JP2845538B2 - Inverter control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial application field) The present invention relates to an inverter control device for performing variable speed control of an electric motor.

(Prior Art) Conventionally, a setting operation section for giving an operation command, a stop command, frequency setting data and various control condition data to a control circuit section of an inverter circuit for driving an electric motor includes an operation command switch, a stop command switch, a frequency A setting volume and a plurality of control condition data setting volumes are provided so as to be connected to the control circuit unit, or a large number of key switches for operation command, stop command, frequency setting and control condition data setting are assembled. Provided to the control circuit unit.

(Problems to be Solved by the Invention) In the former configuration using the conventional setting volume, the setting volume and the A / D converter are divided into a number of functions in response to a demand for multifunctional and high performance inverter circuits. (For example, 78 functions in the control of a three-phase induction motor) and a high-precision
It is necessary to use an A / D converter, and there is a problem that the setting operation unit becomes large and expensive.

In the latter configuration using a conventional key switch, operation,
The key switches that are normally used frequently, such as stop and frequency setting, and the key switches that are not often used except for the initial setting of the control condition data are in a mixed state, so the operation is troublesome and the risk of erroneous operation is large. It is.

The present invention has been made in view of the above circumstances, and its purpose is to reduce the size of the setting operation unit, can be inexpensive, and can easily operate the setting operation unit and minimize erroneous operations, In addition, an object of the present invention is to provide an inverter control device capable of freely removing the setting operation section from the control circuit section.

[Configuration of the Invention] (Means for Solving the Problems) An inverter control device according to the present invention includes a control circuit unit that controls an inverter circuit based on operation-related commands and control condition data stored in a memory. The circuit section is separable via a connector and control power is supplied via the connector, and has a microcomputer, operation-related switch means, control condition data setting switch means, and a power supply monitoring circuit. Under the control of the microcomputer, operation-related commands and control condition data from the operation-related switch means and the control condition data setting switch means are stored in the memory of the control circuit unit, and the voltage is controlled in accordance with the voltage level of the control power supply. Setting for resetting the microcomputer by a power monitoring circuit The work unit is provided, having the features of the setting operation unit, where configured to the driving-related switching means a control condition data setting switch means are arranged separately.

(Operation) According to the inverter control device of the present invention, the setting operation section has operation-related switch means for giving an operation-related command to the control circuit section under the control of the microcomputer, and control condition data setting switch means for giving control condition data. Is set, so the setting volume and the same number of A / D
As compared with the case where a converter is used, the setting operation unit can be made smaller and inexpensive. In addition, since the setting operation section is configured so that the driving-related switch means and the control condition data setting switch means are separately arranged, the operation of the setting operation section, particularly the operation of frequently used driving-related switch means, is performed. And the erroneous operation can be prevented as much as possible. In addition, the setting operation section can be freely removed from the control circuit section via the connector. In this case, however, the inverter circuit is controlled based on commands and data stored in the memory of the control circuit section. There is no problem in operation, and the microcomputer of the setting operation unit is reset by the power supply monitoring circuit according to the voltage level of the control power supply, so that the microcomputer does not perform any extra operation, and
The setting operation section can be shared for command and data setting for the control circuit section of another inverter circuit.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

 First, the overall configuration will be described with reference to FIG.

The inverter circuit 1 includes power supply terminals 2, 3, and 4, and load terminals 5, 6, and 7. A three-phase AC power supply 8 is connected to the power terminals 2, 3, and 4, and the load terminal 5 , 6 and 7 are connected to a motor, for example, a three-phase induction motor 9. or,
The inverter circuit 1 includes a DC power supply circuit 10. The DC power supply circuit 10 includes a full-wave rectifier circuit 11 having an AC input terminal connected to the power supply side terminals 2, 3, and 4, and a full-wave rectifier circuit 11
And a smoothing capacitor 12 connected between the DC output terminals. DC buses 13 and 14 are connected to both terminals of the smoothing capacitor 12. Further, an inverter main circuit 21 is connected between the DC buses 13 and 14 by connecting three transistors 15 to 20 as three switching elements in a three-phase bridge connection. The emitters of the transistors 15 to 17 are connected to the load side terminals 5 and
6 and 7 are connected. And inverter main circuit 2
Six output terminals of the base drive circuit 22 are connected to the bases of the transistors 15 to 20, respectively. still,
The inverter circuit 1 includes a control power supply circuit 23, whose input terminal is connected to the DC buses 13 and 14, and outputs a control power supply having a constant DC voltage between output terminals. In this case, in the control power supply circuit 23, Vcc indicates the control power supply voltage, and E indicates the ground potential.

