JP4504799B2 - Coil test method and apparatus for electric motor - Google Patents

Description

  The present invention relates to a test method and apparatus for a stator coil of an electric motor, and more particularly to a test method and apparatus for determining whether a coil is in an insulating state.

  In order to ensure the quality of an electric motor or the like, it is important that the coil to be used does not break the insulation state. In general, an impulse voltage test is employed as a method for inspecting that a coil is well insulated. This impulse voltage test measures the damped oscillation waveform of the transient response voltage generated in the coil by passing the impulse current through the coil, and the waveform shows the damped oscillation waveform indicated by the coil that is guaranteed to have no winding abnormality. This is a test method for determining whether there is a short circuit in the coil or excess or deficiency in the number of turns.

  FIG. 2 is a graph of a transient response voltage waveform output in a conventional impulse voltage test. The horizontal axis of this graph is time, and the vertical axis is voltage. In the conventional impulse voltage test, the presence or absence of abnormality of the test coil is determined from the difference between the preset sample waveform and the waveform indicated by the test coil. Specifically, for example, the area of the first region R1 or the area of the second region R2 surrounded by the time axis and the curve 21 is calculated and compared with the area of the same region in the sample waveform. And the presence or absence of abnormality of a test coil is determined by whether the difference of the area in both waveforms is contained in a predetermined value range.

  In accordance with this test method, for example, when inspecting a coil of an electric motor having a three-phase winding stator, for example, a damped oscillation waveform generated by applying a voltage of 1000 V between the first phase and the second phase Measure. This damped vibration waveform is compared with the damped vibration waveform of the coil that is guaranteed to have no winding abnormality measured under the same conditions as the previous measurement. The presence or absence of winding abnormality of the coil is determined (see Patent Document 1 and Patent Document 2).

  In the above test method, since the motor rotor is not mounted, the sensitivity of the detected damped vibration waveform is lower than the value detected when the stator is mounted, and winding abnormality is detected. May become difficult.

  Moreover, the transient response voltage waveform of the coil obtained by applying the impulse voltage varies depending on, for example, the environmental temperature. Therefore, when it is necessary to test the test coil in a high temperature environment, the test coil and surrounding members may be affected by changes in the environmental temperature, making determination difficult. Further, the detected response waveform may change due to an allowable individual difference of members constituting the electric motor, an allowable deviation in configuration, and the like. This change makes it difficult to determine whether there is a coil abnormality.

  In the invention disclosed in Patent Document 3, an impulse voltage test is performed by inserting an unmagnetized rotor in a space in which the rotor is inserted for the purpose of solving the above problems. By doing so, the magnetic flux generated from the coil when a voltage is applied efficiently passes through the rotor, the sensitivity of the detected damped vibration waveform is improved, and winding abnormality can be detected more accurately. it can.

  In Patent Document 3, the rotor inserted into the stator is made of a magnetic material having uniform magnetic properties. This is intended to avoid changing the measured inductance value of the coil depending on the position of the rotor relative to the stator. Therefore, it has been unsuitable for testing a coil for a motor having a rotor on which a member that gives direction to the magnetic properties of the rotor, such as a magnet already magnetized, is mounted.

In the invention disclosed in Patent Document 4, even if the electric motor has a mover (mainly a rotor) on which a member that gives direction to the magnetic properties of the rotor, such as a magnet, is mounted, the coil The purpose of this test is to perform the test with high accuracy.To that end, the coil inductance is measured, and the position of the mover relative to the stator, which is considered to have the smallest effect on the test results, is determined by the slight difference in position. Is disclosed.
JP-A-6-88849 Japanese Patent No. 3104433 JP 2002-340966 A JP 2003-75500 A

  However, in the conventional impulse voltage test method, the influence of changes in the environment in which the test is performed (for example, changes in the permeability of members around the coil due to changes in the environmental temperature) and individual differences in the magnetic properties of the motor It is impossible to cancel the influence due to the positional deviation of the rotor in the rotation axis direction, the variation in the magnetizing ratio of the magnet, and the like. For this reason, the threshold value for the determination is dealt with, for example, by providing a width, but when the normal value range and the abnormal value range of the values used for the determination are close, A range of values that overlap each other appears, making determination difficult.

  Further, when the rotor of the electric motor has a magnetized member, the passage of magnetic flux through the rotor is significantly hindered depending on the relative position between the rotor and the stator. As a result, the determination value obtained from the impulse voltage test becomes small, and an overlapping value range appears as in the previous stage, making it difficult to determine whether there is a coil abnormality.

  The present invention solves the above problems and provides a coil test method and apparatus for an electric motor that can more accurately determine the presence or absence of a coil abnormality.

  The test method according to the present invention is a method for testing an insulation failure of a stator coil of an electric motor. The test method determines from the step of positioning the relative position between the rotor of the motor and the test coil at the first position, the step of measuring the inductance value of the test coil at the first position, and the inductance value at the first position. A first determination step for determining insulation failure of the coil based on the reference, an impulse voltage test for the stator coil, and an area of the response waveform obtained by the impulse voltage test is defined as a predetermined reference response waveform. A second determination step of determining an insulation failure of the coil by comparing with the area.

  In the above test method, after the first determination step, a step of positioning a relative position between the rotor of the electric motor and the test coil at a second position different from the first position, and an inductance of the test coil at the second position You may provide the step which measures a value, and the 3rd determination step which determines the insulation defect of a coil based on the determination reference | standard from the measured value of the inductance value of a 2nd position.

  The test apparatus according to the present invention is an apparatus for testing an insulation failure of a coil for an electric motor. The test apparatus includes a rotor positioning means for determining a relative position of the rotor to the stator at a desired position, an inductance measuring means for measuring the inductance of the coil, and an impulse voltage generation for applying the impulse voltage to the coil. Means and control means for controlling each means for testing the motor coil. The control means positions the relative position between the rotor of the electric motor and the test coil at the first position, measures the inductance value of the test coil at the first position, and based on the determination criterion from the measured value of the inductance at the first position. The coil insulation failure is determined, an impulse voltage test is performed on the stator coil, and the area of the response waveform obtained by the impulse voltage test is compared with a predetermined reference response waveform area. Control to determine insulation failure.

  Further, the control means of the test apparatus according to the present invention, after performing the impulse voltage test, further positions the relative position between the rotor and the test coil at a second position different from the first position, And measuring the inductance value of the test coil at the second position and determining the insulation failure of the coil based on the determination criterion from the measured inductance value at the second position. It is also possible to perform control such that an impulse voltage test is performed on the coil to determine the insulation failure of the coil.

  With the method and apparatus according to the present invention, it is possible to cancel the influence of a change in the environment in which the test is performed, and to determine whether there is a coil abnormality with sufficient accuracy.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a motor coil testing apparatus according to the present invention will be described below in detail with reference to the accompanying drawings.

