JP7435136B2 - Insulation testing equipment and insulation testing method - Google Patents

Description

The present invention relates to an insulation testing device and method for testing the insulation state of a coating on a wire forming a coil of a rotating electric machine.

2. Description of the Related Art Rotating electric machines used in motor generators and the like mounted on electric vehicles have been known. The manufacturing process of the rotating electric machine includes a step of inspecting the insulation state of the coating of the wire forming the coil inserted into the slot of the armature core.

The insulation testing device described in Patent Document 1 tests the insulation between the phases before the U-phase, V-phase, and W-phase wires inserted into the slots of the stator core are connected at a neutral point. The interphase insulation test refers to an insulation test between a wire of a given phase and a wire of another phase. Specifically, for example, in an insulation test between a U-phase wire and a V-phase wire, one probe of the insulation testing device is connected to the U-phase wire, and the other probe is connected to the V-phase wire. Then, an AC voltage is applied to the U-phase and V-phase wires from an insulation testing device to measure the amount of discharged charge due to partial discharge.

Japanese Patent Application Publication No. 2005-257549

However, when performing an insulation test between phases, the insulation testing device described in Patent Document 1 distinguishes between a location where the insulation test is performed (hereinafter referred to as a "measurement location") and a location where the insulation test is not performed (hereinafter referred to as "measurement site"). (referred to as "non-measurement area"). Therefore, when a floating potential exists in a non-measurement area, a discharge is induced from the non-measurement area to the measurement area, and the discharge tends to increase. For example, when testing the insulation between a U-phase wire and a V-phase wire, no probe is connected to the W-phase wire and the stator core. Therefore, a discharge is induced from the W-phase wire or the stator core, which is the non-measurement region, to the U-phase wire or V-phase wire, which is the measurement region. In that case, there is a risk that the accuracy of the insulation test will decrease due to over-detection, such as erroneously determining that a wire rod within the standard that meets the predetermined quality standards is a wire rod that does not meet the quality standards and is out of the standard.

In view of the above-mentioned points, an object of the present invention is to provide an insulation testing device and an insulation testing method that can improve testing accuracy.

In order to achieve the above object, according to the invention according to claim 1, an insulation inspection device checks the insulation state of a coating of a plurality of wire rods inserted into a slot (21) of a core (2) of an armature of a rotating electric machine. Inspect the U-phase wire, V-phase wire, and W-phase wire before they are connected. This insulation testing device includes a power supply section (3), a switching section (4), a discharge amount measuring section (5), an insulation determining section (6), and a control section (7). The power supply section has a first terminal (31) and a second terminal (32). The switching unit is capable of switching between a plurality of electrical connection states and disconnection states between each of the U-phase, V-phase, and W-phase wires and cores and the first terminal, and It is possible to switch between a plurality of electrical connection states and disconnection states between each of the wires and cores and the second terminal . The discharge amount measurement unit measures the discharge that occurs between a member electrically connected to the first terminal and a member electrically connected to the second terminal among the U-phase, V-phase, and W-phase wires and cores. Measure the amount. The insulation determining section determines whether the coating of the wire is a product that meets predetermined quality standards and is within specifications based on the amount of discharge measured by the amount of discharge measuring section. The control unit controls the U-phase, V-phase, and W-phase wires and cores of the U-phase, V-phase, and W-phase without electrically cutting off both the first terminal and the second terminal. The switching unit is controlled so that all of the wires and cores are electrically connected to the first terminal or the second terminal.

According to this, floating potential can be eliminated by electrically connecting all of the U-phase, V-phase, and W-phase wires and cores to the first terminal or the second terminal. Therefore, no discharge is induced from the non-measurement area where the insulation test is not being performed to the measurement area where the insulation test is being performed. Therefore, this insulation testing device can prevent over-detection of erroneously determining a wire rod within the standard that meets a predetermined quality standard as a wire rod outside the standard that does not meet the quality standard, and can improve the accuracy of the insulation test.
Note that the discharge amount refers to the number of times that a discharge is considered to have occurred, which is measured every predetermined time based on the amount of charge measured by the discharge amount measuring section.
Further, the wire inserted into the slot of the armature is also called a segment coil.

By the way, the insulation test is sometimes performed in a state where the environmental humidity or the moisture absorption of the film of the wire material (hereinafter, these may be simply referred to as "humidity") is high. In that case, discharge continues to occur between the U-phase, V-phase, and W-phase wires and cores that are electrically connected to the first terminal and those that are electrically connected to the second terminal. There is a tendency for self-sustaining discharges to occur. The reason for this is thought to be that in a humid environment, air and films contain a lot of moisture, which tends to cause ionization of gas atoms, making it easier for electron avalanches to continue. Therefore, in general, in insulation inspection, measures are taken to reduce the partial discharge inception voltage (PDIV) at a constant rate with respect to the rate of increase in humidity. However, even with this measure, there is a problem that when the humidity exceeds a predetermined value, self-sustaining discharge becomes more likely to occur, the rate of over-detection increases, and the accuracy of insulation inspection decreases.

Therefore, in the invention according to claim 6, the insulation state of the coating of a plurality of wire rods inserted into the slot (21) of the core (2) of the armature of a rotating electric machine is changed between the U-phase wire rod, the V-phase wire rod and the W-phase wire rod. The insulation inspection device that inspects the state before the phase wire is connected includes a power supply section (3), a switching section (4), a control section (7), a discharge amount measurement section (5), and an insulation judgment section (6). ) and a humidity detection section (12). The power supply section has a first terminal (31) and a second terminal (32). The switching unit is capable of switching between a plurality of electrical connection states and disconnection states between each of the U-phase, V-phase, and W-phase wires and cores and the first terminal, and It is possible to switch between a plurality of electrical connection states and disconnection states between each of the wires and cores and the second terminal. The control unit controls the U-phase, V-phase, and W-phase wires and cores of the U-phase, V-phase, and W-phase without electrically cutting off both the first terminal and the second terminal. The switching unit is controlled so that all of the wires and cores are electrically connected to the first terminal or the second terminal. The discharge amount measurement unit measures the discharge that occurs between a member electrically connected to the first terminal and a member electrically connected to the second terminal among the U-phase, V-phase, and W-phase wires and cores. Measure the amount. The insulation determining section determines whether the coating of the wire is a product that meets predetermined quality standards and is within specifications based on the amount of discharge measured by the amount of discharge measuring section. The humidity detection unit detects the environmental humidity in which the U-phase, V-phase, and W-phase wire rods and the core are installed. This insulation testing device makes a judgment when the environmental humidity matches a predetermined value regarding the judgment time from the start of applying voltage from the power supply section to the wire until the insulation judgment section judges whether the insulation state of the wire is good or bad. The time is set to a predetermined time for determining whether the insulation state of the wire is good or bad, and the determination time is set shorter than the predetermined time when the environmental humidity is lower than a predetermined value, and when the environmental humidity is higher than the predetermined value. The determination time is set to be longer than the predetermined time.

