JP3489518B2 - Stator inspection method and inspection apparatus - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stator inspection method and inspection apparatus for diagnosing and identifying the electrical insulation state and the location of defective electrical insulation of a winding wound around a stator of a rotary electric machine or the like.

[0002]

2. Description of the Related Art Generally, when diagnosing the insulation state of a winding, a withstand voltage test for applying a high voltage to the ground insulation is performed,
We are also conducting tests to measure the current flowing by applying a DC voltage to the ground insulation using a Megger tester.

[0003]

However, these tests are for diagnosing the state of ground insulation from the presence or absence of dielectric breakdown and the magnitude of leakage current by applying overvoltage to the ground insulation.
It is not possible to identify the rare parts of the winding.

Further, as a method of diagnosing rare between phases of a winding or within a phase, a method of applying an overvoltage to the winding is known, and a rare tester is commercially available as a test device that realizes this. ing. The rare tester can detect mistakes in winding wire connections and mistakes in the number of turns, but cannot identify rare winding points.

For this reason, it is difficult to repair the defective portion of the winding defective product.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a stator inspection method and apparatus that facilitates diagnosis of defective portions of windings.

[0007]

In order to achieve the above object, according to the invention described in claim 1, a method of inspecting a stator (2) having a stator coil (22) wound around a cylindrical stator core (21). And the stator coil (22)
Magnetic field supplying means (13a, 13b, 16, 30, 3) capable of supplying a magnetic field to the magnetic field and changing the magnetic flux with time.
0a, 30b, 40) for detecting the part to which the magnetic field is supplied by the magnetic field supplying means and measuring the electromotive force generated in the stator coil (22) at the part to which the magnetic field is supplied by the magnetic field supplying means. The stator coil (2
It is characterized in that the defective insulation portion of 2) is specified.

According to this, by supplying the magnetic field to the stator coil while changing the magnetic flux with time, an electromotive force can be generated in the stator coil at the magnetic field supplying portion. Then, if there is a poor electrical insulation in the portion of the stator coil to which the magnetic field is supplied, the electromotive force will decrease,
By detecting the magnetic field supply site and measuring the electromotive force generated in the stator coil at the magnetic field supply site, it becomes possible to detect the electrical insulation failure of the stator coil and specify the location of the electrical insulation failure.

According to a second aspect of the present invention, a large number of field coils are arranged in the circumferential direction of the stator coil (22) so as to face the stator coil (22) and flow in each of the plurality of field coils. By controlling the current, an electromotive force can be generated for each stator coil (22) located at a position facing the field coil.

According to the third aspect of the present invention, the field coil arranged facing the stator coil (22) is rotated in the excited state along the circumferential direction of the stator (2),
An electromotive force can be generated in the stator coil (22).

According to the fourth aspect of the present invention, the permanent magnet arranged so as to face the stator coil (22) is rotated along the circumferential direction of the stator (2) to form the stator coil (22). An electromotive force can be generated.

According to a fifth aspect of the present invention, a magnetic field is supplied to the stator coil (22) and the electromotive force generated in the stator coil (22) at the site where the magnetic field is supplied is measured. It is characterized by comparing with the voltage.

According to this, by comparing the voltage of the electromotive force generated in the stator coil at the magnetic field supplying portion with the reference voltage, the defective portion of electrical insulation can be specified.

According to the sixth aspect of the invention, the magnetic field is supplied to one position in the circumferential direction of the stator coil (22) by the magnetic field supply means, and the magnetic field is generated in the stator coil (22) at the part to which the magnetic field is supplied. It is characterized in that the electric power is measured and the integral value of the electromotive force over time is compared with the set value.

According to this, since the integrated value of the electromotive force and the set value are compared, even a slight difference in the electromotive force is determined by the waveform represented by the electromotive force-time graph due to the difference in the inductance of the stator coil. For example, it is possible to determine even a slight difference, and it is possible to more accurately detect the electrical insulation failure of the stator coil and specify the location of the electrical insulation failure.

According to the invention described in claim 7, the magnetic field is simultaneously supplied to the two places in the same phase of the stator coil (22) by the magnetic field supplying means, and the electromotive force generated at the two places of the stator coil (22) is generated. When they cancel each other, it is determined that there is no insulation failure at the two locations of the stator coil (22), and when the difference in electromotive force generated at the two locations of the stator coil (22) is detected, the stator coil (22 ) 2
It is characterized by identifying that there is a defective insulation at a location.

According to this, since the electromotive force is detected only when the magnetic field supplying portion has a poor electrical insulation, the electromotive force is not accurately measured at each position of the magnetic field supplying portion. Can be specified.

Incidentally, in a place where there is no electric insulation defect,
In order for the electromotive forces generated in the stator coils (22) at the two magnetic field supplying portions to cancel each other out, magnetic poles in the core radial direction of the magnetic field supplying means (13a, 13b) as in the invention according to claim 8. Of the stator coil (22) at the two positions of the stator coil (22)
The winding directions at the two locations of 2) may be the same.

Further, in a place where there is no electric insulation defect,
In order for the electromotive forces generated in the stator coils (22) at the two magnetic field supply portions to cancel each other, magnetic poles in the core radial direction of the magnetic field supply means (13a, 13b) as in the invention according to claim 9. Direction of stator coil (22) 2
Make the stator coil (2
The two winding directions of 2) may be reversed.

According to the tenth aspect of the present invention, the electromotive force of the coil for each phase of the stator coil (22) formed by connecting the coils of three phases is measured to identify the location of defective electrical insulation. You can

According to the invention described in claim 11,
The three-phase coils of the Y-connected stator coil (22) are paired in pairs of two phases and the electromotive force of the coils is measured to identify the location of defective electrical insulation.

According to the twelfth aspect of the invention, only one coil phase of the multiphase coil is grounded on the side opposite to the neutral point, and the electromotive force is measured on the side opposite to the neutral point of the other coil phase. An electric power measuring means (17) is connected to measure the electromotive force.

According to this, not only the electric insulation failure in the same phase of the stator coil but also the earth ground of the stator coil and the electric insulation failure between the phases can be detected as the electric insulation failure as follows.

That is, in the case of electrical insulation failure within the same phase, the electromotive force at the location where the electrical insulation failure occurs is reduced by the number of turns in which the electrical insulation failure occurs. Therefore, by measuring the electromotive force, it is possible to detect the electrical insulation failure in the same phase.

