JP2015021852A - Soundness inspection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a soundness inspection device capable of simply and easily inspecting the soundness of an electric machine provided with a coil at a rotor side while making the rotor rotate.SOLUTION: The soundness inspection device inspects a soundness of a rotating coil 102 which is fitted to a synchronous generator functioned by a magnetic action working between a stator and a rotator 100 with the rotating coil wound around the rotator which is stored rotatably inside a stator 200, and includes: a plurality of additional coils 11 provided to have a magnetic flux path inside the rotating coil in common; and a comparator circuit 21 for detecting a voltage difference between electromotive forces generated in the additional coil. The cutting off of an exciting power supply 300 with the rotator in a rotation state and the application of an alternating voltage to the rotating coil from the alternating power supply 30 generate an induction electromotive force. When the voltage difference exceeds a set threshold value, a detection signal outputted from the comparator circuit 21 is amplified, and an alarm light 23 is turned on.

Description

  The present invention relates to a soundness inspection apparatus, and more particularly to an apparatus for inspecting the soundness of a coil in a rotating body.

Electric machines such as an electric motor and a generator that function by generating magnetic flux in a coil on the rotor side are known. For example, in a generator of a hydroelectric power plant, the rotor is rotated by water pressure that drops stored water. The electromotive force generated in the coil is collected. In addition, an electric motor rotates a rotor by the magnetic effect | action with respect to the magnetic force of the permanent magnet by the side of a stator by supplying drive electric power to the coil by the side of a rotor, and generating a magnetic flux, for example.
The coils of this type of electric machine achieve balanced rotation by being arranged at a plurality of positions at equal positions around the rotation axis. This coil needs to perform maintenance work to inspect the insulation between the wires and perform maintenance so as to ensure insulation and generate uniform electromagnetic force (magnetic flux). In addition, about the test | inspection of the soundness of a coil, the patent documents 1-3 are proposed, for example.

JP-A 63-48372 Japanese Utility Model Publication No. 06-47882 Japanese Patent Laid-Open No. 03-18771

In such a soundness inspection device, the coil on the rotor side may be short-circuited due to centrifugal force during rotation as well as in the stopped state, so the coil soundness remains in the rotated state. It is preferable to conduct a sex test.
However, since the maintenance work of the electric machine is generally performed in a stopped state, there is a problem that the reproducibility of the short-circuit state is low.
In addition, for example, as described in Patent Documents 1 and 2, there is a problem that the detection sensitivity is low when the change in the magnetic characteristic is small when the failure detection is performed using the change in the magnetic characteristic. Furthermore, as described in Patent Document 3, if a slip circuit or the like is installed by incorporating a detection circuit in a coil, the configuration of the apparatus becomes complicated and the operation efficiency may be reduced.
Therefore, the present invention provides a soundness inspection apparatus that can easily inspect the soundness of the coil of an electric machine including a coil on the rotor side with a simple configuration while rotating the rotor. It is aimed.

  One aspect of the invention of a soundness inspection apparatus that solves the above problem is that a magnetic action acting between the stator and the rotor is obtained by winding a rotating coil around the rotor that is rotatably accommodated in the stator. A plurality of additional coils provided for each of the rotating coils that share a magnetic flux path in the rotating coil with a soundness inspection apparatus that checks the soundness of the rotating coil by being attached to an electric machine that functions by A voltage detection unit that detects an electromotive force generated in the additional coil; a determination unit that determines soundness of the rotating coil based on a detection result of the electromotive force generated in the additional coil detected by the voltage detection unit; It is characterized by providing.

  As described above, according to one aspect of the present invention, since the electromotive force in the additional coil that shares the magnetic flux path with the rotating coil is detected to determine the soundness, it is not necessary to process the rotating coil, and the additional coil is added. Thus, the soundness of the rotating coil can be inspected. Therefore, the soundness of the rotating coil can be easily inspected with a simple configuration in which an additional coil is added.

FIG. 1 is a diagram illustrating an example of a synchronous generator equipped with an embodiment of a soundness inspection apparatus for an electric machine including a rotating coil according to the present invention, and is a conceptual perspective view illustrating a schematic overall configuration thereof. FIG. 2 is a connection block diagram showing the configuration of the soundness inspection apparatus.

  As one aspect of an embodiment of the present invention, an electric machine that functions by a magnetic action acting between the stator and the rotor by winding a rotating coil around the rotor that is rotatably accommodated in the stator. A plurality of additional coils provided for each of the rotating coils that share a magnetic flux path in the rotating coil, and the additional coil. In addition to including a voltage detection unit that detects an electromotive force generated, and a determination unit that determines the soundness of the rotating coil based on a detection result of the electromotive force generated in the additional coil detected by the voltage detection unit. The following configuration may be provided.

As a first other aspect, an alternating power source that applies an alternating voltage to the rotating coil may be provided.
In this aspect, it is possible to generate an electromotive force that can be easily detected in the additional coil by simply applying an alternating voltage to the rotating coil instead of the exciting current, and the soundness can be easily and reliably inspected. .