According to this, when the humidity is higher than a predetermined value, by setting the determination time longer, the number of discharges measured by the discharge amount measuring section converges over time. Therefore, this insulation testing device can prevent over-detection and improve testing accuracy without being affected by humidity. On the other hand, when the humidity is lower than a predetermined value, the time required for the insulation test can be shortened by setting the determination time short.

The invention according to claim 7 is characterized in that the insulation state of the coating of a plurality of wire rods inserted into the slot (21) of the core (2) of the armature of a rotating electric machine is determined by determining the insulation state of the coating of the wire rod of the U phase, the wire rod of the V phase, and the wire rod of the W phase. This invention relates to an insulation testing method for testing a wire before it is connected. This inspection method ensures that the U-phase, V-phase, and W-phase wires and cores are insulated from both the first terminal (31) and second terminal (32) of the power supply section (3). Instead, all of the U-phase, V-phase, and W-phase wires and cores are electrically connected to the first terminal or the second terminal. Then, a voltage is applied from the power supply unit to the U-phase, V-phase, and W-phase wires and the core, and the member electrically connected to the first terminal among the U-phase, V-phase, and W-phase wires and the core The amount of discharge generated between the terminal and the member electrically connected to the second terminal is measured.

According to this inspection method, as in the invention according to claim 1, by eliminating floating potential, over-detection can be prevented and the accuracy of insulation inspection can be improved.

The invention according to claim 8 also determines the insulation state of the coating of a plurality of wire rods inserted into the slot (21) of the core (2) of the armature of a rotating electrical machine by determining the insulation state of the coating of the wire rod of the U phase, the wire rod of the V phase, and the wire rod of the W phase. This invention relates to an insulation testing method for testing a wire before it is connected. In this method, the U-phase, V-phase, and W-phase wires and cores are electrically connected to the first terminal (31) or second terminal (32) of the power supply section (3). . The environmental humidity in which the U-phase, V-phase, and W-phase wire rods and cores are installed is detected. Regarding the determination time from the start of voltage application from the power supply unit to the wire until the insulation determination unit determines whether the insulation state of the wire is good or bad, the determination time when the environmental humidity matches a predetermined value is the time required to determine whether the insulation state of the wire is good or not. Set a predetermined time for determining pass/fail, set the determination time shorter than the predetermined time when the environmental humidity is lower than the predetermined value, and set the determination time longer than the predetermined time when the environmental humidity is higher than the predetermined value. Set. Then, a voltage is applied from the power supply unit to the U-phase, V-phase, and W-phase wires and the core, and the member electrically connected to the first terminal among the U-phase, V-phase, and W-phase wires and the core The amount of discharge generated between the terminal and the member electrically connected to the second terminal is measured.

According to this testing method, as with the invention according to claim 6, it is possible to prevent over-detection and improve the accuracy of insulation testing without being affected by humidity. On the other hand, when the humidity is lower than a predetermined value, the time required for the insulation test can be shortened by setting the determination time short.

Note that the reference numerals in parentheses attached to each component etc. indicate an example of the correspondence between the component etc. and specific components etc. described in the embodiments to be described later.

FIG. 1 is a schematic diagram showing a circuit configuration of an insulation testing device according to a first embodiment. FIG. 3 is a schematic diagram showing a portion of a plurality of wire rods inserted into slots of a stator core. FIG. 2 is a schematic diagram showing a state in which wires of each phase of a rotating electric machine are connected in series. It is a table comparing the insulation testing methods of the first comparative example and the first embodiment. It is a table comparing the insulation testing methods of the first comparative example and the second embodiment. FIG. 7 is a schematic diagram showing a state in which wires of each phase of a rotating electric machine to be subjected to an insulation test according to a third embodiment are connected in parallel. It is a table comparing the insulation testing methods of the second comparative example and the third embodiment. It is a schematic diagram showing the circuit configuration of the insulation testing device concerning a 4th embodiment. These are experimental results showing changes in the number of discharges due to the influence of humidity.

Embodiments of the present invention will be described below with reference to the drawings. Note that in each of the following embodiments, parts that are the same or equivalent to each other will be denoted by the same reference numerals, and the description thereof will be omitted.

(First embodiment)
A first embodiment will be described with reference to the drawings. As shown in FIGS. 1 to 3, the insulation testing device 1 of this embodiment is a device that tests the insulation state of the coatings of a plurality of wire rods inserted into slots 21 of a stator core 2 of a rotating electrical machine (not shown). Note that the rotating electrical machine is used, for example, as a motor generator mounted on an electric vehicle.

As shown in FIG. 1, the insulation testing device 1 includes a power supply section 3, a switching section 4, a discharge amount measuring section 5, an insulation determining section 6, a control section 7, and the like.
The power supply section 3 is constituted by an AC power supply. The power supply section 3 has a first terminal 31 and a second terminal 32. The first terminal 31 is connected to the switching unit 4 via one wiring 8. The second terminal 32 is connected to the switching unit 4 via the other wiring 9.

The switching unit 4 is electrically connected to the U-phase, V-phase, and W-phase wires and the stator core 2 . As shown in FIG. 2, the U-phase, V-phase, and W-phase wires are inserted into slots 21 of the stator core 2. FIG. 2 schematically shows a part of the stator core 2 and a part of a plurality of wire rods that are inserted into the slots 21 and constitute the U phase, V phase, and W phase. Note that the wire is also called a segment coil.

