JP6246096B2 - Diagnosis method of gas insulated switchgear - Google Patents

Description

  The present invention relates to a state diagnosis method for a gas insulated switchgear. More specifically, the present invention relates to a state diagnosis method suitable for diagnosing whether or not there is a risk of deterioration in insulation performance caused by whiskers in a gas insulated switchgear.

As a method for diagnosing the state of a gas insulated switchgear, methods using SF ₆ decomposition gas analysis using a gas detector tube (SO ₂ , HF) are known (Non-Patent Documents 1 to 4). By this method, the part other than the part where SF ₆ decomposition gas is generated by the discharge at the time of current interruption by the normal switching operation of the switching contact (breaker, disconnector, grounding switch, etc.), that is, the part not including the switching contact Can be diagnosed.

In addition, in Patent Document 1, in consideration of the fact that an abnormality diagnosis cannot be performed using SF ₆ decomposition gas as an index in a portion where SF ₆ decomposition gas is generated, such as a portion including a switching contact. A method for diagnosing abnormalities is proposed. Specifically, when a contact failure or a minute gap occurs near the switching contact and abnormal heating or weak partial discharge occurs, the conductive grease applied to at least the movable part of the switching contact is heated and carbide (carbon ) And the carbide reacts with the SF ₆ decomposition gas to become CF ₄ , so that abnormality diagnosis is performed using CF ₄ as a monitor gas.

JP2012-034531

Chuo Electric Power Research Report H05209 (2006) Hiroyuki Shinkai, Hisashi Goshima, Masafumi Yashima: "Development of diagnostic method for gas-insulated switchgear-Highly sensitive detection method of partial discharge by accumulation of decomposed gas-" IEEJ Transactions B, Vol. 127, No. 1, pp. 231-240 (2007) Hiroyuki Shinkai, Hisashi Goshima, Masafumi Yashima: "Examination of the state diagnosis method of gas-insulated switchgear-Highly sensitive detection method of partial discharge by accumulation of decomposition gas-" Chuo Electric Power Research Report H07020 (2008) Hiroyuki Shinkai, Hisashi Goshima, Masafumi Yashima: "Development of a condition diagnosis method for gas-insulated switchgear (Part 2)-Examination on spacer degradation diagnosis and contact failure detection" IEEJ Transactions B, Vol.129, No.1, pp. 174-181 (2009) Hiroyuki Shinkai, Hisashi Goshima, Masafumi Yashima: “Examination of state diagnosis method of gas-insulated switchgear (Part 2) —Effect of moisture content in SF6, partial discharge on spacer and repeated discharge due to contact failure And detection of abnormal heating-"

  By the way, conventionally, it was a common technical knowledge that whiskers are not generated on the inner surface of a gas insulated switchgear. However, as a result of investigation of the gas insulated switchgear, the present inventor has discovered that whiskers may be generated on the inner surface of the gas insulated switchgear.

  Here, the occurrence of whiskers occurred on the ground side of the gas insulated switchgear. Whisker growth is likely to take a long time. Therefore, it is considered that the risk of deterioration of insulation performance due to whiskers is not high. However, the gas insulated switchgear needs to ensure safety. To do so, obtain information on whether or not partial discharges starting from whiskers are actually occurring in the gas-insulated switchgear, and whether there is a risk of deterioration in insulation performance due to whiskers in the gas-insulated switchgear. Diagnosing whether or not is considered to be extremely important.

  However, in the diagnostic methods described in Non-Patent Documents 1 to 4 and the diagnostic method described in Patent Document 1, information is obtained as to whether or not a partial discharge starting from a whisker is actually occurring in the gas-insulated switchgear. It was not possible to diagnose whether or not the risk of insulation performance deterioration caused by whiskers occurred in the gas insulated switchgear.

  Therefore, an object of the present invention is to provide a method for diagnosing whether or not the risk of insulation performance degradation due to whiskers is occurring in a gas insulated switchgear.

  In order to solve such a problem, the method for diagnosing the state of a gas-insulated switchgear according to the present invention configures a whisker heating product and whisker generated when a partial discharge starting from a whisker occurs in the gas-insulated switchgear. When any product of an element-containing compound is detected in the gas-insulated switchgear to be diagnosed, it is diagnosed that there is a risk of deterioration in insulation performance due to whiskers in the gas-insulated switchgear to be diagnosed. Like to do.

  Here, in the method for diagnosing the state of the gas-insulated switchgear according to the present invention, when the product is detected from the gas section of the gas-insulated switchgear to be diagnosed that does not include the switch contacts, the insulation performance is reduced due to whiskers. It is preferable to diagnose that the risk is occurring in the gas compartment not including the switching contact and the gas compartment including the switching contact.

