JPH0613585Y2 - Transformer failure indicator - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention detects the ground fault, short-circuit fault and overload condition inside the transformer by the sensors built in the transformer. However, the present invention relates to a device that activates the control circuit to display the state outside the transformer.

[Prior Art] As is well known, for example, when a ground fault, a short-circuit fault or an overload condition occurs inside a distribution pole transformer (hereinafter referred to as a transformer), detection and separation of a faulty section including a faulty transformer is performed. Is performed as follows.

When a ground fault occurs in the transformer in the 6 kV ungrounded distribution line, the ground fault direction relay (DG) and the ground fault overvoltage relay (OVG) of the substation operate to shut off the breaker.

After that, the circuit breaker is turned on after a certain period of time, and power is retransmitted if the failure of the transformer is restored, but if the failure continues, the automatic section switch in front of the failed transformer is locked and there is a failed transformer. The sections are separated, and power is transmitted to healthy sections by reclosing the substation breaker.

When a short-circuit fault occurs in the transformer, the fuse of the primary cutout switch inserted in the primary side of the transformer melts, disconnecting the faulty transformer and simultaneously operating the overcurrent relay (OC) at the substation. Then, the circuit breaker is shut off, and the fault section including the fault transformer is separated by the same operation as in the case of a ground fault.

On the other hand, in the case of overload, the primary cutout fuse is blown and the overload transformer is disconnected depending on the degree of overload. In this case, the relays of the substation will not work. Except for the blowout of the primary cutout fuse, the overload condition of the transformer must be determined by measuring the transformer load current.

[Problems to be solved by the device]

As described above, conventionally, a faulty transformer is discovered by visual inspection after separating a wide range of faulty sections including the faulty transformer, and there is a problem that much labor and time are required for restoration. It was

The present invention has been made based on the above circumstances, and the purpose thereof is to make it possible to quickly and easily confirm a failed transformer by detecting and displaying a failure in each transformer. It aims to provide a transformer with a built-in detection and display system, which will significantly reduce the failure recovery time and save labor compared to the conventional faulty transformer exploration.

[Means for solving problems]

The above-mentioned problem is caused by a ground fault detection means which is arranged on the primary side high voltage conductor of the transformer and detects an unbalanced current due to a ground fault and outputs a ground fault current signal and a predetermined value which is inputted with the ground fault current signal. And a ground fault display energy from the ground fault display energy output unit that inputs the ground fault signal and outputs the energy of the ground fault display when the ground fault signal is output. Is input to display a ground fault, ground fault display means, short-circuit detection means arranged to the high voltage side bushing of the transformer to detect a short-circuit current due to a short circuit and output a short-circuit current signal, and the short-circuit current signal. Short-circuit discriminating means for inputting and outputting a short-circuit signal when exceeding a predetermined value, short-circuit display energy output means for inputting the short-circuit signal and outputting energy for short-circuit display, and short-circuit display energy from the short-circuit display energy output means Enter Short-circuit fault display means for indicating a fault, temperature detecting means for detecting the temperature of the primary or secondary winding of the transformer and outputting a temperature signal, and inputting the temperature signal. And an overload from the overload display energy output means for inputting the overload signal and outputting the energy for overload display when the overload signal is exceeded. And an overload display means for inputting display energy and displaying an overload.

[Action]

In the above structure, the ground fault detection means is provided on the primary side high voltage conductor of the transformer, and the unbalanced current due to the ground fault is detected to output the ground fault current signal. The ground fault current signal is input to the ground fault discriminating means and a ground fault signal is output when the value exceeds a predetermined value. The ground fault signal is input to the ground fault display energy output means to output the ground fault display energy. The ground fault display energy from the ground fault display energy output means is input to the ground fault failure display means to display the ground fault. Short-circuit detection means is provided on the high-voltage side bushing of the transformer to detect a short-circuit current due to a short circuit and output a short-circuit current signal. The short-circuit current signal is input to the short-circuit determination means and a short-circuit signal is output when the value exceeds a predetermined value. The short circuit signal is input to the short circuit display energy output means to output the short circuit display energy. The short circuit display energy from the short circuit display energy output means is input to the short circuit failure display means to display the short circuit failure. Temperature detecting means is arranged on the primary winding or the secondary winding of the transformer, and the temperature is detected to output a temperature signal. The temperature signal is input to the overload determination means and an overload signal is output when the temperature signal exceeds a predetermined value. The overload signal is input to the overload display energy output means to output the energy for overload display. The overload energy from the overload display energy output means is input to the overload display means to display the overload. As described above, the failure of the transformer can be detected and the status can be displayed.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, a zero-phase current transformer 1 (hereinafter referred to as ZCT) is arranged on the high voltage lead wire on the primary side of the transformer 20. This Z
Normally there is no output on the secondary side of the CT, but the transformer 20
When a ground fault occurs in the section, an output current due to imbalance occurs on the ZCT secondary side. A voltage proportional to this current is induced in the resistor 2 connected to the ZCT secondary side, this voltage is amplified by the amplifier circuit 3, and is converted to direct current through the voltage doubler rectifier circuit 4. The output of this rectifier circuit is charged into a capacitor and discharged through a discharge resistor. When the voltage across the discharge resistor reaches a predetermined voltage (threshold), the discriminator 5
The bidirectional thyristor is fired, the pulse generator 6 for generating a predetermined pulse for operating the display 7 is driven, and a current flows through the display 7 to operate. This indicator 7
Then, for example, a magnetic reversal element (hereinafter referred to as the product name Magsine) is used.

