JPH118997A - Motor with built-in controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform the maintenance of an inverter, without stopping the line for a long time. SOLUTION: A first power supply system which supplies a motor 20 with power through an inverter 50A from a commercial power source 10, and a second power supply system which directly supplies the motor 20 with power from the commercial power source 10 are prepared in advance, and in the inverter 50A, the fault-judging means 56 judges whether or not the fault has occurred, when the first power supply system is performing the power supply. In the case that the judgment result of the fault occurrence is obtained, the power supply system to the motor 20 is switched from the first power supply system to the second power supply system, by operating switches 57a and 57b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor with a built-in control device, and more particularly, to a motor with a built-in control device that performs variable speed operation using an inverter or the like, which is a variable speed control device.

[0002]

2. Description of the Related Art FIG. 10 is a block diagram showing a conventional motor with a built-in control device. The electric motor with a built-in control device shown in FIG. 10 includes a commercial power supply 10, an electric motor 20, and an inverter 80 as a control device. Inverter 8
Numeral 0 is connected to the commercial power supply 10 via a power supply line 11 and connected to the electric motor 20 via a power supply line 12. The manipulated variables provided for the inverter 80 to drive the motor 20 at variable speed are voltage, current, and frequency. The inverter 80 includes a converter unit 81 for temporarily converting the AC commercial power supply 10 to a direct current,
Inverter unit 8 that converts the direct current into a variable frequency alternating current
2, and a control circuit 83 for controlling the inside of the apparatus.

Next, the operation will be described. In the electric motor with a built-in control device shown in FIG. 10, when the inverter 80 receives the supply of the alternating current from the commercial power supply 10, it is once converted into the direct current by the converter unit 81 and then returned to the alternating current again by the subsequent inverter unit 82 at the subsequent stage. The AC power is supplied to the electric motor 20. The DC-AC conversion in the inverter unit 82 is performed under the control of the control circuit 83.

Next, a specific example of the structure of the electric motor 20 will be described. FIG. 11 is a side sectional view showing a typical structure of a conventional fully enclosed fan-shaped electric motor. In FIG.
Reference numeral 21 denotes a stator core, reference numeral 22 denotes a coil wound around the stator core, reference numeral 23 denotes a frame in which the stator core 21 is fitted on the inner periphery, and reference numeral 24 denotes a driving screw for fixing the stator core 21 driven into the frame 23. 25 is a rotor, 26 is a bracket for supporting the rotor 25, 27 is a fan coupled to the rotor 25, and 28 is a cover for protecting the fan 27. The cover 28 cools the outer periphery of the frame 23 by wind from the fan 27 rotating together with the rotor shaft during operation of the electric motor 20.

The electric motor 20 has a mechanism for generating a torque by a rotating magnetic field generated by applying a current to the coil 22. The coil 22 is a heating element. The temperature rise limit of the coil 22 is determined by the heat-resistant insulation class. For example, in the case of general E-class insulation of a fully-closed external fan type small motor of about 400 W driven by a three-phase power supply, the temperature rise limit is 75 ° C., and the ambient temperature during operation is 40 ° C. Is 11
The temperature is as high as 5 ° C. Accordingly, as an example, the temperature may be 60 to 70 ° C. in the temperature inside the motor or 80 to 90 ° C. on the surface of the motor around the stator core.

When the speed of the electric motor 20 is variable, FIG.
As shown in (1), the motor 20 can be operated by separately installing the inverter 80 and the electric motor 20 and connecting them via the power supply lines 11 and 12, respectively.
If the inverter 80 is installed in the control panel, the installation environment is improved. Therefore, an open type in which the air around the control board is ventilated to the outside air is generally used.

[0007] On the other hand, the electric motor 20 is used for oil, dust, moisture, or the like in the vicinity of a machine tool even outdoors or indoors exposed to the wind and rain.
Since the installation environment, such as floor vibration, is installed in a place where it cannot be said to be good, the shape of the electric motor 20 is often a fully enclosed fan shape. Therefore, the control panel installed in the factory becomes a closed type local operation panel, and the inverter installed in the factory site uses a closed type instead of a general open type in which inside air and outside air flow. . In the case of a sealed inverter, since heat radiation is poor, it is necessary to cool the cooling fins with a cooling fan or increase the size of the cooling fins to improve the cooling performance.

