JPS5848303A - Oil-immersed electric device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] The present invention relates to oil-filled electrical equipment used at high temperatures.

Normal oil-filled electrical equipment such as transformers and capacitors have a maximum temperature of about 90 to 105°O during use, and do not use particularly heat-resistant materials. However, recently, such electrical equipment has become smaller and lighter, and as a result, the operating temperature has become higher. (Or) It has become necessary to develop insulating paper.

For example, in the case of transformers, silicone oil is generally used as the insulating oil and aromatic polyamide paper is used as the insulating paper, but since silicone oil is expensive, transformers made of a combination of these insulating materials The equipment is very expensive.

Furthermore, since silicone oil has a rather high coefficient of thermal expansion, a large converter must be used in transformers used at high temperatures, which poses an obstacle to downsizing the transformer itself.

Mineral-based transformer insulating oils (hereinafter referred to as mineral oils) have been used as insulating oils that are relatively inexpensive and have a low coefficient of thermal expansion, but they are flammable and pose a fire risk, and cannot be used at high temperatures. It is not used in the oil-filled electrical equipment used.

The inventors of the present invention have conducted intensive research in view of such conventional problems, and have found that the m-fatty acid ester of neopentyl polyol has low flammability, which is almost the same as that of silicone oil, and also has a small coefficient of thermal expansion. It is an inexpensive heat-resistant insulating oil,
He discovered that scales can be used as an insulating oil for electrical equipment, leading to the completion of the present invention.

That is, the present invention is characterized by using a heat-resistant insulating oil made of a fatty acid ester of neopentylboriol as an insulating material, and relates to an oil-filled electrical device made of aromatic polyacetate.

Fatty acid ester of neopentyl polyol is a known substance and has already been used as lubricating oil, hydraulic oil, rolling oil, grease, etc.

Specific examples of fatty acid esters of neopentyl polyol include Unistar H581 and Unistar H3281M (both manufactured by NOF Corporation), whose insulating properties are comparable to conventional insulating oils.

Next, neopentyl polyol fat 1! The results of measuring the physical properties of esters will be described. In addition, the product name KIF? is used as silicone oil. 6-50 dimethyl silicone oil (manufactured by Shin-Etsu Chemical Co., Ltd.) from J as mineral oil 02
Those that passed Type 1, No. 2 in the No. 320 test were used as comparative examples.

(a) Flash point and combustion point Flash points were determined by open flash point tests.

The combustion point was also measured in the same manner.

(b) Burning rate The burning rate was measured in accordance with J Engineering 802101.11.

(c) Dielectric breakdown voltage The dielectric breakdown voltage was measured according to O2101.2o from J.

) Viscosity Viscosity is determined using a viscosity needle according to JIS O2101.8.
The kinematic viscosity coefficient (in units of two centistokes (·at)) at 25'O and 80°0 was measured.

Coefficient of thermal expansion The coefficient of thermal expansion was determined from the temperature equation of specific gravity.

The results obtained are shown in Table 1.

Table 1 As can be seen from Table 1, the flash point and combustion point of the fatty acid ester of neopentyl polyol are lower than mineral oil, almost the same as or higher than silicone oil, and the burning rate is higher than that of mineral oil. It was almost comparable to silicone oil. Furthermore, the dielectric breakdown voltage of fatty acid ester of neopentyl polyol was almost the same as that of silicone oil and mineral oil. The viscosity of the fatty acid ester of neopentyl polyol is higher than that of silicone oil at around room temperature;
Because of the high temperature gradient, it was lower than silicone oil at high temperatures. Therefore, at the temperature during actual use, the convection of oil within the electrical equipment is improved and the cooling effect of the equipment is improved. In addition, the fatty acid ester of neopentyl polyol is originally used as a lubricating oil.
Cooling oil circulation pump does not require special consideration for bearing lubrication. Furthermore, the coefficient of thermal expansion of the fatty acid ester of neopentyl polyol was comparable to that of mineral oil and smaller than that of silicone oil.

From the above results, it can be seen that the insulating oil used in the present invention will eliminate the drawbacks of conventional insulating oils made of silicone oil or mineral oil.

The aromatic polyamide paper used in the present invention is known as an H type heat-resistant insulating paper that can be continuously used, and may be one that is used in conventional oil-filled electrical equipment.

A specific example is N0VIC! (manufactured by DuPont in the United States), A Paper, and Mubodo (both manufactured by Mitsubishi Paper Industries), etc., and when used in combination with the fatty acid ester of neopentylboriol mentioned above, the heat resistance of both can be demonstrated. be able to.

The oil-filled electrical equipment of the present invention has the same heat resistance as silicone oil-filled electrical equipment, has small thermal expansion, and has the advantage of being cheaper.

Agent: Ge Shuxin (and 1 other person) Procedural amendment (spontaneous) Commissioner of the Japan Patent Office 1, case description Patent application No. 64-147122
Quantity 2, Name of the invention Oil-filled electrical equipment 3, Relationship to the case of the person making the amendment Patent applicant address 2-2-3 Marunouchi, Chiyoda-ku, Tokyo Name (601) Mitsubishi Electric Corporation Representative Hitoshi Katayuki Section 4, Agent 5, Subject of amendment (1) Column 6 of “Detailed Description of the Invention” of the specification, Contents of amendment (1) Change “generally insulating oil” in line 19 of page 1 of the specification to “ "Insulating oil".

(2) In the first line of page 2, ``I use it'' is corrected to ``I use something.''

that's all

Claims (1)

[Claims] (1) An oil-filled electrical appliance made of aromatic polyamide paper, characterized in that a heat-resistant insulating oil made of fatty acid ester of neopentyl polyol is used as an insulating material.