Moreover, as shown in FIG. 3, the U-phase wire, the V-phase wire, and the W-phase wire are each connected in series. The U-phase wire, the V-phase wire, and the W-phase wire are in a state before being connected at the neutral point in the Y connection.

As shown in FIG. 1, the switching unit 4 connects the U-phase, V-phase, and W-phase wires and the stator core 2 to one wiring 8 connected to the first terminal 31 and the second terminal 32. This is a changeover switch that can switch between an electrically connected state and an electrically disconnected state with the other wiring 9.

The blocking coil 10 provided in the wiring 8 connecting the first terminal 31 and the switching unit 4 prevents a discharge pulse signal (harmonic component) generated by partial discharge occurring in the wire or the stator core 2 from flowing back to the power supply unit 3. This is to prevent Further, the coupling capacitor 11 provided in the wiring 13 connected in parallel to the power supply section 3 and the switching section 4 is for passing only the discharge pulse signal generated by the partial discharge occurring in the wire or the stator core 2. .

The discharge amount measuring section 5 is provided in series with the coupling capacitor 11. The discharge amount measuring section 5 is configured to measure the U-phase, V-phase, and W-phase wires and members of the stator core 2 that are electrically connected to the first terminal 31 via the switching section 4 . The amount of discharge generated between the second terminal 32 and a member electrically connected to it is measured. Specifically, the discharge amount measuring section 5 detects a minute current flowing through the coupling capacitor 11 when a partial discharge occurs, and calculates the amount of discharged charge based on the current value. Then, the discharge amount measurement unit 5 measures the number of times that the discharge is considered to be a discharge based on the amount of discharged charge, and determines the amount of discharge as the amount of discharge.

In this embodiment, the discharge amount measurement unit 5 measures the discharge amount using, for example, the following two parameters. Specifically, the discharge amount measurement unit 5 determines that a discharge is occurring when the amount of charge is greater than a predetermined value and the frequency of charge movement due to alternating current is greater than or equal to a predetermined frequency. I do. Then, the discharge amount measuring section 5 measures the number of times of the discharge every predetermined time and sets it as the discharge amount.

The insulation determination unit 6 determines whether the coating of the wire is a product that meets predetermined quality standards and is within specifications based on the amount of discharge measured by the amount of discharge measurement unit 5. Specifically, if the discharge amount measured by the discharge amount measuring section 5 after a certain period of time has elapsed from the start of discharge is smaller than a predetermined threshold value, the insulation determination section 6 determines that the coating of the wire meets a predetermined quality standard. It is determined that the product is within the range. On the other hand, if the amount of discharge measured by the amount of discharge measuring section 5 after a certain period of time has elapsed from the start of discharge is greater than a predetermined threshold, the insulation determination section 6 determines that the coating of the wire does not meet the predetermined quality standards. Determine that it is a product.

Information regarding the determination result by the insulation determination section 6 is transmitted to the control section 7. The control section 7 controls the operation of each section of the insulation testing device 1. Specifically, the control section 7 controls the output voltage of the power supply section 3. Further, the control unit 7 can control the operation of the switching unit 4.

In the present embodiment, the control unit 7 operates the switching unit 4 so that all of the U-phase, V-phase, and W-phase wires and the stator core 2 are electrically connected to the first terminal 31 or the second terminal 32. control. Further, the control unit 7 controls the operation of the switching unit 4 so that none of the U-phase, V-phase, and W-phase wires and the stator core 2 are insulated from both the first terminal 31 and the second terminal 32. do.

As a result, when performing an insulation test, the insulation testing device 1 electrically connects all of the U-phase, V-phase, and W-phase wires and the stator core 2 to the first terminal 31 or the second terminal 32. It is possible to eliminate floating potential. Therefore, no discharge is induced from the non-measurement area where the insulation test is not being performed to the measurement area where the insulation test is being performed. Therefore, this insulation testing device 1 can prevent over-detection of erroneously determining a wire rod within the standard that meets a predetermined quality standard as a wire rod outside the standard that does not meet the quality standard, and can improve the accuracy of the insulation test.

Furthermore, the insulation testing device 1 of the first embodiment is capable of simultaneously testing a plurality of parts regarding phase-to-phase and ground-to-earth insulation testing. Therefore, compared to a general insulation testing method, the number of testing times is reduced, and the time required for insulation testing can be shortened.

Hereinafter, with reference to the table of FIG. 4, the insulation testing method by the insulation testing device 1 of the first embodiment and the insulation testing method of the first comparative example will be explained in comparison. Note that the first comparative example shows a general insulation testing method for a wire in which a U-phase wire, a V-phase wire, and a W-phase wire are connected in series. Note that the order of the insulation tests listed in the table of FIG. 4 can be changed arbitrarily. This also applies to the tables in FIGS. 5 and 7 that will be referred to in the second and third embodiments described later.

First, an insulation inspection method according to a first comparative example will be explained.
In the first comparative example, the insulation test between the phases is performed in the first to third tests, and the ground insulation test is performed in the fourth test.
Specifically, at the first time, an insulation test is performed between the U-phase wire rod and the V-phase wire rod. In the first insulation test, the switching unit 4 operates to electrically connect the first terminal 31 of the power supply unit 3 to the U-phase wire, and to connect the second terminal 32 of the power supply unit 3 to the V-phase wire. electrically connected. Then, an AC voltage is applied from the power supply unit 3 to the U-phase wire and the V-phase wire, and the amount of discharge generated between the U-phase wire and the V-phase wire is measured by the discharge amount measurement unit 5.

Note that in the first insulation test, the W-phase wire rod and the stator core 2 are not measured. Therefore, if a floating potential exists in the non-measurement area, a discharge is induced from there to the measurement area, and the discharge tends to increase. Therefore, in the first comparative example, over-detection occurs, such as erroneously determining a within-standard wire material that meets predetermined quality standards as a non-standard wire material that does not meet the quality standards, resulting in a decrease in the accuracy of insulation inspection. There is a risk.

Subsequently, in the second time, an insulation test is performed between the V-phase wire and the W-phase wire. At the third time, an insulation test is performed between the W-phase wire rod and the U-phase wire rod. Note that the second and third insulation tests differ only in U, V, and W from the description of the first insulation test, so the description will be omitted.