When the inverter 80 is built in the electric motor 20, the structure shown in FIG. 12 is employed. FIG.
12 is different from FIG. 12 in that an inverter 80 in which a power circuit and a control circuit are integrated is provided in a room where the fan 27 is arranged. This inverter 80 is attached to the heat sink 30 attached to the frame 23.

[0009]

Since the conventional motor is configured as described above, when the inverter 80 fails, the operation of the motor 20 may be interrupted or stopped in a free run. It has been considered that the motor 20 which has been stopped is switched from the inverter power supply to the commercial power supply 10 and restarted. However, when the motor 20 is stopped during machining of an unmanned operation line, a machine tool, or the like, in a device that suffers a large loss due to the stoppage, the only option is to provide a backup control panel or the like. There was a problem of becoming.

When the inverter 80 is out of order, the motor 20 is switched from the inverter power supply to the commercial power supply 10 to restart the operation, and after the abnormality of the inverter 80 is released, the commercial power supply 10 is switched back to the inverter power supply. Therefore, there is a problem that it is necessary to temporarily stop the work on the transfer line, the processing line, and the like.
In the case of a failure, switching the motor 20 from the inverter power supply to the commercial power supply 10 and restarting the operation has a problem that only a constant speed operation can be performed.

Further, in the case of the cooling means directly connected to the rotating shaft of the electric motor 20, when the rotation speed of the motor becomes slow, the amount of cooling air becomes small, so that the cooling effect is also reduced.

The electric motor 2 having the inverter 80 built therein
0, when the motor section and the inverter section are cooled by a common cooling means, there is a problem that the size of the entire apparatus becomes large, and a problem that the cooling performance of the motor section is deteriorated when the size of the inverter section becomes large. there were.

SUMMARY OF THE INVENTION It is a first object of the present invention to provide a motor with a built-in control device capable of performing maintenance of the control device without stopping the line for a long time in order to solve the above-described problems of the conventional example. And

A second object of the present invention is to provide a motor with a built-in control device capable of constructing a system suitable for unmanned operation.

It is a third object of the present invention to provide a motor with a built-in control device capable of fully utilizing the capability of the motor even when the control device fails.

It is a fourth object of the present invention to provide a motor with a built-in control device capable of operating at a constant torque even at a low speed regardless of the rotational speed of the motor.

It is a fifth object of the present invention to provide a motor with a built-in control device which can be downsized as a motor even if the control device is built in the motor.

A sixth object of the present invention is to provide a motor with a built-in control device capable of maintaining good cooling efficiency even if the control device is built in the motor.

As an approximation technique, for example, Japanese Unexamined Patent Publication No.
There are JP-A-1-161992 and JP-A-63-80797. The above-mentioned JP-A-61-161992 and JP-A-63-80797 each have a structure in which a control device is built in an electric motor, and are aimed at preventing a normal system trip.

[0020]

Means for Solving the Problems The above-mentioned problems are solved,
According to an embodiment of the present invention, there is provided an inverter having a power unit circuit and a control circuit in an induction-type motor that generates mechanical power by receiving electric power supplied from a commercial power supply. In a motor with a built-in control device, a first power supply system for supplying power to the motor from the commercial power supply via the inverter and a power supply system for the motor are configured to supply power from the commercial power supply directly to the motor. Switching means for switching to one of a second power supply system to be supplied, and failure determination means for determining whether or not a failure has occurred in the inverter when power is being supplied by the first power supply system. The switching unit switches the power supply system for the electric motor to the first state when the failure determination unit obtains a determination result that a failure has occurred. And switches from the force feed system to the second power supply system.