The control circuit 24 includes a microcomputer 25.
This microcomputer 25 has a built-in RAM 25a as a memory.
And the input / output port is connected to a memory, for example, a rewritable nonvolatile memory 26. The nonvolatile memory 26 stores an operation mode and a number of control items, for example, control condition data of the 78th page. And
The microcomputer 25 has a multi-bit output port connected to an input terminal of the base drive circuit 22 and supplies the base drive circuit 22 with commands and setting data stored in the built-in RAM 25a. Further, an input port and an output port of the microcomputer 25 are connected to terminals of a connector 28 via a buffer 27 for shaping a transmission data waveform. The control circuit section 24 further includes a power supply monitoring circuit 29. The power supply monitoring circuit 29 has an input terminal connected to the output terminal of the control power supply circuit 23, an output terminal connected to the input port of the microcomputer 25, and the control power supply voltage Vcc from the control power supply circuit 23 reaching the set level. The microcomputer 25 is reset (power-on reset) until it reaches this point.
The control circuit section 24 includes a terminal block 30. The terminal block 30 has a plurality of terminals connected to an input port of the microcomputer 25 via a buffer 31,
The plurality of terminals are connected to an external operating device (not shown), and the external operating device is configured as described later.

The setting operation unit 32 is a unit. The setting operation section 32 includes a microcomputer 33 having a built-in RAM 33a as a memory. The input and output ports of the microcomputer 33 are buffers for transmission waveform shaping.
The buffer 27 is connected to the terminal of the connector 28 corresponding to the buffer 27 via 34, so that data transmission is performed between the microcomputers 25 and 33 via the buffer 27, the connector 28 and the buffer 34. I have. The setting operation section 32 is connected to the control power supply circuit 23 through the terminal of the connector 28.
From the control power supply. As is well known, the connector 28 can be inserted and removed, so that the setting operation unit 32 can be electrically and mechanically separated from the control circuit unit 24. Further, the setting operation section 32 includes an operation-related key matrix circuit 35 as operation-related switch means and a key matrix circuit 36 for setting control condition data as control condition data setting switch means. 33
Connected to the input and output ports. Also, the operation section 32
Is a 4-digit segment display 37 for displaying various states and data, an LED 38 for displaying frequency (Hz) units, an LED 39 for displaying percent (%) units, and an LED 40 for displaying seconds (sec) units.
And a panel operation display LED 41, which is connected to a predetermined output port of the microcomputer 33 via driver circuits 42, 43. The setting operation section 32 includes a power supply monitoring circuit 44. This power supply monitoring circuit
44 has an input terminal connected to the terminal on the control power supply side of the connector 28 and an output terminal connected to the microcomputer.
The microcomputer 33 is connected to the input port 33 and resets the microcomputer 33 until the control power supply voltage Vcc reaches a set level.

