JPH0782061B2 - Deterioration diagnosis method for zinc oxide type arrester - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention comprises one or a plurality of series-connected non-linear resistance elements containing zinc oxide as a main component, which are housed in a container to form each phase of a three-phase arrester. The present invention relates to a deterioration diagnosing method for a zinc oxide type arrester, which diagnoses the presence or absence of deterioration of the non-linear resistance element by using a resistance component current having the same phase as the surge arrester terminal voltage passing through the arrester.

[0002]

2. Description of the Related Art In a lightning arrester in which one or a plurality of non-linear resistance elements containing zinc oxide as a main component (hereinafter simply referred to as "elements") are housed in series in a container, due to the characteristics of the elements, a constant voltage The current that can flow under application is extremely small, usually on the order of several μA, and at this level of current, normal element temperature rise and element deterioration due to this temperature rise cannot occur. In practice, the discharge gap in series with is omitted, and therefore, a small current constantly flows through the non-linear resistance element.

However, the element may deteriorate due to repeated operation under abnormal voltage or thermal cycle due to weather conditions. If this deterioration progresses, it can withstand the continuous phase voltage in the system. It will disappear and the element will be destroyed, which will hinder the system operation. Therefore, there is a demand for a monitoring method capable of continuously monitoring the resistance component current that can determine the initial state of deterioration during operation.

FIG. 15 shows the voltage-current characteristics of the device. In the figure, the solid line 25 shows the characteristic when the element is in a normal state, and the alternate long and short dash line 35 shows the characteristic when the deterioration has progressed. Here, the current on the horizontal axis indicates only a resistance current that does not include a capacitive current based on the electrostatic capacitance between the two end faces of the element normally formed in a disc shape. If the phase voltage of the system is Vn,
This current flowing through the device under voltage difference caused by the temperature of the element, the element is deteriorated, resulting a large difference in the current flowing in under the same temperature, for example, the temperature of the element theta ₂ and Then, the current I _R1 flowing when the element is normal is I
It changes greatly with _R2 . Therefore, the presence or absence of deterioration can be accurately determined by measuring the resistance component current that constantly flows and comparing it with the current of the element in the normal state corresponding to the temperature at the time of measurement. In the figure, the magnitude relationship of temperature θ is θ
₂ > θ ₁ .

By the way, when the current passing through the lightning arrester is measured by a current detector connected in series with the lightning arrester, the voltage applied to the lightning arrester is an alternating current at the operating frequency, and therefore, in addition to the resistance current, the capacitance current Is included. FIG. 16 shows a lightning arrester 2 whose upper and lower ends are connected to a line and the ground, respectively. This lightning arrester 2 includes an insulator and an element when the container that accommodates the element is an insulator, and indicates only the element when the container is a grounded metal.

FIG. 17 shows an electrical equivalent circuit of the lightning arrester shown in FIG. Since the element is usually formed in the shape of a disk and a relatively large capacitance C is formed between both end faces of the element, the current passing through the lightning arrester is the resistance component current I _R causing the temperature rise of the element and the electrostatic capacitance. It becomes a vector sum with the capacitance current I _C passing through the capacitance, and in order to determine the deterioration of the element, it is necessary to extract only the resistance current I _R from this vector sum.
In the figure, L indicates the inductance of the ground conductor of the lightning arrester.
When the container of the arrester is an insulator, the capacitance current I _C also includes a capacitance current having the insulator as the capacitance.

FIG. 18 shows a conventional resistance current measuring method, and FIG. 19 shows voltage and current waveforms measured by the method shown in FIG. The lightning arrester 2 connected to the bus bar or the power transmission line 1 is grounded via the current detector 4, and the bus bar or the power transmission line is further connected to the voltage detector 3 and the other end is grounded. The outputs from the current detector 4 and the voltage detector 3 are input to the calculator 8 via the amplifiers 6 and 7, respectively, and the resistance current is calculated. As shown in FIG. 19, the calculation of the resistance component current is performed by calculating the differential waveform of the voltage V measured by the voltage detector 3 from the total current I _S measured by the current detector 4 with the peak value of I _{C in} FIG. It is performed by amplifying and subtracting so as to match the peak value. The resistance component current I _R thus obtained is compared with the normal resistance component current at the element temperature measured in parallel with this measurement to determine the presence or absence of deterioration.

