JP7378381B2 - Discharge detection device for rotating electrical machines - Google Patents

Description

The present invention relates to a discharge detection device for a rotating electric machine.

Conventionally, a discharge detection device for a rotating electrical machine that detects partial discharge occurring in a rotating electrical machine is known.

JP2016-212122A

In this type of discharge detection device for a rotating electric machine, it would be beneficial if a configuration could be obtained that makes it easy to specify the position of component discharge generated in the iron core.

Therefore, one of the objects of the present invention is to obtain a discharge detection device for a rotating electric machine that can easily identify the position of a partial discharge generated in an iron core.

A discharge detection device for a rotating electrical machine according to an embodiment of the present invention is provided in the stator core of a rotating electrical machine including a stator core and a rotor core that rotates with respect to the stator core, and a stator sensor that receives the radiated waves, a rotor sensor that is provided on the rotor core and receives the waves, and a difference in arrival time of the waves to the stator sensor and the rotor sensor. and a discharge occurrence position specifying section that specifies the position of partial discharge.

According to the discharge detection device for a rotating electrical machine according to the embodiment of the present invention, it is possible to obtain a discharge detection device for a rotating electrical machine that can easily identify the position of a partial discharge generated in an iron core.

FIG. 1 is a diagram illustrating the configuration of a rotating electrical machine system according to a first embodiment. FIG. 2 is an exemplary front view of a portion of the rotating electrical machine of the first embodiment. FIG. 3 is an exemplary sectional view of a part of the rotating electric machine of the first embodiment. FIG. 4 is a block diagram exemplarily showing the configuration of the insulation diagnostic device according to the first embodiment. FIG. 5 is a flowchart exemplarily showing the discharge detection process executed by the control unit of the insulation diagnostic device of the first embodiment. FIG. 6 is an exemplary front view of a part of the rotating electrical machine system of the second embodiment.

Exemplary embodiments of the invention are disclosed below. The configuration of the embodiment shown below and the effects and effects brought about by the configuration are merely examples. The present invention can be realized by configurations other than those disclosed in the following embodiments. Further, according to the present invention, it is possible to obtain at least one of various effects (including derivative effects) obtained by the configuration.

Further, the following embodiments include similar components. Those similar components are given common reference numerals, and redundant explanations will be omitted.

(First embodiment)
<Rotating electrical machine system 1>
FIG. 1 is a diagram exemplarily showing the configuration of a rotating electrical machine system 1 according to the first embodiment. As shown in FIG. 1, the rotating electrical machine system 1 includes a rotating electrical machine 100 and an insulation diagnostic device 200. Rotating electric machine 100 is, for example, a three-phase dielectric motor. Note that the rotating electrical machine 100 is not limited to the above. The insulation diagnosis device 200 performs an insulation diagnosis of the rotating electrical machine 100. The insulation diagnosis device 200 performs partial discharge detection as an insulation diagnosis of the rotating electrical machine 100.

<Rotating electrical machine 100>
The rotating electrical machine 100 includes a housing 10, a rotor 20, and a stator 30.

The housing 10 is formed into a box shape. The housing 10 accommodates a portion of the rotor 20 and the stator 30. The housing 10 is also referred to as a case.

The rotor 20 has a rotor shaft 21 and a rotor core 22. A rotor core 22 is fixed to a portion of the rotor shaft 21 between both ends in the axial direction. The rotor 20 rotates around the rotation axis Ax1 with respect to the stator 30. The rotation axis Ax1 is, for example, the center axis (center line) of the rotor shaft 21. Hereinafter, unless otherwise specified, the axial direction, radial direction, and circumferential direction refer to the axial direction, radial direction, and circumferential direction of the rotor 20, that is, the axial direction, radial direction, and circumferential direction of the rotation axis Ax1.

The rotor shaft 21 is supported by the housing 10 via two bearings 23 so as to be rotatable around the rotation axis Ax1. The two bearings 23 are located on both sides of the rotor core 22 in the axial direction. The bearing 23 is, for example, a sliding bearing, a rolling bearing, or the like.

