JPS6362309A - Monitoring device for tap changer - Google Patents

Abstract

PURPOSE:To detect the foreboding of an abnormal state and a trouble by a method wherein a warning signal is outputted from a revolution number diagnosing part when the difference between the number of revolution and the reference number of revolution in a rotating force transfer mechanism exceeds the prescribed value. CONSTITUTION:The third bevel gear 30 is engaged with the second bevel gear 5c, which is one of the rotational elements in a rotating force transfer mechanism 5, and a rotary encoder 31 is coupled to the rotating shaft of the third bevel gear 30. The output data D of the rotary encoder 31 sent from the rotary encoder 31 is inputted to a rotating number diagnosing circuit 32. The rotating number of the rotational elements in the rotating force transfer mechanism 5 is always monitored and whether the rotating number is normal or not is diagnosed, so when the foreboding of an abnormality end a trouble is generated on the main body 1 of a tap changer and the rotating force transfer mechanism 5, said phenomenon can be detected immediately.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention is capable of changing the supplied power, etc. by switching taps during load, and stably changing the supplied power, etc. despite the tap switching. A tap changer body configured to allow switching, that is, a tap changer body equipped with a tap selector and a switching switch that operates in conjunction with the completion of switching of this tap selector, and this tap changer body and a motor. The present invention relates to a monitoring device for a tap changer including a rotational force transmission mechanism that is interlocked and connected.

<Prior Art> FIG. 4 is a schematic diagram of a conventional tap changer of this type, and FIG. 5 is a circuit diagram of its main parts.

In Fig. 4, 1 is the tap changer body, 2 is the tap changer operator, 3 is the drive motor, and 4 is the drive motor 3.
5 is a rotational force transmission mechanism that interlocks and connects the motor 3 and the tap changer body 1;
This includes a motor operating device 4 and a tap changer operating device 2.

Further, 20 is an AC power supply, and 21 is a motor operation switch.

The rotational force transmission mechanism 5 is configured as follows. That is, the rotational force transmission mechanism 5 includes a motor operating device 4, a first rotating shaft 5a extending from the motor operating device 4, and a first bevel gear 5b fixed to an end of the first rotating shaft 5a. , a second bevel gear 5C connected to the first bevel gear 5b ++t1, a second rotating shaft 5d extending from the tap changer operating device 2 and having a second bevel gear 5c fixed to its end, and the tap changer operating device 2. has been done.

Further, in FIG. 5, reference numeral 6 denotes a tap selector, which is composed of an odd-number side tap selection section 6a and an even-number side tap selection section 6b.

The odd-numbered side tap selection section 6a includes a movable contact 7a and a plurality of fixed contacts 8 that can be selectively connected to the movable contact 7a.
a+ + 833+ 8as l 8at 18
dw, each fixed contact 8a++833+8a
s, 8at+8aq are I of tap winding 9, respectively.
Tap for switching ts number 9 a+ + 9 as +
Connected to 98i+9ay, 9a*.

Similarly, the even-numbered tap selection section 6b includes a movable contact 7b and a plurality of fixed contacts 8bg, 8be, 8bh, 8 that can be selectively connected to the movable contact 7b.
b, , 8bw, and each fixed contact 8b.

8 be , 8 bh , and 8 bs are taps 9bx and 9b* for switching the number of windings of tap @ wire 9, respectively.
, 9b*.

9b@, and the fixed contact 8b is connected to the output terminal 10b of the first frozen soil winding 10.

11 is a transposition switch, the positive terminal 11a of which is connected to the intermediate terminal 10c of the 1 frozen soil winding 10, and the negative terminal 11b
1 Frozen Volume! The common terminal 11C is connected to one terminal 9bo of the tap winding 9. 11d is a movable contact in the transposition switch 11.

