JPH07153635A - Malfunction monitoring device of on-load tap changer - Google Patents

Abstract

PURPOSE:To prevent the malfunction of an on-load tap changer from being misjudged even if an operating mechanism is terminated in an unstable state after it is manually operated by a method wherein a first malfunction diagnosis made after the tap changing operation of an on-load tap changer is driven by an electric motor just after it is manually driven is ignored. CONSTITUTION:When a drive signal which detects the current of an electric motor 9 and an operating signal which detects the torque of a drive shaft 23 of an operating mechanism 21 are both detected, that a tap changing operation is carried out by an electric motor is stored, and when only an operating signal is detected, that a tap changing operation is manually carried out is stored, and only a first malfunction diagnosis made after a tap changing operation by an electric motor carried out following a stored tap changing operation which is manually carried out is ignored. When an operating mechanism 21 is manually carried out by a handle crank 22 and both the insertion signal of the handle crank 22 and an operating signal are detected, it is deemed that a tap changing operation is manually carried out. Furthermore, it is judged only by the insertion signal of the handle crank 22 that a tap changing operation is manually carried out.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a load tap changer abnormality monitoring apparatus for monitoring a load tap changer abnormality to prevent an accident.

[0002]

2. Description of the Related Art Generally, a load tap changer is provided in a load tap change transformer when a load of a power transmission and distribution system fluctuates and a voltage change corresponding to the change exceeds a predetermined value. The taps are switched to keep the voltage of the power transmission and distribution system constant. Therefore, if the load tap changer of the power transmission and distribution system fails, there is a risk of power failure over a wide area.Therefore, an abnormality monitoring device has been proposed that can detect a sign of failure and prevent a serious accident. There is.

FIG. 3 is a block diagram of a conventional abnormality monitoring device for a load tap changer disclosed in Japanese Patent Publication No. 4-39764. In FIG. 3, 1 is a switching signal generator that outputs a switching signal for tap switching, and 2 is an electric motor operating mechanism, which is driven by an electric motor (not shown). Reference numeral 3 denotes a load tap changer, and 4 a switching detection unit for detecting a switching signal for starting switching, which sends a detection signal to an abnormality determination unit 6 described later.

A torque detector 5 detects the torque applied to the drive shaft of the tap changer 3 under load. An abnormality determination unit 6 calculates and compares a normal torque characteristic pattern stored in a memory circuit unit 7 described later and an operating torque characteristic pattern during operation of the load tap changer 3 detected by the torque detection unit 5. To determine whether there is an abnormality. Reference numeral 7 is a memory circuit that stores a normal torque characteristic pattern at the time of normal switching operation, and 8 is a display circuit.

In the above structure, when the tap switching signal is output from the switching signal generating section 1, the switching detecting section 4 detects the tap switching signal for starting switching and sends the detection signal to the abnormality determining section 6. On the other hand, the tap switching signal output from the switching signal generator 1 drives the electric motor of the electric motor operating mechanism 2 to operate the load tap switching device 3 to apply torque to the drive shaft 2a. The torque detection unit 5 detects the torque applied to the drive shaft 2a of the tap changer 3 under load and sends a detection signal to the abnormality determination unit 6.

The abnormality judging section 6 compares the normal torque characteristic pattern of the memory circuit 7 with the operating torque characteristic pattern at the time of switching detected by the torque detecting section 5, and judges the failure sign and the failure from the difference. The determination result is output to the display circuit 8. It should be noted that the drive shaft 2a can be manually driven via the electric motor operating mechanism 2 during the test of the load tap changer 3.

Further, in order to prevent accidents of the tap changer under load, an abnormality monitoring device has been put into practical use, which monitors the tap change time as a physical quantity generated during the change operation and detects a sign of abnormality. . By monitoring this tap change time, it is possible to detect an abnormality in the control circuit of the motor operating mechanism that accounts for a large proportion of accidents in the load tap changer.

FIG. 4 is a very general control circuit diagram of an electric motor operating mechanism for driving a tap changer under load. Figure 4
In the figure, 9 is a driving electric motor, and 10 is an ascending electromagnetic contactor for switching the tap to the ascending side, which is composed of a coil 10a, normally open contacts 10b, 10c, 10d and a normally closed contact 10e. Reference numeral 11 denotes a descending electromagnetic contactor for switching the tap to the descending side, which includes a coil 11a and a normally open contact 11b,
It is composed of 11c and 11d and a normally closed contact 11e. Reference numeral 12 is an electromagnetic contactor for braking, which short-circuits the terminals of the electric motor 9 for braking the electric motor 9, and is composed of a coil 12a, a normally open contact 12b, and a normally closed contact 12c.