Both ends of the rotor shaft 21 in the axial direction protrude from the housing 10 to the outside of the housing 10 . A coupling portion 14A is provided at one end of the rotor shaft 21 in the axial direction. The coupling portion 14A is coupled to a coupling target (not shown). The rotating electrical machine 100 is provided with an angle sensor 25 that detects the rotation angle of the rotor 20.

FIG. 2 is an exemplary front view of a portion of the rotating electrical machine 100 of the first embodiment. FIG. 3 is an exemplary sectional view of a portion of the rotating electrical machine 100 of the first embodiment.

As shown in FIG. 2, the rotor core 22 has an outer peripheral part 22a and an inner peripheral part 22b. A plurality of recesses 22c and a plurality of protrusions 22d are provided alternately in the circumferential direction on the outer peripheral portion 22a. In other words, the rotor core 22 includes a base portion 22e and a plurality of convex portions 22d that protrude radially outward from the outer peripheral portion of the base portion 22e and are arranged at intervals in the circumferential direction. A recess 22c is provided between adjacent projections 22d. The plurality of recesses 22c and the plurality of protrusions 22d extend in the axial direction.

Further, as shown in FIG. 3, the rotor core 22 includes a plurality of disc-shaped core blocks 24 arranged in the axial direction. The plurality of core blocks 24 are integrated by a connecting bar 27 and an end ring 26. A duct 22f is provided between two axially adjacent iron core blocks 33. The duct 22f is an air passage.

As shown in FIG. 1, the stator 30 includes a stator core 31 and a stator winding 32. Stator core 31 is located radially outside of rotor core 22 and is formed in a cylindrical shape surrounding rotor core 22 . Stator core 31 is fixed to housing 10 .

As shown in FIG. 2, the stator core 31 has an outer peripheral part 31a and an inner peripheral part 31b. In the inner peripheral portion 31b, a plurality of slots 31c and a plurality of teeth 31d are provided alternately in the circumferential direction. In other words, the stator core 31 includes a base portion 31e and a plurality of teeth 31d that protrude radially inward from the inner peripheral portion of the base portion 31e and are arranged at intervals in the circumferential direction. A slot 31c is provided between adjacent teeth 31d. The base portion 31e is also referred to as a stator core back portion.

Further, as shown in FIG. 3, the stator core 31 includes a plurality of disc-shaped core blocks 33 arranged in the axial direction. The plurality of iron core blocks 33 are integrated with each other. A duct 31f is provided between two axially adjacent iron core blocks 33. The duct 31f is an air passage.

The stator winding 32 shown in FIGS. 1 and 3 is inserted into the slot 31c of the stator core 31 and fixed to the stator core 31. Stator winding 32 extends in the axial direction.

Further, as shown in FIGS. 2 and 3, the rotating electric machine 100 includes a plurality of rotor sensors 40 and a plurality of stator sensors 50. The rotor sensor 40 and the stator sensor 50 can receive waves emitted due to partial discharge generated in the rotating electrical machine 100. Partial discharge occurs, for example, in the stator winding 32 within the slot 31c of the stator core 31, or between the stator winding 32 and the stator core 31. That is, partial discharge occurs, for example, in the stator core 31, and the rotor sensor 40 and stator sensor 50 can receive electromagnetic waves as waves. Note that the rotor sensor 40 and the stator sensor 50 may be capable of receiving light, ultrasonic waves, etc. as waves. The waves are also called radiated waves or radiated signals.

In this embodiment, two rotor sensors 40 are fixed to each core block 24 of the rotor core 22. The two rotor sensors 40 are a first rotor sensor 40A and a second rotor sensor 40B. The rotor sensor 40 is arranged on the outer peripheral portion 22a of each core block 24 of the rotor core 22. The rotor sensor 40 is placed inside the duct 22f. Further, one stator sensor 50 is fixed to each core block 33 of the stator core 31. The stator sensor 50 is arranged on the base portion 31e of each core block 33 of the stator core 31. The rotor sensor 40 is placed inside the duct 31f. The stator sensor 50 is placed inside the duct 31f. Moreover, the two rotor sensors 40 and stator sensors 50 provided in the core blocks 24 and 33 arranged in the radial direction are arranged on the same plane E. Further, the plurality of rotor sensors 40 are arranged in two rows extending in the axial direction, and the two rows are spaced apart in the circumferential direction. Moreover, the plurality of stator sensors 50 are arranged in an example extending in the axial direction. Rotor sensor 40 and stator sensor 50 are also referred to as discharge sensors.

