TW201340132A - A method for dielectrically insulating active electric parts - Google Patents

Abstract

CF3-C (O)-C (CF3)2F, preferably in admixture with inert gas, e.g. N2 or helium, is applied as dielectric insulating gas.

Description

Method of dielectrically insulating active electrical components

The present application claims the priority of the European Patent Application No. 1 119 779 7.3 filed on Nov. 4, 2011, the entire disclosure of which is hereby incorporated by reference.

The invention relates to a method for dielectrically insulating active electric parts, a method comprising CF ₃ -C(O)-C(CF ₃ ) ₂ F(trifluoromethylheptafluoroisopropyl ketone) A dielectric insulating medium and the use of CF ₃ -C(O)-C(CF ₃ ) ₂ F as a component of a dielectric insulating medium.

Solid or gaseous dielectric insulating media are used for insulation between active active parts of various electrical devices such as switching gears or transformers.

As described in WO 2010/142346, in medium or high voltage metal packaged switching gears, such active electrical components are arranged in a hermetic housing containing a dielectric insulating gas. This gas is also used to extinguish the arc.

A mixture of SF ₆ and N ₂ is widely used as a dielectric insulating gas. Much effort has been made to date to provide alternative dielectric insulating gases.

The aforementioned WO 2010/142346 discloses fluoroketones having 4 to 12 carbon atoms suitable as a component of a dielectric insulating gas, the document Place on dodecafluoro-2-methylpentan-3-one. These compounds are said to have high dielectric strength and provide only a small global warming potential.

It is an object of the present invention to provide an improved electrical insulation for active electrical components. This and other objects are achieved by the present invention.

The method of the present invention provides dielectric insulation for active electrical components, wherein the active electrical components are arranged in a hermetic housing containing an insulating gas containing CF ₃ -C(O)-C (CF ₃ ) ₂ F or consist of it.

CF ₃ -C(O)-C(CF ₃ ) ₂ F can be produced using CF ₃ C(O)F and hexafluoropropylene as described in US 3,185,734, or by trifluoroacetic anhydride and hexafluoropropylene. Manufactured as described in Example 1 of WO 2001/005468 in the presence of KF.

The term "active electrical parts" should be understood in a broader sense. Preferably, the term encompasses any part used to produce, distribute or use electrical energy, provided that it includes a hermetic housing in which the dielectric insulating gas provides dielectric insulation for parts that carry voltage or current. effect. Preferably, the active electrical components are medium or high voltage components. The term "medium voltage" relates to voltages in the range of 1 kV to 72 kV; the term "high voltage" relates to voltages greater than 72 kV. While these are preferred active electrical components within the scope of the present invention, such components may also be low voltage components involving voltages of less than 1 kV.

Within the framework of the invention, the singular is intended to include the plural and vice versa.

It is worth noting that the active electrical component of the present invention can be a "stand-alone" component Or the parts may be an assembly of multiple parts, such as a device. These contents will now be explained in detail.

The active electrical component can be a switch, such as a fast earthing switch, a disconnector, a load interrupting switch or a gas pressure circuit breaker, in particular a medium voltage circuit breaker (GIS-MV), a generator circuit breaker. (GIS-HV), a high voltage circuit breaker, a bus bar, a bushing, a gas insulated cable, a gas insulated transmission line, a cable connector, a converter, a transformer or a surge protector.

The active electrical component can also be a rotating electrical machine, a generator, an electric motor, a driver, a semiconductor device, a computer, a power electronics, or a part of a high frequency component, such as an antenna or an ignition coil.

The method of the invention is particularly suitable for medium and high voltage switching transmissions.

In the active electric component, the insulating gas is preferably at a pressure equal to or greater than 0.1 bar (absolute value). Preferably, the insulating gas is at a pressure equal to or lower than 30 bar (absolute). A preferred pressure range is from 1 bar (absolute value) to 20 bar (absolute value).