According to the present invention, it is determined whether or not a failure has occurred in the inverter while the power is being supplied from the commercial power supply to the motor via the inverter by the first power supply system. When the determination result that a failure has occurred is obtained, the power supply system for the motor is switched from the first power supply system to the second power supply system that supplies power from the commercial power supply directly to the motor. The power supply to the inverter is not interrupted, and the motor can be continuously operated, whereby the inverter can be maintained without stopping the line for a long time.

In the motor with a built-in control device according to the next invention, an inverter having a power section circuit and a control circuit is built in an induction type motor that generates mechanical power by receiving electric power supplied from a commercial power supply. An output stop means for stopping an output of the inverter when an abnormality occurs in the inverter while supplying electric power from the commercial power supply to the motor via the inverter in the motor with a built-in control device; and Automatic recovery means for recovering the output of the inverter when the abnormality of the inverter is released while the output of the inverter is stopped by the stopping means.

According to the present invention, when an abnormality occurs in the inverter while power is being supplied from the commercial power supply to the motor via the inverter, the output of the inverter is stopped, and thereafter, the abnormality of the inverter is released. If
Since the output of the inverter is restored, the power supply by the inverter can be automatically restored,
This makes it possible to construct a system suitable for unmanned driving.

An electric motor with a built-in control device according to the next invention is built in an induction type electric motor that generates mechanical power by receiving electric power supplied from a commercial power supply, and has an inverter circuit having a power circuit and a control circuit. And a control device built-in type motor having a backup inverter built in the motor and having a power circuit and a control circuit, wherein a power supply system for the motor is formed by converting the inverter from the commercial power supply. Switching means for switching to one of a first power supply system for supplying electric power to the electric motor via the inverter and a second electric power supply system for supplying electric power from the commercial power supply to the electric motor via the backup inverter; When a failure occurs in the inverter while power is being supplied by the first power supply system, a power supply system for the motor is provided. Selecting means for selecting the backup inverter, and wherein the switching means switches a power supply system for the electric motor from the first power supply system when the backup inverter is selected by the selection means. It is characterized by switching to the second power supply system.

According to the present invention, when a failure occurs in the inverter while power is being supplied from the commercial power supply to the motor via the inverter, the power supply system for the motor is provided. Since the backup inverter is selected, the power supply system for the motor is switched from the first power supply system to the second power supply system for supplying power from the commercial power supply to the motor via the backup inverter. The power supply to the motor is not interrupted, and the motor can be continuously operated, whereby it is possible to achieve the full potential of the motor even when the inverter fails.

A motor with a built-in control device according to the next invention is characterized in that a cooling means is provided in the motor, and the cooling means has a structure not directly connected to a rotating shaft of the motor.

According to the present invention, since the cooling means is not directly connected to the rotating shaft of the motor in the motor,
The rotation speed of the motor does not decrease and the amount of cooling air does not decrease. This facilitates constant-torque operation even during low-speed operation regardless of the rotation speed of the motor.

A motor with a built-in control device according to the next invention is characterized in that the motor is a fully-closed self-cooling type and cools only the inverter.

According to the present invention, only the inverter is cooled in the fully-closed self-cooling type electric motor, so that the motor and the inverter are not cooled by a common cooling means. That is, it is possible to reduce the size of the motor with a built-in control device.

In the motor with a built-in control device according to the next invention, the motor is fixed by shrink-fitting a stator core to a frame in which a bracket for supporting a bearing on the non-load side and a frame are integrally formed of a metal material such as aluminum. The cooling unit is mounted on the rotating shaft on the non-load side, and the power unit circuit is mounted between the bracket supporting the bearing on the non-load side and the cooling unit, and the control circuit is provided on the frame. It is characterized by being installed on the side.

According to the present invention, in the inverter,
Since the power circuit is mounted between the bracket supporting the bearing on the non-load side and the cooling means, and the control circuit is installed on the side of the frame, the motor and the inverter are not cooled by the common cooling means. The cooling efficiency of the electric motor is improved, and the cooling effect can be improved.

[0032]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a motor with a built-in control device according to the present invention will be described below in detail with reference to the accompanying drawings.