Reference numeral 13 denotes a pilot cam switch attached to the shaft of the tap changer, which is closed during the switching operation between the taps and is open at the tap position. Reference numeral 14 denotes an ascending change command switch for instructing an ascending change, which is operated by a commander. 15
Is a descending changeover command switch for instructing the descending changeover, which is operated by the instructor. A current detector 16 detects the current of the electric motor 9 and outputs a current detection signal 16a.

In FIG. 3 and FIG. 4, when the ascending changeover command switch 14 is closed by an instructor, the coil 10a of the ascending electromagnetic contactor 10 is excited and the normally open contact 10 is opened.
b, 10c and 10d are closed, and the normally closed contact 10e is opened. Therefore, the coil 12 of the electromagnetic contactor 12 for braking is
a is excited via the contact 10d, the normally open contact 12b is closed, and the normally closed contact 12c is opened. By closing the contacts 10b and 12b, the electric motor 9 is driven by being supplied with electric power from the power supply.

As a result, the drive shaft of the on-load tap changer 3 is rotated via the electric motor operating mechanism 2, and the tap change operation is started. The pilot cam switch 13 is closed between taps during the tap switching operation. Therefore, the coil 10a is excited through the pilot cam switch 13 and the contact 10c even when the rising changeover command switch 14 is opened, so that the electric motor 9 continues to rotate and the drive shaft 2a is reliably fed to the next tap. .

In such a configuration, when the tap switching time is monitored to determine an abnormality, the current of the electric motor 9 is measured by the current detector 16 and the current is continued from the current duration, or the ascending electromagnetic contactor 10 or Downward magnetic contactor 11
Is being measured.

However, this measured value differs from ten to several tens of percent depending on the switching direction immediately before switching, even if normal tap switching is performed. That is, in the case where the switching is performed immediately before the switching and the switching is performed this time as well, and in the case of the reverse switching in which the switching direction immediately before the switching is different from the switching direction this time, the switching time of the latter is several ten percent to several percent. 10% longer.

Therefore, by focusing on the switching time difference depending on the switching mode of the same direction switching or the reverse switching, and also by monitoring the switching direction and making an abnormality determination, an abnormality monitoring device for detecting an abnormality at a minor stage is also commercialized. Has been done. In this case, the switching direction is determined from the operating state of the ascending change command switch 14 or the descending change command switch 15 shown in FIG.

[0015]

The conventional load tap changer abnormality monitoring device monitors the duration of the current of the drive motor and the operation of the ascending electromagnetic contactor or the descending electromagnetic contactor. Therefore, the switching direction during manual driving could not be detected. Therefore, the abnormality determination when driving the electric motor after the manual driving may be erroneous because the switching direction before driving the electric motor is unknown.

That is, there is a case where an abnormal alarm is issued in spite of the normal operation, or it is determined that the operation is normal even if the operation is abnormal.
Then, when it is erroneously determined to be abnormal, the cause investigation is troublesome and requires a lot of time and labor. The manual drive is a necessary operation for confirmation work when an abnormality is detected and for periodic inspection.

The present invention has been made in order to solve the above problems, and provides an abnormality monitoring device for a load tap changer which detects a manual drive to determine an abnormality.

[0018]

An abnormality monitoring device for a load tap changer according to the present invention detects a drive signal when a motor is driven, and drive signal detection means when an operating mechanism is activated. Actuating signal detecting means for detecting and storing as electric motor drive as being driven by an electric motor when detecting a driving signal and an actuating signal, and manually driving as being manually driven when only actuating signal is detected The storage means and the arithmetic processing means for performing the processing of ignoring the abnormality diagnosis of the load tap changer only once when the motor drive is detected next to the manual drive stored in the storage means. .