<Insulation diagnostic device 200>
FIG. 4 is a block diagram exemplarily showing the configuration of the insulation diagnostic device 200 of the first embodiment. As shown in FIG. 4, the insulation diagnostic device 200 includes a control section 201, a storage device 202, a communication section 203, and an input/output section 204. The control unit 201, the storage device 202, the communication unit 203, and the input/output unit 204 are connected to be able to exchange information and signals.

The storage device 202 stores various information. In this embodiment, the storage device 202 stores the positions of each rotor sensor 40 and each stator sensor 50. The position of the rotor sensor 40 is, for example, a position relative to a rotor reference position, which is a predetermined reference position in the rotor core 22. From the position of the rotor sensor 40 with respect to this rotor reference position and the output of the angle sensor 25 (the angle of the rotor 20 with respect to the rotation reference), the position of the rotor sensor 40 with respect to a predetermined sensor reference position can be calculated. . The sensor reference position is arbitrary, and may be, for example, the position of a certain stator sensor 50. The position of the stator sensor 50 is relative to the sensor reference position. Storage device 202 is a known storage medium.

The communication unit 203 is a communication interface for communicating with other devices. For example, the communication unit 203 includes a communication interface for wireless communication with the rotor sensor 40, a communication interface for wired communication with the stator sensor 50, and a communication interface for wired communication with the angle sensor 25. Note that the communication unit 203 may wirelessly communicate with the stator sensor 50 and the angle sensor 25.

The input/output unit 204 includes an input unit that receives operation instructions from an operator such as a worker, and a display unit that displays an image. The input unit is, for example, a keyboard, a mouse, or the like. The display unit is, for example, a liquid crystal display device, an organic EL (Electro Luminescence) display, or the like. The input/output unit 204 may be a display with a touch panel that integrally includes an input unit and a display unit.

The control unit 201 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory). That is, the control unit 201 is a computer. The CPU reads and executes a program stored in a ROM or the like. Further, the CPU is configured to be able to perform various types of arithmetic processing in parallel. The RAM temporarily stores various data used when the CPU executes programs and performs various arithmetic operations. The control unit 201 is also referred to as a calculation unit or an information processing unit.

The control unit 201 has, as a functional configuration, an acquisition unit 201a and a discharge occurrence position identification unit 201b. These functional configurations are realized as a result of the CPU executing a program stored in a ROM or the like. Note that part or all of the above functional configuration may be realized by dedicated hardware (circuit).

The acquisition unit 201a acquires various information and signals from the rotor sensor 40, stator sensor 50, angle sensor 25, and the like.

The discharge occurrence position identification unit 201b identifies the occurrence position of a partial discharge based on the information acquired by the acquisition unit 201a. The hyperbolic method is used to specify the position of a partial discharge by the discharge occurrence position specifying unit 201b. A method for specifying the position of a partial discharge by the discharge occurrence position specifying section 201b will be described below.

When a partial discharge occurs in the partial discharge generating section D (FIGS. 2 and 3), an electromagnetic wave, which is a wave, is emitted as a pulse signal along with the partial discharge. This electromagnetic wave reaches each rotor sensor 40 and each stator sensor 50. Each rotor sensor 40 and each stator sensor 50 transmits discharge information including a digital signal obtained by converting a received wave into a voltage and a reception time of the electromagnetic wave to the insulation diagnostic device 200. Depending on the position of the partial discharge generating part D, even the same pulse signal can reach each rotor sensor 40 and each stator sensor 50 depending on the distance between each rotor sensor 40 and each stator sensor 50 and the partial discharge generating part D. There will be a difference in time. In other words, there is a difference between the time when electromagnetic waves arrive at a certain stator sensor 50 and the time when electromagnetic waves arrive at a certain rotor sensor 40. That is, a difference in arrival time of electromagnetic waves to the stator sensor 50 and the rotor sensor 40 occurs. In other words, there is a difference between the time when stator sensor 50 receives electromagnetic waves and the time when rotor sensor 40 receives electromagnetic waves. The arrival time difference is also referred to as the reception time difference.

