JPH06153586A - Inverter - Google Patents

Abstract

PURPOSE:To enhance the economical efficiency and the integration degree of the apparatus by a method wherein a rotational-direction display device for an induction motor is used also as a decimal-point display part for a digital display device indicating the output frequency of an inverter. CONSTITUTION:When a display device (a light-emitting diode) 51 indicating the rotational direction of an induction motor is used also as a decimal-point display part for a digital display device 50 indicating the output frequency of an inverter, a light-emitting diode exclusively used for the rotational direction can be omitted. When the induction motor is being turned forward, a decimal point on the digital display device 50 is lit. When it is being turned reversely, the decimal point blinks at definite intervals. Thereby, a forward rotation and a reverse rotation are displayed, and the operating state of the inverter is displayed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The first invention relates to miniaturization of a display device section of an inverter that drives an induction motor.

The second aspect of the present invention relates to miniaturization of an operating portion of an inverter that drives an induction motor.

The third invention relates to the structure of a memory for storing a program of a microprocessor of an inverter control circuit.

The fourth aspect of the present invention relates to a setting device for an inverter, and relates to a setting device for changing a setting value and displaying the setting value.

The fifth aspect of the present invention relates to an inverter device for variable speed control of a three-phase induction motor.

[0006]

2. Description of the Related Art FIG. 19 shows an example of a conventional digital display device 50 for displaying the output frequency and the rotating direction of a first conventional inverter. Conventionally, to display the drive status of the inverter, a digital display unit of the output frequency,
The display section for the direction of rotation indicating the normal rotation / reverse rotation was separately provided. Therefore, in addition to the light emitting diode 51 that digitally displays the output frequency of the inverter, another light emitting diode 52 must be provided in order to indicate the rotation direction of the induction motor.

FIG. 20 shows an example of a second conventional key input device for an inverter. Conventionally, the inverter can be reset at all times, and an input device 41 dedicated to the reset operation is provided to perform the reset operation. for that reason,
As a device for operating the reset of the inverter, an input key or an input terminal had to be provided in addition to the device 42 for the stop operation.

FIG. 21 relates to a third conventional inverter control circuit. In the figure, 1 is a commercial power source,
2 is a forward converter for converting AC to DC, 3 is a capacitor for smoothing pulsating flow, 4 is an inverse converter for converting DC to AC, 5
Is a motor that is a load, and 6 and 7 are current detectors for detecting two phases of the output current of the inverter, which are converted into a voltage proportional to the current. 8 is a speed setting device for setting the speed of the motor, 9 and 10 are changeover switches, 11 and 12 are pull-up resistors, and the result changeover switches 9 and 10 in combination of these specify the rotation direction of the motor 5. Reference numeral 13 denotes a microprocessor, which creates a switch pattern for the inverse converter 4 by setting the speed setter 8 to the change-over switch 10 or by the setting of the display and setter described later.
To drive.

Reference numeral 14 is a memory for storing a program for driving the microprocessor 13, which uses a ROM. Reference numeral 16 is an amplifier circuit, which amplifies the signal generated by the microprocessor 13 and drives the switching element of the inverse converter 4. A memory 17 is electrically erasable and writable, and holds the contents even without a power source, and holds the contents input from the display and setting device 18. Reference numeral 18 denotes a display and setting device, which communicates with the microprocessor 13 and can set the display operation function of the operating state of the inverter, the forward / reverse rotation of the motor 5, and the speed.

Next, the operation will be described. The microprocessor 13 operates by reading and decoding the contents of the memory 14. By this command, the speed setter 8 to the changeover switch 10 or the display and setter 18
Thus, the inverter is operated by creating a switching pattern for the inverse converter 4 according to the set contents. Therefore, the operation of the inverter is
If the contents written in the memory 14 are all necessary and the function is required, all the programs according to the contents must be written in the memory 14.

This is shown in FIG.
Here, the processing contents corresponding to the three functions, processing A, B,
It is assumed that C is present and one of A, B, and C is selected to operate by the branch instruction. For example, even when only the operation A is selected and used, the processes B and C exist in the program, and the memory capacity corresponding to this is required. Moreover, since all the functions are included, the man-hours at the time of development are also required.