(Embodiment 1) First, the configuration will be described. FIG. 1 is a block diagram showing a motor with a built-in control device according to Embodiment 1 of the present invention. The motor with a built-in control device shown in FIG. 1 has a power input structure from a commercial power supply 10, a motor 20, and an inverter 50 as a control device.
A. The commercial power supply 10 and the electric motor 20 are the same as those of the related art, and are connected to the inverter 50A via the power supply lines 11 and 12. The manipulated variables provided for the inverter 50A to drive the electric motor 20 at variable speed are voltage, current, and frequency.

The inverter 50A has an AC commercial power supply 10
Unit 51, which once converts DC to DC, inverter unit 52, which converts DC to AC of variable frequency, arithmetic means 53 for controlling inverter 52, and inverter 5
Failure determining means 56 for determining the failure of 0A itself, and automatically switching between the inverter power supply (supply via the inverter) and the commercial power supply (supplied directly from the commercial power supply 10) based on the determination information of the failure determination means 56. Switch 5
7a and 57b. Note that each of the arithmetic means 53 and the failure determination means 56 may be processed by an MPU, or may be configured by a control circuit or an integrated control circuit, respectively.

Next, the operation will be described. FIG. 2 is a flowchart illustrating the operation according to the first embodiment. In the electric motor with a built-in control device shown in FIG. 1, the inverter 50A converts the AC power supplied from the commercial power supply 10 into the DC power once by the converter unit 51, and returns to the AC power again by the inverter unit 52 at the subsequent stage. Supplies the AC power to the motor 20. At this time, the failure judging means 56 monitors the overcurrent interruption of the inverter 50A and the failure of the main circuit capacitor and the like (step S21). Unless any failure is detected (step S22), the commercial power supply 10 and the converter unit 51 are monitored. Maintain the connection relationship with.

During the monitoring described above, if the failure determination means 56 determines that there is a failure (step S22), the failure determination means 56 switches from the inverter power supply to the commercial power supply by the switches 57a and 57b. (Step S23). That is, the output of the commercial power supply 10 is switched from the converter unit 51 to the switch 57b by the switch 57a.
The switch 57b switches the input of the electric motor 20 from the inverter 52 to the switch 57a. Thereby, through the inverter 50A,
The commercial power supply 10 and the electric motor 20 are directly connected.

As described above, according to the first embodiment, when the inverter 50A breaks down, commercial power can be directly supplied to the motor simply by switching the power supply from the inverter power supply to the commercial power supply. Thus, the power supply to the electric motor 20 is not interrupted, and the electric motor 20 can be continuously operated. Therefore, it is possible to maintain the control device without stopping the line for a long time.

The electric motor with a built-in control device according to the first embodiment may employ the structure shown in FIG. 12 as an example.

(Embodiment 2) In Embodiment 1 described above, the power supplied to the electric motor 20 is switched from the inverter power supply to the commercial power supply in response to a failure of the control device. As in the second embodiment to be described, the power supply may be temporarily stopped at the time of failure, and the inverter power supply may be restarted again upon recovery.
That is, the parts greatly different from the configuration of the first embodiment described above are the configuration in which the power supply to the electric motor 20 is performed only by the inverter power supply device, and the configuration in which the inverter power supply is restored together with the recovery from the failure.

First, the configuration will be described. FIG. 3 is a block diagram showing a motor with a built-in control device according to a second embodiment of the present invention. The motor with a built-in control device shown in FIG. 3 includes a power input structure from a commercial power supply 10, a motor 20, and an inverter 50B as a control device. The commercial power supply 10 and the electric motor 20 are the same as those in the related art, and are connected to the inverter 50B via the power supply lines 11 and 12. The manipulated variables provided for the inverter 50B to drive the motor 20 at a variable speed are voltage, current, and frequency.

The inverter 50B has the same converter unit 51, inverter unit 52 and arithmetic means 53 as in the first embodiment, and a mounted output for temporarily stopping the output of the inverter unit 52 or canceling the stop (retry function). It is constituted by a stop means 60 and an automatic return means 61 for automatically returning by the inverter power supply device using a retry function of the output stop means 60. It should be noted that the above-mentioned calculating means 53, output stopping means 60 and automatic return means 61
May be processed by the MPU, or may be configured by a control circuit or an integrated control circuit, respectively.