  In the gas-insulated switchgear state diagnosis method of the present invention, the whisker is preferably a zinc whisker or a tin whisker.

  According to the present invention, since it is possible to obtain information on whether or not partial discharge starting from a whisker is actually occurring in the gas-insulated switchgear, the risk of lowering the insulation performance caused by the whisker is reduced. It is possible to diagnose whether or not it has occurred in the inside. Therefore, it is possible to take measures such as exchanging the devices constituting the gas-insulated switchgear according to the presence or absence of the risk of deterioration of the insulation performance.

  Hereinafter, embodiments for carrying out the present invention will be described in detail.

  The gas-insulated switchgear state diagnosis method according to the present invention is any one of a whisker heating product generated when a partial discharge starting from a whisker occurs in the gas-insulated switchgear and a compound containing an element constituting the whisker. When the product is detected from the gas insulated switchgear to be diagnosed, it is diagnosed that the risk of lowering the insulation performance caused by the whisker occurs in the gas insulated switchgear to be diagnosed.

  Whisker is generated by crystal growth of various metal materials and alloy materials in a needle shape. If such a material is used for the inner surface of the gas insulated switchgear, whiskers may occur there. And there is a possibility that partial discharge starting from this whisker may occur. For example, in a gas insulated switchgear, tin plating or galvanization may be performed as a rust prevention measure. In this case, tin plating or galvanization is applied to the inner surface of the casing. Therefore, tin whiskers and zinc whiskers are generated on the inner surface of the casing of the gas insulated switchgear, and there is a possibility of causing partial discharge due to these whiskers.

  When the partial discharge starting from the whisker occurs, a compound containing a whisker heating product and an element constituting the whisker (hereinafter referred to as “whisker constituent element”) is generated (hereinafter, this product is referred to as a “whisker-derived product”. Called). When a whisker-derived product is detected from the gas-insulated switchgear to be diagnosed, information that partial discharge starting from the whisker is actually occurring in the gas-insulated switchgear to be diagnosed is obtained. . And when this information is obtained, it can be diagnosed that the risk of insulation performance degradation due to whiskers has occurred in the gas insulated switchgear to be diagnosed. In other words, it can be diagnosed that the risk of lowering the insulation performance due to whiskers has become apparent.

  The whisker-derived product is predicted in consideration of whisker constituent elements, insulating gas species in the gas-insulated switchgear, impurities that may be unintentionally contained in the gas-insulated switchgear, heat and plasma generated during partial discharge, etc. be able to. The whisker constituent element may be determined in consideration of an element constituting a material capable of crystal growth as a whisker among materials used on the inner surface of the gas insulated switchgear.

  When a partial discharge starting from the whisker occurs, heat is generated and a part of the whisker is heated. Thereby, the heating product of a whisker is produced | generated. Specifically, it can exist in the state of fine powder or the like by being cooled in the course of diffusion of the vapor and the vapor starting from the location where the partial discharge occurs.

  Further, when a partial discharge starting from the whisker occurs, the insulating gas is decomposed to generate decomposed gas. The decomposition gas reacts with the heated whisker product to produce a reaction product. Furthermore, in the gas insulated switchgear, in addition to the insulating gas, an unintended impurity (for example, water vapor) can be contained in a trace amount. Accordingly, the reaction product is also generated when this impurity reacts with the heated product of whisker. The reaction product is also generated when the heated whisker product reacts with both the cracked gas and the impurities. In this way, a compound containing a whisker constituent element is generated.

  In addition, the compound containing a whisker constituent element can exist in the state of gas or solid.

For example, a case where the insulating gas is SF ₆ and water vapor is included as an unintended impurity will be described as an example. In this case, a partial discharge starting from a whisker occurs in the gas insulated switchgear. In some cases, whisker-derived products are produced as whisker-derived products, and at least one element selected from the group consisting of sulfur, fluorine, hydrogen and oxygen and a compound comprising whisker constituent elements are produced. Can be predicted.

Here, the dominant species of the whisker-derived product is a reaction product of the heated whisker product and the decomposition gas of the insulating gas. When the detection sensitivity of the analyzer is taken into consideration, it is preferable to set a product with a larger production amount as a detection target. Therefore, it is preferable to predict a reaction product of a whisker heating product and an insulating gas decomposition gas as a whisker-derived product, and use these as detection targets. For example, as described above, in a gas insulated switchgear, tin plating or zinc plating may be applied as a rust prevention measure. In this case, tin whisker derived from tin plating or zinc plating applied to the inner surface And zinc whiskers are generated, and partial discharge may occur from this. In this case, if the insulating gas is SF ₆ , the reaction product of the whisker heating product and the insulating gas decomposition gas is tin sulfide and fluoride, or zinc sulfide and fluoride. It becomes. Therefore, it is preferable to use these compounds as detection targets. If the insulating gas is SF ₆ , a large amount of tin fluoride or zinc fluoride is generated. Therefore, it is more preferable to use these fluorides as detection targets.