[0008]

However, when an automatic monitoring for deterioration diagnosis of a three-phase lightning arrester connected to a three-phase transmission line is performed using this method, as shown in FIG. , 7 and the arithmetic unit 8 are shared, the current detectors 41, 42, 43 and the voltage detector 31, corresponding to the three phases,
32 and 33 are required, and a switch 5 having many switching contacts is required so that the current detection value and the voltage detection value of the same phase can be input to the amplifiers 6 and 7, respectively. Since the progress of deterioration of the element is on the order of time at the earliest, it is possible to sufficiently achieve the purpose by the method of making determination while sequentially switching each phase.

As described above, the diagnosis of deterioration by the conventional method requires a large number of current detectors and wirings (the voltage detector can be shared) as the number of power transmission lines increases, and the size of the switching device becomes large for diagnosis. However, there is a drawback that the control is complicated or complicated, and a simple diagnostic method is desired. It is an object of the present invention to provide a simple diagnostic method which replaces the above-mentioned conventional method in which the number of power transmission lines to which a lightning arrester is connected increases and the number of current detectors and wiring significantly increases.

[0010]

In order to solve the above problems, according to the present invention, one or a plurality of non-linear resistance elements containing zinc oxide as a main component, which are connected in series, are provided in a container. The three-phase vector combination of the currents passing through the respective phases of the three-phase lightning arrester eliminates the capacitive component currents contained in the respective phase currents and creates a composite waveform of only the resistance component currents. Obtained, in the deterioration diagnosis method for diagnosing whether or not there is a lightning arrester in which the non-linear resistance element in the three-phase lightning arrester is deteriorated from this combined waveform, the maximum peak value of the combined waveform of only the resistance current is a predetermined value. It has a non-linear resistance element that generates a pulse voltage at the time of exceeding and also generates a pulse voltage at a predetermined position of the surge arrester terminal voltage waveform of any one of the three phases, and deteriorates from the time difference between the time points when both pulse voltages are generated. Avoidance of phases It is intended to identify the vessel.

Further, according to the present invention, in order to specify the arrester of the phase having the deteriorated nonlinear resistance element, when the maximum peak value of the combined waveform of only the resistance current exceeds the predetermined value, the predetermined value is given. The current waveform having the same peak value as the predetermined value, which is obtained by combining the non-linear resistance element whose deterioration has advanced in advance up to the value and the arrester terminal voltage of each phase, is sequentially reversed in polarity to the composite waveform for each phase. It is assumed that an attempt is made by superimposing and deleting a waveform in the vicinity of a portion passing the predetermined value.

Further, when the maximum peak value of the combined waveform of only the resistance current exceeds a predetermined value, a part or all of the current passing through the arrester of any one phase is excluded except for three or two phases. It is assumed that the currents are vector-synthesized and whether the deteriorated lightning arrester is present or not is diagnosed by comparing the synthesized waveforms. In addition, it is advantageous to combine the three-phase vector of the current passing through each phase of the three-phase surge arrester with a through-type current transformer having an annular iron core that allows the three-phase conductors on the primary side to collectively penetrate. is there.

[0013]

First, the principle of the deterioration diagnosis method according to the present invention will be described. A measurement circuit for three-phase vector combining of the currents passing through each phase of the three-phase lightning arrester is configured as shown in FIG. The composite waveform is obtained as shown in FIG. Figure 1
For example, a zero-phase current transformer is used as the current detector 44, and the grounding side conductors of the lightning arresters 21, 22, and 23 collectively pass through the current transformer core and are grounded, and the current transformer secondary side output is The composite waveform is obtained by inputting it to the amplifier 6 and amplifying it. Note that FIG. 2 additionally shows the combined current waveform 420 and the arrester terminal voltage waveform of each phase.