Next, the operation will be described. FIG. 4 is a flowchart illustrating an operation according to the second embodiment. In the electric motor with a built-in control device shown in FIG. 3, the inverter 50 </ b> B converts the AC power supplied from the commercial power supply 10 into the DC power once by the converter 51, and returns to the AC power again by the inverter 52 at the subsequent stage. Supplies the AC power to the motor 20. At this time, the output stopping means 60 monitors abnormalities including overcurrent interruption of the inverter 50B and failure of the main circuit capacitor (Step S4).
1) While the abnormality is not determined (step S4)
2) The connection between the commercial power supply 10 and the converter unit 51 is maintained.

During the above-mentioned monitoring, if the output stop means 60 determines that there is an abnormality (step S42), the output stop means 60 suspends the supply of the inverter power to the motor 20 (step S43). That state is maintained until it is released (step S
44). Thereafter, when the inverter abnormality is released (step S44), it is determined whether the inverter can be operated by the inverter power supply device by the automatic return means 61, and if there is no problem, the electric motor 20 is automatically returned by the inverter power supply. It is operated (step S45).

As described above, according to the second embodiment, even if the supply of the inverter power to motor 20 is stopped due to the abnormality of inverter 50B, the inverter 50B
Is restored, the power supply by the inverter 50B can be automatically restored. Therefore,
It is possible to construct a system suitable for unmanned driving.

The motor with a built-in control device according to the second embodiment may have the structure shown in FIG. 12 as an example.

(Embodiment 3) In Embodiments 1 and 2 described above, the motor 20 can be restored even if the operation of the motor 20 is continued or temporarily stopped using one control device. However, as in the third embodiment described below, by providing at least one control device for backup in addition to the normally used control device, it is possible to cope with the occurrence of an inverter abnormality. Good. In the following description, a case where only one backup control device is used will be described as an example.

FIG. 5 is a block diagram showing a motor with a built-in control device according to Embodiment 3 of the present invention. The motor with a built-in control device shown in FIG. 5 includes a power input structure from a commercial power supply 10, a motor 20, a main inverter 50C as a control device, a sub-inverter 50D as a backup control device, a main inverter 50C, and a sub-inverter 5.
Selection means 70 for selecting an inverter to be used in accordance with the normality / abnormality of each of 0D, and either one of the main inverter 50C side and the sub inverter 50D side between the commercial power supply 10 and the motor 20 according to the selection information of the selection means 70 Are configured by switches 71a and 71b for switching to. The commercial power supply 10 and the electric motor 20 are the same as the conventional one. Main inverter 50C, sub inverter 5
The manipulated variables given by 0D to drive the motor 20 at variable speed are voltage, current, and frequency.

The main inverter 50C is the same as that of the first embodiment.
And a sub-inverter 50.
D includes a converter 51d, an inverter 52d, and an arithmetic unit 53d similar to those in the first embodiment. The power supply line 11 connects the commercial power supply 10 and the switch 71a, and the power supply line 12 connects the electric motor 20 and the switch 71b. It should be noted that the selection means 70 and the calculation means 53 described
Each of c and 53d may be processed by an MPU, or may be configured by a control circuit or an integrated control circuit, respectively.

Next, the operation will be described. FIG. 6 is a flowchart illustrating the operation according to the third embodiment. In the motor with a built-in control device shown in FIG.
The main inverter 50C takes in the AC power supplied from the commercial power supply 10 via the switch 71a, converts the AC power to DC power once by the converter unit 51c, and returns to the AC power again by the inverter unit 52c at the subsequent stage, and then returns to the AC power source. Is supplied to the electric motor 20 via the switch 71b. At this time, the selection unit 70 monitors an abnormality including an overcurrent interruption of the inverter 50C and a failure of the main circuit capacitor (Step S61), and if no abnormality has occurred (Step S62), disconnects the power supply system. Main inverter 5
Hold at 0.