Embodiment 1
<Configuration of motor coil testing device>
FIG. 1 is a block diagram showing the configuration of a motor coil testing apparatus according to the present invention. The test apparatus includes a constant voltage power source 3 that applies a constant voltage to the electric motor 1 to be tested, an inductance measuring device 4 that measures the inductance of the test coil, an impulse generator 5 that generates a high voltage for an impulse voltage test, And a control device 6 for controlling the operation of the entire test apparatus.

  Test coils 2u, 2v, 2w are inserted in the stator in the electric motor 1, and the test coils are three-phase Y-connected. Here, they are referred to as a U-phase test coil 2u, a V-phase test coil 2v, and a W-phase test coil 2w, respectively. In the electric motor 1, a rotor (not shown) having magnetized magnets is rotatably inserted into the internal space of the stator.

  The three test coils 2u, 2v, and 2w are connected to a constant voltage power source 3, an inductance measuring device 4, and an impulse generator 5. The constant voltage power supply 3 electrically turns a rotor having a magnetized magnet (not shown) by energizing the three-phase coil, and the relative positional relationship of the rotor with respect to the stator 1 is set to a desired value. It is possible to determine the positional relationship. Next, the inductance measuring device 4 can measure the inductance in two phases (for example, a U-V phase, a V-W phase, and a W-U phase) composed of an arbitrary combination of three-phase test coils. The impulse generator 5 can apply an impulse voltage of approximately 2800 volts between any two phases of the three-phase test coil.

  The control device 6 is connected to the constant voltage power source 3, the inductance measuring device 4, and the impulse generator 5, and the rotation of the rotor by the constant voltage power source 3, the measurement of an arbitrary two-phase inductance value by the inductance measuring device 4, The application of the impulse voltage between any two phases by the impulse generator 5 can be controlled. Further, the control device 6 receives and stores the measured inductance value and the damped oscillation waveform of the transient response voltage generated by the application of the impulse voltage, and performs arithmetic processing based on the data, and obtains the test result. It is possible to output.

<Coil test method>
In the present invention, in addition to the conventional impulse voltage test, a measurement test of the inductance value of the coil is performed, and the presence or absence of coil abnormality is comprehensively determined by combining these test results.

(Short-circuit presence / absence and change in inductance)
In the present invention, focusing on the fact that the inductance value changes depending on the presence or absence of a short circuit of the coil, the short circuit is detected using the measured value of the inductance value.

  FIG. 4 shows the position of a rotor having a magnetized member relative to the stator, and the inductance value of a normal coil and an abnormal coil in which a short circuit (1T short) is provided between windings adjacent to the U phase at only one location. It is a graph which shows the relationship. In the same figure, curves 41, 42 and 43 show the inductance values between the U-V, V-W and W-U phases of the normal coil, respectively, and curves 41a, 42a and 43a show the U-V and V-W of the abnormal coil, respectively. , Inductance values between W-U phases are shown. Details of how to obtain each measured value will be described later. From the figure, it can be seen that the inductance value (41a, 43a) of the abnormal coil is 20% or more smaller than the inductance value (41, 42, 42a, 43) of the normal coil depending on the rotor angle. .

  Therefore, by measuring the inductance value, it is possible to easily determine whether there is an abnormality in the coil. However, the inductance value shows a remarkable change when two different points in the coil are short-circuited by contact or the like. Even if there is an abnormality such as peeling of the coating on the coil, if the parts having the abnormality of the coil are not in contact with each other, the inductance value indicates a normal value. Therefore, the non-contact abnormality is detected by an impulse voltage test.

(Relationship between response waveform area and inductance value by impulse voltage test)
The relationship between the response waveform area obtained by the impulse voltage test and the inductance value will be described.

  FIG. 3 is a graph showing the relationship between the waveform area and the inductance value of the coil. The horizontal axis of this graph is the inductance value of the coil, and the vertical axis is the area of the response waveform, which is the area of the region R1 in FIG. The inductance of the coil is changed by changing the position of the rotor having the magnetized member, the impulse voltage is applied to each of the rotors, the above-mentioned area of the obtained transient response voltage waveform is evaluated, and on the graph plane Plotted (black dots in FIG. 3). A straight line 31 is obtained by approximating the plotted points with a linear expression. As is apparent from the figure, the inductance value of the coil and the area of the response waveform show a proportional relationship.

  As described above, the inductance value of the coil varies depending on the measurement environment, individual differences among the motor components, and the presence or absence of a coil short-circuit abnormality. However, if the relationship between the inductance value of the coil and the area of the response waveform is used, even if the inductance value fluctuates, the response waveform area of a normal coil that shows such an inductance value (without a non-contact coil abnormality) can be calculated. Precise prediction is possible, and the presence or absence of non-contact abnormality of the coil can be determined from the measured response waveform area. When there is a non-contact abnormality, the waveform area obtained by the impulse voltage test changes greatly. Therefore, the presence or absence of non-contact abnormality of the coil can be easily determined by an impulse voltage test.

  As described above, the test method of the present invention uses the impulse voltage test and the inductance value measurement test in combination, so that an abnormality caused by a short circuit is detected by the inductance value measurement test, and a non-contact abnormality that cannot be detected by the inductance value measurement test. Can be detected by an impulse voltage test, and the presence / absence of normality / abnormality regarding the insulation state of the coil can be accurately determined. Furthermore, when used in combination, the effect of correcting the fluctuation of the measured value due to minute fluctuations in the environment around the test coil can be obtained, thereby enabling more strict determination.

  Next, the test method according to the present invention will be described in detail with reference to FIGS. First, a determination criterion determination method used when determining the quality of a coil will be described.

(Determination of judgment criteria)
Prior to testing the test coil, a determination reference value is determined in advance using a normal coil that is guaranteed to have no abnormality in the coil. Therefore, an electric motor provided with a normal coil is arranged as shown in FIG. 1, and an inductance value of the normal coil and a response waveform by an impulse voltage test are measured.

  The configuration of the normal coil is the same as that of the test coil, that is, has a three-phase Y connection. For the coils of two phases (U-V phase, V-W phase, and W-U phase) of the three phases, the relative position of the rotor to the stator is changed by a predetermined angle, and the rotor rotates each time. When the angle and the inductance value are measured, the inductance value changes as shown in FIG. 4 as the rotation angle of the rotor changes. A U-V phase inductance value is plotted as a curve 41, a V-W phase inductance value as a curve 42, and a W-U phase inductance value as a curve 43.

Each inductance value changes periodically with the rotation of the rotor due to the configuration of the coil in the stator and the rotational symmetry of the rotor. Each of the curves 41, 42, and 43 has a period (360 degrees ÷ 4 (number of magnets) = 90 degrees) due to the periodicity of the four magnets arranged on the rotor, and is arranged on the stator. And a phase difference (30 degrees, that is, a phase difference between the first position θ ₁ , the second position θ ₂ , and the third position θ ₃ ) due to the configuration of the three-phase coil.