A fourth conventional inverter device will be described. First, the conventional system configuration will be described.
However, since the conventional system configuration diagram has the same outline as the diagram of the embodiment of the present invention, it will be described with reference to FIG. PW
The M inverter 20 receives the switching signal from the drive circuit 40 and drives the induction motor 30. CPU
60 is a PWM signal calculation unit 61, an external terminal processing unit 62,
The set value processing unit 63 is divided into three parts. PW in it
The M signal calculation unit 61 receives the operation information of the inverter from the external terminal processing unit 62 and the set value processing unit 63, and generates the PWM signal to be sent to the drive circuit 40. Also,
The external terminal processing unit 62 determines the ON / OFF state of the external terminal 70 for inputting a command such as forward rotation or reverse rotation, and sends the determination signal to the PWM signal calculation unit 61. The set value processing unit 63 includes a key input discriminating means 65 for discriminating the on / off state of the set value input key 80 including several input keys.
It is composed of a time measuring means 64 for measuring the time when the input key is on and a set value calculating means 66 for calculating a set value based on the information, and the calculated result is the PWM signal calculating section 61. And is output to the set value display section 90.

In the prior art, when changing the set value such as frequency, the set value processing unit 63 holds the set value in the minimum unit of the set value while pressing the up and down keys for moving the set value. Was going up and down. This situation will be briefly described with reference to the flowchart of FIG. The time measuring means 64 in FIG. 9 has two timers, and these two timers are activated when the setting key is pressed. The timer 1 in FIG. 23 counts the total time when the up and down keys are pressed, and the timer 2 shows the time interval for actually changing the set value. That is, in this example, when the total time (timer 1) during which the key is pressed is within 2S, 0.
Every 5S, 0.1 if timer 1 exceeds 2S
The value of the set value is increased or decreased for each S. That 0.5S,
The timer 2 counts the time of 0.1S. That is, the changing speed of the set value is changed by the timer 2.

That is, the set value changes slowly (every 0.5S) for 2 seconds after the up / down key is pressed, and changes rapidly (every 0.1S) after 2 seconds. The timers 1 and 2 are cleared to 0 when no key is input as shown in the figure. The above is an example of the conventional technique. In this case, in order to clear the set value to 0, for example, the up and down keys must be continuously pressed until the set value becomes 0. Furthermore, the set value and its display are not always integer values when the hand is released from the up and down keys. In another conventional type, the number of input keys is increased and the set value is directly substituted.

FIG. 24 is a schematic flowchart of software for determining a fourth conventional V / F pattern, which is a part of software of a microprocessor for controlling an inverter. The configuration of the inverter is the same as the configuration diagram showing the present invention shown in FIG. 12, in which 1 is a three-phase commercial power supply, 21 is a three-phase full-wave rectifier, 3 is a smoothing capacitor, and 4 is a direct current to an alternating current. An inverse converter for converting into a three-phase induction motor, 5 a three-phase induction motor, 22 an inverse converter driving base amplifier, 23 a control microprocessor, 24 a motor current detector,
Reference numeral 25 is a speed setting signal, and 10 is the entire inverter device.

Next, the operation will be described. In FIG. 24, the process until the output voltage is determined will be sequentially described. (1) Read the frequency to be output (2a), (2) Read the coefficients a and b (2b), usually a and b are determined by the characteristics of the motor, but the values are steady operation (low speed) at each frequency.
The optimum value is set. (3) Output voltage v from f, a, and b
Is calculated and output (2c). (2h) This processing is incorporated in the control processing routine of the microprocessor to calculate and output the output voltage for each cycle.

[0017]

Since the first conventional inverter device is configured as described above, it is necessary to provide a display device dedicated to the rotation direction, which is uneconomical.

Since the second conventional inverter device is constructed as described above, it requires an input device and is uneconomical.

Since the third conventional inverter device is constructed as described above, all the functions of the inverter have to be programmed in the memory in advance as described above. Also, when the functions cannot be stored in one memory, the memory was exchanged as needed, but in this case, it is necessary to remove the cover of the inverter and replace the memory, which can be performed by a general user. It wasn't something.