During the above monitoring, if an abnormality occurs in the main inverter 50C and the selection means 70 determines that there is an abnormality (step S62), the selection means 70 switches the power supply system by the switches 71a and 71b to the main inverter 5C.
Switching from 0C to sub-inverter 50D. That is,
The output of the commercial power supply 10 is switched from the converter unit 51c to the converter 51d by the switch 71a.
An operation of switching the input of the electric motor 20 from the inverter unit 52c to the inverter unit 52d is performed by 1b (step S63). Thus, after the occurrence of an abnormality in the main inverter 50C, the electric motor 2
0 is supplied with inverter power.

As described above, according to the third embodiment, when the main inverter 50C breaks down, the inverter power is continuously supplied only by switching the power supply from the main inverter 50C to the backup sub-inverter 50D. The motor 20
Power supply to the motor 2
0 can be driven. Therefore, it is possible to make full use of the capability of the electric motor 20 even when the inverter fails.

The motor with a built-in control device according to the third embodiment described above may have the structure shown in FIG. 12 as an example.

(Embodiment 4) The above-described Embodiments 1 to
As a further improvement of the third embodiment, the fourth embodiment described below
As described above, a cooling means that is not directly connected to the electric motor 20 may be provided.

FIG. 7 is a side sectional view showing an internal configuration of a motor with a built-in control device according to a fourth embodiment of the present invention. In the configuration shown in FIG. 7, the same components as those in FIG. 12 of the conventional example are denoted by the same reference numerals, and description thereof will be omitted. In FIG. 7, reference numeral 50E denotes the inverter according to any one of the first, second, and third embodiments. The mounting structure of the inverter 50E employs the same method as that of the conventional inverter 70.

In the conventional example, as shown in FIG. 12, a fan 27 as a cooling means is connected to the rotor 25. However, in the fourth embodiment, as shown in FIG. A certain forced cooling fan 29 is connected to the rotor 25 and is not directly connected to the rotating shaft of the electric motor 20. This forced cooling fan 29 is protected by a cover 28. In the cooling chamber, the wind from the forced cooling fan 29 independent of the rotation speed of the
3 is cooled.

Next, the operation will be briefly described. The forced cooling fan 29 rotates at a constant speed even during low-speed operation by the control device 50, so that stable cooling air can be secured.

As described above, according to the fourth embodiment, the forced cooling fan 29 independent of the rotation speed of the electric motor 20 is provided, so that the low-speed operation is constant regardless of the rotation speed of the electric motor 20. It becomes easy to perform torque operation.

(Embodiment 5) Embodiments 1 to 5 described above.
As a further improvement of the third embodiment, the fifth embodiment described below
As described above, only the inverter unit may be cooled in consideration of the size of the cooling unit.

FIG. 8 is a side sectional view showing an internal configuration of a motor with a built-in control device according to a fifth embodiment of the present invention. In the configuration shown in FIG. 8, the same components as those in FIG. 12 of the conventional example are denoted by the same reference numerals, and description thereof will be omitted.

In FIG. 8, reference numeral 50F denotes an inverter according to any one of the first, second, and third embodiments. The mounting structure of the inverter 50F employs the same method as that of the conventional inverter 70, and the cooling target is not limited. Since only the inverter 50F is provided, the inverter 50F
F is covered with a heat sink 30, and the cover 28 and the forced cooling fan 29 as in the above-described fourth embodiment are removed (see FIGS. 8 and 12).

Next, the operation will be briefly described. Since the heat radiating plate 30 has a heat radiating area capable of cooling even when the inverter 50F has no cooling air from the aforementioned forced cooling fan 29 (see FIG. 8), a sufficient cooling effect can be obtained. it can. Also, regarding the cooling of the electric motor 20, a sufficient cooling effect can be obtained by adopting a structure that can be cooled by a self-cooling type.

As described above, according to the fifth embodiment, since the inverter section is cooled by a self-cooling type, a motor having a built-in inverter as a control device, that is, a small-sized motor as a control device built-in type motor is provided. Is possible.