12 is an odd number side switching opening/closing part 12a and an even number side switching opening/closing part 1
2b, and includes a movable contact 13 common to the odd-numbered side switching section 12a and the even-numbered side switching section 12b. The odd number side switching opening/closing part 12a includes a terminal 14a directly connected to the movable contact 7a of the odd number side tap selection part 6a in the tap selector 6, and the movable contact 7a.
A is provided with a terminal 16a connected to the terminal 16a via a current limiting resistor 15a. Further, the even number side switching opening/closing part 12b has a terminal 14b directly connected to the movable contact 7b of the even number side tap selection part 6b of the tap selector 6, and a terminal 14b connected to the movable contact 7b via a current limiting resistor 15b. terminal 16
b is provided. Note that the input terminal 10a of the first frozen earth winding 10 is connected to a bushing part (not shown).

Among the above configurations, the tap selector 6 and the switching switch 12 constitute the tap switching device main body 1 shown in FIG. 4.

The tap changer operating device 2 includes a movable contact 7a of the odd-numbered tap selection section 6a and a movable contact 7b of the even-numbered tap selection section 6b.
, the movable contact 13 of the switching switch 12 and the movable contact lid of the shift switch 11 are operated in association with each other. Since the specific structure for this purpose is well known, the explanation thereof will be omitted.

This operation using the tap changer operating device 2 is executed when the drive motor 3 is driven by turning on the motor operation switch 21. Specifically, it is as follows.

That is, when the motor 3 rotates, the tap selector 6 is first operated via the rotational force transmission mechanism 5 including the motor operating device 4 and the tap changer operating device 2. The targets of this operation are both the odd-number side tap selection section 6a and the even-number side tap selection section 6b, and these are operated alternatively and alternately.

That is, the operation is started from one tap selection section (6a or 6b) that is not currently energized, and after the operation for that tap selection section is completed, the other tap selection section (6b or 6a) is operated.

In the state shown in FIG. 5, one blow-up winding 10→negative terminal 11b of shift switch 11→one terminal 9bo of tap winding 9→
Tap 9bh=Fixed contact 8b of even number side tap selection part 6b
i-Movable contact 7b → Odd number side terminal 14 of switching switch 12
The current is energized along the path b→movable contact 13-neutral point. That is, the even number side tap selection section 6b is energized. Therefore, what is first operated by the rotation of the motor 3 is the movable contact 7a of the odd-numbered tap selection section 6a, which is currently in a non-energized state.

Below, from the current state in which the movable contact 7b of the even-numbered tap selection section 6b is connected to the fixed contact 8b, the fixed contact 8b
An example of the change up to the state of being connected to s will be explained.

The movable contact 7a (currently in the non-energized state M) of the odd-numbered side tap selection section 6a, which is connected to the fixed contact 8as, rotates counterclockwise to connect the fixed contact 8a? connected to. After this connection is completed, the movable contact 13 in the switching switch 12 is instantaneously switched from the even-numbered switching section 12b to the odd-numbered switching section 12a. During a very short period of time during this switching, it is inevitable that the terminal 16b of the even-numbered side switching section 12b and the terminal 16a of the odd-numbered side switching section 12a will bridge, and because of this bridging, Circulation occurs between the odd-numbered side and the even-numbered side in the tap winding 9, but the current-limiting resistors 15a and 15b suppress this reflux.

By switching the movable contact 13 as described above, the tap winding 9
The output from the even-numbered tap 9ba is switched from the even-numbered tap 9ba to the odd-numbered tap 9a2. Therefore, the part of the tap selector 6 that is energized changes to the odd-numbered tap selection section 6a.

As the motor 3 continues to rotate, the movable contact 7b (currently in a non-energized state) of the even-numbered tap selection section 6b rotates clockwise and is connected to the fixed contact 8b@. After this connection is completed, the movable contact 13 in the switching switch 12
is instantaneously switched from the odd-numbered side switching opening/closing part 12a to the even-numbered side switching opening/closing part 12b. Even during a very short period of time during this switching, the current limiting resistors 15a and 15b suppress the return current in the tap winding 9 due to bridging.