In the fourth conventional inverter device, when changing the set value of the inverter, the set value is changed in the minimum unit of the set value. To set the set value to 0, the set value is set to 0. It was necessary to keep pressing the up and down keys until. Further, in order to set the set value to an integer value, it is necessary to remove the hand from the up and down keys and then perform the fine adjustment again, which causes a problem that it takes time and effort to set the value. Further, there is a problem that the type having a large number of setting keys becomes expensive in terms of cost and becomes large in terms of space.

Since the fifth conventional output voltage processing is configured as described above, when the motor generated torque is insufficient with respect to the load torque including the acceleration torque at the time of acceleration, the motor current increases more than necessary. was there. Therefore, the output capacity of the inverter and the motor capacity can be increased.
In order to reduce the acceleration torque, it is necessary to set a long acceleration time, etc., and there is a problem that the vehicle cannot be operated efficiently.

The first aspect of the present invention has been made to solve the above-mentioned problems, and a conventional light emitting diode for determining the rotational direction of an induction motor is used as a light emitting diode for displaying an output frequency. By using in combination with
The purpose is to reduce the number of light emitting diodes.

The second invention is made to solve the above-mentioned problems, and resetting of the inverter is not necessary except when there is an abnormality, and when the abnormality occurs, the inverter is already stopped. Focusing on the fact that no stop operation is required, the purpose is to reduce the number of input devices by using the reset input device and the stop input device together by using the stop input device in normal times as the reset input device only when there is an abnormality. To do.

The third invention is made to solve the above-mentioned problems, and can be carried out without removing the cover or the like of the inverter.

The fourth invention is made to solve the above-mentioned problems, and in order to reduce the cost as much as possible and to make the apparatus itself as small as possible, the number of setting keys is set to the minimum necessary, and moreover, the keys are set. It is an object of the present invention to provide an inverter setting device that reduces the troublesome operation.

A fifth aspect of the present invention has been made to solve the above problems, and an object thereof is to make it possible to set the acceleration time to be short and to reduce the capacity of the inverter and the motor.

[0027]

In the inverter device according to the first aspect of the present invention, paying attention to the decimal point display that is always present in the digital display of the inverter output frequency, the forward / reverse rotation of the induction motor can be identified by the state of the decimal point. It is configured to.

The inverter device according to the second aspect of the present invention is used together with a stop input device, and the input device is used as a stop / reset input device. A reset function is assigned when the inverter is abnormal, and a stop function is provided in other cases. As for the allocation, one input device is configured to be utilized to the maximum by assigning two functions.

The inverter device according to the third invention is
The memory is housed in a card-shaped package, and the inverter is provided with a mechanism for connecting with a connector.

The inverter device according to the fourth invention is
Key input discriminating means for discriminating whether or not the up / down input key is turned on, time measuring means for measuring time when the input key is turned on, on / off state of the input key and on time of the input key And a set value calculating means for calculating the set value.

The inverter device according to the fifth invention is
V / based on output voltage for a specific time during and after acceleration
The F pattern is provided with control that can be varied at any ratio.

[0032]

In the first aspect of the invention, when the induction motor is in the normal rotation, the decimal point of the digital display of the output frequency lights up,
If the decimal point flashes at regular intervals during reverse rotation,
The operating status of the inverter is expressed.

In the second invention, if the inverter is in an abnormal state due to an error, the inverter is reset by turning on the stop / reset input device,
If it is in a normal state, turning the stop / reset input device ON causes the inverter to stop.

In the inverter device according to the third aspect of the present invention, the memory is packaged in the form of a card and connected by a connector, and by placing the memory in a place where it can be detached from the outside of the inverter, the cover of the inverter is not removed. , Memory can be replaced.

In the inverter device according to the fourth aspect of the present invention, the key input state in setting the operating frequency of the inverter is determined by the key input determining means, and the on time of the key can be measured by the time measuring means. . The set value can be calculated by the set value calculating means based on the result.

In the inverter device according to the fifth aspect of the present invention, the means for increasing the output voltage by the ratio increases the motor generated torque substantially constant over the entire output frequency range.