  For example, the whisker-derived product may be detected by directly collecting the gas in the gas-insulated switchgear and analyzing whether the whisker-derived product is contained in the gas. Alternatively, after the adsorbent capable of adsorbing the whisker-derived product is brought into contact with the gas in the gas insulated switchgear, it is analyzed by analyzing whether or not the whisker-derived product is adsorbed in the adsorbed material. May be. For example, an adsorbent that has the effect of separating substances according to the molecular size of the substance (molecular sieving effect) is used to adsorb part or all of the whisker-derived product, and an insulating gas and further an insulating property. By preventing the gas decomposition gas from being adsorbed, it is possible to easily detect a product serving as a diagnostic index. In addition, as a product analysis method, when analyzing a product as a gas, for example, a method using FTIR (Fourier transform infrared spectrophotometer), gas chromatography, or the like can be used. In the case of analyzing the product by dissolving it in a liquid, for example, liquid chromatography mass spectrometry, ion chromatography and the like can be mentioned.

  Next, as an example of the state diagnosis method of the gas insulated switchgear according to the present invention, a case where a gas compartment not including an open / close contact and a gas compartment including an open / close contact are used as a diagnosis target gas compartment will be described.

  When a gas compartment that does not include an open / close contact is used as a diagnosis target gas compartment, when a whisker-derived product is detected from the gas compartment that does not include an open / close contact, the portion starting from the whisker in the gas compartment that does not include the open / close contact It is diagnosed that a discharge has occurred and a risk of deterioration of insulation performance due to whiskers has occurred in the gas insulated switchgear.

  When a gas compartment including a switching contact (a gas compartment including a circuit breaker, a disconnector, and a ground switch) is a diagnosis target gas compartment, when a whisker-derived product is detected from the gas compartment including the switching contact, this switching contact In the gas compartment including the whisker, a partial discharge is generated, and it is diagnosed that there is a risk of lowering the insulation performance caused by the whisker in the gas insulated switchgear. However, when a material capable of crystal growth as a whisker is used for the switching contact, a heating product of this material or a reaction product of this heating product and a decomposition gas of an insulating gas in the gas insulated switchgear Etc. may be generated. Therefore, in this case, it is preferable to use a whisker-derived product containing a whisker constituent element that is not used for the switching contact.

Heretofore, it has been common technical knowledge that whiskers are not generated on the inner surface of the gas insulated switchgear. Therefore, in the state diagnosis method using the conventional SF ₆ decomposition gas analysis, it has not been possible to diagnose whether or not there is a risk of lowering the insulation performance due to whiskers. Moreover, the whisker-derived product is not adsorbed by the adsorbent in the gas-insulated switchgear, and it has never been known that the whisker-derived product is generated. On the other hand, according to the present invention, it is possible to diagnose whether or not the risk of insulation performance deterioration due to whiskers has been manifested in the gas-insulated switchgear, and to whiskers that may have been overlooked so far. It is possible to diagnose whether or not there is a risk of deterioration of the insulation performance of the gas insulated switchgear caused by the occurrence.

  In general, the gas insulated switchgear equipment is generally made at the same factory in the same period, and the material composition among the equipment is considered to be the same or similar. . Therefore, when a whisker-derived product is detected in a part of the gas compartment, a partial discharge starting from the whisker occurs in another gas compartment or a partial discharge starting from the whisker occurs. There is a possibility, and it may be possible to roughly diagnose that there is a risk of deterioration in insulation performance due to whiskers. For example, if it is diagnosed that there is a risk of deterioration in insulation performance due to whiskers in a gas section that does not include switching contacts, it is roughly estimated that there is a risk of deterioration in insulation performance due to whiskers in gas sections that include switching contacts. Diagnosis may be made automatically. Thereby, it is possible to diagnose the risk of lowering the insulation performance caused by whiskers in the entire gas insulated switchgear regardless of the material used for the switching contact.