In the fourth test, the insulation between the U-phase, V-phase, and W-phase wires and the stator core 2 is inspected. In the fourth insulation test, the switching unit 4 operates to electrically connect the first terminal 31 of the power supply unit 3 to the U-phase, V-phase, and W-phase wires, and connect the second terminal 32 of the power supply unit 3 to the wires of the U, V, and W phases. Stator core 2 is electrically connected. Then, AC voltage is applied from the power supply section 3 to the U-phase, V-phase, and W-phase wires and the stator core 2, and the amount of discharge generated between the U-phase, V-phase, and W-phase wires and the stator core 2 is the amount of discharge. Measured by the measuring section 5.

In the first comparative example, in the first to fourth insulation inspections, it was determined that the coating of the U-phase, V-phase, or W-phase wire rod was a substandard product that did not meet the predetermined quality standards. , the product will be discarded.

Next, an insulation testing method according to the first embodiment will be explained.
In the first embodiment, the inter-phase insulation test and the ground insulation test are performed simultaneously in the first and second times, and the ground insulation test is performed in the third time.
Specifically, at the first time, an insulation test is performed between the U-phase wire rod, the V-phase and W-phase wire rods, and the stator core 2. In the first insulation test, the switching unit 4 operates to electrically connect the first terminal 31 of the power supply unit 3 to the U-phase wire, and connect the second terminal 32 of the power supply unit 3 to the V-phase and W-phase wires. The wire and stator core 2 are electrically connected. Then, an AC voltage is applied from the power supply unit 3 to the U-phase wire, the V-phase, W-phase wire, and the stator core 2, and between the U-phase wire, the V-phase, W-phase wire, and the stator core 2. The amount of discharge that occurs is measured by the amount of discharge measuring section 5.

Next, an insulation test is performed for the second time between the V-phase wire rod, the W-phase and U-phase wire rods, and the stator core 2. In the second insulation test, the switching unit 4 operates to electrically connect the first terminal 31 of the power supply unit 3 to the V-phase wire, and connect the second terminal 32 of the power supply unit 3 to the W-phase and U-phase wires. The wire and stator core 2 are electrically connected. Then, an AC voltage is applied from the power supply unit 3 to the V-phase wire, the W-phase, U-phase wire, and the stator core 2, and between the V-phase wire, the W-phase, U-phase wire, and the stator core 2. The amount of discharge that occurs is measured by the amount of discharge measuring section 5.

Finally, at the third time, an insulation test is performed between the U-phase, V-phase, and W-phase wires and the stator core 2. In the third insulation test, the switching unit 4 operates to electrically connect the first terminal 31 of the power supply unit 3 to the U-phase, V-phase, and W-phase wires, and connect the second terminal 32 of the power supply unit 3 to the wires of the U phase, V phase, and W phase. Stator core 2 is electrically connected. Then, AC voltage is applied from the power supply unit 3 to the U-phase, V-phase, W-phase wires and the stator core 2, and the amount of discharge generated between the U-phase, V-phase, W-phase wires and the stator core 2 is increased. It is measured by the discharge amount measuring section 5.

In the first embodiment, in the first to third insulation inspections, if it is determined that the coating of any of the U-phase, V-phase, and W-phase wires is a substandard product that does not meet the predetermined quality standards. , the product will be discarded.

In this way, the insulation testing method according to the first embodiment requires fewer tests compared to the insulation testing method of the first comparative example, so the time required for insulation testing can be shortened. This also leads to a reduction in the number of insulation testing devices 1, that is, a reduction in equipment investment.

Note that the first and second wiring connection states in the first embodiment described above will be referred to as the first series connection measurement state. In other words, the first series connection measurement state means that the wire of one of the U-phase, V-phase, and W-phase is electrically connected to the first terminal 31, and the wire of the other two phases is electrically connected to the first terminal 31. The stator core 2 and the second terminal 32 are electrically connected to each other.

Furthermore, the third wiring connection state in the first embodiment described above will be referred to as the second series connection measurement state. That is, the second series connection measurement state means that all the U-phase, V-phase, and W-phase wires are electrically connected to the first terminal 31, and the stator core 2 and the second terminal 32 are electrically connected. connected.
In both the first series connection measurement state and the second series connection measurement state, no non-measurement portion occurs.

The insulation testing device 1 and its method of the first embodiment described above have the following effects.
(1) In the first embodiment, during an insulation test, the control unit 7 controls the switching unit 4, and all of the U-phase, V-phase, and W-phase wires and the stator core 2 are connected to the first terminal 31 and the second terminal. 32 so as not to be in an insulated state with respect to both. In addition, at this time, the control unit 7 controls the switching unit 4 so that all of the U-phase, V-phase, and W-phase wires and the stator core 2 are electrically connected to the first terminal 31 or the second terminal 32. Make it. This makes it possible to eliminate non-measurable parts during insulation testing. Therefore, in the first embodiment, unlike the first comparative example, discharge is not induced from the non-measurement site to the measurement site. Therefore, the insulation testing device 1 and its method of the first embodiment can prevent over-detection and improve the accuracy of insulation testing.

(2) In the first embodiment, during the insulation test, the control unit 7 controls the switching unit 4 to set the above-described first series connection measurement state and second series connection measurement state. Thereby, the insulation testing device 1 and its method of the first embodiment can reduce the number of tests compared to the general testing method described as the first comparative example. Therefore, the insulation testing device 1 and its method of the first embodiment can improve the accuracy of insulation testing by eliminating floating potentials, and can shorten the time required for insulation testing.

(Second embodiment)
A second embodiment will be described. The second embodiment differs from the first embodiment in that a part of the inspection method by the insulation inspection device 1 is changed, and the other parts are the same as the first embodiment. I will only explain about.
In addition, in the second embodiment, similarly to the first embodiment, it is assumed that the U-phase wire, the V-phase wire, and the W-phase wire are each connected in series.

The table of FIG. 5 shows an insulation testing method using the insulation testing apparatus 1 of the second embodiment. Note that the insulation testing method of the first comparative example described in the table of FIG. 5 is the same as that described in the description of the first embodiment, so the description will be omitted.