Here, a receiving sensor is used as a general term for each rotor sensor 40 and each stator sensor 50. With two receiving sensors as reference points, a locus of points having a constant distance difference from these reference points becomes a hyperbola with both reference points as focal points. A hyperbola between the stator sensor 50 on a certain plane E and the first rotor sensor 40A on the plane E, and a hyperbola between the stator sensor 50 and the second rotor sensor 40B on the plane E. and seek. Note that at this time, the position of each rotor sensor 40 when receiving the electromagnetic waves can be calculated from the output of the angle sensor 25. Then, a hyperbola between the stator sensor 50 on the plane E and the first rotor sensor 40A on the plane E, and a gap between the stator sensor 50 and the second rotor sensor 40B on the plane E. By determining the coordinates (intersection position) of the intersection with the hyperbola, the position (position in the circumferential direction and radial direction) of the partial discharge generating portion D on the plane E can be specified. In addition, partial discharge occurs at the position in the axial direction of the stator sensor 50 or the plurality of rotor sensors 40 where the received electromagnetic wave intensity (voltage value) is largest among the plurality of stator sensors 50 or the plurality of rotor sensors 40. It is specified (determined) as the axial position of section D. In this way, the position (circumferential, radial, and axial positions) of the partial discharge generating portion D can be determined. Note that the hyperbolas of each of a plurality of sets of the plurality of rotor sensors 40 and the plurality of stator sensors 50 may be obtained, and the coordinates of the intersection of the plurality of hyperbolas may be specified as the position of the partial discharge generating portion D.

The insulation diagnostic device 200, together with the rotor sensor 40 and the stator sensor 50, constitutes a discharge detection device 300 for a rotating electrical machine that specifies the position of partial discharge.

Next, the discharge detection process executed by the control unit 201 of the insulation diagnostic device 200 will be described based on FIG. 5. FIG. 5 is a flowchart exemplarily showing the discharge detection process executed by the control unit 201 of the insulation diagnostic device 200 of the first embodiment.

First, the acquisition unit 201a acquires discharge information from the rotor sensor 40 and the stator sensor 50 (S11). The acquisition unit 201a also receives angle information indicating the angle of the rotor 20 transmitted from the angle sensor 25 via the communication unit 203.

Next, the discharge occurrence position specifying unit 201b calculates the arrival time difference of the electromagnetic waves to the stator sensor 50 and the rotor sensor 40 from the information acquired by the acquisition unit 201a, and specifies the position where the partial discharge occurs using the method described above. (S12).

Next, the control unit 201 outputs discharge occurrence position information indicating the position of the partial discharge specified by the discharge occurrence position specifying unit 201b (S13). For example, the control unit 201 displays discharge occurrence position information on the display unit. Note that this output may be performed by the discharge occurrence position specifying section 201b, or may be performed by an output section (not shown) as a functional section.

<Effects of embodiment>
As described above, in this embodiment, the electric discharge detection device 300 for a rotating electric machine includes the stator sensor 50, the rotor sensor 40, and the electric discharge occurrence position specifying section 201b. The stator sensor 50 is provided in a stator core 31 of a rotating electric machine 100 that includes a stator core 31 and a rotor core 22 that rotates with respect to the stator core 31, and detects waves ( As an example, receive electromagnetic waves). The rotor sensor 40 is provided on the rotor core 22 and receives waves (for example, electromagnetic waves). The discharge occurrence position specifying unit 201b specifies the position of partial discharge based on the difference in arrival time of waves to the stator sensor 50 and the rotor sensor 40.

According to such a configuration, the discharge occurrence position specifying unit 201b, based on the difference in arrival time of waves to the stator sensor 50 provided on the stator core 31 and the rotor sensor 40 provided on the rotor core 22, Since the position of the partial discharge is specified, it is easy to specify the position of the partial discharge generated in the iron core (for example, the stator iron core 31). Moreover, according to such a configuration, both partial discharges between different phases and between different phases can be detected.