In the case of grounding, the electromotive force is detected between the portion to which the electromotive force measuring means is connected and the earth portion, but the electromotive force measuring means generates the electromotive force between the earth portion and the ground portion. Since no power is detected, the ground point can be identified.

Further, in the case of poor electrical insulation between the phases, in the two coil phases having the poor electrical insulation, no current flows in the short-circuited coil portion, and therefore the electromotive force is measured to measure the interphase. Poor electrical insulation can be detected.

According to a thirteenth aspect of the present invention, an electromotive force measuring means (17) for grounding a neutral point of a multiphase coil and measuring the electromotive force on the side opposite to the neutral point of each coil phase.
The same effect as that of the invention described in claim 12 can be obtained by connecting the.

According to the fifteenth aspect of the present invention, a constant bias voltage is applied to the ground side circuit of the coil.

According to this, it is possible to prevent erroneous determination due to voltage fluctuation due to noise or the like.

In the sixteenth aspect of the present invention, the stator coil (22) has a plurality of partial windings (221a, 221b,
221c), and the partial winding (221a,
221b, 221c) for each partial electromotive force, and based on the detected partial electromotive force, the partial winding (221a,
221b, 221c) is detected.

In the seventeenth aspect of the invention, a plurality of partial windings (221) forming the stator coil (22) are provided.
a, 221b, 221c) are sequentially supplied with a magnetic field to detect the electromotive force at both ends where a plurality of partial windings are connected, and the electromotive force detected at both ends corresponding to each magnetic field supply position is
The feature is that it is set as a partial electromotive force.

According to this, since the partial electromotive force of each partial winding is detected, it becomes easy to detect in which partial winding the defective electrical insulation occurs.

According to the eighteenth aspect of the present invention, the stator inspection method according to any one of the first to seventeenth aspects is used to identify a defective insulation portion of the stator coil (22) and perform insulation treatment on the defective insulation portion. Is added to eliminate the insulation failure.

According to this, the faulty electrical insulation can be identified by the stator inspection method according to any one of claims 1 to 17. Therefore, conventionally, when the defective portion of electrical insulation could not be identified, the defective product was discarded, but if the insulating treatment is applied to the defective portion of electrical insulation, the stator can be repaired.

According to a nineteenth aspect of the present invention, there is provided an inspection device for a stator (2) having a stator coil (22) wound around a cylindrical stator core (21), the magnetic field being supplied to the stator coil (22). And a magnetic field supplying means (13) capable of changing the magnetic flux with time.
excitation position detecting means (18, 13b) for detecting a portion where the magnetic field is supplied to the stator coil (22).
40) and an electromotive force measuring means (17) for measuring an electromotive force generated in the stator coil (22).

According to this method, similarly to the method described in claim 1, the portion of the stator coil to which the magnetic field is supplied and the electromotive force corresponding thereto are measured. Therefore, the rare portion of the stator coil can be specified. Is possible.

According to the twentieth aspect of the present invention, the magnetic field supplying means includes a large number of field coils (30) arranged to face the stator coil (22), and a current flowing through each of the plurality of field coils. With the current control means (40) for controlling the electric field, an electromotive force can be generated for each stator coil (22) at a position facing the field coil.

According to the twenty-first aspect of the present invention, the magnetic field supplying means rotates the field coil (30a, 30b) and the field coil along the circumferential direction of the stator (2) in the excited state. By constituting with the means (16), an electromotive force can be generated in the stator coil (22).

According to the twenty-second aspect of the present invention, the magnetic field supplying means includes the permanent magnets (13a, 13b), and the turning means (16) for rotating the permanent magnets along the circumferential direction of the stator (2). The stator coil (2
An electromotive force can be generated in 2).

According to the twenty-third aspect of the present invention, the magnetic field supplying means are arranged opposite to each other at two locations in the same phase of the stator coil (22) and supply a pair of magnetic fields to the stator coil (22). Member (13a, 13b, 30a, 30
b) and a turning means (16) for rotating the pair of field members along the circumferential direction of the stator (2).

According to this method, the electromotive force is detected only when the magnetic field supplying portion has a poor electrical insulation, similarly to the method according to the seventh aspect. Therefore, the value of the electromotive force at each position of the magnetic field supplying portion is calculated. The location of defective electrical insulation can be identified without accurate measurement.

Incidentally, in a place where there is no electric insulation defect,
In order for the electromotive forces generated in the stator coils (22) at the two magnetic field supply sites to cancel each other, a pair of field members (13a, 13b, 30) as set forth in claim 24.
a, 30b), the directions of the radial magnetic poles are reversed,
Stator coil (22) facing the pair of field members
The winding directions of may be the same.

Further, in a place where there is no electric insulation defect,
In order for the electromotive forces generated in the stator coils (22) at the two magnetic field supply sites to cancel each other, a pair of field members (13a, 13b, 30) as set forth in claim 25.
a, 30b) have the same direction of the magnetic poles in the radial direction, and the stator coils (2) facing the pair of field members.
The winding directions of 2) may be reversed.

According to the twenty-sixth aspect of the present invention, the magnetic field supplying means includes one field member (13a, 30a), and the one field member is rotated along the circumferential direction of the stator (2). By constituting with the turning means (16) for rotating, the electromotive force can be generated in the stator coil (22).

The invention as set forth in claim 27 is characterized in that a comparison means (51) for comparing the integrated value of the electromotive force with respect to time and the set value is provided.

According to this, since the integrated value of the electromotive force and the set value are compared, it is easy to determine even a slight difference in the electromotive force, and it is possible to detect the electrical insulation failure of the stator coil more accurately and It is possible to specify the location of defective insulation.

The invention described in claim 28 is characterized in that a comparison means (19) for comparing the voltage of the electromotive force and the reference voltage is provided.

According to this, by comparing the electromotive force generated in the stator coil at the magnetic field supplying portion with the reference voltage, it is possible to specify the defective portion of electrical insulation.

According to a twenty-ninth aspect, the electromotive force of the coil for each phase of the stator coil (22) formed by connecting the coils of three phases is measured to identify the defective portion of electrical insulation. You can

According to the thirtieth aspect, the three-phase coils of the Y-connected stator coil (22) are paired in pairs of two phases, and the electromotive force of the coils is measured to identify the location of defective electrical insulation. be able to.