First, the rotor is aligned with a position (for example, position θ ₁ ) where the inductance value of any one of the U-V phase, V-W phase, and W-U phase is maximized, and incremented by 30 degrees from that position. (Preferably in increments of 15 degrees) and at least 90 degrees (preferably over 360 degrees) of inductance values for each of the U-V, V-W, and W-U phases. At the same time, an impulse voltage is applied to each of the U-V phase, the V-W phase, and the W-U phase at each position to measure the area of the response waveform. Here, the area of the portion indicated as the first region R1 in FIG. 2 is obtained as the area of the response waveform.

  The rotor can be rotated by energizing a predetermined phase with a constant voltage power supply 3. In this method, the stator and the rotor can be aligned even if they are sealed and the position of the rotor cannot be visually recognized from the outside. If the stator and the rotor are visible, a scale or the like may be attached to the stator and / or the rotor, and the operator may rotate and align the rotor. It is also possible to perform mechanical alignment by the control device 6 using an encoder. Further, the response waveform area is not limited to the area of the first region R1 in FIG. 2, and may be the area of the second region R2, or the area of the first region R1 and the second region R2, or after that. It may be the sum of the areas including the area of the region.

  Next, the relationship between the inductance value of the normal coil and the area of the response waveform is specified based on the obtained data.

  In accordance with the example shown in FIG. 3, from the measurement data obtained for each of the U-V phase, the V-W phase, and the W-U phase, the inductance value is x-axis and the waveform area is y-axis. Plot and approximate each case with a linear expression (y = ax + b). Then, the slope (a) of the straight line obtained by approximation and the intercept (b) on the vertical axis are recorded. If the U-phase, V-phase, and W-phase coils are substantially the same, the values of the three slopes (a) and the values of the three intercepts (b) obtained here are substantially Are the same.

  Through the above operations, the U-V phase, V-W phase at the rotor position where the inductance value of any one of the U-V phase, V-W phase, and W-U phase of the normal coil has the maximum value. , And the inductance value of each phase of the W-U phase, the area of the response waveform of each phase of the U-V phase, the V-W phase, and the W-U phase at that position, and the inductance value and the response waveform The linear equation parameters (slope and intercept) when the relationship with the area is linearly approximated are obtained. These values relating to the normal coil are used as reference values in determining the abnormality of the coil.

(Coil abnormality judgment method)
Hereinafter, a method for determining the presence / absence of a test coil abnormality will be described with reference to the flowchart of FIG.

In step S101, the test coil is aligned to a position where the inductance value of any of the U-V phase, the V-W phase, or the W-U phase is a maximum value (for example, the first position θ ₁ in FIG. 4). , Second position θ ₂ or third position θ ₃ ).

  Next, the inductance values of the U-V phase, the V-W phase, and the W-U phase are measured at the rotor position matched in step S101 (step S102).

  The inductance value of each phase measured in step S102 is the same as the rotor position in the measurement in step S102 among the inductance values of each phase measured for the normal coil (or the same phase is the maximum). The inductance value measured at the rotor position) is compared for each phase (step S103). As a result of the comparison, when the measured value of the inductance in any phase is equal to or less than the predetermined ratio of the reference inductance value, it is determined that a short circuit abnormality exists in the coil constituting the phase, and the result is output (step S111). ). Here, the predetermined ratio is preferably set to about 80%.

  Here, the predetermined ratio will be described. In FIG. 4, curves 41a, 42a, and 43a intentionally cause a one-turn short for each of the U-V phase (curve 41a), the V-W phase (curve 42a), and the W-U phase (curve 43a). The measured inductance values of the three-phase coils are plotted. A 1T short is a short between adjacent windings of a coil. The inductance value indicated by the coil having 1T short indicates the value closest to the normal inductance value among the inductance values indicated by the coil having short. When the coil has a short circuit as shown in FIG. 4, the inductance value is smaller than that in a normal state, but as shown by an arrow A in FIG. It appears most prominently at the rotor position. Since the reduction ratio of the inductance value at that time is about 20%, in the present embodiment, the predetermined ratio is set to about 80%.

  As a matter of course, when the U phase has a 1T short, the inductance value (curve 42a) indicated by the VW phase does not change compared to the inductance value indicated by the normal coil. That is, in a three-phase coil having one short circuit, one of the three measured inductance values indicates a normal value. Therefore, after the first measurement, the inductance measurement position is changed and the measurement is performed again so that no measurement is lost.

  Returning to FIG. 5, if it is determined in step S103 that there is no abnormality, the rotor is rotated 30 degrees or 60 degrees in order to change the measurement position (step S104). This angle corresponds to the phase difference between the phases determined by the configuration of the coils in the stator. In other words, by rotating the rotor clockwise or counterclockwise by 30 degrees or 60 degrees, the rotor has a phase different from the phase in which the inductance value has shown the maximum value in step S101 and step S102. The rotor is positioned at a rotor position where the inductance value of any of the phases shows a maximum value.

  At this rotor position, the inductance values of the U-V phase, the V-W phase, and the W-U phase are measured in the same manner as in step S102 (step S105). Then, the comparison is performed in the same manner as in step S103 based on the measured value (step S106). As a result, if it is determined that there is an abnormality in the coil, the result is output (step S111), and if it is determined that there is no abnormality, the process proceeds to step S107. Further, the rotor position may be set to another position where the inductance value of the coil is maximized, and a series of steps similar to steps S101 to S103 or steps S104 to S106 may be repeated.

  When there is a short circuit having a contact between coils of one turn or more in any of the U-phase, V-phase, and W-phase, an abnormality is detected in at least one of step S103 and step S106. However, as described above, in the measurement based on the inductance value, it is difficult to detect an abnormality that does not have contact between coils. Therefore, in order to detect such a coil abnormality, an impulse voltage test is performed in subsequent steps S107 to S109.

  Using the inductance values of the U-V phase, V-W phase, and W-U phase measured in step S105, the U-V phase, V- The reference response waveform area of each phase is obtained from a linear expression that approximates the relationship between the inductance value and its response waveform area for the W phase and the W-U phase (step S107).

  Then, an impulse voltage test is performed on each of the U-V phase, the V-W phase, and the W-U phase at the position determined in step S104 (step S108). Then, the area of the obtained response waveform is compared with the reference response waveform area calculated in step S107 (step S109).

  FIG. 6 shows the relationship (X) between the inductance value and the response waveform area by the impulse voltage test shown by a normal coil, and the relationship (Y) between the inductance value and the response waveform area shown by a coil having a non-contact abnormality. It is a figure. From the figure, it can be seen that the value (Y) of the waveform area with respect to the inductance value of the coil having non-contact abnormality is about 50% of the value (X) indicated by the normal coil. If there is a non-contact abnormality in the coil, discharge occurs in the impulse voltage test (step S108), the area of the response waveform is about 50% of the reference response waveform area, and the inductance value is non-contact. It is because it does not change by abnormality.

