 11 causes the inverter control unit 11 to input temperature data and flow rate data. The analog control data such as is written in address 4 of the volatile memory 18. At the same time, digital control data such as on / off data input from the digital input terminal 12a is written in the address 5 of the volatile memory 18.

On the other hand, the communication control unit 19 reads the data at addresses 4 and 5 of the volatile memory 18 and sends the read data to the PC 24 in response to the request. PC
When 24 receives the control data, it changes the frequency command value of the inverter device from the analog control data such as temperature data, calculates the operation stop command from the digital control data such as ON / OFF data, and communicates the frequency command value and the operation stop command. It transmits to the control unit 19 for use. When the communication control unit 19 receives the frequency command value, the communication control unit 19 writes it in the address 1 of the volatile memory 18, and when the operation stop command is received, the volatile memory 18 is written.
Write at address 2.

Then, the inverter control unit 11 reads the frequency command value from the address 1 of the volatile memory 18, reads the operation stop command from the address 2, and outputs the read frequency command value and the operation stop command to the analog output terminal 12c and the digital output terminal 12c. Output from the output terminal 12d to the external operating device. At the same time, a switching pattern is created based on the read command signal and output to the base drive circuit 6. Then
The base drive circuit 6 performs switching control of the inverter main circuit 5 based on the given switching pattern, and operates the induction motor 9 according to the detection signal.

According to the above embodiment, the terminal block 12 is validated and the terminal block 12 is activated even when the function of "controlling the inverter circuit 1 based on the control command from the PC 24" is selected.
The control data input from the input terminals 12a and 12b of 1 is communicated from the inverter control unit 11 to the PC 24. Therefore, the digital input terminal 12 of the terminal block 12
a and the analog input terminal 12b are effectively used as general-purpose terminals, and as a result, the control data input terminal is connected to the PC.
There is no waste of separately connecting to 24.

Further, since the terminal block 12 is validated even when the function of "controlling the inverter circuit 1 based on the control command from the PC 24" is selected, the control command calculated by the PC 24 is output to the output terminal of the terminal block 12. 12c and 12d
Can be output to an external controller. Therefore, unlike the conventional case where the control command is output to the external operating device through the PC 24, the output terminal of the invar control unit 11 is effectively used, and as a result, there is no waste of separately connecting the output terminal to the PC 24.

In the above embodiment, the volatile memory 18 and the communication control unit 19 are provided as the communication means between the inverter control unit 11 and the PC 24, but the present invention is not limited to this, and the inverter control unit 11 is not limited thereto. Alternatively, the serial communication port and the communication port of the PC 24 may be directly connected to read / write data bidirectionally from / to the RAM 11a of the inverter control unit 11.

[0038]

As is apparent from the above description, the inverter device of the present invention has the following effects. According to the means described in claim 1, the terminal block is enabled even when the external control means is selected, and the data inputted from the input terminal of the terminal block is supplied from the control means to the external control means.
Therefore, the digital input terminal and the analog input terminal of the terminal block are effectively used as general-purpose terminals, and as a result, there is no waste of separately connecting a terminal for data input to the external control means.

According to the second aspect, since the terminal block is validated even when the external control means is selected, the data of the external control means can be output from the output terminal of the terminal block. Therefore, the output terminal of the control means is effectively used, and as a result, there is no waste of separately connecting the output terminal to the external control means. According to the third aspect, the data of the external control means can be output from the analog output terminal of the control means. According to the means described in claim 4, the analog data input to the analog input terminal of the terminal block can be converted into digital data and supplied to the external control means.

[Brief description of drawings]

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

FIG. 2 is a diagram showing stored contents of a volatile memory.

[Explanation of symbols]

1 is an inverter circuit, 11 is an inverter control unit (control means), 12 is a terminal block, 12a is a digital input terminal (input terminal), 12b is an analog input terminal (input terminal), 12
Reference numeral c is an analog output terminal (output terminal), 12d is a digital output terminal (output terminal), and 24 is a PC (external control means).

Claims (4)

[Claims] 1. A control means for controlling an inverter circuit based on a control command, a terminal block having an analog input terminal, a digital input terminal, an analog output terminal, and a digital output terminal connected to the control means, and this terminal block. And an external control means for calculating a control command and outputting it to the control means when data is supplied from the input terminal of the control means through the control means. 2. The inverter device according to claim 1, wherein the control means outputs the data given from the external control means from an output terminal of the terminal block. 3. The inverter device according to claim 2, wherein one of the data given from the external control means to the control means is data for an analog output terminal of the terminal block. 4. One of the data given from the control means to the external control means is a digital conversion result of an analog signal inputted from the analog input terminal of the terminal block to the control means. Inverter device.