The field member in this specification refers to a member capable of supplying a magnetic field, such as a permanent magnet or a field coil.

Further, the reference numerals in the above-mentioned parentheses show the correspondence with the concrete means described in the embodiments described later.

[0053]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention shown in the drawings will be described.

(First Embodiment) FIG. 1 is an overall external view of a stator inspection device, and FIG. 2 is a schematic diagram showing a state of arrangement of magnets on the inner peripheral side of a stator in an insulation diagnostic device.

The stator 2 as a diagnosis target of the insulation diagnosis apparatus 1 is composed of a stator core 21 and a stator coil 22. The stator core 21 has a cylindrical shape, and 36 slots are formed at equal intervals to accommodate the stator coil 22.

The stator coil 22 is U-shaped or I-shaped.
It is formed by joining a plurality of character-shaped conductor segments. The conductor segments are joined to each other on the stator core 21 with at least one joining portion within the magnetic pole pitch. These joints are arranged side by side at one axial end of the stator core 21.

In this embodiment, the stator core 21 has three
Phase coils are provided and each phase is Y-connected to form a stator coil 22. In this embodiment,
As shown in FIG. 2, the stator coil 22 is formed by lap winding. The lap winding stator coil 22 is composed of lap winding portions as a plurality of partial windings. Then, for each phase, for example, a linear portion of a winding wound in three windings is arranged every three slots on a stator core 21 having 36 slots, and each of the X phase and the Y phase, the Y phase and the Z phase, and the Z phase and the X phase has one slot. They are arranged one after another.

A pedestal portion 11 on which the stator 2 is arranged is provided above the insulation diagnostic device 1. Further, a magnet rotating portion 12 protruding in a cylindrical shape is provided at the center of the pedestal portion 11. Two permanent magnets (field members) 13a and 13b are formed on the outer peripheral portion of the magnet rotating portion 12 in the circumferential direction.
They are arranged at symmetrical positions apart from each other by 0 °. In addition,
The magnet 13a is arranged so that the N pole faces the outer peripheral side and the magnet 13b has the S pole faces the outer peripheral side. That is, the magnets 13a and 13b have opposite magnetic poles. Then, when the stator 2 is arranged on the pedestal portion 11, the inner peripheral surface of the stator 2 and the magnets 13a and 13b are separated by a predetermined distance. The magnets 13a and 13b are preferably strong, and are made of ferrite in this embodiment.

The insulation diagnostic device 1 has a DC motor power source 15, and this DC motor power source 15 is a magnet rotating part 1.
DC motor (turning means) 16 installed in the lower part of 2
It is connected to the. Then, the magnet rotating unit 12 is rotated at a high speed (750 rpm in the present embodiment) in the direction of arrow A by the DC motor 16.

Insulation diagnostic device 1 includes stator coil 2 described above.
It has three connecting clips 14X, 14Y, 14Z that can be connected to the respective ends 22X, 22Y, 22Z of the two 3-phases. End 22 of each phase of Y-connected stator coil 22
X, 22Y, 22Z are these connecting clips 14X, 1
It is connected to a measuring instrument (electromotive force measuring means) 17 via 4Y and 14Z. Further, the connection portion 14e is the insulation diagnostic device 1
Is connected to the measuring instrument 17, and the measuring instrument 17 is grounded.

FIG. 3 shows a circuit diagram of the stator coil 22 of this embodiment in the measuring instrument 17. In the circuit according to the present embodiment, the electromotive force is measured between the X phase and the Y phase and between the Y phase and the Z phase of the stator coil 22 by the known voltmeter 17b. Switching between the X-phase and the Y-phase and between the Y-phase and the Z-phase is performed by the select switch 17a in the measuring instrument 17. In the present embodiment, the Y-phase end portion 22Y
A bias voltage of 3V is applied to the (ground side circuit) to drift 3V toward the positive side. The measurement result measured by the measuring instrument 17 is the judgment indicator 19 connected to the measuring instrument 17.
Is displayed in.

Next, the operation of the insulation diagnostic device 1 will be described. Generally, if the magnetic flux penetrating the N-turn winding is Φ, the induced electromotive force is E, k is a constant, and t is time,

[0063]

It is known that E = kNdΦ / dt holds, and the electromotive force E is proportional to the number of turns N and the changing speed of the magnetic flux Φ. Therefore, if the rate of change of the magnetic flux Φ is constant under a certain winding, the number of turns N
It can be seen that the electromotive force E changes as the value changes. Therefore, if the magnet is moved under a certain winding, the electromotive force E is generated by the Fleming's right-hand rule, so if there is a rare, it is estimated that the electromotive force changes because the number of turns N in that portion is changed. it can.

The magnet rotating portion 12 located on the inner peripheral portion of the stator 2 is driven by the DC motor 16 at a constant speed and is indicated by an arrow A.
Is rotated in the direction of. Since the two magnets 13a and 13b are provided on the outer circumference of the magnet rotating unit 12, when the magnet rotating unit 12 is rotated, an electromotive force is generated. The electromotive force generated in the stator coil 22 is measured by the measuring device 17 and displayed on the determination display device 19.

Around the outer circumference of the magnet rotating part 12, 18 in the circumferential direction.
Magnets 13a and 13b arranged at positions apart by 0 °
Has the opposite magnetic pole orientation. Further, the stator coils 22 provided in 36 slots formed at equal intervals are
At the positions separated by 180 °, the winding directions of the coils are the same. Here, having the same winding direction means 180
° Stator coil 22 mounted in spaced slots
When the magnetic flux is equally changed, an electromotive force is generated to cause a current to flow in the same axial direction of the stator core 21.

In the present embodiment, the magnets 13a and 13b arranged at positions separated from each other by 180 ° have opposite magnetic poles, so that the electromotive forces generated near the respective magnets cancel each other. As a result, when the normal stator coil 22 which is not rare is measured, the judgment indicator 19 shows a constant value as shown in FIG. In addition, when the normal stator coil 22 is measured, the electromotive force is 0V, but as described above, since the Y-phase end portion 22Y is drifted to the plus side by 3V, the determination indicator 19 indicates 3V. There is. The reason why the Y-phase end 22Y drifts toward the positive side in this way is to make it easier to find a grounding point, as will be described later.