  Thus, in this embodiment, when the response waveform area obtained as a result of the impulse voltage test is less than 50% of the reference response waveform area, it is determined that there is an abnormality (step S109). The reference value for this determination can be changed.

  If it is determined in step S109 that there is an abnormality, the result is output (step S111). If it is determined that there is no abnormality, no abnormality is output in step S110.

<< Embodiment 2 >>
(Coil abnormality judgment method)
Another example of the method for determining whether or not there is an abnormality in the test coil will be described with reference to the flowchart of FIG.

  In the coil abnormality determination method described below, the basic principle that forms the basis of the method is substantially the same as the coil abnormality determination method of the first embodiment.

In the coil abnormality determination method of the present embodiment, the relative position of the rotor with respect to the stator having the test coil can be determined only by an electrical method depending on the configuration of the electric motor, and The position of the rotor that can be positioned in the position where the two inductance values are the same among the three inductance values (for example, θ ₄ , θ ₅ , θ ₆ , Etc., hereinafter referred to as a high-inductance crossing position).

In this method, a high inductance crossing position is used for the determination. Therefore, in the “determination of determination criterion” in the first embodiment, the inductance is also detected at a high inductance crossing position (for example, θ ₄ ) that is further rotated by 15 degrees from the position (for example, θ ₃ ) at which any inductance value is maximized. measurements were performed and the measurement of the impulse voltage response waveform area value, the remaining did not show the same inductance value in the high inductance intersections theta ₅ or theta _{6 (position} theta ₄ rotated further position theta ₄ than 30 degrees or 60 degrees of the inductance value, that one inductance one of the two inductance values showing the same inductance value at a position theta ₄ measures the measurement and impulse voltage response waveform area also inductance value at a position) having the same preferable.

First, in step S201 of FIG. 7, the test coil is at a high inductance crossing position where any two of the U-V phase, V-W phase, or W-U phase inductance values are the same at a relatively high value. The positions are aligned (for example, the fourth position θ ₄ , the fifth position θ ₅ , or the sixth position θ ₆ in FIG. 4). When any two of the three inductance values of a normal coil are the same at the same rotor position, the same inductance value can be calculated from the average value of the maximum value and the minimum value of the normal coil inductance value. There are two types of values: a high value and a value less than the average value of the maximum value and the minimum value of the normal coil inductance value. Here, the relatively high value refers to a value higher than the average value of the maximum value and the minimum value of the normal coil inductance value. The rotor position where the two inductance values are the same is apparent from the configuration of the rotor magnet and the configuration of the stator coil.

  Next, at the rotor position matched in step S201, among the inductance values of the U-V phase, the V-W phase, and the W-U phase, if the coil is normal, it has the same inductance value. Two sets of two-phase inductance values are measured (step S202).

  The two sets of two-phase inductance values measured in step S202 are the same high-inductance crossing positions that are substantially the same as the rotor position in the measurement in step S202 among the same two-phase inductance values measured for the normal coil. The inductance value of the normal coil measured in step S203 is compared (step S203). As a result of the comparison, when the measured value of the inductance in any two phases is equal to or less than a predetermined ratio of the reference inductance value, it is determined that a short circuit abnormality exists in the coils constituting the two phases, and the result is output ( Step S214).

Referring again to FIG. 6, the actual measurement points on the approximate line X relating to the relationship between the normal coil inductance and the waveform area can be roughly divided into a set 61, a set 62, a set 63, and a set 64. The inductance value of the normal coil at the high inductance crossing position is an actual measurement point plotted in the set 62. An average (L _c ) of the inductance values of the actual measurement points included in the set 62 may be obtained and used as a reference inductance value. In this method, since the reference inductance value used for the determination may be only L _c , it may be determined that a short-circuit abnormality exists in the test coil that exhibits an inductance value that does not reach a predetermined ratio with respect to L _c .

  Next, using the two sets of two-phase inductance values measured in step S202, the reference response waveform area of each phase is obtained from the relationship between the inductance value and the response waveform area obtained in the determination of the prior criterion. Is obtained (step S204).

  Then, the impulse voltage test is performed on the two phases measured in step S202 at the position positioned in step S201 (step S205). Then, the area of the obtained response waveform is compared with the reference response waveform area calculated in step S204 (step S206).

  As is apparent from FIG. 4, the two-phase combination that was not measured in step S202 shows a very small inductance value at the position determined in step S201. The difference from the above is very small and difficult to judge. Two sets of two-phase inductance values can be measured at any one of a plurality of high-inductance crossing positions, and an impulse voltage test can also be performed. It is possible to determine the included short circuit abnormality and the non-contact abnormality in the two sets of two phases. Therefore, in the following steps, the purpose is to re-verify the short-circuit abnormality included in the coil measured in step S202, and to determine the presence or absence of a set of two-phase non-contact abnormality that was not determined in step S205. To do.

If it is determined in step S206 that there is no abnormality, the rotor is rotated 30 degrees (to the position of θ ₅ ) or 60 degrees (to the position of θ ₆ ) (step S207). This angle corresponds to the phase difference between the phases determined from the configuration of the test coil in the stator. In other words, by rotating the rotor clockwise or counterclockwise by 30 degrees or 60 degrees, the rotor is made up of the remaining two sets of two phases that did not show the same inductance value in step S201 and step S202. The inductance value will show the same inductance value as one of the two sets of two phases that showed the same inductance value in step S201 and step S202 (if the coil is normal). Positioned at the inductance crossing position.

  At this high inductance crossing position, the inductance value of the phase not measured in step S202 is measured (step S208). Then, the comparison is performed in the same manner as in step S203 based on the measured value (step S209). As a result, if it is determined that there is an abnormality in the coil, the result is output (step S214), and if it is determined that there is no abnormality, the process proceeds to step S210.

  Next, using the two-phase inductance values measured in step S208, the reference response waveform area of the phase is obtained from the relationship between the inductance value and the response waveform area obtained in the determination of the prior determination criterion ( Step S210).

  Then, the impulse voltage test is performed on the two phases measured in step S208 at the position positioned in step S207 (step S211). Then, the area of the obtained response waveform is compared with the reference response waveform area calculated in step S210 (step S212).

  If it is determined in step S212 that there is an abnormality, the result is output (step S214). If it is determined that there is no abnormality, no abnormality is output in step S213.