As a second other aspect, the first switch connected so as to intervene in the middle of the body side circuit to which the rotating coil is connected, the rotating coil and the first switch of the body side circuit, A branch line for branching the alternating power supply between the second switch and a second switch connected so as to intervene in the middle of the branch line.
In this aspect, the alternating voltage can be applied to the additional coil from the alternating power source by simply switching the first and second switches, and the soundness can be easily and easily inspected without adverse effects during operation.

As a third other aspect, the determination unit may determine the soundness of the rotating coil based on a voltage difference of electromotive force generated in the additional coil detected by the voltage detection unit.
In this aspect, it is possible to determine the soundness of each rotating coil simply by detecting the voltage difference of the electromotive force generated between the additional coils of each rotating coil, and the soundness can be easily and easily inspected.

As a fourth other aspect, the determination unit may determine that a defect has occurred in the rotating coil on the side where the voltage difference has occurred.
In this aspect, the occurrence of a defect in the corresponding rotating coil can be determined according to the magnitude of the voltage difference of the electromotive force between the additional coils for each rotating coil, and the soundness can be easily and easily inspected.
This rotating coil defect can be reported simply by turning on and blinking the alarm light, and by rearranging the combination of rotating coils to be compared, the position of the defect can be easily identified and reported. May also be automated.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 and FIG. 2 are diagrams showing an example of a synchronous generator equipped with an embodiment of a soundness inspection apparatus for an electric machine including a rotating coil according to the present invention.
(Synchronous generator)
First, the configuration of the synchronous generator will be described. In FIG. 1, a salient pole type synchronous generator (electric machine) is an electric machine installed in, for example, a hydroelectric power station. In the synchronous generator, the rotor 100 is rotatably accommodated in the stator 200, and a field is generated (formed) on the rotor 100 side that is rotated by hydraulic power or the like, so that the stator 200 side is magnetically actuated. It is manufactured in a structure that generates an electromagnetic voltage of a desired frequency in a power generation coil (winding).

In the rotor 100, a rotating coil (field winding) 102 is connected in series by a conductive cable and a conductive band 105 on the outer peripheral surface side of the body portion 101 that faces the power generation coil of the stator 200. Yes. The rotating coil 102 functions as an electromagnet (power generation field) by a direct current supplied from an external excitation power source (power generation power source) 300.
The excitation power supply 300 is connected to the rotating coil 102 via a connection cable 119 that is in conductive contact with the slip ring 111, and supplies a direct current to the rotating coil 102 via the thyristor rectifier circuit 301 and the first opening / closing switch 302.・ It is connected so that it can be shut off. That is, the first opening / closing switch 302 constitutes a first switch interposed in the middle of the circuit on the main body side.

(Health inspection device)
Next, the structure of the soundness inspection apparatus installed in the salient pole type synchronous generator will be described.
In addition to the excitation power source 300, a branch cable (branch line) 39 is branched and connected to the rotating coil 102 of the synchronous generator between the slip ring 111 and the first opening / closing switch 302, and an AC power source (alternating power source) 30. Are connected in parallel.
The AC power supply 30 is connected to the rotating coil 102 so that an alternating voltage can be supplied and interrupted via a second opening / closing switch 32. That is, the second opening / closing switch 32 constitutes a second switch interposed in the middle of the branch cable 39.

Moreover, the additional coil 11 is installed in each outer surface of the rotating coil 102. The additional coil 11 is provided so as to have a common magnetic flux path so that the exciting magnetic flux generated by the voltage supply to the rotating coil 102 passes through the coil.
As a result, the additional coil 11 can generate an induced electromotive force when the magnetic flux generated by the power supply to the rotating coil 102 and passing through the coil changes.
For this reason, when an alternating voltage is supplied (applied) to the additional coil 11 from the AC power supply 30 to the rotating coil 102, a shared voltage (inductive electromotive force) corresponding to the number of turns of the winding of each rotating coil 102 connected in series is applied. ) Can be generated.

The additional coils 11 are connected to the comparator circuit 21 through the conducting cable 15 as a pair. The comparator circuit 21 detects the voltage difference of the induced electromotive force generated for each additional coil 11, and when the detected voltage exceeds a preset threshold value, a defect is generated in the rotating coil 102 (lack of soundness). A detection signal for determination is output.
That is, the comparator circuit 21 constitutes a voltage detection unit and a determination unit. Here, the case where the comparator circuit 21 detects the occurrence of a defect by detecting the voltage of the induced electromotive force generated in the additional coil 11 will be described as an example. However, the present invention is not limited to this. Then, the presence or absence of a defect in the rotating coil 102 may be determined by measuring and comparing the voltage of the induced electromotive force for each additional coil 11.

The comparator circuit 21 is connected to an alarm light 23 via an amplifier circuit 22. The alarm light 23 is lit by receiving a detection signal from the comparator circuit 21 as a lighting signal. The comparator circuit 21 is housed and installed in the case 20 together with the amplifier 22.
Thereby, an operator of the salient pole type synchronous generator can grasp that a defect such as a short circuit has occurred between the windings of the rotating coil 102 when the alarm light 23 is turned on.