As can be seen from the current waveform of FIG. 2, the waveform of this composite current has a voltage-current characteristic of the element, that is, the current sharply increases as the applied voltage increases, and the current sharply decreases as the applied voltage decreases. As a result, the current waveform takes a waveform including a large amount of the third harmonic, and the position of its peak value coincides with the position of the peak value of the voltage waveform. Therefore, if the element of the arrester of any phase in the three-phase arrester has deteriorated, the peak value of the current of that phase is the peak value of the current of the remaining phase that appears every 60 ° electrical angle following this peak value. It is diagnosed that the element of the phase is deteriorated. However, since only the combined current waveform is measured by the measuring circuit of FIG. 1, it is not possible to identify the phase in which the element is deteriorated only from this waveform.

However, in the present invention, the pulse voltage time point generated when the value of the combined waveform of the resistance component current reaches the level of the predetermined value obtained when the arrester element deteriorates, and the reference phase. By determining the time difference from the time of the pulse voltage generated at the peak voltage position, the phase difference between the deteriorated arrester element and the reference phase can be found, so the phase of the transmission line to which the deteriorated arrester element is connected can be specified. it can.

Further, by superimposing the current waveform of the arrester element that has deteriorated in advance on each phase in the opposite polarity, if there is a phase in which the current waveform of the deterioration level disappears, the deterioration of the arrester is connected to that phase. It is understood that it is an element that has. Furthermore, in a current detector that seeks vector composition of three-phase resistance component current, when a value exceeding a predetermined value that proves deterioration of the lightning arrester element is obtained, the current waveform of any one of the phases is sequentially removed. By measuring, it is possible to detect the arrester element in which the phase exhibiting the predetermined value is deteriorated.

[0017]

EXAMPLES The present invention will be described below based on examples.
FIG. 3 shows a circuit configuration for deterioration diagnosis according to the first embodiment of the present invention. In this embodiment, lightning arresters 21, 22, 23 are connected to the respective phases 11, 12, 13 of the bus or power transmission line, and the ground side thereof is commonly installed via one current detector 44, and The voltage detector 3 is connected to one of the phases of the bus and the transmission line, here, the phase 11. As the current detector 44, a zero-phase current transformer having characteristics suitable for deterioration diagnosis of the lightning arrester is used.

The current detected by the current detector 44 and amplified by the amplifier 46 is input to the calculator 47, and the input current value is sufficient to prove the preset reference level equivalent value, that is, the initial deterioration of the arrester element. A pulse voltage is generated when a value (reference level shown in FIG. 4) corresponding to a level set as a certain level is exceeded, and this pulse voltage is input to the calculator 49. On the other hand, the waveform of the bus or the phase voltage measured by the voltage detector 3 is input to the calculator 48, a pulse voltage is generated at the peak value of the voltage waveform input here, and the pulse voltage is input to the calculator 49. To do. The calculator 49 calculates the time difference between the pulse voltage generated at the peak position of this voltage waveform and the pulse voltage generated when the magnitude of the combined current exceeds the reference level, and identifies the deteriorated phase according to FIG. That is, as shown in FIG. 5, the phase of the bus or transmission line to which the voltage detector is connected is defined as the R phase, and the pulse voltage generated at the peak voltage position of the R phase is used as the reference pulse that forms the origin of the time measurement. Is measured until the pulse voltage generated when the magnitude exceeds the reference level. When this time is almost zero, the deteriorated phase is the same phase as the reference phase, and if the electrical angle is equivalent to 120 ° If the phase is equivalent to 240 ° in electrical angle, the deteriorated phase can be specified as the next phase at low cost and easily.

FIG. 6 shows a circuit configuration for deterioration diagnosis according to the second embodiment of the present invention. Similar to the first embodiment, this embodiment shows a circuit configuration for identifying a deteriorated phase, and a voltage transformer having a surge arrester, a so-called PT.
(Potential Transformer) or voltage divider so-called P
The secondary side of the D (Potential Device) 50 is connected via a switch 54 to a superposed current generator 55, which will be described in detail below, and the output side of this generator is a zero-phase current transformer which is a current detector. output conductor 55 _a which penetrates is connected to the core 44.