On the other hand, when the stator coil 22 has an in-phase rare, the number of turns is reduced at the rare portion, so that the electromotive force changes. In this case, when the electromotive force is measured in the stator coil 22 having the rare portion 22d in FIG.
When one of the magnets 13a, 13b at a position separated by 80 ° passes through the rare portion 22d, the electromotive forces generated by the two magnets 13a, 13b at a position separated by 180 ° are not canceled each other, and Only the output waveform as shown in FIG. 5 is obtained. Here, the interval between the Min value and the Max value of the electromotive force is 30 °, which is the slot interval of the same phase. The quality of the product (stator) depends on the electromotive force Min value, M
A judgment value (± 0.5 V in this embodiment) is set for the ax value, and if the change in electromotive force is within the judgment value, the product is judged to be normal, and if the fluctuation in electromotive force exceeds the judgment value, the product is abnormal. Judge that there is.

The rare portion when the stator coil 22 is rare is specified by the rotation position signal from the magnet rotating unit 12. Since the magnets 13a and 13b are arranged at positions separated by 180 °, the pair of Max value and Min value that deviates from the judgment value during one rotation of the magnet rotating unit 12 is 2.
The point is measured. However, since the magnets 13a and 13b located 180 ° apart are arranged so that the magnetic poles thereof are in opposite directions, the rare portion can be identified by the change in the waveform and the winding specifications. That is, in the present embodiment, when the magnet 13a with the N pole facing the outer peripheral side passes through a place where there is a rare and the number of turns decreases, the magnet 13a changes to the negative side when approaching the rare place. , When moving away from a rare place, it changes to the plus side. On the contrary, when the magnet 13b whose south pole faces the outer peripheral side passes through a rare place where the number of turns decreases, it changes to the positive side when the magnet 13b approaches the rare place, and the rare place When moving away from, it changes to the negative side.

More specifically, the rare portion is specified as follows. The rotation position of the magnet is obtained from a signal of an encoder (excitation position detecting means) 18 attached to the DC motor. The encoder 18 triggers the position signal according to the slot position of the measurement phase, and the rare portion can be specified by obtaining the Min value and Max value positions of the electromotive force. For example, if the stator core 21 of 36 slots is measured, the position signal is triggered 36 times per 360 degrees, that is, every 10 degrees, and the Max value is detected for the trigger after 30 ° after detecting the Min value of the electromotive force. Then, it can be specified that there is a rare portion between the slots where the Min value and the Max value are detected.

In this embodiment, when the magnets 13a and 13b are passing through a normal area with no rare, the electromotive force is 0 (constantly 3 V due to drift in measurement) and is constant. Min value and Max can be used to identify rare points.
No exact value is required. That is, it suffices to be able to detect a change from a certain value to a plus side or a minus side by a predetermined value (0.5 V in this embodiment) or more. Therefore, the magnet 1
High accuracy is not required for the measurement of the rotational positions of 3a and 13b. In the case of the 36-slot stator 2 as in this embodiment, it is possible to detect even an error of about ± 3 °.

In the structure in which a plurality of conductor segments are joined together to form a stator coil as in the present embodiment, a partial electromotive force of the coil may change due to a failure at these joints. . For example, a short circuit between two adjacent joints can reduce the electromotive force of the coil within one pole pitch. In this embodiment, a failure in a part of the series of stator coils 22 can be detected by observing the electromotive force at both ends of the stator coil 22 in correspondence with the supply position of the field magnetic flux.

When the stator coil 22 and the stator core 21 are grounded, that is, in the state shown in the circuit diagram of FIG. 7, the electromotive force changes as shown in FIG. In the case of the circuit diagram shown in FIG. 7, since it is grounded to the stator core 21 in the X phase, what is measured by the measurement unit 17 is the portion Xb between the grounded portion and the end 22X of the X phase. It is the electromotive force generated. In the present embodiment, the two magnets 13a and 13b are provided in the portion Xa and the portion Xb which is located 180 ° apart in the circumferential direction of the stator core 21.
Positive and negative waveforms appear because the electromotive forces generated in the two do not cancel each other out. Further, in the present embodiment, the Y-phase end portion 22Y was measured by drifting to the positive side of 3V. However, if there is a grounded portion, it cannot be drifted and the electromotive force waveform at the normal portion is lowered as shown in FIG. . Therefore, when a waveform that does not drift appears, it is understood that it is grounded.

Next, when the stator coil 22 has interphase rare, for example, when the X phase-Y phase is rare as shown in FIG. 8, Xa from the rare portion of the X phase to the neutral point 22N. From the coil part and the rare part of the Y phase to the neutral point 22
Since the Ya coil portion up to N is short-circuited, no current flows.

On the other hand, when one of the pair of magnets 13a, 13b located 180 ° apart is located in the portion Xa and the other is located in the portion Xb, the two magnets 13a located 180 ° apart. , 13b do not cancel each other out, the in-phase voltage of the X phase is shown in FIG.
(Upper row) In addition, a pair of magnets 13a,
Even when one of the magnets 13b is located at the portion Ya and the other is located at the portion Yb, the electromotive forces generated by the two magnets 13a and 13b located at 180 ° apart are not canceled each other. The in-phase voltage of each phase is as shown in FIG. 9 (middle stage). Then, what is detected by the voltmeter 17b is the total of the in-phase voltages of the X phase and the Y phase, as shown in FIG.
The output waveform of the electromotive force as shown in is obtained. It should be noted that the X phase and the Y phase are arranged one slot apart from each other, so
The in-phase voltages of the phase and the Y phase have a phase difference θd for one slot.

By measuring the X phase-Y phase and the Y phase-Z phase, respectively, the X phase, Y phase, and Z phase are all measured. When the Y phase is defective, defects can be found in both the X phase and the Y phase and between the Y phase and the Z phase. In other words, between X phase-Y phase, Y phase-
After measuring each of the Z phases, if the defect can be found both times, the Y phase is defective, and if the defect is once, the X phase or the Z phase is defective.

The ground point can be specified by applying a position signal trigger corresponding to the slot positions of the X phase, Y phase, and Z phase.

Since the rare portion of the stator coil 22 can be identified as described above, the stator 2 can be reworked by inserting an insulating member such as an insulating paper, an insulating film or a non-woven fabric into the rare portion for insulation treatment. . As a result, the stator 2, which was conventionally discarded when the defective portion could not be identified, can be repaired and used.