Also, drive signal detecting means for detecting a drive signal when the electric motor is driven, operation signal detecting means for detecting an operation signal when the operating mechanism operates, and an insertion signal when the handle crank is inserted. Insertion signal detection means for storing the electric motor drive as the one driven by the electric motor when the drive signal and the operation signal are detected, and the manual drive as the one manually driven when the operation signal and the insertion signal are detected. Storage means for storing, and arithmetic processing means for performing a process of ignoring the abnormality diagnosis of the load tap changer only once when the motor drive is detected next to the manual drive stored in the storage means Is.

[0020]

According to the present invention, the drive signal is detected by the drive signal detecting means when the electric motor is driven, and the operation signal is detected by the operation signal detecting means when the operating mechanism is operated, and the drive signal and the operation signal are detected. When it is driven by the electric motor, it is stored in the electric motor drive and the storage means, and when only the operation signal is detected, it is stored in the manual drive and the storage means, and the electric motor drive is next to the manual drive stored in the storage means. When it is detected, the abnormality diagnosis is ignored only once, and the abnormality diagnosis is performed.

Also, when the electric motor is driven, the drive signal detecting means detects the drive signal, and when the operating mechanism operates, the operating signal detecting means detects the operating signal, and the handle crank for manually operating the operating mechanism is inserted. When the insertion signal is detected, the insertion signal is detected by the insertion signal detection means, and when the driving signal and the operation signal are detected, the driving signal is stored in the electric motor drive and storage means as being driven by the electric motor, and the operation signal and the insertion signal are detected. When the electric motor drive is detected next to the manual drive stored in the storage means, the abnormality diagnosis is ignored only once and the abnormality diagnosis is performed.

[0022]

【Example】

Example 1. FIG. 1 is a block diagram of an abnormality monitoring device for a load tap changer according to the present invention. In FIG. 1, reference numeral 17 denotes a tap selector which, when the voltage change exceeds a predetermined limit, is switched from one tap to another tap by a switching signal. Reference numeral 18 denotes a switching switch, which switches from one tap to the other tap corresponding to the tap selector 17.
Reference numeral 19 is a converter. Tap selector 17 and switching switch 1
8 and the converter 19 constitute a load tap changer 20. Reference numeral 21 denotes an operation mechanism using the electric motor 9 as a drive source, and an insertion shaft 2 into which a manually driven handle crank 22 can be inserted.
1a is provided.

Reference numeral 23 is a drive shaft, which is the electric motor 9 of the operating mechanism 21.
Is transmitted to the tap changer 20 under load. A torque detector 24 is attached to the drive shaft 23 and outputs a torque detection signal 24a. Reference numeral 25 denotes a tap switching signal generating means which issues a tap switching signal 25a to instruct a signal converting means 28, which will be described later, to start an abnormality diagnosis, and also sends a signal to the digital input interface 27. Reference numeral 26 is a tap position signal generating means, which outputs a tap position signal 26a according to a change in tap position. 27 is a digital input interface for tap switching signal 25a and tap position signal 26
The digital signal a is output to the arithmetic processing means 31 described later.

Reference numeral 28 denotes a signal converting means which receives the tap switching signal 25a which is a command to start the measurement of the abnormality diagnosis and converts the current detection signal 16a and the torque detection signal 24a into an electric analog signal of a predetermined value. 29 is an A / D conversion means, which converts the analog signal from the signal conversion means 28 into a digital signal and outputs it to the arithmetic processing means 31 which will be described later.

Reference numeral 30 denotes a storage means which uses the current detection signal 16a or the tap switching signal 25a as a drive signal, the torque detection signal 24a or the tap position signal 26a as an actuation signal, and the electric motor 9 when the drive signal and the actuation signal are detected. The motor drive is stored as being driven by, and the manual drive is stored as being manually driven when only the operation signal is detected. Further, the abnormality determination standard for the operation mode and various data are stored.

An arithmetic processing unit 31 constantly monitors the current detection signal 16a or the tap switching signal 25a as a drive signal and the torque detection signal 24a or the tap position signal 26a as an operation signal. When the drive signal is not detected and only the actuation signal is detected, the content is compared with the contents of the storage means 30 to determine the manual drive. Further, when the drive signal and the operation signal are detected, it is determined that the motor is driven.

Further, when the previous tap switching operation is determined to be manual driving and stored, but when the next tap switching operation is determined to be motor driving, only the tap position is stored and abnormality diagnosis is not performed. . Then, when it is subsequently determined that the motor is driven, the subsequent abnormality diagnosis is performed. Reference numeral 32 is an output means for outputting an abnormality alarm or the like.