Now, the setting operation section 32 will be further described with reference to FIG. The operation-related key matrix circuit 35 has an “operation” key 35a, a “stop” key 35b, a “△ (frequency up setting)” key 34c, a “▽ (frequency down setting)” key 35d, and an “operation mode” key 35e. doing. The control condition data setting key matrix circuit 36 is operated by a “9.
36a, "8 terminal" key 36b, "7 jump" key 36c,
"6. Multi-step speed" key 36d, "5. External F" key 36e, "4.
"Overload" key 36f, "3 limit" key 36g, "2 acceleration / deceleration" key 36h, "1 V / F" key 36i, "0 maximum F" key 3
6j, “・ (decimal point) / read” key 36k, “write” key 36l,
"Setting display" key 36m, "Second function" key 36n, "Clear"
It has a key 36o and a "shift" key 36p. And
The setting operation unit 32 is unitized with a case 32a, and has a display 37, LEDs 38 to 41, and keys 35a to 3
5e is arranged on the left half of the front panel of the case 32a, and the keys 36a to 36p are arranged on the right half of the front panel of the case 32a. The matrix circuit 36 is arranged separately on the left and right.

Next, the operation of the present embodiment will be described with reference to FIG.

When the three-phase induction motor 9 is controlled by the inverter circuit 1 at a variable speed, the control items are many, for example, as many as 78, and the nonvolatile memory 26 has the control of the 78 as shown in FIG. After the items are classified into 20 blocks from “No. 0” to “No. 19”, several kinds of control items related to each block are stored together with standard control condition data. FIG. 3 shows a partial representative example of the title display and the control items.

First, when the three-phase AC power supply 8 is turned on to the inverter circuit 1, the DC power supply circuit 10 outputs a DC power supply voltage, and in response to this, the control power supply circuit 23 outputs the control power supply voltage Vcc, and the inverter circuit 1 and the control circuit Supply to section 24. As a result, the microcomputer 25 of the control circuit unit 24 starts operation, clears the contents stored in the internal RAM 25a, and performs initialization. After this initialization, the microcomputer 25 reads out the control items and the control condition data stored in the nonvolatile memory 26 and writes them in the built-in RAM 25a. Control power circuit
Since the control power supply voltage Vcc from 23 is also supplied to the setting operation unit 32 via the connector 28, the microcomputer 33 starts operation, clears the stored contents of the built-in RAM 33a, and performs initialization. After this initialization, the microcomputer 33 sends a data read command to the microcomputer 25 via the buffer 34, the connector 28 and the buffer 27, whereby the microcomputer 25 reads necessary data from the built-in RAM 25a or the nonvolatile memory 26. Buffer 27,
The signal is sent to the microcomputer 33 via the connector 28 and the buffer 34. Accordingly, the microcomputer 33 writes the data transmitted as described above into the built-in RAM 33a.

Next, a driving operation and a data setting operation by the setting operation unit 32 will be described.

When the microcomputers 25 and 33 complete the initial setting, the microcomputers 25 and 33 are in a mode of receiving an operation command, a stop command, and a frequency setting input. In this case, the inverter circuit 1
The operation command, the stop command, and the input of the frequency setting are input not only by operating the setting operation unit 32, but also by operating an external operating device (not shown) connected to the terminal block 30 of the control circuit unit 24 or an optional host communication. Is to be given. When the microcomputers 25 and 33 are initially set, the terminal mode is set to one of the terminal block command mode, the setting operation section command mode, and the option higher-level communication command mode in accordance with the command mode selection data in the nonvolatile memory 26. Therefore, in order to enable the input of the operation command, the stop command, and the frequency setting from the setting operation unit 32, it is necessary to set the operation mode to the setting operation unit command mode.
In this case, when the "operation mode" key 35e of the operation-related key matrix circuit 35 is pressed, the mode is switched and set each time the operation is pressed, and the mode is sequentially displayed on the display 37. When the setting operation unit command mode is set in this way, the microcomputer 33 energizes the panel operation display LED 41 to emit light. In such a state, when the "drive" key 35a is pressed, the microcomputer 33 sends an operation command to the microcomputer 25 via the buffer 34, the connector 28 and the buffer 27, and the microcomputer 25 Is stored in the built-in RAM 25a. Thereafter, when the "stop" key 35b is pressed, the microcomputer 33 sends a signal for clearing the operation command to the microcomputer via the buffer 34, the connector 28 and the buffer 27.
Then, the microcomputer 25 clears the operation command stored in the built-in RAM 25a. An external operation device (not shown) connected to the terminal block 30 is also provided with an operation-related key matrix circuit similar to the operation-related key matrix circuit 35 and a display similar to the display 37.