(Second Embodiment) In the first embodiment, the pair of magnets 13a and 13b are arranged at symmetrical positions apart from each other by 180 ° in the circumferential direction of the outer peripheral portion of the magnet rotating portion 12. However, even if only one magnet is arranged in the magnet rotating unit 12, the rare portion can be specified as follows.

In the second embodiment, only the magnet 13a having the N pole facing the outside is arranged, and the magnet 13b having the S pole facing the outside is not arranged on the outer peripheral portion of the magnet rotating portion 12. Other configurations are the same as those in the first embodiment.

FIG. 10 is a schematic development view of the stator coil, and FIG. 11 is a view showing electromotive force generated in the winding. Figure 1
Reference numeral 0 indicates the coil 221 of one phase of the multi-phase stator coils 22. The coil 221 is formed on the stator coil 21 as a series of windings connected by a plurality of partial windings 221a, 221b, 221c for each magnetic pole pitch. Note that, in FIG. 10, only three overlapping winding portions are shown for simplicity. Further, in FIG. 10, the front side of the drawing is the outer peripheral side of the stator 2. Therefore, the magnet 13a has the N pole on the front side of the paper surface and the S pole on the opposite side, and the magnet 13a moves on the back side of the stator coil in the paper surface.

The stator coil 221 of FIG. 10 is a lap winding, and 221a, 221b and 221c respectively form a lap winding portion as a partial winding of the winding stator coil 221. The overlapping winding portion 221a is a rare portion 221d.
have.

When the magnet rotating unit 12 is rotated in the direction of arrow A in FIG. 1, that is, when the magnet 13a is moved rightward in FIG. 10 at a constant speed, the inspection field is overlapped as a partial winding. It is supplied to each of the winding parts 221a, 221b, 221c, and an electromotive force is generated. In FIG. 10, when the magnet 13a approaches the overlapping winding portions 221b and 221c, positive electromotive forces Vb and Vc are generated as shown in FIG. Further, when the magnet 13a moves away from the lap winding portions 221b and 221c, negative electromotive forces -Vb and -Vc are generated.

That is, the magnet 13a sequentially magnetizes a plurality of partial windings to generate a partial electromotive force for each partial winding. Then, by detecting the electromotive force induced in the partial winding, a failure such as rare in the partial winding can be detected.

The field for inspection is made by moving the magnet 13a along the axial direction or the circumferential direction of the stator 2 so as to change the direction of the magnetic flux or magnetic field interlinking with the partial winding. . Further, in detecting the electromotive force of the partial winding, it is necessary to identify the partial winding to which the magnetic field is supplied. For example, when electromotive force is observed at both ends of a series of windings including multiple partial windings, a device that detects the position where the magnetic field is supplied is used, and the electromotive force is detected at each detected position. To observe. The electromotive force may be detected for each partial winding.

In the second embodiment shown in FIG. 10, in the coil 221 of one phase, the lap winding portion 22 as a plurality of partial windings is provided for each magnetic pole pitch over the entire circumference of the stator core 21.
1a, 221b and 221c are formed. And
The magnet 13a as a single field magnetic pole is attached to the stator core 21.
The magnetic field is sequentially supplied to the plurality of windings by rotating the inner circumference of the coil. Then, by observing the electromotive force output to both ends of this one-phase coil 221 in correspondence with the position of the magnet 13a, the partial winding in which the abnormal electromotive force is observed can be specified.

For such detection, a DC motor (turning means) 16 for rotationally driving the magnet 13a, and an encoder (excitation position detecting means) 18 for detecting the rotational position of the magnet 13a in correspondence with the position of the partial winding of the stator core 21, It is composed of a measuring device (electromotive force measuring means) 17 for detecting the dielectric electromotive force of the coil, and a judgment display device 19 for identifying and displaying or instructing the failure location based on the outputs of the encoder 18 and the measuring device 17. .

Overlap winding portion 221 having rare portion 221d
In a, the number of turns of the overlapping winding portion 221a is reduced due to rare. Therefore, the overlapping winding portions 221b and 221c
Even if the magnet 13a is moved at a constant speed similar to the above case, it is smaller than the electromotive force generated when the magnet 13a approaches and moves away from the lap winding portions 221b and 221c. As a result, the electromotive force generated in the winding 221 when the magnet 13a passes through the inside of the winding 221, is as shown in FIG.

(Third Embodiment) In the first and second embodiments, the magnets 13a and 13b are permanent magnets.
As in the third embodiment shown in FIG. 12, it is possible to use a field coil instead of the permanent magnet.

FIG. 12 schematically shows the structure of the magnet rotating unit 12 and the like, and the structure of the portion not shown is the same as that of the first embodiment. Two field coils (field members) 30a, 3
0b is a coil 302 on a core 301 made of a ferromagnetic material such as iron.
And is built in the magnet rotating unit 12. The coil 302 is connected to the power supply 15 via the brush 31 and the slip ring 32. Then, the core 301 that is magnetized by passing a current through the coil 302
Both magnetic pole surfaces are exposed at positions separated by 180 ° from the circumferential surface of the magnet rotating portion 12. The magnet rotating unit 12 including the field coils 30a and 30b is rotated by a DC motor (turning means) 16.

As a result, while the insulation diagnostic device 1 is operating, a current is passed through the coil 302 (that is, the field coil 3).
When the magnet rotating unit 12 is rotated (with 0a and 30b in the excited state), the N pole and the S pole respectively appear on the exposed surface of the core 301, so that an electromotive force is generated in the stator coil 22 at a portion facing the core 301. Occur. Therefore, the same effect as the first embodiment is obtained.

In this embodiment, the field coil 30a,
Although an example of using two 30b has been shown, if one field coil is provided, the same operational effect as the second embodiment is obtained.

(Fourth Embodiment) In each of the above embodiments, an example in which the permanent magnets or the field coils are rotated has been described. However, as in the fourth embodiment shown in FIG. 13, a large number of field coils are fixed. (Without rotating), a magnetic field can be supplied to each part of the stator coil at a position facing the field coil to generate an electromotive force.