(Embodiment 6) Embodiments 1 to 5 described above.
As a further improvement of the third embodiment, the fifth embodiment described below
In order to improve the cooling method of the motor unit, the power unit circuit of the control unit is installed between the bracket supporting the bearing on the non-load side and the cooling unit, and one control unit is installed on the side of the frame. It may be.

FIG. 9 is a side sectional view showing an internal configuration of a motor with a built-in control device according to Embodiment 6 of the present invention. In the configuration shown in FIG. 9, the same components as those in FIG. 11 of the conventional example are denoted by the same reference numerals, and description thereof will be omitted. In FIG. 9, 50G is the inverter of any of the first, second and third embodiments, and 59 is a control circuit including a smoothing capacitor. Control circuit 59 including this smoothing capacitor
Is mounted on the frame 23.

Next, the operation will be briefly described. In general, when the capacity of the motor 20 increases, the size of the smoothing capacitor of the inverter 50G also increases. When this smoothing capacitor is installed on the non-load side of the motor 20, the size of the inverter increases. The wind may not be able to cool the frame of the electric motor 20 effectively. Therefore, in the sixth embodiment, by attaching the control circuit 59 including the smoothing capacitor to the frame 23, the cooling air from the cooling fan 27 causes
Cooling of the electric motor 20 can be ensured.

As described above, according to the sixth embodiment, the control circuit 59 including the relatively large smoothing capacitor is provided on the side surface of the frame 23 of the motor 20, so that the cooling efficiency of the motor 20 is improved. And the cooling effect can be improved.

[0067]

As described above, according to the present invention, a failure occurs in the inverter when power is supplied from the commercial power supply to the motor via the inverter by the first power supply system. It is determined whether or not a failure has occurred, and when a determination result that a failure has occurred is obtained, the power supply system for the motor is changed from the first power supply system to the second power supply system for directly supplying power from the commercial power supply to the motor. Since the switching is performed, the power supply to the motor is not interrupted, the motor can be continuously operated, and thereby the maintenance of the inverter can be performed without stopping the line for a long time. This produces an effect that a built-in motor can be obtained.

According to the next invention, when an abnormality occurs in the inverter while the electric power is supplied from the commercial power supply to the motor via the inverter, the output of the inverter is stopped, and thereafter, the abnormality of the inverter is released. If so,
Since the output of the inverter is restored, the power supply by the inverter can be automatically restored,
Thereby, there is an effect that an electric motor with a built-in control device that can construct a system suitable for unmanned operation is obtained.

According to the next invention, when a failure occurs in the inverter while power is supplied from the commercial power supply to the motor via the inverter, the power supply system for the motor is controlled. As the backup inverter is selected, the power supply system for the motor is switched from the first power supply system to the second power supply system for supplying power to the motor from the commercial power supply via the backup inverter. The power supply to the motor is not interrupted, and the motor can be operated continuously, which enables the motor with a built-in control device to fully demonstrate the capability of the motor even in the event of an inverter failure. The effect is obtained.

According to the next invention, since the cooling means is not directly connected to the rotating shaft of the motor in the motor, the number of rotations of the motor does not decrease and the amount of cooling air does not decrease. This makes it possible to obtain an electric motor with a built-in control device that facilitates constant-torque operation even during low-speed operation regardless of the rotational speed of the motor.

According to the next invention, only the inverter is cooled in the fully-closed self-cooling type electric motor, so that the motor and the inverter are not cooled by a common cooling means. There is an effect that a motor with a built-in control device that can be downsized as a motor, that is, a motor with a built-in control device is obtained.

According to the next invention, in the inverter, the power section circuit is mounted between the bracket supporting the bearing on the non-load side and the cooling means, and the control circuit is mounted on the side surface of the frame. Thus, there is an effect that the cooling efficiency of the electric motor is improved, and a motor with a built-in control device capable of improving the cooling effect is obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a motor with a built-in control device according to a first embodiment of the present invention.

FIG. 2 is a flowchart illustrating an operation according to the first embodiment.