[0037]

【Example】

Example 1. FIG. 1 shows a display device 50 according to an embodiment of the first invention. The overall configuration of the control device of this embodiment is shown in FIG. FIG. 1 shows a display example of the digital display device 50 in the case where the output frequency of the inverter is 62.3 Hz. The decimal point in the figure is lit when the rotation is forward, and blinks when the rotation is in reverse, It plays a role of normal / reverse rotation display. Further, in FIG. 2, 70 is an external terminal, 41 is a key input device, and the output frequency of the inverter and the information of the rotation direction inputted from these are transmitted to the CPU 100 as the information in the CPU. In the CPU, an input signal from the outside is first decoded by the input device processing unit 101, converted into a form that can be calculated, and then the PWM signal calculation unit 1
Sent to 02. The PWM signal calculation unit 102 generates a switching signal which is the basis of the PWM waveform from the received data, transmits it to the inverter 110 through the drive circuit 40, and controls it. At this time, the PWM signal calculation unit 1
02 also transmits the information of the PWM waveform to the display device processing unit 103 at the same time. The display device processing unit 103 converts the information on the output frequency and the rotation direction into display data and outputs the data to the digital display device 50. That is, along with the display of the output frequency in FIG. 1, the information on the rotation direction is simultaneously output to the display device by lighting / flashing the decimal point.

FIG. 3 is a flow chart showing the display procedure of the rotation direction when the blinking of the decimal point at the time of reverse rotation is set at intervals of 1 second. First, the rotation direction of the induction motor is determined, and if it is not in reverse rotation, the output frequency is displayed with a decimal point as it is. On the other hand, if it is in reverse rotation, the timer showing the elapsed time for timing the blinking of the decimal point is incremented and compared with the set time. If the timer is 1 second or more and less than 2 seconds, the decimal point is turned on. , If not, output as off. The timer clears when it reaches 2 seconds or more, so the decimal point is turned on and off alternately every second during reverse rotation.

Example 2. FIG. 4 shows the overall configuration of the control device according to an embodiment of the second invention. In FIG. 4, 70 is an external terminal, and 41 is a key input device, and the information input from this is transmitted to the CPU 100. Inside the CPU, an input signal from the outside is first decoded by the input device processing unit 101. In the present invention, the input signal from the stop / reset input device is read as a reset or stop signal depending on the state of the inverter, and if it is a reset signal, it is transmitted to the reset execution unit 104 to be an inverter reset. If the signal is a stop signal, it is converted into a form that can be calculated by the input device processing unit 101 as with the frequency input, and then sent to the PWM signal calculation unit 102. The PWM signal calculation unit 102 generates a switching signal which is the basis of the PWM wave number form from the received data, and the drive circuit 4
It is transmitted to the inverter 110 through 0 to perform control. At this time, the PWM signal calculation unit 102 simultaneously transmits the information of the PWM waveform to the display device processing unit 103. The display device processing unit 103 converts the information on the output frequency and the rotation direction into display data and outputs the data to the digital display device 50.

FIG. 5 is a flowchart showing the procedure of processing in the input device processing section related to the stop / reset input. First, it is determined whether or not there is an input from the stop / reset input device. Next, if there is an input, the current state of the inverter is determined, and if an error is occurring, it is regarded as a stop / reset input, and if no error is occurring, it is regarded as a stop input. Thus, the signal from the stop / reset input device will be fully dependent on the state of the inverter.
Identified by the street signal.

Example 3. An embodiment of the third invention will be described below with reference to the drawings. In FIG. 6, reference numeral 120 represents the entire inverter. 121 is an inverter cover, 122
Is a chassis of the inverter, 123 is a display panel for displaying the output frequency of the inverter, 124 is a connector for connecting the setting device of the inverter, 200 is a memory card, and the program of the microprocessor in the inverter is built in this. ing.

FIG. 7 is a diagram showing the circuit configuration of the inverter according to the present invention. The difference from the conventional example is that a connector 15 is arranged between the microprocessor 13 and the memory 14. By arranging this connector 15 and making the memory 14 into a card, the memory can be replaced without removing the external cover as shown in FIG.