By switching the movable contact 13 as described above, the tap winding 9
The output state is switched from the odd-numbered tap 9at to the even-numbered tap 9b, and the intended operation is completed.

Note that the shift switch 11 is configured to temporarily switch from the negative terminal 11b to the type terminal 11a in conjunction with the movable contact 7b of the even-numbered tap selection section 6b passing the fixed contact 8b. However, since this point is not directly related to the present invention, detailed explanation will be omitted.

<Problems to be Solved by the Invention> The conventional tap changer described above has the following problems with respect to inspection of the tap change operation.

That is, the tap changer operating device 2 is provided with a handle shaft (not shown) for manual operation separately from the motor 3, and the driving torque on this manual handle shaft can be measured and the motor 3 can be measured using an oscillogram. Tap switching operations are tested by measuring the flowing current. However, this inspection was typically performed at very long intervals, such as every five years or every 50,000 switchovers.

Therefore, between inspections, the tap changer body 1. If a sudden failure occurs in the tap changer operating device 2, etc., the tap changer operation will not function properly, and the power supply, etc., will not be able to be changed normally by changing the taps, which will disrupt the power supply, etc. There was a problem.

The present invention has been made in view of the above circumstances, and by constantly monitoring the tap switching operation,
The purpose is to be able to detect signs of abnormalities and failures.

<Means for Solving the Problems> In order to achieve the above object, the present invention has the following configuration.

That is, the tap changer monitoring device of the present invention includes a tap changer main body including a tap selector and a switching switch that operates in conjunction with the completion of switching of the tap selector; the tap changer main body and a motor; A rotational force transmission mechanism that interlocks and connects the rotational force transmission mechanism, a rotational speed sensor that detects the rotational speed of the rotating element in this rotational force transmission mechanism, and a difference between the rotational speed detected by this rotational speed sensor and a reference rotational speed is greater than a certain value The engine is equipped with a rotation speed diagnostic section that detects this and outputs an alarm signal.

In the above configuration of the present invention, the term "rotation speed j" has a broad meaning that includes not only the so-called rotation speed but also the rotation speed and the presence or absence of rotation.

Effect〉 The effects of the configuration of the present invention are as follows.

In other words, if there is an abnormality or a sign of failure in the mechanical parts that drive the tap selector or switching switch, the load on the motor will be abnormal compared to normal, and the rotational force transmission mechanism will be affected accordingly. The difference between the rotation speed and the reference rotation speed becomes a certain value or more. Then, the rotation speed diagnosis section outputs an alarm signal, indicating an abnormality.

Signs of failure can be detected.

<Example> Hereinafter, an example of the present invention will be described in detail based on the drawings.

1 and 2 relate to an embodiment of the present invention, in which FIG. 1 is a schematic configuration diagram of a monitoring device for a tap changer, and FIG. 2 is a block circuit diagram of a rotation speed diagnostic section.

In FIG. 1, the same reference numerals as those shown in FIG. 4 according to the conventional example refer to the same parts as the two parts indicated by the reference numerals in this embodiment, and unless otherwise specified,
The configuration and operation of connection relationships, etc., are also the same between this embodiment and the conventional example.

This embodiment also has the circuit configuration shown in FIG.

The configuration of this embodiment differs from the conventional example as follows.

As shown in FIG. 1, a third bevel gear 3 is connected to a second bevel gear 5C, which is one of the rotating elements in the rotational force transmission mechanism 5.
0 are in mesh with each other, and a rotary encoder 31, which is an example of a rotation speed sensor, is coupled to the rotation shaft of the third bevel gear 30. Output data D from this rotary encoder 31
is input to the rotation speed diagnostic circuit 32, and an output terminal of the rotation speed diagnostic circuit 32 is connected to an alarm 33.

The above third bevel gear 30. Low reencoder 31,
The rotation speed diagnosis circuit 32 constitutes the rotation speed diagnosis section A.

As shown in FIG. 2, the rotary encoder 31
Slit plate 3 that rotates in conjunction with bevel gear 30
1a, a photodiode 31b that irradiates light onto the slit of the slit plate 31a, and a light receiving section 31C that receives the light that has passed through the slit.