FIG. 3 is a block diagram illustrating a motor with a built-in control device according to a second embodiment of the present invention;

FIG. 4 is a flowchart illustrating an operation according to the second embodiment.

FIG. 5 is a block diagram showing a motor with a built-in control device according to a third embodiment of the present invention.

FIG. 6 is a flowchart illustrating an operation according to the third embodiment.

FIG. 7 is a side sectional view showing an internal configuration of a motor with a built-in control device according to a fourth embodiment of the present invention.

FIG. 8 is a side sectional view showing an internal configuration of a motor with a built-in control device according to a fifth embodiment of the present invention.

FIG. 9 is a side sectional view showing an internal configuration of a motor with a built-in control device according to Embodiment 6 of the present invention.

FIG. 10 is a block diagram showing a conventional motor with a built-in control device.

FIG. 11 is a side sectional view showing an example of an internal configuration of a conventional motor with a built-in control device.

FIG. 12 is a side sectional view showing another example of the internal configuration of a conventional motor with a built-in control device.

[Explanation of symbols]

10 commercial power supply, 20 electric motor, 50A, 50B, 50
E, 50F, 50G inverter, 50C main inverter, 50D sub inverter, 51, 51c, 51d
Converter unit, 52, 52c, 52d Inverter unit, 53, 53c, 53d Operation unit, 56 Failure determination unit, 57a, 57b, 71a, 71b switch, 59
Control circuit, 60 output stop means, 61 automatic return means, 70 selection means.

Claims (6)

[Claims] 1. An electric motor with a built-in control device in which an inverter having a power circuit and a control circuit is built in an induction motor that generates mechanical power by receiving electric power supplied from a commercial power supply. From the first power supply system for supplying power to the motor via the inverter and the second power supply system for supplying power to the motor directly from the commercial power supply. Switching means; and failure determination means for determining whether a failure has occurred in the inverter while power is being supplied by the first power supply system. Switching a power supply system for the electric motor from the first power supply system to the second power supply system when a determination result that a failure has occurred is obtained; Controller built-in electric motor, characterized. 2. An electric motor with a built-in control device in which an inverter having a power section circuit and a control circuit is built in an induction motor that generates mechanical power by receiving electric power supplied from a commercial power supply. If an abnormality occurs in the inverter while supplying power to the motor through the inverter, output stop means for stopping the output of the inverter; and stopping the output of the inverter by the output stop means. Automatic resetting means for resetting the output of the inverter when the abnormality of the inverter is released during the operation. 3. An inverter built in an induction motor that generates mechanical power by receiving electric power supplied from a commercial power supply, and has an inverter having a power circuit and a control circuit; and an inverter built in the motor. A motor with a built-in control device including a backup inverter having a power circuit and a control circuit, wherein a power supply system for the motor supplies power to the motor from the commercial power supply via the inverter. Switching means for switching to one of a first power supply system and a second power supply system for supplying electric power from the commercial power supply to the electric motor via the backup inverter; and power supply by the first power supply system. If a fault occurs in the inverter during operation, the backup inverter is selected as a power supply system for the electric motor. And a switching unit that switches a power supply system for the electric motor from the first power supply system to the second power supply system when the backup inverter is selected by the selection unit. An electric motor with a built-in control device. 4. The control according to claim 1, wherein cooling means is provided in the electric motor, and the cooling means has a structure not directly connected to a rotating shaft of the electric motor. Built-in motor. 5. The motor according to claim 1, wherein the electric motor is a fully-closed self-cooling type, and cools only the inverter.
The electric motor with a built-in control device according to any one of the above. 6. The motor, wherein a stator core is fixed to a frame in which a bracket and a frame for supporting a bearing on the non-load side are integrally formed of a metal material such as aluminum by shrink fitting or the like, and a cooling shaft is provided on the rotation shaft on the non-load side. The power unit circuit is mounted between the bracket supporting the bearing on the non-load side and the cooling means, and the control circuit is provided on a side surface of the frame. Claim 1
6. The electric motor with a built-in control device according to any one of claims 5 to 5.