When the frequency is set prior to the operation of the "drive" key 35a as described above, when the "押 圧" key 35c is pressed, the frequency command value increases at a predetermined rate according to the operation time. When the "▽" key 35d is pressed, the frequency set value is decreased at a rate determined according to the operation time, and the frequency set value is displayed on the display 37. , Frequency setting value data is buffered by microcomputer 33, connector 2
8 and a buffer 27 to be sent to the microcomputer 25.
The frequency command value data of 5a will be rewritten.

Now, the operation of setting the control condition data by the control condition data setting key matrix circuit 36 will be described. First,
By pressing the "setting display" key 36m, the microcomputer 33 is set to the receiving mode of the control condition data setting key matrix circuit 36. Then, the key of the block number (No.) to which the control item to be set belongs is pressed. For example, as shown in FIG. 3, when it is desired to set a control item of "standard setting" in a block "No. 0" belonging to "first function", a "0.maximum F" key 36j
Is pressed, the microcomputer 33 displays the display 37.
Will now display the title character of "Hi yP"
Indicates that the "standard setting" control item has been selected. To set the next control item of the “highest frequency”, when the “shift” key 36p is pressed, the microcomputer 33 shifts the control item and displays “FH” on the display 37.
Is displayed, indicating that the control item of “highest frequency” has been selected. Hereinafter, each time the "shift" key 36p is pressed, the microcomputer 3
3 shifts the control items one by one and causes the display 37 to display title characters. For example, when it is desired to set the control item of “starting frequency” in the block “No. 10” belonging to the “second function”, the “second function” key 36
When the n is pressed and then the "0.maximum F" key 36j is pressed, the microcomputer 33 displays "F-
The title character of "Shi" is displayed to indicate that the control item of "start frequency" has been selected. The control items of the blocks belonging to other first functions and the control items of the blocks belonging to the second function can be selected by the same operation. After selecting the control item to be set in this way, when the "..readout" key 36k is pressed, the microcomputer 33 sends a signal for reading out the control condition data of the selected control item to the buffer 34, Connector 28 and buffer 27
Through the microcomputer 25. In response, the microcomputer 25 reads the control condition data of the control item corresponding to the read signal from the built-in RAM 25a and sends it to the microcomputer 33 via the buffer 27, the connector 28 and the buffer 34, and the microcomputer 33 The sent control condition data is stored in the built-in RAM3.
It is stored in 3a and displayed on the display 37. When the control condition data is to be changed, the keys 36a to 36j with numerical values of "9" to "0" and the key 36k with a decimal point of "." Enter the change data. The changed data is sequentially stored in the built-in RAM 33a by the microcomputer 33 and displayed on the display 37. After the control condition data is changed in this way, when the "write" key 36l is pressed, the microcomputer 33 causes the control condition data changed and stored in the built-in RAM 33a to fall within the data setting range of the control item. Is checked, and if it is determined to be no (out of range), the display 37 is caused to display a setting error. Then, when the microcomputer 33 determines that the changed control condition data is within the set range, the microcomputer 33 sends the rewrite signal and the control condition data to the microcomputer 25 via the buffer 34, the connector 28, and the buffer 27, The microcomputer 25 rewrites the data of the corresponding control item in the built-in RAM 25a. Similarly, the microcomputer 33 sends a rewrite signal and control condition data to the non-volatile memory 26, and rewrites the data of the corresponding control item in the non-volatile memory 26.

In the above case, the control condition data of the control item is changed by selectively pressing the keys 36a to 36k after selecting the control item to be set. And "▽" key 35d. That is, when the “△” key 35c or the “▽” key 35e is pressed, the microcomputer 33 operates at a predetermined rate from the control condition data stored in the built-in RAM 33a within the data setting range of the control item. The data is raised or lowered, and this is displayed on a display 37, and the rewrite signal and its raised or lowered changed control condition data are sequentially transmitted to the microcomputer 25 via the buffer 34, the connector 28 and the buffer 27. Therefore, the microcomputer 25 sequentially writes and stores the control condition data sent to the built-in RAM 25a in the corresponding control item.