Example 4. Further, as in the case of another invention, even when the number of memory cards corresponding to the functions increases, the memory can be easily replaced without removing the cover of the inverter. In addition, the commercial power source 1 to the memory 14, the amplifier circuit 16 to
The contents and operation of the display and setting device 18 are the same as those of the conventional example, and the description thereof will be omitted.

Next, the operation will be described. There are three contents regarding the function and operation of the inverter, and for these, there are programs of process A, process B, and process C, respectively. In addition to this, there is a required common process regardless of which function is performed. For example, a combination of the common process and the process A fulfills one function. The same applies to the other cases as well, and a memory card storing each of these is prepared. Therefore, for the required function, select a memory card, install an inverter, and operate it.

By this operation, one memory including all the functions of A, B, and C was conventionally prepared, so that the memory capacity was correspondingly increased. On the other hand, since the program that does not work is not included,
The memory capacity of unnecessary parts is small.

Example 5. An embodiment of the fourth invention will be described below with reference to FIGS. FIG. 9 is a diagram showing the configuration of this embodiment. However, since the configuration is the same as the conventional technique, the description thereof will be omitted. The present invention relates to a set value processing unit 63 inside a CPU, and an outline of the processing is shown in FIG.
0, shown in FIG. The processing of FIG. 10 corresponds to claim 4, and the processing of FIG. 11 corresponds to another embodiment.

First, the operation of FIG. 10 (claim 4) will be described. When both the up and down keys for moving the set value up and down in the set value input section are pressed at the same time, the timer 1 for counting the time during which the key is pressed is activated. This timer 1 keeps counting while pressing the up and down keys, and sets the set value to 0 when the timer 1 exceeds several seconds (1 s in FIG. 10). However, if both of the up and down keys are not pressed at the same time, or if both of the up and down keys are pressed at the same time and the timer that counts time does not exceed 1 s, the operation of setting the set value to 0 is not possible. not going.

Example 6. Next, regarding another embodiment, FIG.
Will be explained. The present invention relates to an operation when a certain setting item such as a set frequency is changed by pressing the up and down keys and the same key is continuously pressed for several seconds or longer. That is, the change width of the set value to be changed is changed according to the time during which the key is pressed. That is, in this example, the change width is 0.1 during the time of pressing the key for 1 to 5 s, 1 for 5 to 8 s, and 10 for exceeding 8 s. However, even if it is between 5 and 8 s, if the number after the decimal point is not 0, 0.
The set value is changed one by one, and the change width is set to 1 when the number after the decimal point becomes 0. This also applies to the case of 8 s or more.

However, all of these times are managed by the timer 1, and the setting value is actually increased or decreased when the timer 2 exceeds 0.5 s, as in the prior art. However, the change speed of the set value is not changed unlike the conventional example. Thus, the set value can be set quickly, and the set value can be an integer when the input key is released. Further, in another embodiment, similarly, when the setting up / down key is pressed for a predetermined time or more and then the hand is released, for example, even if the set value at that time is 19.8, the setting is performed up to 20.0. I try to increase the value and stop at an integer value. If you want to set the set value finely, such as 20.3, press the key until the set value is displayed at 20.0, then
Fine adjustment can be performed by releasing the input key and pressing the key again. The above is the outline of the present invention, but the value (1s, 5s, 8s) of the timer 1 described above can be changed by software, and in that case, it may be changed according to the purpose of use.

Example 7. An embodiment of the fifth invention will be described below by taking software processing using a microprocessor as an example. FIG. 12 is as described in the related art. The process until the output voltage is determined in FIG. 13 will be described step by step. (1) Read the output frequency (2a),
(2) Read coefficients a and b (2a), (3) f, a,
The output voltage v is calculated from b (2c), (4) Next, it is determined whether or not the vehicle is currently accelerating (2d), and if it is accelerating (5), the output voltage calculated in the previous stage is multiplied by the ratio α (2f). 2g),
If that value is used as the output voltage (2h), and (6) if acceleration is not in progress, it is determined whether or not it is within a preset time after completion of the current acceleration, and if it is within the time, the same processing as (5) is performed. (7)
If it is out of time, the output voltage v is output as it is. In this case, the output voltage becomes as shown in FIG. 14 with respect to time.