The superposed current generator 55 degrades the current passing through the lightning arrester under the ground voltage of the bus or transmission line to a current level set as a magnitude large enough to prove the initial degradation of the lightning arrester element. The current waveform obtained when the ground voltage is applied to the non-linear resistance element is synchronized with the secondary voltage when the secondary voltage of PT or PD 50 is introduced through switch 54. The circuit configuration is such that the reverse polarity is output and the waveform of the three-phase vector combined current obtained on the secondary side of the zero-phase current transformer 44 in the circuit state of the switch 54 is the switch. It is intended to specify the arrester of the phase in which the element has deteriorated depending on how it changes by alternately closing each phase of 54.

That is, as shown in FIG. 7, the switch 5
The composite waveform (a) of only the resistance current obtained when the arrester element is healthy in all three phases in the circuit state of 4 is a waveform
Deformation as shown in (b), and when the maximum peak value exceeds a preset deterioration level, an alarm is issued via an alarm circuit not shown in Fig. 6, and at least one phase of the arrester has deteriorated. Will be informed. As a result, when the switch 54 is closed manually or automatically, the PT or PD 50
The phase voltages of the respective phases obtained on the secondary side of the are taken into the superimposed current generator 55 so as to have opposite polarities,
The current having the same waveform as the deterioration level current in (b) is output in the opposite polarity.

Therefore, assuming that when the R phase of the switch 54 is closed, a waveform in which the current waveform of the deterioration level disappears as shown in (c) on the secondary side of the zero-phase current transformer 44,
It is found that the lightning arrester deteriorated at least in the R phase. Next, assuming that a waveform as shown in (d) is obtained when the R phase of the switch 54 is opened and the T phase is closed, in this case, the current waveform of the deterioration level has not disappeared, so the element of the T phase arrester It can be seen that is not deteriorated. Similarly, even when only the S phase of the switch 54 is closed, the current waveform of the deterioration level as shown in the waveform (e) does not disappear, so that the deterioration phase can be finally identified as the R phase by the abnormal switch operation.

FIG. 8 shows how the combined current waveform changes during the diagnostic process when the elements of the arrester deteriorate in two phases. When the R-phase and S-phase of the switch 54 are closed by the operation of an alarm device (not shown), the waveform of the combined current changes as shown in FIG. Suppose it disappeared. Next, when the S-phase and T-phase of the switch are closed, the deterioration level current of one phase does not change, as shown in Fig. 6 (c), and there is a deterioration level current in the adjacent phase. The current waveform of the difference with a healthy resistance current appears,
It is assumed that the remaining one-phase current waveform moth disappears. Furthermore, when the T phase and the S phase of the switch are closed, the current waveform of one phase disappears, and the current waveform of the difference between the deterioration level current and the healthy resistance component current is present in the phase adjacent to this. It is assumed that the current waveform of the remaining one-phase deterioration level does not change. The method of operating the switch is arbitrary, but it is possible to specify that the deterioration phases are the R phase and the S phase from the change in the waveform of the combined current when the switch is operated every two phases.

FIG. 9 shows a circuit configuration for deterioration diagnosis according to the third embodiment of the present invention. A current detector for obtaining a three-phase vector composite waveform of the currents passing through the lightning arresters 21, 22, and 23 forming each phase of the three-phase lightning arrester, and here, each lightning arrester penetrating the annular core of the zero-phase current transformer 4 The bypass side circuits 61, 62, 63 that straddle the zero-phase current transformer 4 are connected to the ground side conductor of the switch via switches 61a, 62a, 63a, and by closing these switches, one of the currents passing through the arrester is reduced. It is considered that the part is shunted to the bypass circuit without penetrating the zero-phase current transformer. The shunt ratio to this bypass circuit is 100 when the current ratio of the zero-phase current transformer is 100.
It is as large as 0: 1 and the impedance of the current transformer seen from the primary side can be almost ignored. Therefore, when a conductor with the same cross-sectional area as the current transformer primary side is used as the conductor of the bypass circuit, It is considered to be around 50%.