In the second embodiment, the inter-phase insulation test and the ground insulation test are performed simultaneously in the first and second times.
Specifically, at the first time, an insulation test is performed between the V-phase and W-phase wire rods, the U-phase wire rod, and the stator core 2. In the first insulation test, the switching unit 4 operates to electrically connect the first terminal 31 of the power supply unit 3 to the V-phase and W-phase wires, and to connect the second terminal 32 of the power supply unit 3 to the U-phase wires. The wire and stator core 2 are electrically connected. Then, AC voltage is applied from the power supply unit 3 to the V-phase and W-phase wires, the U-phase wire and the stator core 2, and the voltage is applied between the V-phase and W-phase wires, the U-phase wire and the stator core 2. The amount of discharge that occurs is measured by the amount of discharge measuring section 5.

Next, the insulation of the W-phase and U-phase wire rods, the V-phase wire rod, and the stator core 2 is inspected for the second time. In the second insulation test, the switching unit 4 operates to electrically connect the first terminal 31 of the power supply unit 3 to the W-phase and U-phase wires, and to connect the second terminal 32 of the power supply unit 3 to the V-phase wires. The wire and stator core 2 are electrically connected. Then, AC voltage is applied from the power supply section 3 to the W-phase and U-phase wires, the V-phase wire and the stator core 2, and the AC voltage is applied between the W-phase and U-phase wires, the V-phase wire and the stator core 2. The amount of discharge that occurs is measured by the amount of discharge measuring section 5.

In the second embodiment, in the case where it is determined in the first and second insulation tests that the coating of any of the U-phase, V-phase, and W-phase wires is a substandard product that does not meet the predetermined quality standards. , the product will be discarded.

As explained above, in the second embodiment, during an insulation test, the wires of any two phases among the U phase, V phase, and W phase are electrically connected to the first terminal 31, and The wire of one phase and the stator core 2 and the second terminal 32 are electrically connected. Thereby, floating potential can be eliminated by electrically connecting all of the U-phase, V-phase, and W-phase wires and the stator core 2 to the first terminal 31 or the second terminal 32. Therefore, similarly to the first embodiment, the insulation testing device 1 and method of the second embodiment can prevent overdetection and improve the accuracy of insulation testing.

Furthermore, the insulation testing method according to the second embodiment requires fewer tests compared to the insulation testing method of the first comparative example, so the time required for insulation testing can be shortened.
Furthermore, the insulation testing method according to the second embodiment can reduce the number of times of testing even compared to the insulation testing method according to the first embodiment.

(Third embodiment)
A third embodiment will be described. The third embodiment differs from the first embodiment etc. in that part of the inspection method by the insulation testing device 1 is changed, and the other aspects are the same as in the first embodiment etc. Only the different parts will be explained.

In addition, as shown in FIG. 6, in the third embodiment, the U-phase wire, the V-phase wire, and the W-phase wire are each connected in parallel. In the following description, among the U-phase wire rods, one of the wire rods connected in parallel will be referred to as the U1 wire rod, and the other wire rod will be referred to as the U2 wire rod. Among the V-phase wire rods, one wire rod connected in parallel is called a V1 wire rod, and the other wire rod is called a V2 wire rod. Among the W-phase wire rods, one wire rod connected in parallel is called a W1 wire rod, and the other wire rod is called a W2 wire rod.

Referring to FIG. 7, the insulation testing method by the insulation testing device 1 of the third embodiment and the insulation testing method of the second comparative example will be explained in comparison. Note that the second comparative example shows a general insulation inspection method for a wire in which a U-phase wire, a V-phase wire, and a W-phase wire are connected in parallel.

First, an insulation inspection method according to a second comparative example will be explained.
In the second comparative example, an insulation test between phases is performed in the first to third times, an insulation test within a phase is performed in the fourth to sixth times, and a ground insulation test is performed in the seventh time.
Specifically, at the first time, an insulation test is performed between the wires U1 and U2 and the wires V1 and V2. In the first insulation test, the switching unit 4 operates to electrically connect the first terminal 31 of the power supply unit 3 to the wires of U1 and U2, and connect the second terminal 32 of the power supply unit 3 to the wires of V1 and V2. are electrically connected. Then, an AC voltage is applied from the power supply section 3 to the wires U1 and U2 and the wires V1 and V2, and the amount of discharge generated between the wires U1 and U2 and the wires V1 and V2 is measured by the discharge amount measuring section 5. be measured.

Note that in the first insulation test, the wires W1 and W2 and the stator core 2 are not measured. Therefore, if a floating potential exists in the non-measurement area, a discharge is induced from there to the measurement area, and the discharge tends to increase.

Subsequently, an insulation test is performed for the second time between the V1 and V2 wires and the W1 and W2 phase wires. At the third time, an insulation test is performed between the wires W1 and W2 and the wires U1 and U2. Note that the second and third insulation tests differ only in U, V, and W from the description of the first insulation test, so the description will be omitted.

At the fourth time, an insulation test is performed between the wire rod U1 and the wire rod U2. In the fourth insulation test, the first terminal 31 of the power supply section 3 and the wire of U1 are electrically connected by the operation of the switching section 4, and the second terminal 32 of the power supply section 3 and the wire of U2 are electrically connected. connected to. Then, an AC voltage is applied from the power supply section 3 to the wire rod U1 and the wire rod U2, and the amount of discharge generated between the wire rod U1 and the wire rod U2 is measured by the discharge amount measuring section 5.
In addition, in the fourth insulation test, the wires V1, V2, W1, and W2 and the stator core 2 are non-measured parts. Therefore, if a floating potential exists in the non-measurement area, a discharge is induced from there to the measurement area, and the discharge tends to increase.

Subsequently, at the fifth time, an insulation test is performed between the V1 wire and the V2 phase wire. At the sixth time, an insulation test is performed between the wire rod W1 and the wire rod W2. Note that the fifth and sixth insulation tests differ only in U, V, and W from the description of the fourth insulation test, so the explanation will be omitted.