Example 8. The process until the output voltage is determined in FIG. 15 will be described step by step. (1) The conditions (2a to 2e) up to the condition of increasing the output voltage are the same as in the first embodiment. (2) Next, the width β for increasing the output voltage is read and β is added to the value calculated in 2c to obtain the output voltage (4a, 4b). In this case, the output voltage becomes as shown in FIG. 16 with respect to time.

Example 9. The process until the output voltage is determined in FIG. 17 will be described step by step. (1) The same as in the first embodiment until the reference output voltage is calculated (2a to 2c),
(2) If it is during acceleration, the output voltage is calculated again as in the first and second embodiments, and the output voltage is output (2f, 2g, or 4a, 4b). (3) The motor current is preliminarily measured after the acceleration is completed. It is judged whether it is larger or smaller than the set value IS (6a, 6
b), if large, recalculate the output voltage as in (2),
Output to output voltage. (4) When it becomes smaller than IS, the output voltage returns to the reference output voltage. In this case, the output voltage becomes as shown in FIG. 7 with respect to time.

In each of the seventh, eighth and ninth embodiments, the output voltage can be increased and the motor-generated torque can be increased during acceleration and during the time when the motor speed does not follow the frequency of the inverter after acceleration.

In the above description, the output voltage of the inverter has been described. However, in an inverter capable of varying the excitation voltage component in the voltage applied to the motor, it is more effective to raise the excitation voltage component. Needless to say.

[0055]

As described above, according to the first aspect of the invention, since the display of the rotation direction of the induction motor can be used also as the decimal point display portion of the digital display device which shows the output frequency of the inverter, it is dedicated to the rotation direction. By omitting the display device, economic efficiency and degree of integration can be improved.

As described above, the second aspect of the present invention limits the ownership of the reset function of the inverter only when the inverter is abnormal, and switches the stop and reset functions depending on the state of the inverter, thereby stopping and inputting the reset input device. Can be integrated into one input device, so that by omitting the redundant input device, it is possible to improve economy and downsize.

As described above, according to the third invention,
Since the program memory that defines the operation of the inverter can be replaced without removing the cover, it is not necessary to remove the cover each time the function is changed, and it can be performed by a general user. Has features.
In addition, since the programs for functions can be divided and stored in the memory card, you only have to install the programs for the necessary parts, and you do not have to have the unnecessary program parts. Have.

As described above, according to the fourth aspect of the invention, when it is desired to change the set value to 0, both the up and down keys should be pressed simultaneously for 1 s or more, and when the set value should be changed, the up and down keys should be pressed. Since the range of change of the set value is changed depending on the duration of time, the set value can be changed quickly, and when the up and down keys are released, the set value is displayed as an integer value. As a result, the number of input keys for setting values can be reduced as much as possible, and the cost and space can be reduced. On the contrary, it is possible to reduce the troublesome key operation due to the small number of input keys.

As described above, according to the fifth invention, the acceleration torque can be further increased by increasing the output voltage only while the motor is accelerating.
This has the effect of shortening the acceleration time and reducing the inverter capacity and motor capacity.

[Brief description of drawings]

FIG. 1 is a front view of a digital display device showing an embodiment of the first invention.

FIG. 2 is a block diagram showing a control device for an inverter of the first invention.

FIG. 3 is a flowchart showing an embodiment of the first invention.

FIG. 4 is a block diagram showing a control device for an inverter of the second invention.

FIG. 5 is a flowchart showing an embodiment of the second invention.

FIG. 6 is a diagram showing the structure of an inverter device according to an embodiment of the third invention.

FIG. 7 is a diagram showing a circuit configuration of an embodiment of the third invention.

FIG. 8 is a diagram showing a flow of a program according to an embodiment of the third invention.

FIG. 9 is a configuration diagram according to an embodiment of the fourth invention.

FIG. 10 is a flow chart showing an outline of the operation of the fourth invention.

FIG. 11 is a flow chart showing an outline of the operation of another embodiment of the fourth invention.

FIG. 12 is a schematic configuration diagram of an inverter according to an embodiment of the fifth invention.