Further, the rotation speed diagnosis circuit 32 includes a waveform shaping circuit 34.degree. gate circuit 35. Motor start detection circuit 36. Motor stop detection circuit 37. Delay circuit 38. The pulse counter 39 is composed of a reference rotation speed memory 40 and a rotation speed comparison circuit 41.

The waveform shaping circuit 34 receives output data D from the light receiving section 31C.
The signal waveform is shaped and output to the gate circuit 35. The delay circuit 38 delays the detection signal of the motor start detection circuit 36 by a predetermined period of time and outputs it to the gate circuit 35 as a gate open signal. The gate circuit 35 opens the gate in response to the gate open signal from the delay circuit 38, outputs the output data D of the waveform shaping circuit 34 to the pulse counter 39, and closes the gate in response to the gate close signal from the motor stop detection circuit 37. It is. The pulse counter 39 is reset by the detection signal of the motor start detection circuit 36, counts the number of pulses of the output data D from the gate circuit 35, and outputs the count value to the rotation speed comparison circuit 41. The rotation speed comparison circuit 41 compares the rotation speed N, which is the count value from the pulse counter 39, and the reference rotation speed N ref stored in the reference rotation speed memory 40, and calculates the absolute value of the difference between the two (I
An alarm signal S is output when N-Nref l) becomes -room or more.

Next, the operation of the structure of this embodiment, which is different from the conventional example, will be explained based on the time chart of FIG. 3.

At time t, when the motor operation switch 21 is turned on, the motor 3 starts rotating, and each rotating element (30, 5a, 5b, 5c, 5d, 2) in the rotational force transmission mechanism 5 is driven. Along with this, the slit plate 31a rotates, and the irradiation light from the photodiode 31b is intermittently incident on the light receiving section 31C, and the light receiving section 31c outputs a pulse signal. This output data D is waveform-shaped in the waveform shaping circuit 34 and output to the gate circuit 35.

The motor starting current I0 flows between times t and t1, and at time t0 the motor starting detection circuit 36 outputs a detection signal and the pulse counter 39 is reset. The time when 1. becomes stable. Until then, the gate open signal from the delay circuit 38 is not output.

At time t1, a gate open signal is output and the gate circuit 3
5, the output data D is output to the pulse counter 39, and the pulse counter 39 calculates the number of pulses of the output data D during the period from time t1 to time t when the motor 3 stops, that is, the rotation speed of the rotational force transmission mechanism 5. Count N sequentially.

This count value is compared with the reference rotation speed Nref in the rotation speed comparison circuit 41, and if the difference is less than a certain value, it is judged as normal and no alarm signal S is output. However, when the difference exceeds a certain value, An alarm signal S is output to the alarm device 33.

A more specific explanation is as follows.

As the motor 3 is started, the movable contact 7a of the non-energized side, for example, the odd-numbered tap selection section 6a, starts rotating from the fixed contact 3al toward the fixed contact 8ay.

Then, the movable contact 7a changes to the fixed contact 8a at time t2.
s, and completely separates from the fixed contact 8as at time t. In this case, since frictional resistance acts between the movable contact 7a and the fixed contact 8as, the load on the motor 3 increases once and then decreases, so the motor drive current i also increases once and then decreases.

At this time, the number of rotations per unit time decreases.

From time t when the movable contact 7a leaves the fixed contact 8as to time t# when it starts contacting the adjacent fixed contact 3a, no frictional resistance is applied to the movable contact 7a, so the motor drive current i is remains constant. Time t at which the movable contact 7a starts contacting the fixed contact 8at at time tO and then stops.

Since the frictional resistance increases once and then decreases, the motor drive current i also increases once and then decreases.

At this time as well, the number of rotations per unit time decreases.

Time when the movable contact 7a stopped 1. The motor drive current i is stable from the time t to the time t when the motor 3 stops, and the number of rotations per unit time is also constant.