  As described above, the first and second embodiments focus particularly on the relationship between the response waveform area obtained by the impulse voltage test and the inductance value of the coil. That is, in the method according to the present invention, since the inductance value of the coil varies depending on the test environment (ambient temperature, insertion state of the rotor into the stator, etc.), the impulse voltage test corresponding to the change of the coil inductance value is performed. By looking at the response waveform area according to, it is possible to absorb the change in the test environment into the change in the inductance value and cancel the determination error due to the change in the test environment. For example, since the response waveform area has temperature dependence, the response waveform area changes when the ambient temperature changes. For this reason, depending on the ambient temperature during the test, even if the response waveform area is the same, the coil may be abnormal or normal. Further, the inductance value of the test coil also has temperature dependence. In this embodiment, since the response waveform area with respect to the inductance value is viewed, for example, a change in ambient temperature can be included in the change in inductance value, and a determination error due to a change in test environment can be canceled. That is, in the present invention, an error due to environmental fluctuations or the like is canceled by adding a change in inductance of the test coil to the determination material based on the above relationship.

<< Embodiment 3 >>
In the first and second embodiments described above, the relationship between the response waveform area and the inductance value (see FIG. 3) is used, and a measure is taken so that the temperature dependence of the response waveform area does not affect the determination. ing. However, the temperature dependence of the inductance value still exists. However, since the influence is slight, abnormality determination is possible even with the determination method according to the above embodiment. However, if the distance between the temperature environment where the inductance value of the normal coil is measured and the temperature environment where the determination is actually made increases, the influence may not be negligible. Therefore, in the present embodiment, the fluctuation of the inductance value of the test coil due to the temperature dependence of the inductance value is corrected by calculation. Thereby, the inductance value of the test coil in the temperature environment where the inductance value of the normal coil is measured is obtained by calculation, and abnormality is determined. As a result, the test coil is judged to be abnormal using the inductance value measured under the same temperature environment as that of the normal coil, and the temperature dependence of the inductance value can be canceled, and the accuracy of this test can be improved. Can be improved.

  Depending on the environment in which the test coils 2u, 2v, and 2w are tested, taking into account the temperature dependence of the inductance value is effective in increasing the accuracy of the determination. For example, the case where the test coils 2u, 2v, and 2w placed in the paint drying furnace are tested in the furnace as they are can be cited as an example. If the environment for measuring the inductance value of the normal coil is 20 ° C. and the temperature in the furnace is 100 ° C., the temperature difference in the measurement environment reaches 80 ° C. The inventor of the present invention has found that the inductance value increases by about 5% due to a temperature difference of 20 ° C. to 100 ° C., that is, + 80 ° C.

  In the present embodiment, the inductance value is corrected based on the temperature when the inductance values of the test coils 2u, 2v, and 2w are measured.

  Further, there is a clear relationship between the inductance value and the impulse voltage response waveform area (see FIG. 3). As can be easily inferred from this, the temperature dependence of the response waveform area of the test coil can be corrected in addition to the inductance value. Therefore, in the present embodiment, the temperature dependence of the response waveform area may be corrected by calculation.

  Furthermore, in this embodiment, the number of steps required for the determination is increased as compared with the above-described embodiment, but not only the presence / absence of abnormality in the test coil but also the coil having abnormality is any. It is possible to determine with certainty.

  Other points not specifically described are substantially the same as those of the other embodiments.

<Configuration of motor coil testing device>
FIG. 8 is a block diagram showing the configuration of the present apparatus in the third embodiment. The configuration of this apparatus is the same as the apparatus configuration in the first and second embodiments except that the temperature sensor 7 is provided in the electric motor 1. The temperature sensor 7 can measure the temperature of the test coils 2u, 2v, and 2w or the temperature of the surrounding environment in the vicinity of the test coils 2u, 2v, and 2w. Further, the temperature sensor 7 is connected to the control device 6 so as to be able to transmit a signal, thereby transmitting measured temperature data to the control device 6. The temperature sensor 7 may have a specification that continuously measures the temperature and sequentially transmits the temperature to the control device 6. Further, the temperature sensor 7 may be configured to be able to receive a signal from the control device 6, in which case the temperature is measured at a timing based on a command from the control device 6 and the data is transmitted to the control device 6. To do.

  The control device 6 has the same specifications as those of the first and second embodiments, and at least can receive a signal from the temperature sensor 7. It may be possible to transmit a control signal to the temperature sensor 7. The control device 6 stores the temperature data transmitted from the temperature sensor 7 and uses it for determining the abnormality of the test coil.

<Coil test method>
In the test method in the present embodiment, when measuring the inductance values and response waveforms of the test coils 2u, 2v, and 2w, the steps of measuring the temperatures of the test coils 2u, 2v, and 2w, and the measurement based on the temperature Performing a temperature correction of the value. Further, in the step of performing the abnormality determination, the abnormality determination is performed based on the temperature-corrected measurement value.

  Except for the steps described in the preceding paragraph, the content of each step in the first and second embodiments is substantially the same as the content of each step in the present embodiment.

(Determination of judgment criteria)
Similar to the previous embodiment, in this embodiment, prior to testing the test coil, the determination reference value is determined in advance using a normal coil that is guaranteed to have no abnormality in the coil. Therefore, an electric motor having a normal coil is arranged as shown in FIG. 1, and the inductance value of the normal coil and the response waveform by the impulse voltage test are measured. At that time, the temperature of the measurement environment is measured using the temperature sensor 7. Measure and the control device 6 stores the temperature. The measurement is preferably performed in at least two temperature environments having different temperatures, such as normal temperature (about 20 ° C.) and a temperature in the coating drying furnace (about 100 ° C.). Using these measured values, the correction formula described in detail below is determined.

(Coil abnormality judgment method)
In the coil abnormality determination method described below, the basic principle that forms the basis of the method is substantially the same as the coil abnormality determination method in the first and second embodiments. This method is different from the above two embodiments in that the measured inductance value and response waveform area are corrected using the measured environmental temperature.

In the coil abnormality determination method of the present embodiment, the relative position of the rotor with respect to the stator having the test coil can be determined only by an electric method by the configuration of the electric motor as in the first embodiment, and Depending on the configuration of the test coil, the electrically positionable rotor position is a position where any one of the three inductance values has a maximum value (for example, θ ₁ , θ ₂ , θ ₃ , etc. in FIG. 4). It is an effective method even when including. Further, as in the second embodiment, the relative position of the rotor with respect to the stator provided with the test coil can be determined only by an electric method depending on the configuration of the electric motor. The position of the rotor that can be positioned in the position where the two inductance values are the same among the three inductance values (for example, θ ₄ , θ ₅ , θ ₆ , Etc., hereinafter referred to as a high-inductance crossing position).

That is, in the present embodiment, a high-inductance intersection position may be used for the determination, or a position (for example, θ ₁ , θ ₂ , θ ₃ ) where any one of the inductance values becomes maximum may be used. .

