JPH01312474A - Abnormality judging apparatus of on-load tap changer - Google Patents

Abstract

PURPOSE:To judge the abnormality of an on-load tape changer by comparing the driving torque which is generated in the on-load tap exchanging device when one tap is changed with an upper limit value and a lower limit value which are set at certain values. CONSTITUTION:When a tape changing signal is outputted from a tap-change- signal generating part 6, a change detecting part 7 receives this signal and outputs the signal to an abnormality judging part 8. Meanwhile, a motor 4 starts rotation based on the tap changing signal from the tap-change-signal generating part 6. An on-load tap changing device 1 which is mechanically linked with a motor operating mechanism 2 through a driving shaft 3 starts tap changing operation. Driving torque is applied to the driving shaft 3. A torque detecting part 5 detects the driving torque and sends the detected signal to an abnormality judging part 8. The abnormality judging part 8 receives the driving torque pattern of the driving shaft 3 from the torque detecting part 5 and compares the pattern with an upper limit reference value A and a lower limit reference value B of the driving torque which are stored in a memory part 9. When the pattern is deviated from the reference values A and B for a specified time, abnormality is judged.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to an abnormality determination device for a tap changer under load,
In particular, the present invention relates to an abnormality determination device that determines a mechanical abnormality in an on-load tap changer by detecting drive torque.

(Prior art) In general, an on-load tap changer is composed of an on-load tap changer and an electric operation mechanism, and when the load of the power transmission and distribution system fluctuates, the output voltage of the transformer corresponding to the fluctuation will exceed a certain value. A switching signal is created in the switching signal generation section of the on-load tap changer when the change occurs, and the tap provided in the on-load tap change transformer is switched by driving the electric operating mechanism.
The voltage of the power transmission and distribution system is kept constant. This power transmission and distribution system is often the main line, and if the on-load tap switching device fails, there is a risk of widespread power outage.

(Problem to be solved by the invention) Conventionally, fault detection for on-load tap changers has been done.

The insulating oil decomposes due to the arc generated inside the on-load tap changer, and a large amount of gas is generated, which detects the oil flow.The current transformer measures the current flowing through the on-load tap changer transformer. Some methods are being considered, such as those that detect short circuits between taps, and those that measure the switching time in a switching signal generating section of the on-load tap switching device and compare it with the normal tap switching time to detect the presence or absence of tap congestion.

However, conventional systems can detect accidents such as dielectric breakdown, arcing, and short circuits between taps that occur inside the tap changer when on load.

Signs of failure could not be detected in advance. In addition, since tap congestion is detected by comparing it with the regular tap switching time,
It takes more than 5 seconds to determine whether there is a tap traffic jam, and a quick response cannot be determined.The present invention was developed in consideration of the above points.

The object is to provide an abnormality determination device for an on-load tap changer that can reliably detect failures in the on-load tap changer in a short time and prevent serious accidents.

[Structure of the Invention (Means for Solving the Problems)] In order to achieve the above object, the present invention detects the drive torque during operation of the on-load tap changer, and uses this value and the drive torque stored in the memory circuit. Compare the upper and lower reference values of
It is designed to determine that there is an abnormality if the value deviates from the reference value for a certain period of time. The drive torque value of the tap changer changes under load. the drive torque value during the operation and the upper limit of the drive torque stored in the storage unit;
It is compared with the lower limit reference value, and if it deviates from the reference value for a certain period of time or more, it is determined to be abnormal and displayed on the abnormality display section.

(Embodiment) An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, 1 is a load tap changer housed and fixed in a transformer tank 1; 2 is an electric operating mechanism for driving the load tap changer 1 provided outside the tank 1;
3 is a drive shaft that connects the on-load tap changer 1 and the electric operating mechanism 2; 4 is a driving electric motor provided inside the electric operating mechanism 2;

Reference numeral 5 denotes a torque detection unit provided in the middle of the drive shaft 3 driven by the electric motor 4, and detects the drive torque of the drive shaft 3;
8 is a tap switching signal generation unit that outputs a tap switching signal to the electric operating mechanism 2; 8 is an abnormality determination unit that inputs the drive torque value detected by the torque detection unit 5 and the switching detection unit 7 and determines an abnormality; Reference numeral 9 denotes a storage unit that stores the reference values of the glodarum and drive torque used in the abnormality determination unit 8, and 10 represents an abnormality display unit that displays the results determined by the abnormality determination unit 8.