FIG. 10 shows switches 61a, 62a and 63a.
FIG. 11 shows an example of a passing current waveform of each phase of the arrester when all are opened, and FIG. 11 shows a three-phase vector combined waveform of the passing currents of each phase shown in FIG. 10, that is, a combined waveform of only resistance current. As shown in this waveform example, when deterioration of the element occurs in the R-phase arrester, the switch 61 of the bypass circuit is used.
FIG. 12 shows a current waveform obtained on the secondary side of the current transformer when a, 62a and 63a are alternately closed. In the figure, for example, reference symbol R / 2 + S + T indicates a current waveform obtained on the secondary side of the current transformer when the lightning arrester 21 is an R-phase lightning arrester and the switch 61a is closed. Similarly, the code R + S / 2 +
T is the sign R + S + T when the switch 62a is closed.
/ 2 shows a current waveform when the switch 63a is closed.

As seen in FIG. 12, switch 61a
The maximum peak value of the combined current when the switch is closed is reduced to a deterioration level that is set to a value large enough to prove the initial deterioration of the element, that is, below the set level, and does not change when the switch 62a is closed, and the switch 63a When is closed, it is reduced below the set level again. A method of identifying the arrester of the phase in which the element has deteriorated from the change of the current waveform due to such a switch operation will be collectively described after the modification of the present embodiment described below.

FIG. 13 shows a modification of the embodiment shown in FIG. In this modification, switches 61a, 62a, 63a are included.
The ratio of the shunt currents to the bypass circuits 61, 62, and 63 when the circuit is closed is from about 50% in the embodiment of FIG.
The circuit configuration is set to 0%, and low impedances 71, 72, 73 are respectively inserted in the ground conductor of each phase of the arrester for direct current, and switches 61a, 62a, 6
3a is a zero-phase current transformer 44 and low impedances 71, 72,
It is inserted in series in the bypass circuits 61, 62, 63 that straddle 73. Here, low impedance 71, 72,
The impedance of 73 should be small enough not to raise the ground voltage appearing at the busbar or transmission line terminal to a value that threatens the insulation of the busbar or the transmission line when the lightning arrester is operated by a lightning strike. I shall.

In such a circuit structure, it is assumed that the deterioration of the element occurs in the R-phase lightning arrester 21, and the zero-phase current transformer 44-2.
If the maximum peak value of the combined current waveform obtained on the next side exceeds the set level, the computing unit 45 discriminates this excess and sends a control signal to the switch control unit 75 to switch the switch 6
1a, 62a and 63a are alternately opened and closed at appropriate time intervals. FIG. 14 shows how the combined current waveform changes at this time. In the figure, for example, symbol S + T indicates that when the current on the primary side of the current transformer is only the passing current of the S-phase lightning arrester and the T-phase lightning arrester, that is, when the switch 61a is closed, the entire passing current of the R-phase lightning arrester is commutated. A current waveform obtained on the secondary side of the current transformer when the above is performed is shown. Similarly, reference sign T + R indicates a current waveform when the switch 62a is closed, and reference sign R + S indicates a current waveform when the switch 63a is closed.

As shown in FIG. 14, the switch 61
When a and 63a are closed, the maximum peak value of the combined current is reduced to a preset deterioration level, that is, below a set level, and does not change when the switch 62a is closed. As described above, from FIG. 12 and FIG. 13, Table 1 shows the relationship between the switch operation and the change in the maximum peak value of the combined current.

[0030]

[Table 1] That is, it can be seen that the maximum peak value of the combined current does not change only when the switch belonging to the phase next to the phase in which the element has deteriorated is closed. Therefore, when the switches are alternately closed and the combined current peak value does not change when the switch of a certain phase is operated, the arrester of the phase preceding the phase to which the switch belongs can be identified as the deteriorated phase.