In FIG. 1, when the electric motor 9 is driven by the tap switching signal, the current detection signal 16a of the driving signal and the tap switching signal 25a are detected. Then, the torque detector 24 attached to the drive shaft 23 detects the torque detection signal 24a as an operation signal. Further, the tap position signal generating means 26 detects the fluctuation of the tap position by using the tap position signal 26a as an operation signal. However, the drive signal may be only one of the current detection signal 16a and the tap switching signal 25a, and the actuation signal may be only one of the torque detection signal 24a and the tap position signal 26a.
Further, the drive signal may be an operation signal when the electromagnetic contactor 10 shown in FIG. 4 operates.

Example 2. FIG. 2 is a block diagram showing another embodiment. In FIG. 2, reference numeral 33 denotes a handlebar switch, which outputs an insertion signal 33a when the handlebar crank 22 is inserted into the insertion shaft 21a of the operation mechanism 21 to a digital input interface 34 described later. Reference numeral 34 denotes a digital input interface which converts the tap switching signal 25a, the tap position signal 26a and the insertion signal 33a into digital signals and outputs them to the arithmetic processing means 36 which will be described later.

Reference numeral 35 denotes a storage means, which uses the current detection signal 16a or the tap switching signal 25a as a drive signal, the torque detection signal 24a or the tap position signal 26a as an actuation signal, and the electric motor 9 when the drive signal and the actuation signal are detected. The motor drive is stored as being driven by the motor, and the manual drive is stored as being manually driven when the operation signal and the insertion signal 33a are detected.

Reference numeral 36 denotes an arithmetic processing means, which is a current detection signal 16a or a tap switching signal 25a as a drive signal, a torque detection signal 24a or a tap position signal 26a as an operation signal, and an insertion signal 33a when the handle crank 22 is inserted. And are constantly monitored. When the drive signal and the actuation signal are detected, the contents of the storage means 35 are compared and it is determined that the motor is driven. When the actuation signal and the insertion signal 33a are detected, the contents are compared with the contents of the storage means 35 to determine the manual driving.

Further, when the previous tap switching operation is determined to be manual driving and is stored, but when the next tap switching operation is determined to be motor driving, only the tap position is stored and abnormality diagnosis is not performed. . Then, when it is subsequently determined that the motor is driven, the subsequent abnormality diagnosis is performed.

Example 3. In the second embodiment, the manual drive is performed when the actuation signal and the insertion signal 33a are detected.
It is also possible to detect only the insertion signal 33a and determine that the driving is manual.

[0034]

As described above, according to the present invention, when the drive signal and the operation signal are detected, the motor drive and the storage means are stored, and when only the operation signal is detected, the manual drive and the storage means are stored. When the electric motor drive is detected next to the manual drive stored in the storage means, the abnormality diagnosis is ignored only once, so that erroneous determination of the abnormality diagnosis can be prevented even if the switching direction by the manual drive is unknown.

Further, when a drive signal and an actuation signal are detected, they are stored in the electric motor drive and storage means, and when an actuation signal and an insertion signal are detected, they are stored in the manual drive and storage means, and the stored manual drive is stored. Since the abnormality diagnosis is ignored only once when the electric motor drive is detected next, the erroneous determination of the abnormality diagnosis can be prevented even if the switching direction by the manual drive is unknown.

Further, when a drive signal and an actuation signal are detected, they are stored in the motor drive and storage means, and when only an insertion signal is detected, they are stored in the manual drive and storage means, and next to the stored manual drive. When the motor drive is detected, the abnormality diagnosis is ignored only once. Therefore, even if the switching direction by the manual drive is unknown, it is possible to prevent erroneous determination of the abnormality diagnosis with a simple configuration.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an abnormality monitoring device for a load tap changer showing an embodiment of the present invention.

FIG. 2 is a configuration diagram showing another embodiment of the present invention.

FIG. 3 is a configuration diagram of a conventional abnormality monitoring device for a tap changer during load.

FIG. 4 is a general control circuit diagram of a motor operating mechanism that drives a tap changer during load.