In FIG. 13, a large number of field coils 30 each having a coil wound around a core are fixedly assembled to the pedestal portion 11 (see FIG. 1) of the insulation diagnostic apparatus 1 and the stator coil 22 is provided. One for each lap winding part,
The stator coils 22 are arranged side by side in the circumferential direction. The current control device (current control means / excitation position detection means) 40 controls the current flowing through each field coil 30 and the timing at which the current flows. As shown in FIG. 14, the current is controlled in a triangular wave shape. Are sequentially applied to each field coil 30. Therefore, the same magnetic flux change as the magnetic flux received by the stator coil when the permanent magnet or the field coil is rotated can be given to the stator coil by controlling the current. In addition, the position signal of the field coil that is passing current is sent from the current control device 40 to the determination indicator 19.

According to the above structure, since the magnetic flux changes in proportion to the current flowing through each field coil 30, the field coil 3
The magnetic flux can be temporally changed by controlling the current flowing to 0. Therefore, even if the field coil 30 is fixed, the electromotive force can be generated in the stator coil 22.

Then, as shown in FIG. 14, an electric current is sequentially applied to the field coil 30 to generate an electromotive force in the lap winding portion of the portion to which the magnetic field is supplied, and the electromotive force is measured to determine the stator coil. The electrical insulation failure of 22 can be detected. Further, since the electromotive force and the position of the field coil through which the current is flowing are observed on the determination indicator 19 in association with each other, it is possible to identify the defective portion of electrical insulation.

One field coil 30 may be arranged for each segment conductor straight line portion (portion located in the slit), or if there is no influence on the output voltage of the same pole and other phase, it may be adjacent. It may also be used as the field coil 30 of the other pole.

Further, as described above, a large number of field coils 30 are provided.
The current may be sequentially applied to each of the two magnetic field coils, or the magnetic field pitches may be separated in the same phase of the two field coils 30 or the stator coils 22 that are arranged symmetrically apart from each other by 180 ° in the circumferential direction. Two field coils 30 at different positions may be paired, and a current may be sequentially supplied to each paired field coil 30.

(Fifth Embodiment) In the above first embodiment,
The presence / absence of electrical insulation failure is determined based on the Min value and the Max value of the electromotive force. However, as in the fifth embodiment shown in FIG. 15, the presence / absence of electrical insulation failure is determined based on the integrated value of the electromotive force. You can

In FIG. 15, the voltage waveform storage means 50 receives the magnet rotation position signal from the encoder 18 and also the voltage waveform of the electromotive force measured by the measuring device 17. The voltage waveform storage means 50 has a portion S indicated by hatching in FIG. 16, that is, a set voltage V of the electromotive force.
The portion S exceeding s, -Vs is integrated, and the integrated value and the magnet rotation position signal are stored together.

Then, the integrated value is input to the comparator 51, which compares the integrated value with the set threshold value and sends the comparison result to the judgment display unit 19. When the integrated value is smaller than the set threshold value, it is determined that the electric insulation of the stator coil 22 is poor, and the presence of the electric insulation failure and the location of the electric insulation failure are displayed on the determination display unit 19. In this way, by comparing the integral values, it is possible to improve the accuracy of determining whether or not there is an electrical insulation defect.

When the field coil is fixed and inspected as in the fourth embodiment, instead of the magnet rotation position signal, the position signal of the field coil that is flowing the current is stored as a voltage waveform. It may be input to the means 50.

(Sixth Embodiment) In the first embodiment, FIG.
Although the electromotive force was measured between the X-phase and the Y-phase and between the Y-phase and the Z-phase of the stator coil 22 by the circuit shown in FIG. 5, it is possible to determine the presence or absence of electrical insulation failure even if the electromotive force is measured for each phase. it can.

That is, after the neutral point 22N is welded and before the neutral point 22N is subjected to the insulation treatment, the neutral point 22N is grounded as in the sixth embodiment shown in FIG. By connecting the voltmeter 17b to the ends 22X, 22Y, 22Z on the side of the anti-neutral point 22N of the phases, the electromotive force can be measured for each phase. The other configurations are the same as those in the first embodiment.

According to this embodiment, when the X phase is rare in the phase,
When the X-phase and the stator core 21 are grounded, the output waveforms shown in FIGS. 5 and 6 are obtained, and when the X-phase and other phases are rare, the output waveforms shown in the upper part of FIG. 9 are obtained. The same effect as the first embodiment is obtained.

In the present embodiment, an example of measuring the X-phase electromotive force is shown. However, by connecting the voltmeter 17b to the ends 22Y and 22Z of the other phases, the electromotive force of the Y-phase and Z-phase is detected. Can be measured.

(Seventh Embodiment) In each of the above embodiments, Y
An example of the connected stator coil 22 is shown,
Even with a stator coil connected in a polygonal shape (for example, delta connection), the insulation failure can be detected by measuring the electromotive force.

The seventh embodiment shown in FIG. 18 shows a method of measuring electromotive force in the case of a stator coil in which only one phase coil is housed in one slot and which is connected in a delta connection. Is grounded, and the voltmeter 17b is connected to the other end of the X phase.

According to the present embodiment, the output waveform as shown in FIG. 4 is obtained under normal conditions. Then, at the time of rare phase in-phase of the X phase as shown by the broken line A in FIG. 18, the electromotive force detected by the voltmeter 17b has a waveform as shown in FIG.
The output waveform as shown in FIG. 20 is obtained when the X phase and other phases are rare as indicated by the broken line B in FIG. 20, and is generated when the X phase and the stator core 21 are grounded as indicated by the broken line C in FIG. The electric power has an output waveform as shown in FIG.

(Other Embodiments) In the first embodiment, the magnets 13 arranged at positions separated by 180 ° in the circumferential direction.
The directions of the magnetic poles of a and 13b were opposite, and the winding directions of the stator coil 22 at positions separated by 180 ° were the same. However, the positions of the two magnets 13a and 13b are not limited to the positions separated from each other by 180 °. That is, if the magnets 13a and 13b whose magnetic poles are opposite to each other are arranged at positions separated from each other by a predetermined angle and the winding directions of the stator coils 22 at the positions separated from each other by the predetermined angle are the same, the same operational effect is obtained. Is obtained.

Further, the magnets 13a and 13b arranged at positions separated by a predetermined angle in the circumferential direction may have the same magnetic pole direction, and the winding direction of the stator coil 22 at a position separated by a predetermined angle may be reversed. The effect of is obtained.
That is, the stator coils 22 installed in the slots spaced apart from each other by a predetermined angle are attached to the magnets 1 separated from each other by the same predetermined angle.
When the magnetic field is changed by the magnets 3a and 13b, the magnets 1 are placed in a positional relationship such that electromotive forces cancel each other out.
3a and 13b may be arranged.