Next, the operation of the above embodiment will be explained.

When the tap switching signal is output from the switching signal generator 6,
The switching detection section 7 detects the tap switching signal.

A signal is output to the abnormality determination section 8.

On the other hand, the electric motor 4 starts rotating in response to the tap change signal output from the change signal generator 6, and the on-load tap changer 1, which is mechanically connected to the electric operation mechanism 2 via the drive shaft 3, starts the tap change operation. The drive torque is applied to the drive shaft 3. The torque detection section 5 detects the drive torque of the drive shaft 3 and sends a detection signal thereof to the abnormality determination section 8.

By the way, in general, when the on-load tap changer normally completes one tap change, a drive torque pattern as shown in FIG. 2 appears on the drive shaft 3. Abnormality determination section 8
The drive torque and arm turn of the drive shaft 3 that occur during one-tap switching are input from the torque detection section 5, and compared with the upper limit reference value A and the lower limit reference value B of the drive torque stored in the storage section 9.

If it deviates from the reference values A and B for a certain period of time or more, it is determined to be abnormal.

The upper limit reference value A of the driving torque is set between the torque value generated when the motor 40 rotations are restricted due to some kind of failure and the maximum torque value of the tap changer 1 on load.

Further, the lower limit reference value B of the driving torque is set to be between the torque value when the electric motor 4 rotates under no load and the minimum torque value when switching one tap except when starting and stopping. When the driving torque value during operation deviates from the reference values A and B, the reference time for determining an abnormality is determined by the characteristics at the time of starting and stopping, and is set to about 100 ms, for example.

In this way, the actual driving torque value of the on-load tap changer 1 is compared with the set upper limit reference value, so excessive torque due to welding of the movable contact of the tap selector or galling of the sliding part, etc. Phenomena can be determined in a short time. In addition, since the drive torque value is similarly detected and compared with the set lower limit reference value, it is possible to determine in a short time an under-torque phenomenon due to breakage of the drive shaft or the like. Since these detections are determined to be abnormal if they deviate from the reference value for a certain period of time, malfunctions due to external noise are eliminated, and when the motor is started or stopped, there is no malfunction, and the reliability of abnormality determination is improved.

[Effects of the Invention] As described above, according to the present invention, the on-load tap changer is
The drive torque generated during tap switching is set to a certain value, and compared with the lower limit reference value, and if it deviates from the reference value for more than a certain period of time, it is determined to be abnormal. It is possible to provide an abnormality determination device for an on-load tap switching device that can reliably determine the condition in a short time.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram showing an embodiment of the present invention, and FIG. 2 is a waveform diagram showing driving druts and turns of a load tap changer. 1... Load tap changer, 2... Electric operation mechanism. 3... Drive shaft, 4... Electric motor, 5... Torque detection section, 6... Tap switching signal generation section, 7... Switching detection section, 8... Abnormality determination section, 9...・Storage part, 10...
Abnormality display section. Applicant's representative Patent attorney Takehiko Suzue Figure 1 Figure 2

Claims (1)

[Claims] In an abnormality determination device for an on-load tap changer, in which the on-load tap changer is driven by an electric operating mechanism in response to a switching signal from a switching signal generating section, the on-load tap changer and an electric A torque detection section that detects the drive torque of the drive shaft that connects the operating mechanism, a storage section that stores the reference values of the set upper and lower limit drive torques, and the reference values stored in this storage section and the drive torque during operation. An abnormality determining device for an on-load tap switching device, comprising: an abnormality determining section that compares the value with the reference value and determines that the abnormality is abnormal if the value deviates from the reference value for a certain period of time or more.