CN107861057A - A kind of determination method of the key parameter of separator used for lightning protector - Google Patents

Abstract

A method for determining the key parameters of a disconnector for a lightning arrester, the steps are as follows: (1) obtain the leakage current on the outer surface of the lightning arrester under extreme conditions through artificial pollution tests, so as to determine the long-term operating current of the disconnector for the lightning arrester; The aging test is used to obtain the internal leakage current of the arrester after aging; combined with the external leakage current obtained by the artificial pollution test, the minimum operating current I of the disconnector for the arrester is determined; I=k (I _{outer MAX} + I _inner ) where, I _{outer MAX} is the arrester Use the continuous operating current of the disconnector; I is the _internal leakage current of the arrester after aging. The invention utilizes the leakage current of the lightning arrester during the artificial pollution test to confirm the continuous operating current of the disconnector for the lightning arrester, and combines the leakage current of the lightning arrester after the lightning impact aging test to confirm the minimum operating current of the disconnector for the lightning arrester. The key parameters of the disconnector for lightning arrester can be effectively and accurately confirmed.

Description

A Method for Determining Key Parameters of Disconnectors Used in Lightning Arresters

technical field

The invention relates to a method for determining key parameters of a disconnector for a lightning arrester, belonging to the technical field of lightning arresters.

Background technique

Distribution network surge arresters are usually made of composite insulating material jackets, which are not easy to be found from the appearance after a fault, difficult to find the fault point, and cannot be repaired in time, forming a continuous ground fault, which is not conducive to the economical and reliable operation of the power system. The disconnector is the supporting equipment of the arrester, which is used in series with the arrester. When the arrester is faulty, it will be disconnected from the system with the arrester, so that the arrester will be out of operation and prevent the continuous grounding fault of the power grid. And after the disconnector operates, there should be an obvious disconnection mark, which is convenient for quickly finding the fault point and reducing the maintenance work of the operating personnel. But the special technical standard about the disconnector is still far from perfect at present. National standard GB11032-2010 and DL/T1294-2013 guidelines for the use of disconnectors for metal oxide arresters in AC power systems and other relevant standards are only part of the technical requirements for some disconnectors. However, the two most important key technical parameters (long-term running current and minimum operating current) of arrester disconnectors only give a simple definition, and do not determine its value, and even do not know how to determine these two parameters. Give specific instructions.

Contents of the invention

The purpose of the present invention is to solve the problem of determining the key parameters of the disconnector for lightning arresters, and the present invention discloses a method for determining the key parameters of disconnectors for lightning arresters.

The technical scheme of the present invention is as follows, a method for determining the key parameters of a disconnector for a lightning arrester, the steps are as follows:

(1) Obtain the external leakage current of the arrester under extreme conditions through the artificial pollution test to determine the long-term operating current of the disconnector for the arrester;

(2) Obtain the internal leakage current of the arrester after aging through the lightning impact aging test, and combine the external leakage current obtained by the artificial pollution test to determine the minimum operating current I of the disconnector for the arrester:

I=k (I _{outer MAX} +I _inner )

Among them, I _{outside MAX} is the continuous operating current of the disconnector for the arrester; I _inside is the internal leakage current of the arrester after aging; k is the safety margin of the minimum operating current, which is the allowable value of the uncertainty of the total leakage current, mainly It is related to the operating environment of the arrester; the k value is taken as 1.5 during the test analysis.

The continuous operating current of the disconnector for the arrester is the maximum value of the leakage current on the outer surface of the arrester.

Described artificial pollution test comprises the following steps:

(1) Sample pretreatment: Rinse the sample with deionized water and dry it in a dustproof container;

(2) Sample smearing: use quantitative brushing method;

(3) Retest of salt density and gray density: randomly select a test product to test whether the applied salt density and gray density meet the requirements;

(4) Pressurization test: use artificial fog chamber to humidify the test sample, and use constant pressure method to pressurize;

(5) Leakage current measurement: Use a multimeter and an oscilloscope to detect the leakage current.

The lightning impact aging test refers to GB11032-2010, and the residual voltage value of the lightning current impact of the zinc oxide arrester is tested and recorded at an interval of 1 minute per impact, and the leakage of the arrester under the condition that the zinc oxide arrester is at normal temperature is measured after a certain number of intervals current value.