FIG. 13 is a flowchart showing an operation according to an embodiment of the fifth invention.

FIG. 14 is a diagram showing a graph showing an operation according to an embodiment of the fifth invention.

FIG. 15 is a flowchart showing an operation according to another embodiment of the fifth invention.

FIG. 16 is a diagram showing a graph representing an operation according to another embodiment of the fifth invention.

FIG. 17 is a flowchart showing an operation according to another embodiment of the fifth invention.

FIG. 18 is a diagram showing a graph showing the operation according to another embodiment of the fifth invention.

FIG. 19 is a diagram showing a surface of a conventional digital display device according to a first embodiment.

FIG. 20 is a diagram showing the surface of a conventional key input device for an inverter according to a second embodiment.

FIG. 21 is a diagram showing a circuit configuration of an inverter device of a third conventional example.

FIG. 22 is a diagram showing a program flow of an inverter device of a third conventional example.

FIG. 23 is a flowchart showing the operation of the fourth conventional example.

FIG. 24 is a flowchart showing the operation of the fifth conventional example.

[Explanation of symbols]

 1 Commercial Power Supply 2 Forward Converter 3 Smoothing Capacitor 4 Inverting Converter 5 Motor 6 Current Detector 7 Current Detector 8 Speed Setting Device 9 Changeover Switch 10 Changeover Switch 11 Pullup Resistor 12 Pullup Resistor 13 Microprocessor 14 Memory 15 Connector 16 Amplifier circuit 17 Memory 18 Display and setting device 20 PWM inverter 21 Three-phase full-wave rectifier 22 Inverter drive base amplifier 30 Induction motor 40 Drive circuit 41 Input device 42 Stopping operation device 50 Digital display device 51 Light emitting diode 52 Light emitting diode 60 CPU 61 PWM signal arithmetic unit 62 external terminal processing unit 63 set value processing unit 64 time measuring means 65 key input determination means 66 set value calculating means 70 external terminal 80 set value input key 90 set value display section 100 CPU 101 input device Processing unit 102 PWM signal calculation unit 103 Display device processing unit 104 Reset execution unit 110 Inverter 120 Entire inverter 121 Cover 122 Chassis 123 Display panel 124 Connector 200 Memory card

Front page continuation (72) Inventor Masayasu Hasegawa 5107-5, Kamio, Higashiodasone, Kita-ku, Nagoya City Mitsubishi Electric Engineering Co., Ltd.Nagoya Works (72) Hiroki Ichikawa, 5-chome, Higashiodasone-cho, Kita-ku, Nagoya 1071 Mitsubishi Electric Engineering Co., Ltd.Nagoya Works (72) Inventor Kohiro Arisato 5107, Kami-ku, Kita-ku, Nagoya-shi

Claims (5)

[Claims] 1. An inverter device for displaying the rotation direction of an induction motor, wherein the display device is also used as a decimal point display portion of a digital display device for indicating the output frequency of the inverter. 2. A reset input device for resetting an inverter, wherein the ownership of the reset function is limited to when the inverter is abnormal, and the input device is also used as a stop input device of the inverter. 3. An inverter device for converting a commercial power source into an alternating current of arbitrary frequency and voltage, and a microprocessor for controlling on / off of each switching element,
An inverter device comprising a memory for storing the program, the memory being housed in a compact card-like shape, and the memory being removable without removing a cover of the inverter. 4. An up / down key of the inverter, which has two key switches for increasing / decreasing a set value such as a frequency, and presses one of the keys to increase the numerical value and the other key to decrease the numerical value. An inverter device that has the function of clearing the set value to 0 when both the up and down keys are pressed for a predetermined time or longer and the function of displaying the set value. 5. In an inverter device for driving a three-phase induction motor, a function for judging whether acceleration or low speed is in progress, a timer function for setting a specific time after acceleration, and a reference V / F. It has a control circuit with a control function that can arbitrarily change the output voltage with respect to the pattern (output voltage characteristic with respect to the output frequency), and the output voltage is used as a reference V during the acceleration and during a preset time after the acceleration. An inverter device characterized in that it can be varied at an arbitrary ratio with respect to the voltage generated by the / F pattern.