In the first to third embodiments described above, the measurement was performed with a combination of two phases, that is, between the X phase and the Y phase and between the Y phase and the Z phase, but the measurement may be performed with another combination between the two phases.

In the first to fourth embodiments described above, the stator coil 22 is lap-wound, but the present invention is also applicable to a wave-wound stator coil. Further, the present invention can be applied to stators other than 36 slots, for example, 72 slot stators.

In the first embodiment, the magnet rotating unit 12
Although a pair of magnets are arranged at positions separated by 180 ° in the circumferential direction with the magnetic poles reversed in direction, both magnetic pole surfaces of the magnets are arranged on the circumferential surface of the magnet rotating portion 12 as in the third embodiment. If it is exposed to, the same effect can be obtained with one magnet.

In the above embodiment, the stator 2 was reworked by inserting the insulating member in the rare portion. However, it is also possible to repair the rare portion by adding an insulating treatment by a method of inserting a spatula or the like between the rare coils to provide a gap.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of a stator inspection device of the present invention.

FIG. 2 is a schematic diagram showing an arrangement of magnets on an inner peripheral side of a stator in the insulation diagnosis device.

FIG. 3 is a circuit diagram of a stator coil in a measuring instrument.

FIG. 4 is a diagram showing measurement results of electromotive force when the stator coil has no rare.

FIG. 5 is a diagram showing a result of measuring an electromotive force when a stator coil has a rare phase.

FIG. 6 is a diagram showing a result of electromotive force measurement when a stator coil is grounded.

FIG. 7 is a circuit diagram when the stator coil is grounded.

FIG. 8 is a diagram showing a result of measuring an electromotive force when a stator coil has an interphase rare.

FIG. 9 is a diagram showing a result of electromotive force measurement when the stator coil has a rare phase.

FIG. 10 is a diagram showing how the magnet is moved inside the winding wire in the second embodiment.

11 is a diagram showing an electromotive force generated in the winding of FIG.

FIG. 12 is a schematic diagram showing a configuration of a magnet rotating unit 12 in the inspection device of the third embodiment.

FIG. 13 is a schematic diagram showing the arrangement of field coils and the like in the inspection device of the fourth embodiment.

FIG. 14 is a diagram showing a current supply pattern for the field coil of FIG. 11.

FIG. 15 is a block diagram showing the configuration of an electrical insulation failure determination unit in the inspection device of the fifth embodiment.

FIG. 16 is a characteristic diagram of an electromotive force provided for explaining the operation of the fifth embodiment.

FIG. 17 is a circuit diagram inside a measuring device in the inspection device of the sixth embodiment.

FIG. 18 is a circuit diagram inside a measuring device in the inspection apparatus of the seventh embodiment.

FIG. 19 is a diagram showing an electromotive force measurement result when a stator coil has a rare metal in a phase.

FIG. 20 is a diagram showing a result of electromotive force measurement when the stator coil has interphase rare.

FIG. 21 is a diagram showing a result of electromotive force measurement when the stator coil is grounded.

[Explanation of symbols]

2 ... Stator, 21 ... Stator core, 22 ... Stator coil, 13a, 13b ... Permanent magnet constituting magnetic field supplying means, 16 ... DC motor constituting magnetic field supplying means, 30,
30a, 30b ... Field coil forming magnetic field supply means,
40 ... A current control device constituting a magnetic field supply means.

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Atsushi Kamiya 1-1, Showa-cho, Kariya City, Aichi Prefecture, Denso Co., Ltd. (72) Inventor, Mitsuru Kato 1-1-1-1, Showa Town, Kariya City, Aichi Prefecture, Denso Co., Ltd. ( 72) Inventor Takashi Tousawa, 1-1, Showa-cho, Kariya city, Aichi Prefecture DENSO CORPORATION (56) References JP-A-5-119102 (JP, A) JP-A-7-27837 (JP, A) JP-A 2-219435 (JP, A) (58) Fields surveyed (Int.Cl. ⁷ , DB name) G01R 31/34 G01R 31/00-31/06 H02K 11/00

Claims (30)