This magsine is intended to display a predetermined display by rotating a plate whose front surface and back surface are color-coded by the interaction of an electromagnet and a permanent magnet.

The display 7 is not limited to the one using the magnetic action by the current, and an optical means such as an LED may be used.

When a short-circuit fault occurs, the bushing current transformer 8 (hereinafter referred to as BCT) embedded in the high-voltage side bushing of the transformer 20 detects the short-circuit current, and the current is proportional to the resistor 9 connected to the BCT secondary side. It is induced as a generated voltage, and this voltage is converted to direct current through the voltage doubler rectifier circuit 10.

The output of this rectifier circuit is charged into a capacitor and discharged through a discharge resistor, and when the voltage across the discharge resistor reaches a predetermined voltage (threshold value), the bidirectional thyristor of the discriminator 11 is fired and the pulse generator is generated. 12 is driven and the display 13 is operated. The display 13 uses a magsine as in the case of ground fault detection.

On the other hand, when the transformer 20 is overloaded, the temperature sensor 1 embedded in the primary winding or the secondary winding in advance is used.
4 (for example, optical fiber temperature sensor) detects the temperature and outputs it as a DC voltage. The detection circuit 15 has a built-in determination circuit to detect as an overload condition when both the primary and secondary windings exceed a certain timed threshold value.
Let me judge.

The bidirectional thyristor of the discriminator 16 is fired by the determination signal from the detection circuit 15 to drive the pulse generator 17 and operate the display 18 (magsine).

It should be noted that the various detection and display circuits of these transformers 20 are integrated into the transformer case to make them compact.

In this case, the power required for the normal detection display is supplied from the secondary side of the transformer 20, which is not shown, but a backup battery is built in assuming a power failure.

In addition, a reset button is provided for performing a return operation when each display operates. In addition, as an application example of this transformer, at the stage when the total automation of distribution is advanced,
By connecting an appropriate interface and communication line, it can be expected to develop to centralized management of transformer failures and loads.

[Effect of device]

According to the present invention, since failure detection and status display are performed for each transformer, it is possible to quickly and easily confirm failure occurrence.
This has the effect of significantly reducing the labor and time required for confirmation.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention. 1 ... Zero-phase current transformer, 3 ... Amplification circuit, 5 ... Discriminator, 6 ... Ballus generator, 7 ... Indicator, 8 ... Bushing current transformer, 14 ... Temperature sensor, 19 ... … Alester, 20 …… Transformer

Claims (1)

[Scope of utility model registration request] 1. A ground fault detecting means which is disposed on a primary side high voltage conductor of a transformer and detects an unbalanced current due to a ground fault and outputs a ground fault current signal, and the ground fault current signal is inputted and predetermined. A ground fault discrimination means for outputting a ground fault signal when the value exceeds the value, a ground fault display energy output means for inputting the ground fault signal and outputting energy for ground fault display, and a ground fault display from the ground fault display energy output means Ground fault display means for inputting energy to indicate a ground fault, short-circuit detection means for detecting a short-circuit current due to a short-circuit arranged in the high voltage side bushing of the transformer and outputting a short-circuit current signal, and the short-circuit current signal And a short-circuit indication energy output means for inputting the short-circuit signal and outputting the energy of the short-circuit indication by inputting the short-circuit signal, and a short-circuit indication from the short-circuit indication energy output means. Enter energy Short-circuit fault display means for indicating a fault, temperature detecting means for detecting the temperature of the primary or secondary winding of the transformer and outputting a temperature signal, and inputting the temperature signal. And an overload from the overload display energy output means for inputting the overload signal and outputting the energy for overload display when the overload signal is exceeded. A failure display device for a transformer, comprising: an overload display means for inputting display energy and displaying an overload.