At the seventh time, an insulation test between the U-phase, V-phase, and W-phase wires and the stator core 2 is performed. In the seventh insulation test, the switching unit 4 operates to electrically connect the first terminal 31 of the power supply unit 3 to the wires U1, U2, V1, V2, W1, and W2, and the second terminal of the power supply unit 3 Terminals 32 and stator core 2 are electrically connected. Then, AC voltage is applied from the power supply section 3 to the wires U1, U2, V1, V2, W1, W2 and the stator core 2, and between the wires U1, U2, V1, V2, W1, W2 and the stator core 2. The amount of discharge that occurs is measured by the amount of discharge measuring section 5.

In the second comparative example, in the first to seventh insulation tests, it was determined that the coating of any of the wires U1, U2, V1, V2, W1, and W2 was a substandard product that did not meet the predetermined quality standards. If so, the product will be discarded.

Next, an insulation testing method according to the third embodiment will be described.
In the third embodiment, the inter-phase insulation test and the ground insulation test are performed simultaneously in the first and second times, and the intra-phase insulation test and the ground insulation test are performed simultaneously in the third time.
Specifically, at the first time, an insulation test is performed between the V-phase and W-phase wire rods, the U-phase wire rod, and the stator core 2. In the first insulation test, the switching unit 4 operates to electrically connect the first terminal 31 of the power supply unit 3 to the wires V1, V2, W1, and W2, and connect the second terminal 32 of the power supply unit 3 to the wires U1. , U2 and the stator core 2 are electrically connected. Then, an AC voltage is applied from the power supply section 3 to the wires V1, V2, W1, and W2, the wires U1 and U2, and the stator core 2, and the wires V1, V2, W1, and W2, the wires U1, U2, and the stator core 2 are The amount of discharge generated between the stator core 2 and the stator core 2 is measured by the amount measuring section 5 .

Next, at the second time, an insulation test is performed between the wires W1, W2, U1, and U2, the wires V1, V2, and the stator core 2. In the second insulation test, the first terminal 31 of the power supply section 3 and the wires W1, W2, U1, and U2 are electrically connected by the operation of the switching section 4, and the second terminal 32 of the power supply section 3 and the wires of V1 are electrically connected. , V2 and the stator core 2 are electrically connected. Then, an AC voltage is applied from the power supply section 3 to the wires W1, W2, U1, and U2, the wires V1 and V2, and the stator core 2, and the wires W1, W2, U1, and U2, the wires V1, V2, and the stator core 2 are connected to each other. The amount of discharge generated between the stator core 2 and the stator core 2 is measured by the amount measuring section 5 .

Finally, at the third time, an insulation test is performed between the wires U1, V1, and W1, the wires U2, V2, and W2, and the stator core 2. In the third insulation test, the switching unit 4 operates to electrically connect the first terminal 31 of the power supply unit 3 to the wires U1, V1, and W1, and connect the second terminal 32 of the power supply unit 3 to the wires U2, V2. , W2 and the stator core 2 are electrically connected. Then, an AC voltage is applied from the power supply unit 3 to the wires U1, V1, W1, the wires U2, V2, W2, and the stator core 2, and the wires U1, V1, W1, the wires U2, V2, W2 and The amount of discharge generated between the stator core 2 and the stator core 2 is measured by the amount measuring section 5 .

In the third embodiment, in the first to third insulation tests, it is determined that the coating of any of the wires U1, U2, V1, V2, W1, and W2 is a substandard product that does not meet the predetermined quality standards. If so, the product will be discarded.

In this manner, the insulation testing method according to the third embodiment requires fewer tests compared to the insulation testing method of the second comparative example, so the time required for insulation testing can be shortened.

Note that the first and second wiring connection states in the third embodiment described above will be referred to as the first parallel connection measurement state. That is, the first parallel connection measurement state means that the wire rods connected in parallel in any two of the U phase, V phase, and W phase are electrically connected to the first terminal 31, and The wires and stator core 2 connected in parallel in the other phase are electrically connected to the second terminal 32.

Furthermore, the third wiring connection state in the third embodiment described above will be referred to as the second parallel connection measurement state. In other words, the second parallel connection measurement state is one in which the first terminal 31 is electrically connected to the wire rod on one side connected in parallel in all phases of the U phase, V phase, and W phase, and The second terminal 32 is electrically connected to the other wire rod and the stator core 2 connected in parallel in all the phases, the V phase, and the W phase.
In both the first parallel connection measurement state and the second parallel connection measurement state, no non-measurement portion occurs.

In the third embodiment described above, during the insulation test, the control unit 7 controls the switching unit 4 to set the above-described first parallel connection measurement state and second parallel connection measurement state. Thereby, the insulation testing device 1 and its method according to the third embodiment can reduce the number of times of testing compared to the general testing method described as the second comparative example. Therefore, the insulation testing device 1 and method of the third embodiment can improve the accuracy of insulation testing by eliminating floating potentials, and can shorten the time required for insulation testing.

(Fourth embodiment)
A fourth embodiment will be described. In the fourth embodiment, a part of the configuration of the insulation testing device 1 and a part of the testing method thereof are changed from the first embodiment etc., and the other parts are the same as the first embodiment etc. Therefore, only the parts that are different from the first embodiment etc. will be explained.

As shown in FIG. 8, the insulation testing device 1 of the fourth embodiment includes a humidity detection section 12. The humidity detection unit 12 detects the environmental humidity in which the U-phase, V-phase, and W-phase wire rods and the stator core 2 are installed, or the moisture absorption of the coating of the wire rods. In the following description, the environmental humidity or the moisture absorption of the film of the wire may be simply referred to as "humidity." Furthermore, the humidity detected by the humidity detection unit 12 is sometimes referred to as "detected humidity."

In the insulation testing device 1 of the fourth embodiment, the determination time from the start of applying voltage to the wire from the power supply section 3 until the insulation determination section 6 determines whether the insulation state of the wire is good or bad is set based on the detected humidity. . The determination time is set longer than the determination time when the detected humidity is higher than a predetermined value than the determination time when the detected humidity is lower than a predetermined value. Note that the predetermined value is set through experiments and the like, and is set, for example, between 40% and 60%.

Here, the significance of changing the determination time depending on the detected humidity will be explained with reference to the graph of FIG. 9. FIG. 9 shows experimental results showing changes in the number of discharges due to the influence of humidity for a plurality of wire rods.