(Health inspection method)
Next, a soundness inspection method using the soundness inspection apparatus will be described.
First, when the operation of the salient-pole synchronous generator is stopped, while the rotation of the rotor 100 is continued or immediately after inertial rotation, the first open / close switch 302 is turned off and the supply of the excitation current to the rotating coil 102 is interrupted. Then, the second open / close switch 32 is turned on to apply an alternating voltage to the rotating coil 102.
Then, an alternating voltage is applied to the rotating coil 102 to generate an induced electromotive force in accordance with the number of turns while a centrifugal force due to rotation is applied, in other words, in a state equivalent to that during operation. Can do.

At this time, when each of the rotating coils 102 is healthy and no short circuit or the like occurs, there is no difference in the induced electromotive force generated, and the voltage difference detected by the comparator circuit 21 may exceed the set threshold value. In addition, the alarm light 23 is not turned on. As a result, it can be determined by confirming that the rotating coil 102 is healthy in a state equivalent to that during operation.
Further, when a short circuit or the like occurs in, for example, one of the rotating coils 102, a warning light 23 is generated when a difference occurs in the induced electromotive force generated and the voltage difference detected by the comparator circuit 21 exceeds a set threshold value. Lights up. As a result, it can be determined by confirming that a short circuit or the like has occurred in the operating state of the rotating coil 102 and is not healthy.

Therefore, the rotor 100 main body side does not require a major design change simply by adding the additional coil 11, and the detection system has a simple configuration in which only the AC power supply 30, the comparator circuit 21, etc. are added. The soundness of the rotating coil 102 can be determined and inspected while rotating the rotor 100 in the same manner as the operating state. Further, since the additional coil 11 is disconnected during operation, there is no adverse effect on power generation.
As a result, when the operator grasps (determines) that a defect such as a short circuit has occurred in the rotating coil 102 at the time of rotation, the operator or the like performs maintenance to confirm the presence or absence of a short circuit or the like of each rotating coil 102. However, it is not necessary to wastefully maintain maintenance time despite being healthy.

Here, in the present embodiment, the comparator circuit 21 confirms the soundness by checking the presence / absence of a defect based on the voltage difference of the induced electromotive force between the additional coils 11. 102 may be specified so that maintenance can be performed easily and easily.
For example, instead of the comparator circuit 21, the voltage detection of the induced electromotive force generated in the additional coil 11 may be performed individually to identify the defect occurrence location. Further, instead of detecting the induced electromotive force due to the alternating voltage, a system configuration for detecting the induced electromotive force according to a field change caused by occurrence of a short circuit during operation may be provided.
Further, the combination of the additional coils 11 connected to the comparator circuit 21 may be switched, and the defective rotating coil 102 may be specified from the combination of the additional coils 11 in which the voltage difference of the induced electromotive force is generated.
In this case, it is possible to easily recognize the rotating coil 102 in which the defect is generated by a pattern such as a light emission color of the alarm light 23, lighting, blinking, and a repetition time interval.

  The scope of the present invention is not limited to the illustrated and described exemplary embodiments, but includes all embodiments that provide the same effects as those intended by the present invention. Further, the scope of the invention is not limited to the combinations of features of the invention defined by the claims, but may be defined by any desired combination of particular features among all the disclosed features. .

DESCRIPTION OF SYMBOLS 11 Additional coil 15 Conduction cable 21 Comparator circuit 22 Amplification circuit 23 Alarm light 30 AC power supply 32 2nd opening / closing switch 39 Branch cable 100 Rotor 101 Body 102 Rotation coil 105 Conduction cable and conduction band 111 Slip ring 119 Connection cable 200 Stator 300 Excitation power supply 301 Thyristor rectifier circuit 302 First open / close switch

Claims (5)

A rotating coil is wound around the rotor that is rotatably accommodated in the stator, and is attached to an electric machine that functions by a magnetic action acting between the stator and the rotor, and the soundness of the rotating coil is inspected. A soundness inspection device,
A plurality of additional coils provided for each of the rotating coils that share a magnetic flux path in the rotating coil, a voltage detecting unit that detects an electromotive force generated in the additional coil, and the additional that the voltage detecting unit detects And a determination unit that determines the soundness of the rotating coil based on the detection result of the electromotive force generated in the coil.   The soundness inspection apparatus according to claim 1, further comprising an alternating power source that applies an alternating voltage to the rotating coil.   A first switch connected so as to intervene in the middle of the body side circuit to which the rotating coil is connected, and the alternating power supply is branched between the rotating coil and the first switch of the body side circuit The soundness inspection apparatus according to claim 2, further comprising: a branch line to be connected; and a second switch connected so as to be interposed in the middle of the branch line.   The said determination part determines the soundness of the said rotating coil based on the voltage difference of the electromotive force which arises in the said additional coil which the said voltage detection part detects, The Claim 1 characterized by the above-mentioned. The health inspection device described.   The soundness inspection apparatus according to claim 4, wherein the determination unit determines that a defect has occurred in the rotating coil on the side where the voltage difference has occurred.

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