Further, in this embodiment, for example, one stator sensor 50 and one or more rotor sensors 40 are provided on a plane E perpendicular to the axial direction of the rotor core 22.

According to such a configuration, for example, the circumferential and radial positions of partial discharge can be identified (estimated).

Further, in this embodiment, the discharge detection device 300 for a rotating electric machine includes a plurality of stator sensors 50 arranged at intervals in the axial direction, and a plurality of rotors arranged at intervals in the axial direction. A sensor 40 is provided.

According to such a configuration, for example, the axial position of partial discharge can be specified (estimated).

(Second embodiment)
FIG. 6 is an exemplary front view of a portion of the rotating electrical machine system 1 according to the second embodiment. In this embodiment, one rotor sensor 40 and one stator sensor 50 are provided on each plane E, and the method of specifying the position of partial discharge by the discharge occurrence position specifying section 201b is the first. Different from the embodiment.

When a plurality of pulse signals are emitted while the rotor 20 is rotating, the first position P1 of the rotor sensor 40 when receiving the first pulse signal, which is a certain pulse signal, and the next pulse of the first pulse signal. A second position P2 of the rotor sensor 40 when the second pulse signal is received is calculated from the output of the angle sensor 25. A hyperbola between the stator sensor 50 and the rotor sensor 40 on the plane E due to reception of the first pulse signal, and a hyperbola between the stator sensor 50 and the rotor sensor 40 on the plane E due to reception of the second pulse signal. Find the hyperbola of and. Then, a hyperbola between the stator sensor 50 and the rotor sensor 40 on the plane E due to the reception of the first pulse signal, and a hyperbola between the stator sensor 50 and the rotor sensor 40 on the plane E due to the reception of the second pulse signal. By determining the coordinates of the intersection with the hyperbola in between, the circumferential position of the partial discharge generating portion D can be specified. The radial position of the partial discharge generating portion D can be determined by the same method as in the first embodiment.

According to such a configuration, since only one rotor sensor 40 and one stator sensor 50 are provided on each plane E, it is easy to simplify the configuration of the discharge detection device 300 for a rotating electric machine.

Note that in each of the above embodiments, an example was shown in which only one stator sensor 50 was provided on each plane E, but the present invention is not limited to this. For example, a plurality of stator sensors 50 may be provided on each plane E.

Furthermore, in each of the above embodiments, an example has been shown in which the rotor core 22 and the stator core 31 are provided with the ducts 22f and 31f, and the rotor sensor 40 and the stator sensor 50 are disposed in the ducts 22f and 31f. , but not limited to. For example, the ducts 22f and 31f may not be provided in the rotor core 22 and the stator core 31, and the rotor sensor 40 and the stator sensor 50 may be embedded in the rotor core 22 and the stator core 31.

Although several embodiments of the invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and changes can be made without departing from the gist of the invention. These embodiments and their modifications are included within the scope and gist of the invention, as well as within the scope of the invention described in the claims and its equivalents.

22... Rotor core, 31... Stator core, 40... Rotor sensor, 50... Stator sensor, 100... Rotating electrical machine, 300... Discharge detection device for rotating electrical machine, E... Plane.

Claims (3)

A stator sensor that is provided on the stator core of a rotating electrical machine that includes a stator core and a rotor core that rotates with respect to the stator core, and that receives waves radiated due to partial discharge;
a rotor sensor provided on the rotor core and receiving the waves;
a discharge occurrence position specifying unit that specifies the position of the partial discharge based on the arrival time difference of the waves with respect to the stator sensor and the rotor sensor;
Discharge detection device for rotating electric machines equipped with The discharge detection device for a rotating electric machine according to claim 1, wherein one of the stator sensors and one or more of the rotor sensors are provided on a plane perpendicular to an axial direction of the rotor core. a plurality of stator sensors arranged at intervals in the axial direction of the rotor core;
a plurality of rotor sensors arranged at intervals in the axial direction of the rotor core;
The discharge detection device for a rotating electric machine according to claim 1 or 2, comprising:

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