The vertical axis in FIG. 9 indicates the number of discharges. The number of discharges is the same as the amount of discharge explained in the first embodiment. In other words, the number of discharges is defined as a discharge when the amount of charge calculated by the discharge amount measurement unit 5 is equal to or greater than a predetermined value, and the frequency at which the charge is moved by alternating current is equal to or greater than a predetermined frequency. , the number of times the discharge occurs every predetermined period of time.
The horizontal axis in FIG. 9 indicates the time elapsed from the start of application of voltage from the power supply unit 3 to the wire. In this experiment, it is assumed that the voltage applied to the wire from the power supply section 3 is not changed in accordance with the humidity.

In FIG. 9, the transition of the number of discharges when the "detected humidity" detected by the humidity detection unit 12 is low humidity is shown in a cross-hatched bar graph. Further, the transition of the number of discharges when the "detected humidity" is medium humidity is shown in a hatched bar graph. In addition, the transition of the number of discharges when the "detected humidity" is high humidity is shown as a white bar graph.

As shown by the cross-hatched bar graph, in the case of low humidity, the number of discharges is close to a predetermined standard value at time t1. After time t2, the number of discharges is a very small value. Note that the predetermined standard value is a value that is set in consideration of, for example, the lifetime of the rotating electrical machine.

As shown by the hatched bar graph and the white bar graph, in the case of medium humidity or high humidity, the number of discharges exceeds a predetermined standard value from the start of voltage application to time t5. After time t6, the number of discharges falls below a predetermined standard value, and at time t10, the number of discharges has a very small value.

As shown by the cross-hatched bar graph in FIG. 9, when the humidity is low, the time from the start of discharge until the number of discharges decreases is short. On the other hand, as shown by the hatched bar graph and the white bar graph in FIG. 9, when the humidity is high, the time from the start of discharge until the number of discharges decreases becomes longer. Therefore, in the fourth embodiment, the determination time when the humidity is higher than a predetermined value is set longer than the determination time when the humidity is lower than the predetermined value. Thereby, even when the humidity is higher than a predetermined value, the number of discharges measured by the discharge amount measuring section 5 converges over time. Therefore, this insulation testing device 1 and method can prevent over-detection and improve the accuracy of insulation testing without being affected by humidity. On the other hand, when the humidity is lower than a predetermined value, the time required for the insulation test can be shortened by setting the determination time short.

(Other embodiments)
The present invention is not limited to the embodiments described above, and can be modified as appropriate within the scope of the claims. Furthermore, the embodiments described above are not unrelated to each other, and can be combined as appropriate, except in cases where combination is clearly impossible. Furthermore, in each of the above embodiments, it goes without saying that the elements constituting the embodiments are not necessarily essential, except in cases where it is specifically stated that they are essential or where they are clearly considered essential in principle. stomach. In addition, in each of the above embodiments, when numerical values such as the number, numerical value, amount, range, etc. of the constituent elements of the embodiment are mentioned, when it is clearly stated that it is essential, or when it is clearly limited to a specific number in principle. It is not limited to that specific number, except in cases where In addition, in each of the above embodiments, when referring to the shape, positional relationship, etc. of constituent elements, etc., the shape, It is not limited to positional relationships, etc.

(1) In each of the above embodiments, the insulation testing device 1 was described as one that tests the insulation state of the coating of the wire rod assembled to the stator core 2 as an armature included in a rotating electric machine, but the invention is not limited to this. The insulation testing device 1 may be used to test the insulation state of a coating on a wire rod assembled to a rotor core serving as an armature included in a rotating electric machine.

(2) In the first embodiment, the plurality of wire rods forming the U phase, the plurality of wire rods forming the V phase, and the plurality of wire rods forming the W phase are all connected in series, and Although the explanation has been made assuming that the insulation is inspected before the wires are connected at the neutral point, the present invention is not limited to this. The plurality of wire rods constituting the U phase, the plurality of wire rods constituting the V phase, and the plurality of wire rods constituting the W phase are all connected at a neutral point before being connected in series. The insulation may be tested in the previous state.

(3) In the third embodiment, the U-phase wire, the V-phase wire, and the W-phase wire are each connected in two parallels, but the invention is not limited to this. It can be applied to many parallel connections such as wire connections.

(4) In the above embodiment, the wires are Y-connected, but the present invention is not limited to this, and can be applied to Δ-connection, ΔY-connection, YΔ-connection, ΔΔ-connection, YY-connection, and the like.

(5) In the fourth embodiment, the determination time when the detected humidity is higher than the predetermined value is set longer than the determination time when the detected humidity is lower than the predetermined value, but the present invention is not limited to this. The applied voltage when the detected humidity is higher than a predetermined value may be set lower than the applied voltage when the detected humidity is lower than a predetermined value. Note that the voltage applied at that time may be reduced at a higher rate when the humidity exceeds a predetermined humidity (for example, 40 to 60%).

1 Insulation inspection device 2 Stator core 3 Power supply unit 4 Switching unit 5 Discharge amount measurement unit 6 Insulation determination unit 7 Control unit 21 Slot 31 First terminal 32 Second terminal

Claims (8)