 Next, the operation of the control circuit unit 24 will be described.

The microcomputer 25 checks the input from the terminal block 30 at a predetermined cycle and sends the command to the internal RAM 2.
5a, and similarly communicates with the microcomputer 35 at a predetermined cycle to read from and write to the built-in RAM 25a. Similarly, microcomputer 25
Checks the operation command of the built-in RAM 25a at a predetermined cycle, and if the operation command is stored,
The inverter circuit 1 is controlled based on the frequency command value data of the built-in RAM 25a and the control condition data of each control item, thereby controlling the frequency and voltage of the three-phase induction motor 9.
In such a state, the connector 28 is removed and the setting operation section
Even if 32 is electrically and mechanically separated from the control circuit section 24, the microcomputer 25 continues to control the inverter circuit 1 based on the data in the built-in RAM 25a. Thereafter, when the connector 28 is connected again, the control power supply voltage Vcc is supplied to the power supply monitoring circuit 44 via the connector 28, and the power supply monitoring circuit 44 supplies a reset signal to the microcomputer 33 for a fixed time. And the microcomputer 33 is reset. The microcomputer 33 includes a power supply monitoring circuit.
When the reset by 44 is released, the same operation as described above is performed to clear the internal RAM 33a, and then necessary data is read from the internal RAM 25a or the non-volatile memory 26 and stored in the internal RAM 33a. Return to the state before tripping.

When the "stop" key 35b of the operation-related key matrix circuit 35 in the setting operation unit 32 is pressed in the operation state of the three-phase induction motor 9 as described above, the microcomputer 25 responds accordingly. The microcomputer 25 clears the operation command stored in the built-in RAM 25a, the microcomputer 25 determines that there is no operation command when checking the operation command of the built-in RAM 25a, and stops the control of the inverter circuit 1; The operation of the electric motor 9 is stopped.

When the connector 28 is disconnected in the operation state of the three-phase induction motor 9 as described above, a signal to clear the operation command is issued by pressing the stop key from the external operation device. If it is output, the clear signal is given to the microcomputer 25 via the terminal block 30 and the buffer 31, and the microcomputer 25 clears the operation command of the built-in RAM 25a. As a result, the microcomputer 25 stops controlling the inverter circuit 1, and the operation of the three-phase induction motor 9 is stopped. Thereafter, when an operation command is output by pressing the operation key from the external operating device, the operation command is given to the microcomputer 25 via the terminal block 30 and the buffer 31, and is stored in the built-in RAM 25a. The operation command is stored, and the operation of the three-phase induction motor 9 is started.