The beneficial effects of the present invention are that the present invention utilizes the leakage current of the arrester during the artificial pollution test to confirm the continuous operating current of the disconnector for the arrester, and confirms the minimum operating current of the disconnector for the arrester in combination with the leakage current of the arrester after the lightning impact aging test. The key parameters of the disconnector for arrester can be effectively and accurately confirmed, which provides a reference for the standardized production and use of the disconnector for arrester, and is suitable for promotion and application in power systems.

Description of drawings

Fig. 1 is the implementation flow chart of the method of the present invention.

Detailed ways

The specific embodiment of the present invention is shown in Fig. 1 .

In this embodiment, a method for determining key parameters of a disconnector for a lightning arrester uses artificial pollution tests and lightning impact aging tests to determine the continuous operating current and the minimum operating current of the disconnector for lightning arresters according to the leakage current of the lightning arrester.

As shown in Figure 1, the specific operation steps of the artificial pollution test are as follows:

(1) Sample pretreatment: Rinse the insulating surface of the arrester with deionization to remove the dirt on the arrester. After cleaning, place it in a dust-proof container to dry and wait for use.

(2) Sample contamination: refer to the quantitative brushing method, calculate the amount of NaCl and kaolin required for each arrester sample according to the surface area of the insulating surface of the arrester sample and the pollution level, and weigh it with an electronic balance. The amount of NaCl and kaolin is weighed and packed with clean test paper respectively. Pour the NaCl and kaolin wrapped with test paper into a glass cup cleaned with deionized water, add an appropriate amount of deionized water to dissolve, stir with a fine brush and paint all on the surface of the arrester sample. Hang it on the sample rack of the arrester and wait for 24 hours to dry, and prepare to put it into the artificial fog chamber for pollution test.

(3) Retesting of salt density and gray density: Randomly select a sample of the lightning arrester after being smeared to measure whether its pollution degree meets the expected requirements.

(4) Pressurization: use a steam generator to humidify the pollution test room, record the temperature and humidity of the site, and when the humidity reaches 100%, put the sample of the arrester that has been polluted into the artificial fog room and apply a constant voltage.

(5) Measurement of leakage current: While applying voltage to the arrester test product, use an oscilloscope and a multimeter to record the instantaneous value of the arrester leakage current at each moment.

The lightning impulse aging test refers to GB11032-2010, and any appropriate lightning impulse current within the range of 0.01 to 2 times the nominal current can be selected. requirements) are subject to arbitrary deviations. During the test, test and record the residual voltage value of the lightning current impact of the zinc oxide arrester at an interval of 1 minute between each impact, and measure the leakage current value of the arrester when the zinc oxide arrester is at normal temperature after a certain number of intervals.

As shown in FIG. 1, it is a flow chart of the implementation of the method of this embodiment. Obtain the leakage current I _of the arrester under different pollution degrees through the artificial pollution test, and use the maximum value I _MAX as the continuous operating current of the disconnector for the arrester; obtain the leakage current I _of the aged arrester through the lightning impact aging test, and Adding it to the leakage current under pollution, the result is the minimum operating current I of the disconnector for the arrester.

Claims (4)

1. A method for determining the key parameters of a disconnector for a lightning arrester is characterized in that the steps of the method are: (1) Obtain the leakage current on the outer surface of the arrester through the artificial pollution test to determine the long-term operating current of the disconnector for the arrester; (2) Obtain the internal leakage current of the arrester after aging through the lightning impact aging test; combine the external leakage current obtained by the artificial pollution test to determine the minimum operating current I of the disconnector for the arrester; I=k (I _{outer MAX} +I _inner ) Among them, I _{outside MAX} is the continuous operating current of the disconnector for the arrester; I _inside is the internal leakage current of the arrester after aging; k is the safety margin of the minimum operating current, which is the allowable value of the total leakage current uncertainty. 2. the determining method of the key parameter of a kind of lightning arrester according to claim 1 is characterized in that, described artificial pollution test comprises sample pretreatment, sample smear, salt dense ash dense retest, adding pressure test and leakage current measurement. 3. the determining method of the key parameter of a kind of lightning arrester according to claim 1 is characterized in that, described lightning impact aging test, every impact 1 interval 1min, test and record zinc oxide arrester lightning current impact Residual voltage value; and measure the leakage current value of the arrester when the zinc oxide arrester is at normal temperature after a certain number of intervals. 4. The method for determining key parameters of a disconnector for a lightning arrester according to claim 1, wherein the continuous operating current of the disconnector for a lightning arrester is the maximum value of the leakage current on the outer surface of the lightning arrester.