In the present embodiment, the relative positional relationship between the rotor and the stator is changed, and abnormality determination based on the inductance value and the response waveform area is performed three times each. Corresponding to these three measurements, the relative positions of the three rotors to the stator are three sets of two phases (U-V phase, V-W phase, and W-U phase) of normal coils. Each of the inductance values may be a combination of positions showing a value larger than the average value of the maximum value and the minimum value at least once out of three measurements. For example, these three relative positions may be θ ₁ , θ ₂ , and θ ₃ in FIG. In this case, three sets of two phases each show a maximum value at any position. Further, for example, θ ₄ , θ ₅ , and θ ₆ in FIG. ₄ may be used. Further, even if a position where any two phases show the maximum value and a position where the two sets of two phases are the same at a value larger than the average value of the maximum value and the minimum value are combined, 3 It suffices that the two phases of the set each have a value that is at least once greater than the average value of the maximum value and the minimum value. When measured at these three positions, the difference between the measured inductance value when the coil is normal and the measured value when the coil is abnormal appears significantly for each of the three sets of two phases. The presence or absence of abnormality can be accurately determined. Further, by comprehensively judging these results, it is possible to specify in which phase an abnormality exists. In the following description, as an example, abnormality determination is performed at θ ₁ , θ ₂ , and θ ₃ .

  A method for determining the presence / absence of abnormality of the test coil in the present embodiment will be described with reference to the flowcharts of FIGS. 9 and 10.

In step S301, the test coils, the inductance value is the maximum position of the two phases, for example, is aligned with the first position theta ₁ in FIG.

  In step S302, the control device 6 measures the temperature of the test coil using the temperature sensor 7, and records the temperature. Here, the temperature of the test coil is Tm.

In step S <b> 303, the two-phase inductance value showing the maximum value at least at the first position θ <b> ₁ of the test coil is measured as in the above-described embodiment, and the measured value is sent to the control device 6.

  Next, in step S304, temperature correction of the inductance measurement value obtained in step S303 is performed. The temperature correction procedure will be described below.

In advance, the inductance value and impulse response waveform area of the normal coil are measured at two temperatures. The control device 6 stores the measured temperatures (T1 and T2) (normal coil measurement temperature), the inductance values (L1 and L2), and the response waveform areas (S1 and S2) in each. As for T1 and T2, for example, T1 is normal temperature (about 20 ° C.), and T2 is furnace temperature (about 100 ° C.). Using these temperatures and inductance values, the control device 6 corrects the measured inductance value of the test coil to the inductance value of the test coil at one temperature of the normal coil measurement temperature, for example, T1, using the following calculation formula. The inductance value L of the test coil whose temperature has been corrected (the inductance value of the test coil at the temperature T1) is given by the following equation.
L = (1− (α × (Tm−T1))) × Lm
here,
α = (L2−L1) / (L1 × T2−L2 × T1)
L1: Measurement value of inductance of normal coil at temperature T1
L2: Inductance measurement value of normal coil at temperature T2
Lm: measured value of inductance of test coil
Tm: Temperature for measuring the inductance value of the test coil

  The above relational expression relating to the temperature dependence of the inductance value has been found by the inventor of the present invention. FIG. 11 shows a graph plotting the relationship between temperature and measured inductance. The temperature is plotted on the horizontal axis, and the inductance value is plotted on the vertical axis, and the inductance values measured at a plurality of different temperatures (eight points in the figure) are plotted with dots 11. In this way, the inductance value changes depending on the temperature. However, by correcting the inductance measurement value by the above correction formula, it is possible to prevent the fluctuation of the determination due to the temperature dependence of the inductance value. Even if the test coil 1 is not tested under the same temperature condition, it is possible to cancel out the temperature dependence of the inductance value and perform an accurate determination.

  Returning to FIG. 9, in step S <b> 305, the calculation value for determination is calculated in the same manner as in the first and second embodiments, using the measured inductance value (L) subjected to temperature correction. The determination method in the present embodiment is substantially the same as the determination method in the first and second embodiments, except that the measured inductance value of the test coil that has been subjected to temperature correction is used.

  Next, in S306, similar to the first and second embodiments, the inductance value measured in step S303 and corrected in step S304 is used to determine the prior determination criteria. The reference response waveform area is obtained from a linear equation that approximates the relationship between the response waveform area and the response waveform area.

In step S307, at the position (first position θ ₁ ) positioned in step S301, a two-phase impulse voltage response waveform area showing a maximum at least at the first position θ ₁ is measured, and the measured value (Sm To the control device 6.

  Next, in step S308, temperature correction of the waveform area measured in step S307 is performed. The temperature correction procedure will be described below.

Here, the impulse response waveform area of the normal coil measured in advance and the temperature (T1 and T2) at which it was measured are used. Using these temperatures and response waveform areas (S1 and S2), the control device 6 calculates the response waveform area as one of normal coil measurement temperatures, for example, T1, for example, the response waveform area (S ). The response waveform area S of the test coil whose temperature is corrected (the response waveform area of the test coil at the temperature T1) is given by the following equation.
S = (1− (α × (Tm−T1))) × Sm
here,
α = (S2−S1) / (S1 × T2−S2 × T1)
S1: Response waveform area of normal coil at temperature T1
S2: Response waveform area of normal coil at temperature T2
Sm: measured value of response waveform area of test coil
Tm: Temperature in measurement of response waveform area of test coil

  The relational expression related to the temperature dependence of the response waveform area is found by the inventor of the present invention. FIG. 12 shows a graph plotting the relationship between temperature and response waveform area. Temperature is plotted on the horizontal axis and response waveform area is plotted on the vertical axis, and response waveform area values measured at a plurality of different temperatures (at eight points in the figure) are plotted with dots 12. In this way, the response waveform area changes depending on the temperature, but by correcting the response waveform area measurement value by the above correction formula, it is possible to prevent the blurring of the determination due to the temperature dependence of the response waveform area, Therefore, even if the test coil 1 is not tested under the same temperature condition as that of the normal coil, the temperature dependence of the response waveform area can be canceled out and accurate determination can be performed.

  Returning to FIG. 9, in step S309, when the response waveform area (S) obtained as a result of the impulse voltage test and the subsequent temperature correction is less than 50% of the reference response waveform area, it is determined that there is an abnormality. The reference value for this determination can be changed. The determination method in the present embodiment is substantially the same as the determination method in the first and second embodiments, except that the measured response waveform area measurement value of the test coil subjected to temperature correction is used.

  If it is determined in step S309 that there is an abnormality, the result is output (step S329). If it is determined that there is no abnormality, the process proceeds to step S310.

In step S310, the test coils, the position where the inductance value is the maximum of the other two phases, for example, is aligned with the second position theta ₂ in FIG.

  In step S311 to step S318, the test using the inductance value and the response waveform area is performed on the two phases where the inductance value is maximum at the second position at the position positioned in step S310 at least in the second position. I do. Thereby, the presence or absence of abnormality is determined for the two phases where the inductance value has a maximum at the second position.