[0031]

As described above, according to the present invention,
One or a plurality of series-connected nonlinear resistance elements containing zinc oxide as a main component are housed in a container, and a current passing through each phase of the three-phase arrester is converted into a three-phase vector. By synthesizing, the capacitive component current contained in each phase current is erased to obtain the composite waveform of only the resistance component current, and from this composite waveform, there is an arrester in which the non-linear resistance element in the three-phase arrester has deteriorated. In the deterioration diagnosis method for diagnosing whether or not there is a pulse voltage when the maximum peak value of the combined waveform of only the resistance current exceeds a predetermined value, and a surge arrester terminal voltage waveform of any one of the three phases is generated. A method in which a pulse voltage is generated at a predetermined position and the time difference between the two pulse voltage generation times is obtained, and when the maximum peak value of the combined waveform of the resistance current only exceeds a predetermined value, the pulse voltage is preset to this predetermined value. Progressing deterioration Obtained by combining the non-linear resistance element and the arrester terminal voltage of each phase, the current waveform having the same peak value as the predetermined value is sequentially superimposed on the composite waveform in reverse polarity for each phase, and the predetermined value is set. A method of measuring a change in a waveform in the vicinity of a passing portion, and further, when a maximum peak value of a combined waveform of only the resistance component current exceeds a predetermined value, a part of a current passing through a surge arrester of any one phase or A three-phase lightning arrester in which three surge arresters are accommodated in a conventional common container by utilizing a method of vector-combining three-phase or two-phase currents Thus, the disadvantage that it is not possible to specify which phase of the non-linear resistance element has deteriorated is solved, and an effect that the deterioration element in the three-phase arrester can be specified easily at low cost is obtained.

[Brief description of drawings]

FIG. 1 is a circuit configuration diagram for explaining the present invention.

2 is a waveform diagram showing a combined current waveform of a three-phase surge arrester obtained by the circuit configuration of FIG. 1 and respective relative ground voltage waveforms of a bus bar or a transmission line which cause this waveform, which are superimposed on the combined current waveform.

FIG. 3 is a circuit configuration diagram for a surge arrester element deterioration diagnosis showing an embodiment of the present invention.

FIG. 4 is a waveform diagram showing the mutual time relationship of the voltage and current obtained by the circuit configuration of FIG. 3 and the pulse voltage obtained from these voltages and currents.

FIG. 5 is a pulse voltage waveform diagram for identifying a deterioration phase.

FIG. 6 is a circuit configuration diagram for a surge arrester element deterioration diagnosis showing another embodiment of the present invention.

7 is a waveform diagram showing a change situation of a three-phase vector composite current waveform in a diagnostic process for identifying a phase of a lightning arrester obtained by the circuit configuration of FIG. 6 when the phase is deteriorated.

FIG. 8 is a waveform diagram showing a change state of a three-phase vector composite current waveform in a diagnostic process for identifying the two phases of a lightning arrester when the elements of the two phases are deteriorated.

FIG. 9 is a circuit configuration diagram for a surge arrester element deterioration diagnosis showing another embodiment of the present invention.

10 is a waveform diagram showing a passing current waveform of each phase of the lightning arrester when the element of the first phase of the lightning arrester obtained by the circuit configuration of FIG. 9 is deteriorated.

FIG. 11 is a waveform diagram showing a three-phase vector composite current waveform of the current passing through each phase of the arrester shown in FIG.

FIG. 12 is a waveform diagram showing a three-phase vector composite current waveform excluding a part of the current passing through the arrester of any one phase.

FIG. 13 is a circuit configuration diagram for a surge arrester element deterioration diagnosis according to a modification of the embodiment shown in FIG.

FIG. 14 is a waveform diagram showing a two-phase vector composite current waveform excluding all of the current passing through the arrester of any one phase.

FIG. 15 is a diagram showing the difference between the normal characteristics of the arrester element and the characteristics when it is deteriorated.

FIG. 16 is a single line diagram showing a connection state of the lightning arrester with an external circuit.

FIG. 17 is an equivalent circuit of a lightning arrester showing a current component in a current passing through the lightning arrester.

FIG. 18 is an example of a conventional measurement circuit diagram configured for one phase of a lightning arrester in order to extract only a resistance current from a current passing through the lightning arrester.