According to this embodiment, the following effects can be obtained. That is, in the setting operation unit 32, a driving-related key matrix circuit 35 including frequently used keys 35a to 35e and a key 36 that is not used much except in the initial stage.
Since the control condition data setting key matrix circuit 36 including a to 36p is provided separately on the left and right sides of the front panel of the case 32a, the operation thereof, especially the operation of the operation-related key matrix circuit 35, can be easily performed. Therefore, it is possible to prevent operation errors as much as possible, and it is not necessary to use a setting volume and an A / D converter. Therefore, the size can be reduced and the cost can be reduced. Further, since the setting operation section 32 is detachably connected to the control circuit section 24 by the connector 28, the setting operation section 32 can be freely and electrically separated from the control circuit section 24 freely. In this case, the change control condition data from the setting operation unit 32 is stored in the built-in RAM 25a of the microcomputer 25 in the control circuit unit 24, and the inverter circuit 1 is controlled based on the data in the built-in RAM 25a. There is no hindrance to the operation of the induction motor 9. Further, in this case, the setting operation unit 32
A microcomputer 33 and a power supply monitoring circuit 44 are provided. When the microcomputer 33 is electrically connected to the control circuit unit 24 via the connector 28, the microcomputer 33 is surely reset by the power supply monitoring circuit 44. Does not perform unnecessary operations, and therefore, the setting operation unit 32 can be used for setting commands and data to the control circuit units of other inverter circuits, which is different from the case where a setting operation unit is provided for each control circuit unit. And become extremely cheap. Further, the nonvolatile memory 26 has a large number of control items (for example, 78
After the control items are classified into 20 blocks, the control items related to each block are stored together with the standard control condition data, and the control items to be set are selected by keys 36a to 36j for selecting block numbers. Since the selection is made by using the key 36n (if necessary) and the key 36p, the control item can be easily selected and the control condition data can be easily changed. Moreover, the setting operation unit 32
After changing the control condition data in the microcomputer in the control circuit unit 24.
Since the internal RAM 25a is rewritten and stored, the load on the microcomputer 25 of the control circuit unit 24 is small,
Therefore, the control condition data can be easily changed even during the operation of the three-phase induction motor 9, and particularly, the setting operation section
When the “△” key 35c or the “▽” key 35d of the 32 is pressed, the microcomputer in the control circuit unit 24
Since the control condition data of the internal RAM 25a is raised or lowered by a predetermined ratio within the data setting range, the control condition data is changed while observing the operation state of the three-phase induction motor 9. Can be very convenient.

In the above embodiment, the operation-related key matrix circuit 35 and the control condition data setting key matrix circuit 36 are arranged separately on the left and right in the setting operation section 32. You may make it arrange | position.

In addition, the present invention is not limited to the embodiment described above and shown in the drawings. For example, the present invention can be applied to not only a three-phase induction motor but also all motors driven by an inverter circuit. Needless to say, the present invention can be modified and implemented as appropriate.

[Effect of the Invention] As described above, the inverter control device of the present invention
In the setting operation unit, the operation-related switch means and the control condition data setting switch means are separately arranged, and
The setting operation unit can be separated from the control circuit unit via a connector, and the microcomputer of the setting operation unit is reset according to the voltage level of the control power supply. In addition to being able to achieve low cost, the operation of the setting operation section is easy and erroneous operation can be prevented as much as possible, and the setting operation section can be freely removed from the control circuit section, so that it can be used for other control circuit sections. This has an excellent effect that sharing can be achieved.

[Brief description of the drawings]

FIG. 1 shows an embodiment of the present invention, FIG. 1 is an explanatory view of an electric configuration, FIG. 2 is a top view of a setting operation section, FIG. 3 is a storage control item of a nonvolatile memory, its title display, keys and FIG. In the drawing, 1 is an inverter circuit, 9 is a three-phase induction motor (motor), 21 is an inverter main circuit, 23 is a control power circuit, 24
Is the control circuit, 25 is the microcomputer, 25a is the built-in R
AM (memory), 26 is non-volatile memory (memory), 28 is a connector, 30 is a terminal block, 32 is a setting operation unit, 33 is a microcomputer, 33a is a built-in memory, 35 is an operation-related key matrix circuit (operation-related switches Means), 36 is a control condition data setting key matrix circuit (control condition data setting switch means), and 37 is a display.

Claims (1)

(57) [Claims] 1. An inverter circuit for driving an electric motor, a control circuit unit for controlling the inverter circuit based on operation-related commands and control condition data stored in a memory, and a connector for the control circuit unit via a connector. It has a microcomputer, operation-related switch means, control condition data setting switch means, and a power supply monitoring circuit which are separable and are provided so as to be supplied with control power through the connector, and operate under control of the microcomputer. Operation-related commands and control condition data from the related switch means and the control condition data setting switch means are stored in the memory of the control circuit unit, and the microcomputer is reset by the power supply monitoring circuit according to the voltage level of the control power supply. And a setting operation section as described above. An inverter control apparatus characterized by being configured such that the driving-related switching means a control condition data setting switch means are arranged separately.