  The above-described embodiment is an example of a preferred embodiment of the present invention, but is not limited thereto, and various modifications can be made without departing from the gist of the present invention. For example, when a gas (insulating gas) is circulated in the gas insulated switchgear, the whisker-derived product and the whisker itself can move in the gas insulated switchgear. Therefore, when a whisker-derived product is detected from a part of the circulation type gas insulated switchgear, it is diagnosed that there is a risk of lowering the insulation performance due to the whisker in the entire gas insulated switchgear. be able to.

Further, in the above-described embodiment, the case where the insulating gas is SF ₆ has been described. However, when a gas other than SF ₆ is used as the insulating gas, the whisker constituent elements and the insulating properties in the gas-insulated switchgear are also included. The whisker-derived product is predicted in consideration of the gas type, impurities that may be unintentionally included in the gas-insulated switchgear, the amount of heat generated during partial discharge, etc., and the insulation caused by the whisker is the same as in the above embodiment. You may make it diagnose whether the performance fall risk has arisen.

  In addition, since the whisker-derived product always contains a whisker constituent element, it may be detected whether the gas or adsorbent collected from the gas insulated switchgear contains a whisker constituent element. Good.

  Examples of the present invention will be described below, but the present invention is not limited to these examples.

  Generated by zinc or tin as a whisker constituent element and gas in gas insulated switchgear by HSC Chemistry (Production company: Autokumpu Research oy, Pori, Finland, A. Roine, version 4.0), which is chemical equilibrium calculation software An analysis was performed on the products that could be made.

The analysis conditions were as follows.
<Heating temperature>
25 ℃ → 3000 ℃
<Substances present in the gas compartment>
SF ₆ (g): 1 kmol
・ H ₂ O (g): 100 × 10 ⁻⁹ kmol
Sn (s) or Zn (s): 0.001 kmol

  In the above analysis conditions, “g” is a gas and “s” is a solid.

As a result of analyzing the products that can be generated by zinc and the gas in the gas-insulated switchgear, ZnF ₂ , ZnS, and Zn are generated as gas components, and ZnF ₂ is generated as other than the gas components. all right.

Further, as a result of analysis of products which can be produced by the gas in the tin and gas insulated switchgear, a gas _component, SnF, be SnF _2, SnF _3, SnF _4, and Sn is produced was found.

  From the above analysis results, it was found that a heating product of whisker and a compound containing a whisker constituent element can be generated.

  Here, when a partial discharge starting from the whisker occurs, plasma is generated. The above analysis is an analysis based on a simple equilibrium calculation, and generation of a high energy state due to plasma generation is not considered. When considering the generation of a high energy state due to plasma generation, all compounds that can be considered as heated products of whiskers and compounds containing whisker constituent elements (reaction products of whisker constituent elements and gas components in gas insulated switchgear) Can be a whisker-derived product.

For example, when a partial discharge starting from a zinc whisker occurs, examples of the candidate whisker-derived product include Zn, ZnF ₂ , ZnH, Zn (H ₃ ), ZnO, and ZnS as gas components. It is. Other than the gas components, Zn, ZnF ₂ , ZnO, Zn (OH) ₂ , ZnSO ₄ , ZnS, and the like.

Further, for example, when a partial discharge starting from tin whisker occurs, examples of the candidate whisker-derived product include Sn, Sn ₂ , SnF, SnF ₂ , SnF ₃ , SnF ₄ , SnH as gas components. Sn (H ₃ ), SnH ₄ , SnO, SnO ₂ , SnS, SnS ₂ , and Sn ₂ S ₂ . Other than the gas components, Sn, SnF ₂ , SnO, SnO ₂ , Sn (OH) ₂ , SnSO ₄ , Sn (SO ₄ ) ₂ , Sn (HS) ₂ , SnS, SnS ₂ , Sn ₂ S ₃ , and Sn ₃ S ₄ etc.

  By making the above whisker-derived product as a detection target, it is considered that it is possible to diagnose whether or not the risk of lowering the insulation performance caused by the whisker is generated in the gas insulated switchgear.

Claims (3)

  Either the heated product of the whisker or the compound containing the element constituting the whisker generated when a partial discharge starting from the whisker occurs in the gas insulated switchgear is a gas-insulated switchgear to be diagnosed. A method for diagnosing a state of a gas-insulated switchgear, comprising: diagnosing that a risk of deterioration in insulation performance due to the whisker occurs in the gas-insulated switchgear to be diagnosed when detected from within the apparatus.   When the product is detected from the gas compartment not including the switching contact of the gas insulated switchgear to be diagnosed, the risk of insulation performance degradation due to the whisker is not including the switching contact. The method of claim 1, wherein the method is diagnosed as occurring in a containing gas compartment.   The method according to claim 1, wherein the whisker is a zinc whisker or a tin whisker.