During a very short time between time t4 and time t after the movable contact 7a contacts the fixed contact 8at and stops, the movable contact 13 in the switching switch 12 contacts the terminals 14b and 16b of the even-numbered switching switch 12b. It is instantaneously switched from the state to the state in which it contacts the terminals 14a, 16a of the odd-numbered side switching opening/closing part 12a. Thereafter, the motor 3 stops at time t.

Tap changer body 1. If there is no abnormality or sign of failure in the tap changer operating device 2, etc., and the entire mechanism is normal, the total number of revolutions counted within the period of time t and xt at the time of tap change is constant Ns.

The total rotation speed Ng and the reference rotation speed Nr during normal operation
The absolute value of the difference from ef IN3-Nref l is a constant value α
When it is smaller than , that is, lNs - Nref l<α, no alarm signal S is output.

However, the tap changer body 1. If there is an abnormality or a sign of failure in the tap changer operating device 2, etc., the load applied to the motor 3 will fluctuate, and the total rotation speed Ns and reference rotation speed Nref will change.
The difference I Ns −Nref l becomes larger than the constant value α. That is, in the case of lNs-Nrefl≧α, the alarm signal S is output and the alarm device 33 is activated. That is, for example, an alarm lamp, an alarm buzzer is activated, or an alarm is displayed on a CRT display.

This makes it possible to constantly diagnose abnormalities and signs of failure under load.

Causes of the abnormality in the total rotational speed Ns include looseness in the rotational force transmission mechanism 5, damage to rotating elements, running out of grease, solidification of grease, and the like.

The present invention also includes the following configuration as an example.

(i) A gear is attached to the first rotating shaft 5a or the second rotating shaft 5d, and a rotary encoder is coupled to this gear.

(ii) A mark is attached to a part of the surface of the first rotating shaft 5a or the second rotating shaft 5d, and the number of rotations is detected by optically detecting the mark.

(iii) A rotary encoder is attached to the internal mechanism of the motor operating device 4 or the tap changer operating device 2.

In the illustrated embodiment, the rotary encoder 31 is used as the rotational speed sensor, but the rotational speed sensor may be other than the rotary encoder.

<Effect of the invention> According to the present invention, the following effects are achieved.

That is, while the tap changer is in operation, the rotation speed diagnosis section constantly monitors the rotation speed of the rotating element in the rotational force transmission mechanism and diagnoses whether the rotation speed is normal or not. If there is a sign of abnormality or failure in the main body or the rotational force transmission mechanism that drives it, this can be immediately known.

Therefore, it becomes possible to investigate the causes of abnormalities and failures and carry out repairs before an actual accident occurs.

Therefore, for example, it is possible to prevent the power supply from suddenly malfunctioning or becoming unavailable.

[Brief explanation of drawings]

Figures 1 to 3 relate to embodiments of the present invention, in which Figure 1 is a schematic configuration diagram of a tap changer monitoring device, Figure 2 is a block circuit diagram of the rotation speed diagnosis section, and Figure 3 is the operation. This is a time chart for explanation. Further, FIGS. 4 and 5 relate to a conventional example, with FIG. 4 being a schematic configuration diagram of a tap changer, and FIG. 5 being a circuit diagram of its main parts. l...Tap changer body 3...Motor 5...Rotational force transmission mechanism 6...Tap selector 12...Switching switch 31...Rotary encoder (rotation speed sensor) A... Rotation speed diagnosis section

Claims (1)

[Claims] (1) a tap changer body including a tap selector and a switching switch that operates in conjunction with the completion of switching of the tap selector; a rotational force transmission mechanism that interlocks and connects the tap changer body and a motor; A rotation speed sensor detects the rotation speed of the rotating element in this rotational force transmission mechanism, and outputs an alarm signal when the difference between the rotation speed detected by this rotation speed sensor and a reference rotation speed is greater than a certain level. A tap changer monitoring device equipped with a rotation speed diagnostic section.