[Explanation of symbols]

16 Current Detector (Drive Signal Detection Means) 17 Tap Selector 18 Switching Switch 20 Load Tap Switch 21 Operating Mechanism 22 Handle Crank 24 Torque Detector (Actuation Signal Detection Means) 25 Tap Switching Detection Signal Generating Means (Drive Signals) Detection means) 26 tap position detection signal generation means (actuation signal detection means) 30, 36 storage means 31, 37 arithmetic processing means 33 handle switch (insertion signal detection means)

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[Procedure amendment]

[Submission date] March 1, 1994

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] Explanation of code

[Correction method] Change

[Correction content]

[Explanation of Codes] 16 Current Detector (Drive Signal Detecting Means) 17 Tap Selector 18 Switching Switch 20 Load Tap Changer 21 Operating Mechanism 22 Handle Crank 24 Torque Detector (Actuation Signal Detecting Means) 25 Tap Change Detection Signal generating means (drive signal detecting means) 26 tap position detection signal generating means (actuation signal detecting means) 30, 3 5 storage means 31,3 6 processing means 33 handle switch (insertion signal detecting means)

[Procedure Amendment 2]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 2

[Correction method] Change

[Correction content]

[Fig. 2]

Claims (8)

[Claims] 1. A load tap changer, wherein the changeover switch and the tap selector are operated by an electric motor through an operation mechanism or manually operated through the operation mechanism to perform a tap changeover operation. In an abnormality monitoring device for a load tap changer that monitors an operating state and detects an abnormality, drive signal detection means that detects a drive signal when the electric motor is driven,
Actuating signal detecting means for detecting an actuating signal when the operating mechanism is actuated, and storing as an electric motor drive as being driven by the electric motor when detecting the driving signal and the actuating signal, and detecting only the actuating signal Storage means for storing the manual drive as manually driven, and an abnormality diagnosis of the load tap changer when the motor drive is detected next to the manual drive stored in the storage means. An abnormality monitoring device for a load tap changer, comprising: an arithmetic processing unit that performs a process of ignoring only once. 2. The tap switching operation is performed by operating the switching switch and the tap selector with an electric motor through an operating mechanism or by inserting a manual handle crank through the operating mechanism to operate. In an abnormality monitoring device for a load tap changer that monitors the operating state of the load tap changer and detects an abnormality, drive signal detection means for detecting a drive signal when the electric motor is driven, and the operation mechanism are activated. An actuating signal detecting means for detecting an actuating signal, an inserting signal detecting means for detecting an inserting signal when the handle crank is inserted, and one driven by the electric motor when detecting the driving signal and the actuating signal Storage means for storing as electric motor drive, and storing as manual drive as being manually driven when the operation signal and the insertion signal are detected, A load comprising an arithmetic processing means for ignoring the abnormality diagnosis of the load tap changer only once when the electric motor drive is detected next to the manual drive stored in the means. Time tap changer abnormality diagnosis device. 3. A tap under load adapted to perform a tap switching operation by operating a switching switch and a tap selector with an electric motor via an operating mechanism or by operating a manual handle crank via the operating mechanism. In an abnormality monitoring device for a load tap changer that monitors the operating state of a switch and detects an abnormality, drive signal detection means for detecting a drive signal when the electric motor is driven, and an operation signal when the operating mechanism is activated. And an insertion signal detection means for detecting an insertion signal when the handle crank is inserted, and an electric motor drive that is driven by the electric motor when the drive signal and the operation signal are detected. And a storage means for storing the manual drive as a manual drive when only the insertion signal is detected, and the storage means stored in the storage means. An abnormality of the load tap changer, comprising an arithmetic processing means for ignoring the abnormality diagnosis of the load tap changer only once when the motor drive is detected after the manual drive. Diagnostic device. 4. The abnormality monitoring device for a load tap changer according to claim 1, wherein the drive signal detecting means is a current detector for detecting a current of the electric motor. 5. The load according to any one of claims 1 to 3, wherein the drive signal detecting means detects an operation of a power supply switch which is activated when power is supplied to the electric motor. Abnormality monitoring device for tap changer. 6. The abnormality monitoring device for a load tap changer according to claim 1, wherein the drive signal detecting means detects a tap change signal for instructing the start of tap change. . 7. The abnormality of the load tap changer according to claim 1, wherein the actuating signal detecting means is a torque detector for detecting the torque of the drive shaft of the operating mechanism. Monitoring equipment. 8. The abnormality monitoring of the on-load tap changer according to claim 1, wherein the operation signal detecting means is a tap position signal generating means for detecting a change in tap position. apparatus.