Next, in step S319, the test coil is yet another of the remaining two phases positions inductance value is maximized, for example, is aligned with the third position theta ₃ in FIG.

  In step S320 to step S327, at the position positioned in step S319, as in steps S302 to S309 and steps S311 to S318, at least the inductance value of the two phases having the maximum inductance value in the third position is determined. And a test using the response waveform area. Thereby, the presence or absence of abnormality is determined for the two phases where the inductance value has a maximum at the third position.

  If there is no abnormality in all the tests, an output with no abnormality is made (step S328).

  In the above embodiment, an electric motor having a magnet in the rotor is tested. However, an electric motor having no magnetized member in the rotor can be tested. In this case, the inductance value does not vary with the rotor position as shown in FIG. 4 and the inductance value is constant, but the inductance value of the coil having the short circuit is the same as that of the normal coil. Decrease. Further, the area of the response waveform of the coil having the non-contact abnormality is similarly reduced.

  In the above embodiment, the coil is a three-phase Y-connection, but a coil having a Δ-connection is also possible.

  Moreover, it is desirable to use a high frequency band as the inductance measurement frequency used by the inductance measuring device 4 used in the measurement of the inductance value. In the case of measuring the inductance value of a coil having a short circuit, the inventors of the present invention have found that a difference from the inductance value indicated by a normal coil appears clearly. This will be described below.

  FIG. 13 is a graph showing the relationship between the measured inductance value of a normal coil, the measured inductance value of a coil having a 1T short, and the inductance measurement frequency used for the measurement. The horizontal axis is the inductance measurement frequency shown on a logarithmic scale, and the vertical axis is the measured inductance value. The change in the measured inductance value of the normal coil due to the measurement frequency is approximated by a straight line 81, while the change in the measured inductance value of the coil having 1T short-circuit is approximated by a straight line 82 and displayed. Points on the straight lines 81 and 82 indicate actual measurement values. As is clear from FIG. 8, the difference in the inductance measurement value between the normal coil and the coil having the short circuit is increased by setting the measurement frequency high.

  Therefore, setting the threshold value for determination becomes easier by setting the inductance measurement frequency to a higher frequency band.

  The measurement frequency is a factor that fluctuates the inductance value of the coil, such as errors in the positional relationship between the rotor and the stator in the horizontal and vertical directions, errors due to positioning of the rotor and the stator, and fluctuations due to the measurement temperature. In consideration of factors such as fluctuations in the magnetization rate of the rotor magnet, the range of variation in the inductance value assumed in a normal coil, and the variation in inductance value assumed in a coil having one short of 1T short circuit It is preferable to use a high frequency band that does not overlap the range.

  The coil test method and apparatus for an electric motor according to the present invention cancels the influence due to fluctuations in the environment in which the test is performed, and can determine the presence or absence of coil abnormality with sufficient accuracy. Useful.

1 is a block diagram of a device configuration according to Embodiment 1. FIG. It is a graph of the transient voltage waveform obtained by an impulse voltage test. It is a graph which shows the relationship between the inductance value of a normal coil, and the area of 1st area | region R1 of the transient voltage waveform obtained by an impulse voltage waveform. It is a graph which shows the relationship between the position with respect to the stator of the rotor which has the magnetized member, and the inductance value of the coil which has a normal coil and 1T short. It is a flowchart of the coil abnormality determination method of Embodiment 1 which concerns on this invention. FIG. 4 is a graph showing a relationship between the graph shown in FIG. 3 and the inductance value and transient voltage waveform of a coil having non-contact abnormality. It is a flowchart of the coil abnormality determination method of Embodiment 2 which concerns on this invention. It is a block diagram which shows the structure of the apparatus of this embodiment. It is a flowchart of Embodiment 3 which concerns on this invention. It is a flowchart of Embodiment 3 which concerns on this invention. It is a graph which shows the temperature dependence of an inductance value. It is a graph which shows the temperature dependence of a response waveform area. It is a graph which shows the relationship between an inductance measurement frequency, and the inductance actual value of a coil which has a normal coil and one 1T short.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Electric motor 2u ... U-phase winding 2v ... V-phase winding 2w ... W-phase winding 3 ... Constant voltage power supply 4 ... Inductance measuring instrument 5 ... Impulse generator 6 ... Control device 7 ... Temperature sensor 21 ... Transient voltage waveform 31 ... Inductance-waveform area approximate straight line 41 ... Normal U-V phase inductance value interpolation curve 42 ... Normal V-W Phase inductance value interpolation curve 43 ... Normal W-U phase inductance value interpolation curve 44 ... U-phase 1T short U-V phase inductance value 45 ... U-phase 1T short V-W phase inductance value 46 ... U phase 1T short W-U phase inductance value X ... Normal coil inductance-waveform area approximate line Y ... Non-contact abnormal coil inductance-waveform area approximate line 61 Measured value set 62 at the position where the inductance value is maximum in the normal coil ・ ・ ・ Measured value set 63 at the high inductance crossing position in the normal coil ・ ・ ・ Measured value at the low inductance crossing position in the normal coil Set 64... Measured value set 81 at a position where the inductance value is minimum in a normal coil... Normal coil inductance measured value approximate straight line 82... 1T short coil inductance measured value approximate straight line

Claims (19)