FIG. 19 is a current waveform diagram showing the waveform of the total current passing through the arrester and the waveform of the current component in the total current.

FIG. 20 is an example of a conventional measurement circuit diagram for a three-phase lightning arrester for extracting only a resistance current from the current passing through the lightning arrester.

[Explanation of symbols]

 2, 21, 22, 23 Lightning arrester 3, 31, 32, 33 Voltage detector 4, 41, 42, 43, 44 Current detector 50 Voltage transformer (PT) or voltage divider (PD) 54 Switch 55 Superposed current generator 61, 62, 63 Bypass circuit 61a, 62a, 63a Switch 420 Three-phase vector combined current waveform

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Nobuyuki Takao Inventor No. 1 Tanabe Shinden, Kawasaki-ku, Kawasaki-shi, Kanagawa Fuji Electric Co., Ltd. No. 1 in Fuji Electric Co., Ltd. (72) Inventor Yoshihiro Tanabe 1-1, Tanabe Nitta, Kawasaki-ku, Kawasaki-shi, Kanagawa Fuji Electric Co., Ltd. (56) Reference JP-A-54-34043 (JP, A)

Claims (4)

[Claims] 1. One or a plurality of units connected in series,
A non-linear resistance element containing zinc oxide as a main component is housed in a container, and a current contained in each phase of the three-phase arrester is combined by three-phase vector synthesis to obtain a capacitance contained in each phase current. In the deterioration diagnosis method for deciding whether or not there is a lightning arrester in which the non-linear resistance element in the three-phase lightning arrester is deteriorated from the resultant waveform by erasing the partial current and obtaining the combined waveform of only the resistance partial current, The pulse voltage is generated when the maximum peak value of the combined waveform of only the partial current exceeds the predetermined value, and the pulse voltage is generated at the predetermined position of the arrester terminal voltage waveform of any one of the three phases, and the both pulses are generated. A method of diagnosing deterioration of a zinc oxide lightning arrester, characterized in that a lightning arrester of a phase having a non-linear resistance element deteriorated is identified from a time difference between voltage generation points. 2. One or more serially connected,
A non-linear resistance element containing zinc oxide as a main component is housed in a container, and a current contained in each phase of the three-phase arrester is combined by three-phase vector synthesis to obtain a capacitance contained in each phase current. In the deterioration diagnosis method for deciding whether or not there is a lightning arrester in which the non-linear resistance element in the three-phase lightning arrester is deteriorated from the resultant waveform by erasing the partial current and obtaining the combined waveform of only the resistance partial current, When the maximum peak value of the combined waveform of only the partial current exceeds a predetermined value, the predetermined value is obtained by combining the non-linear resistance element that has advanced deterioration up to the predetermined value and the arrester terminal voltage of each phase. The current waveform having the same peak value as that of the phase is sequentially superimposed on the composite waveform in reverse polarity for each phase, and the waveform in the vicinity of the portion passing the predetermined value is erased. Identify the arrester Degradation diagnosis method of the zinc oxide arrester, characterized and. 3. One or a plurality of units connected in series,
A non-linear resistance element containing zinc oxide as a main component is housed in a container, and a current contained in each phase of the three-phase arrester is combined by three-phase vector synthesis to obtain a capacitance contained in each phase current. In the deterioration diagnosis method for deciding whether or not there is a lightning arrester in which the non-linear resistance element in the three-phase lightning arrester is deteriorated from the resultant waveform by erasing the partial current and obtaining the combined waveform of only the resistance partial current, When the maximum peak value of the combined waveform of only the partial current exceeds the predetermined value, the three-phase or two-phase current is vector-combined except some or all of the current that sequentially passes through the arrester of any one phase. A method of diagnosing deterioration of a zinc oxide lightning arrester, which comprises identifying a phase arrester having a linear resistance element. 4. The method according to any one of claims 1 to 3, wherein the three-phase vector combination of the electric currents passing through the respective phases of the three-phase arrester is performed by collectively penetrating the three-phase conductor on the primary side. A method for diagnosing deterioration of a zinc oxide lightning arrester, which has an annular core.