JPS5928372Y2 - Gapless lightning arrester deterioration detector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a deterioration detector for detecting the degree of deterioration of a surge arrester element in a gapless surge arrester whose arrester element is a nonlinear resistor whose main component is zinc oxide.

When a gapless lightning arrester deteriorates, the resistance component iR of its leakage current increases.

Therefore, the degree of deterioration of the lightning arrester can be known by measuring the resistance component iR.

However, since the arrester element of a gapless arrester has a large dielectric constant, it is equivalent to a capacitor at the normal ground voltage.
In a power surge arrester, the leakage current i of the capacitance component.

flows. Also, when the degree of progress of deterioration is small, i is compared to iR.

is extremely large, and as mentioned above, it has been difficult to detect deterioration of the lightning arrester by measuring the resistance component iR.

Therefore, there is a device that measures power consumption W instead of iR to determine the degree of deterioration progress.

This method corresponds very well to the deterioration phenomenon of lightning arresters, making it possible to precisely observe the degree of deterioration.

However, in order to measure the power consumption W, it is necessary to measure the terminal voltage in addition to the leakage current of the lightning arrester.

FIG. 1 is a diagram for explaining a conventional deterioration detector.
The leakage current IL is detected by a resistor or current transformer 2 connected in series with the lightning arrester 1, the voltage divided by the voltage transformer 3 is detected, and the rain detection signal is input to the wattmeter to connect the lightning arrester. Measure the power consumption of 1.

In this case, the distance between the lightning arrester 1 and the voltage transformer 3 is often large, and the main purpose of the voltage transformer 3 is to be used as a protective relay, so this output is used to detect lightning arrester deterioration. Doing so is undesirable as it may cause malfunction of protective relays, etc.

An object of the present invention is to provide a deterioration detector that can detect the voltage and current components of a single surge arrester when detecting the power consumption of a gapless surge arrester and measuring its degree of deterioration.

The present invention focuses on the fact that a lightning arrester functions as a voltage divider, and detects the overall power consumption from the conducting current and divided voltage.

FIG. 2 shows an embodiment of the present invention.

Between the lightning arrester 4 and the ground, there is a leak current detector 5 (Fig. 2 shows an example of a resistor) consisting of a linear resistance or current transformer for detecting leak current, which has the same non-linear resistance characteristics as the lightning arrester element. Connect the non-linear resistor element 6.

With this configuration, the current signal I of the lightning arrester 5 is detected from the resistor 5, and the voltage divided by the voltage applied to the lightning arrester 4 and the voltage applied to the nonlinear resistor element 6 is transferred to the nonlinear resistor. It is detected from the element 6, and this detected voltage V is made the terminal voltage of the earth arrester 4.

Since the element 6 has the same characteristics as the resistor of the lightning arrester 4, the detected voltage (2) is proportional to the terminal voltage of the lightning arrester 4 because elements with the same characteristics are connected in series.

The rain detection voltage (2) and current (1) are input into the wattmeter 7, and the degree of deterioration of the lightning arrester 4 is detected from the output of the wattmeter 7.

Note that a non-linear resistor element 8 is connected in parallel to the resistor 5 or the current transformer, and the current when the lightning arrester current of the lightning arrester 4 flows is bypassed to the resistor element 8 without flowing through the resistor 5. to protect it from its burnout.

For this detector protection, a shorting switch may be provided in parallel with the series circuit of the non-linear resistor element 6 and the resistor 5, the shorting switch is normally closed, and the shorting switch is opened when deterioration is detected.

According to the above embodiment, a resistor 5, a current transformer, or a non-linear resistor element 6 is connected in series between the ground terminal of the lightning arrester 4 and the earth.
The leakage current IL and the terminal voltage (2) of the lightning arrester 4 can be detected from the lightning arrester 4, and the degree of deterioration can be easily detected without using the detection voltage signal of the voltage transformer located away from the lightning arrester 4.

As explained above, the gapless surge arrester deterioration detector according to the present invention includes a nonlinear resistor element having the same voltage nonlinear resistance characteristics as the surge arrester element, and a leakage current detection resistor or A current transformer is connected in series, the terminal voltage of the lightning arrester is detected from the terminal of the non-linear resistor element, the leakage current of the lightning arrester is detected from the leakage current detection resistor or the terminal voltage of the current transformer, and these rain detection values are detected. Since the power consumption of the lightning arrester, that is, the degree of deterioration of the lightning arrester is measured, it is possible to easily and precisely measure the degree of deterioration of the lightning arrester, which is highly effective for confirming the safety of the lightning arrester and for maintenance and inspection.

[Brief explanation of drawings]

FIG. 1 is a diagram for explaining deterioration detection of a conventional gapless lightning arrester, and FIG. 2 is a circuit diagram showing an embodiment of the present invention. 4... Gapless lightning arrester, 5... Leak current detector, 6... Non-linear resistor element, 7
...Water meter, 8...Nonlinear resistor element.

Claims (1)

[Scope of utility model registration request] In a gapless surge arrester that uses a non-linear resistor as an arrester element, a non-linear resistor element having the same voltage non-linear resistance characteristics as the non-linear resistor is connected in series with a leakage current detector to connect the ground terminal of the arrester to the earth. , detect the terminal voltage of the lightning arrester from the terminal voltage of the non-linear resistor element, detect the leakage current of the lightning arrester from the terminal voltage of the leakage current detector, and detect the power consumption of the lightning arrester from both of the above detected values. A deterioration detector for a no-gap surge arrester, characterized in that it measures the degree of deterioration of the surge arrester.