A method for testing insulation failure of a stator coil of an electric motor,
Positioning a relative position between the rotor of the electric motor and the test coil at a first position;
Measuring an inductance value of the test coil at the first position;
A first determination step of determining an insulation failure of the test coil based on a determination criterion from a measured value of the inductance value at the first position;
Performing a first impulse voltage test on the test coil of the stator;
The area of the resulting response waveform by said first impulse voltage test, by comparing the first reference response waveform area, have a second determination step of determining an insulation failure of the test coil,
The first reference response waveform area is determined according to a measured value of the inductance value of the test coil based on a relationship between an inductance value obtained in advance with respect to a normal coil and an impulse voltage response waveform. A coil test method for an electric motor. The first reference response waveform area is an inductance value of the test coil measured at a relative position where the relative positional relationship between the rotor and the test coil is substantially equal to the relative positional relationship at the first position. The coil test method for an electric motor according to claim 1, wherein the coil test method is determined according to a measured value. further,
Measuring the temperature of the test coil; and
Correcting the inductance measurement based on the temperature; and
2. The motor coil testing method according to claim 1, wherein in the first determination step, an insulation failure of the test coil is determined using the corrected measured inductance value. further,
Measuring the temperature of the test coil; and
Correcting the area of the response waveform based on the temperature,
2. The method according to claim 1, wherein in the second determination step, the insulation failure of the test coil is determined using the corrected response waveform area. The said 1st position is a position where the said inductance value becomes maximum in the change of the inductance value of the said test coil accompanying rotation of the said rotor, The Claim 1 thru | or 4 characterized by the above-mentioned. Coil test method for electric motors. The first position is, in a change in the inductance value of the normal coil caused by the rotation of the rotor, the two inductance values of any two phases with different normal coils together, the inductance value of the normal coil 5. The method for testing a coil for an electric motor according to claim 1 , wherein the position is substantially the same as a value larger than an average value of the maximum value and the minimum value. 6. After the first determination step,
Positioning a relative position between the rotor of the electric motor and the test coil at a second position different from the first position;
Measuring an inductance value of the test coil at the second position;
7. The method according to claim 1 , further comprising a third determination step of determining an insulation failure of the test coil based on the determination criterion from a measured value of the inductance value at the second position. The coil test method for motors as described. further,
A first position changing step for changing the relative position to a second position different from the first position;
After the first position changing step,
Measuring an inductance value of the test coil in the second position;
A third determination step of determining an insulation failure of the test coil based on a determination criterion from a measured value of the inductance value at the second position;
Performing a second impulse voltage test on the test coil of the stator; and
A fourth determination step of determining an insulation failure of the test coil by comparing an area of the response waveform obtained by the second impulse voltage test with a second reference response waveform area;
Have
The second reference response waveform area is determined based on a relative positional relationship between the rotor and the test coil based on a relationship between an inductance value obtained in advance with respect to a normal coil and an impulse voltage response waveform. The electric motor according to claim 1, wherein the electric motor is determined according to a measured value of an inductance value of the test coil measured at a relative position substantially equal to a relative positional relationship in Coil test method. further,
A second position changing step for changing the relative position to a third position different from the first position and the second position;
After the second position changing step,
Measuring an inductance value of the test coil in the third position;
A fifth determination step for determining an insulation failure of the test coil based on a determination criterion from a measured value of the inductance value at the third position;
Performing a third impulse voltage test on the test coil of the stator; and
A sixth determination step of determining an insulation failure of the test coil by comparing an area of the response waveform obtained by the third impulse voltage test with a third reference response waveform area;
Have
The third reference response waveform area is determined based on the relative position relationship between the rotor and the test coil based on the relationship between the inductance value obtained in advance with respect to a normal coil and the impulse voltage response waveform. The coil test method for an electric motor according to claim 8, wherein the coil test method is determined according to a measured value of an inductance value of the test coil measured at a relative position substantially equal to a relative positional relationship in. 10. The motor coil test method according to claim 1 , wherein, in the first determination step, the determination criterion is determined based on an inductance value of the normal coil. 11. An apparatus for testing an insulation failure of a coil for an electric motor,
a) rotor positioning means for determining a relative position of the rotor to the stator at a desired position;
Inductance measuring means for measuring the inductance of the test coil,
Impulse voltage generating means for applying an impulse voltage to the test coil; and
Control means for controlling each means for testing the test coil;
b) The control means
A relative position between the rotor of the electric motor and the test coil is positioned at a first position, an inductance value of the test coil is measured at the first position, and a determination criterion is obtained from the measured value of the inductance at the first position. a first determination to determine the insulation failure of the test coil on the basis of, also, the first carried out an impulse voltage test to the subject coil, the first impulse voltage response waveform obtained by the test of the stator From the area of the control , to perform a second determination to determine the insulation failure of the test coil based on the first reference response waveform area value ,
The first reference response waveform area is determined according to a measured value of the inductance value of the test coil based on a relationship between an inductance value obtained in advance with respect to a normal coil and an impulse voltage response waveform. Electric motor coil testing equipment. The first reference response waveform area is an inductance value of the test coil measured at a relative position where the relative positional relationship between the rotor and the test coil is substantially equal to the relative positional relationship at the first position. The coil test apparatus for an electric motor according to claim 11, wherein the coil test apparatus is determined according to a measured value. Furthermore, the coil test apparatus for motors of Claim 11 which has a temperature sensor connected to the said control means so that signal transmission is possible, which measures the temperature of the said test coil. The control means corrects the measured value of the inductance of the test coil based on the temperature of the test coil measured by the temperature sensor, and based on the determination criterion from the correction value of the inductance value obtained as a result. The coil test apparatus for an electric motor according to claim 13 , wherein an insulation failure of the test coil is determined. The control means corrects the measured value of the response waveform area of the test coil based on the temperature of the test coil measured by the temperature sensor, and calculates the predetermined waveform from the correction value of the response waveform area obtained as a result. The coil test apparatus for an electric motor according to claim 13 , wherein an insulation failure of the test coil is determined based on a reference response waveform area value. The control means further positions the relative position between the rotor of the electric motor and the test coil at a second position different from the first position after measuring the inductance at the first position, and the second position. in claims measure the inductance value of the test coil, from the measured value of the inductance values of the second position, and controls to determine an insulation failure of the test coil on the basis of the criterion, it is characterized by The coil test apparatus for an electric motor according to any one of 11 to 15 . The control means further performs a second impulse voltage test after the determination of the insulation failure of the test coil based on the measured value of the inductance value at the second position and the determination criterion, and the second impulse voltage test. The area of the response waveform obtained by the above is controlled to determine the insulation failure of the test coil by comparing with the second reference response waveform area,
The second reference response waveform area is determined based on the relative position relationship between the rotor and the test coil based on the relationship between the inductance value obtained in advance with respect to a normal coil and the impulse voltage response waveform. The coil test apparatus for an electric motor according to claim 16 , wherein the coil test apparatus is determined in accordance with an inductance value of the test coil measured at a relative position substantially equal to a relative positional relationship in . A method for testing insulation failure of a stator coil of an electric motor,
Measuring an inductance value of the test coil; and
Performing an impulse voltage test on the test coil of the stator;
A determination step of determining an insulation failure of the test coil by comparing an area of the response waveform obtained by the impulse voltage test with a reference response waveform area;
Have
The reference response waveform area depends on the measured value of the inductance value of the test coil obtained in the measuring step based on the relationship between the inductance value obtained in advance for a normal coil and the impulse voltage response waveform. A method for testing a coil for an electric motor, characterized by being determined. An apparatus for testing an insulation failure of a coil for an electric motor,
Inductance measuring means for measuring the inductance of the test coil,
Impulse voltage generating means for applying an impulse voltage to the test coil; and
Comprising control means for controlling each means,
b) The control means
An inductance value of the test coil is measured, an impulse voltage test is performed on the test coil of the stator, and an area of the response waveform obtained by the impulse voltage test is calculated based on a reference response waveform area value. Control to determine the insulation failure of the coil,
The reference response waveform area is determined according to a measured value of the inductance value of the test coil based on a relationship between an inductance value obtained in advance with respect to a normal coil and an impulse voltage response waveform. Coil testing device for electric motors.

Images