The insulation state of the coating of a plurality of wire rods inserted into the slot (21) of the core (2) of the armature of a rotating electrical machine is determined before the U-phase wire, V-phase wire, and W-phase wire are connected. In insulation inspection equipment that inspects conditions,
a power supply unit (3) having a first terminal (31) and a second terminal (32);
A plurality of electrical connection states and disconnection states can be switched between each of the U-phase, V-phase, and W-phase wires and each of the cores and the first terminal, and each of the U-phase, V-phase, and W-phase a switching unit (4) capable of switching between a plurality of electrical connection states and disconnection states between each of the wire and the core and the second terminal;
Measure the amount of discharge that occurs between the U-phase, V-phase, and W-phase wires and the core that is electrically connected to the first terminal and the second terminal. a discharge amount measuring section (5) to
an insulation determination unit (6) that determines whether or not the coating of the wire is a product that meets predetermined quality standards based on the discharge amount measured by the discharge amount measurement unit;
Each of the U-phase, V-phase, and W-phase wires and the core are electrically disconnected from both the first terminal and the second terminal. An insulation testing device comprising: a control unit (7) that controls the switching unit so that all of the wire and the core are electrically connected to the first terminal or the second terminal. The control unit is configured such that wires of any two phases among U-phase, V-phase, and W-phase are electrically connected to the first terminal, and the wire of another phase and the core are connected to the first terminal. The insulation testing device according to claim 1, wherein the switching unit is controlled so that the two terminals are electrically connected. The U-phase wire, V-phase wire, and W-phase wire are each connected in parallel,
The control unit includes:
The wire rods connected in parallel in any two phases of the U phase, V phase, and W phase are electrically connected to the first terminal, and the wire rods connected in parallel in another phase and the controlling the switching unit so that the core and the second terminal are electrically connected to a first parallel connection measurement state;
The first terminal is electrically connected to the wire on one side that is connected in parallel in all the U, V, and W phases, and the wire is connected in parallel in all the U, V, and W phases. According to claim 1, the switching unit is controlled so that the wire rod on the other side of the wire and the core and the second terminal are electrically connected to each other, and a second parallel connection measurement state is set. Insulation testing equipment described. The U-phase wire, V-phase wire, and W-phase wire are each connected in series,
The control unit includes:
The wire of any one of the U-phase, V-phase, and W-phase is electrically connected to the first terminal, and the wire of the other two phases and the core are electrically connected to the second terminal. controlling the switching unit so that the switching unit is in a first series connection measurement state;
The switching unit is configured such that all the wires of the U phase, V phase, and W phase are electrically connected to the first terminal, and the core and the second terminal are electrically connected. The insulation testing device according to claim 1, wherein the insulation testing device controls the voltage to set the second series connection measurement state. The insulation testing device further includes a humidity detection unit (12) that detects the environmental humidity in which the U-phase, V-phase, and W-phase wires and the core are installed,
Regarding the determination time from the start of voltage application from the power supply section to the wire until the insulation determination section determines whether the insulation state of the wire is good or bad, the determination time when the environmental humidity matches a predetermined value is the insulation state of the wire. The determination time when the environmental humidity is lower than a predetermined value is set to be shorter than the predetermined time, and the determination time when the environmental humidity is higher than the predetermined value is set to a predetermined time for determining whether the The insulation testing device according to any one of claims 1 to 4, wherein the insulation testing device is configured to be set for a longer period of time. The insulation state of the coating of a plurality of wire rods inserted into the slot (21) of the core (2) of the armature of a rotating electrical machine is determined before the U-phase wire, V-phase wire, and W-phase wire are connected. In insulation inspection equipment that inspects conditions,
a power supply unit (3) having a first terminal (31) and a second terminal (32);
A plurality of electrical connection states and disconnection states can be switched between each of the U-phase, V-phase, and W-phase wires and each of the cores and the first terminal, and each of the U-phase, V-phase, and W-phase a switching unit (4) capable of switching between a plurality of electrical connection states and disconnection states between each of the wire and the core and the second terminal;
Each of the U-phase, V-phase, and W-phase wires and the core are electrically disconnected from both the first terminal and the second terminal. a control unit (7) that controls the switching unit so that all of the wire and the core are electrically connected to the first terminal or the second terminal;
Measure the amount of discharge that occurs between the U-phase, V-phase, and W-phase wires and the core that is electrically connected to the first terminal and the second terminal. a discharge amount measuring section (5) to
an insulation determination unit (6) that determines whether or not the coating of the wire is a product that meets predetermined quality standards based on the discharge amount measured by the discharge amount measurement unit;
A humidity detection unit (12) that detects the environmental humidity in which the U-phase, V-phase, and W-phase wire rods and the core are installed,
Regarding the determination time from the start of applying voltage to the wire from the power supply section until the insulation determination section determines whether the insulation state of the wire is good or bad, the determination time when the environmental humidity matches a predetermined value is the insulation state of the wire. The determination time when the environmental humidity is lower than a predetermined value is set to be shorter than the predetermined time, and the determination time when the environmental humidity is higher than the predetermined value is set to a predetermined time during which the quality of the product can be determined. An insulation testing device configured to be set for a longer period of time. The insulation state of the coating of a plurality of wire rods inserted into the slot (21) of the core (2) of the armature of a rotating electrical machine is determined before the U-phase wire, V-phase wire, and W-phase wire are connected. In the insulation testing method, which tests the
With respect to both the first terminal (31) and the second terminal (32) of the power supply section (3), each of the U-phase, V-phase, and W-phase wires and the core are not electrically interrupted. , U-phase, V-phase, W-phase wires and the core are all electrically connected to the first terminal or the second terminal;
A voltage is applied from the power supply unit to each of the U-phase, V-phase, and W-phase wires and the core, and the U-phase, V-phase, and W-phase wires and the core are electrically connected to the first terminal. An insulation testing method comprising measuring the amount of discharge generated between a member electrically connected to the second terminal and a member electrically connected to the second terminal. The insulation state of the coating of a plurality of wire rods inserted into the slot (21) of the core (2) of the armature of a rotating electrical machine is determined before the U-phase wire, V-phase wire, and W-phase wire are connected. In the insulation testing method, which tests the
The U-phase, V-phase, and W-phase wires and the core are electrically connected to a first terminal (31) or a second terminal (32) of the power supply unit (3);
Detecting the environmental humidity in which the U-phase, V-phase, and W-phase wire rods and the core are installed;
Regarding the determination time from the start of voltage application to the wire from the power supply unit until the insulation determination unit determines whether the insulation state of the wire is good or bad, the determination time when the environmental humidity matches a predetermined value is the determination time of the insulation state of the wire. A predetermined time for determining pass/fail is set, a determination time when the environmental humidity is lower than a predetermined value is set shorter than the predetermined time, and a determination time is set for the predetermined time when the environmental humidity is higher than the predetermined value. By setting it longer and
A voltage is applied from the power supply unit to each of the U-phase, V-phase, and W-phase wires and the core, and the U-phase, V-phase, and W-phase wires and the core are electrically connected to the first terminal. An insulation testing method comprising measuring the amount of discharge generated between a member electrically connected to the second terminal and a member electrically connected to the second terminal.

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