(57) [Claims] 1. A method for inspecting a stator (2) having a stator coil (22) wound around a cylindrical stator core (21), the method comprising: supplying a magnetic field to the stator coil (22); Magnetic field supplying means (13
a, 13b, 16, 30, 30a, 30b, 40) for detecting a portion to which a magnetic field is supplied by the magnetic field supply means and for supplying a magnetic field by the magnetic field supply means. 22) A method of inspecting a stator, characterized in that a defective insulation portion of the stator coil (22) is specified by measuring an electromotive force generated in the stator coil (22). 2. The magnetic field supplying means arranges a large number of field coils (30) in a circumferential direction of the stator coil (22) so as to face the stator coil (22), and the plurality of field coils are arranged. The electromotive force is generated for each of the stator coils (22) located at a position facing the field coil (30) by controlling a current flowing through each (30). Inspection method of stator. 3. The magnetic field supplying means includes a field coil (30a, 30a, 30a) arranged to face the stator coil (22).
The stator inspection method according to claim 1, wherein 30b) is rotated along the circumferential direction of the stator (2) in an excited state to generate an electromotive force in the stator coil (22). 4. The permanent magnets (13a, 1a, 1a, 1a, 1a, 1a, 1a, 1a, 1a, 1a, 1a, 1c) arranged to face the stator coil (22).
The stator inspection method according to claim 1, wherein 3b) is rotated along a circumferential direction of the stator (2) to generate an electromotive force in the stator coil (22). 5. A magnetic field is supplied to the stator coil (22) by the magnetic field supply means, and an electromotive force generated in the stator coil (22) at a portion to which the magnetic field is supplied is measured. The method for inspecting a stator according to any one of claims 1 to 4, characterized by comparing with a reference voltage. 6. The magnetic field is supplied to one location in the circumferential direction of the stator coil (22) by the magnetic field supply means, and the electromotive force generated in the stator coil (22) at the location where the magnetic field is supplied is measured. 5. The integrated value of the time of the electromotive force and a set value are compared with each other.
Any one of the above is the inspection method of the stator. 7. The magnetic field supplying means simultaneously supplies a magnetic field to two points in the same phase of the stator coil (22), and electromotive forces generated at two points of the stator coil (22) cancel each other. Occasionally, it is determined that there is no insulation failure at the two locations of the stator coil (22), and when detecting the difference in electromotive force generated at the two locations of the stator coil (22), the stator coil (22) The method for inspecting a stator according to any one of claims 1, 3, 4, 5, and 6, characterized in that there is insulation failure at two locations. 8. The directions of the magnetic poles in the radial direction of the core of the magnetic field supplying means are opposite at the two locations of the stator coil (22), and the winding directions at the two locations of the stator coil (22) are the same. The stator inspection method according to claim 7, wherein 9. The direction of the magnetic poles in the core radial direction of the magnetic field supplying means is the same at two positions of the stator coil (22), and the magnetic poles of the stator coil (22) are the same.
The stator inspection method according to claim 7, wherein the winding directions of the portions are opposite to each other. 10. The stator coil (22) is formed by connecting coils of three phases, the electromotive force of each phase of the coils of the three phases is measured, and insulation of the stator coil (22) is performed. The stator inspection method according to claim 1, wherein a defective portion is specified. 11. The stator coil (22) is formed by Y-connecting three-phase coils, and the three-phase coils are paired in two-phase pairs to measure an electromotive force. (10) The method for inspecting a stator according to any one of claims 1 to 9, wherein the defective insulation location is identified. 12. The stator coil (22) is formed by connecting multi-phase coils, wherein only one coil phase of the multi-phase coils is grounded on the side opposite to the neutral point and the other coil is grounded. An electromotive force measuring means (17) for measuring the electromotive force is connected to the anti-neutral side of the phase,
10. The stator inspection method according to claim 1, wherein an electromotive force is measured. 13. The stator coil (22) is formed by connecting multi-phase coils, grounds a neutral point of the multi-phase coils, and connects the neutral point side of each coil phase to the neutral point side. 10. The stator inspection method according to claim 1, wherein an electromotive force measuring means (17) for measuring electromotive force is connected to measure the electromotive force. 14. The stator inspection method according to claim 12, wherein the stator coil (22) is formed by connecting coils of three phases. 15. The method of inspecting a stator according to claim 12, wherein a constant bias voltage is applied to a ground side circuit of the coil. 16. The stator coil (22) is composed of a plurality of partial windings (221a, 221b, 221c), and detects partial electromotive force for each partial winding (221a, 221b, 221c), The stator inspection method according to any one of claims 1 to 15, wherein the insulation state of the partial windings (221a, 221b, 221c) is detected based on the detected partial electromotive force. 17. The plurality of partial windings (221a, 221b, 221) forming the stator coil (22).
The magnetic field is sequentially supplied to c), and the plurality of partial windings (221a, 221b, 221c)
The both-end electromotive force detected at both ends of the stator is set, and the both-end electromotive force detected corresponding to each supply position of the magnetic field is set as the partial electromotive force. Inspection method. 18. The method for inspecting a stator according to claim 1, wherein a defective insulation portion of the stator coil (22) is identified, and insulation treatment is applied to the defective insulation portion to perform insulation. A stator manufacturing method characterized by eliminating defects. 19. An inspection apparatus for a stator (2) having a stator coil (22) wound around a cylindrical stator core (21), wherein a magnetic field is supplied to the stator coil (22) and a magnetic flux is applied for a time. Magnetic field supplying means (13
a, 13b, 16, 30, 30a, 30b, 40), and an excitation position detecting means (18, 40) for detecting a portion where the magnetic field supplying means supplies a magnetic field to the stator coil (22). An electromotive force measuring means (17) for measuring an electromotive force generated in the stator coil (22). 20. The magnetic field supplying means controls a plurality of field coils (30) arranged to face the stator coil (22), and a current control means for controlling a current flowing through each of the plurality of field coils. 20. The inspection device for a stator according to claim 19, further comprising (40). 21. The magnetic field supplying means comprises a field coil (3
0a, 30b) and a swirling means (16) for rotating the field coil along the circumferential direction of the stator (2) in an excited state. apparatus. 22. The magnetic field supplying means is a permanent magnet (13).
20. Stator inspection device according to claim 19, characterized in that it comprises a, 13b) and a swivel means (16) for rotating the permanent magnet along the circumferential direction of the stator (2). 23. A pair of field members (13a, 13a, 13a, 13a, 13a, 13a, 13a, 13a, 13a, 13b, 13a, 13b, 13a, 13b, 13c, 13d, 13a, 13b, 13c, 13d, 13c, 13d, 13d, 13d, 13d, 13d, 13d, 13d, 13d, 13d, which are arranged to face each other in two positions in the same phase of said stator coil. 13b, 30a, 30b) and a turning means (16) for rotating the pair of field members along the circumferential direction of the stator (2). The stator inspection device according to any one of claims. 24. The pair of field members (13a, 13)
b, 30a, 30b), the directions of the magnetic poles in the radial direction are opposite to each other, and the winding directions of the stator coils (22) facing the pair of field members are the same. The stator inspection device according to claim 23. 25. The pair of field members (13a, 13a)
b, 30a, 30b) have the same radial magnetic pole orientation, and the winding directions of the stator coils (22) facing the pair of field members are opposite. The stator inspection device according to claim 23. 26. One magnetic field member (13a, 3a, 3a, 3a, 3a, 3a, 3a, 3a, 3a) arranged to face the stator coil (22) to supply a magnetic field to the stator coil (22).
0a) and a swirl means (16) for rotating the one field member along the circumferential direction of the stator (2).
The inspection device for the stator according to any one of 1. 27. The stator inspection device according to claim 19, further comprising a comparison means (51) for comparing an integral value of the electromotive force with a set value. . 28. The stator inspection device according to claim 19, further comprising a comparison means (19) for comparing the voltage of the electromotive force with a reference voltage. 29. A stator inspection device in which the stator coil (22) is formed by connecting three-phase coils, wherein the electromotive force measuring means (17) is a coil for each phase of the three-phase coil. 29. The stator inspection device according to claim 19, wherein the electromotive force of the stator is measured. 30. A stator inspection device in which the stator coil (22) is formed by connecting three-phase coils in a Y-connection, wherein the electromotive force measuring means (17) comprises two different phases of the three-phase coils. 29. The stator inspection device according to claim 19, wherein the electromotive force is measured in pairs.