The partial pressure of CF ₃ -C(O)-C(CF ₃ ) ₂ F depends, inter alia, on its concentration in the insulating gas. If the dielectric insulating gas consists of CF ₃ -C(O)-C(CF ₃ ) ₂ F, the partial pressure of the dielectric insulating gas is equal to the total pressure and corresponds to the range given above. If the dielectric insulating gas contains an inert gas, the partial pressure of CF ₃ -C(O)-C(CF ₃ ) ₂ F is correspondingly lower. It is preferably a CF ₃ -C(O)-C(CF ₃ ) ₂ F partial pressure equal to or less than 10 bar (absolute).

In a preferred embodiment, the insulating gas contains CF ₃ -C(O)-C(CF ₃ ) ₂ F and an inert gas. The term "inert gas" refers to a gas that is non-reactive under the conditions of active electrical components. For example, any other dielectric insulating gas may be additionally used as the "inert gas" in addition to CF ₃ -C(O)-C(CF ₃ ) ₂ F.

Preferably, the composition of the dielectric insulating gas and, in particular, the content of CF ₃ -C(O)-C(CF ₃ ) ₂ F in the inert gas should be such that in the climatic conditions of the appliance or at ambient temperature, in the appliance Under the pressure of the part, there is almost no condensation of components in the dielectric insulating gas. The term "substantially free of condensation" is intended to mean that up to 5% by weight of the dielectric insulating gas, preferably up to 2% by weight, condenses. For example, the content of CF ₃ -C(O)-C(CF ₃ ) ₂ F, the type and amount of inert gas are selected such that the partial pressure of CF ₃ -C(O)-C(CF ₃ ) ₂ F is less than The pressure at which CF ₃ -C(O)-C(CF ₃ ) ₂ F is condensed at a reasonable low temperature.

In another preferred embodiment, the insulating gas contains CF ₃ -C(O)-C(CF ₃ ) ₂ F and air or synthetic air.

In the insulating gas, the content of CF ₃ -C(O)-C(CF ₃ ) ₂ F is preferably equal to or more than 1% by volume. In the insulating gas, the content of CF ₃ -C(O)-C(CF ₃ ) ₂ F is preferably equal to or less than 30% by volume. The remainder to 100% by volume is an inert gas. Alternatively, the remaining portion to 100% by volume may be air or synthetic air. Most preferably, the content of CF ₃ -C(O)-C(CF ₃ ) ₂ F in the dielectric insulating gas is from 5% by volume to 25% by volume. Preferably, the inert gas is selected from the group consisting of nitrogen and helium. It is particularly preferable to use nitrogen as an inert gas, and the insulating gas of the present invention mainly consists of CF ₃ -C(O)-C(CF ₃ ) ₂ F and nitrogen.

A further object of the invention relates to the use of CF ₃ -C(O)-C(CF ₃ ) ₂ F as a dielectric insulating gas or as a dielectric insulating gas component.

The advantage of CF ₃ -C(O)-C(CF ₃ ) ₂ F is its low boiling point of about 25 °C.

The description of the present invention should be prioritized if the disclosure of any patents, patent applications, and publications incorporated herein by reference is inconsistent with the description of the present application. The following examples further illustrate the invention and are not intended to limit it.

Example 1: Production of CF ₃ -C(O)-C(CF ₃ ) ₂ F

As described in Example II of US 3,185,734, by CF ₃ -C(O)-F and hexafluoropropylene in the presence of KHF 2 in acetonitrile in an autoclave, reacting at 100 ° C for 4 hours and at 125 ° C The reaction was carried out for 5 hours to produce CF ₃ -C(O)-C(CF ₃ ) ₂ F.

Example 2: Production of Dielectric Insulating Gas

As described in WO 98/23363, CF ₃ -C(O)-C(CF ₃ ) ₂ F and N ₂ (volume ratio) are generated in a device comprising a static mixer and a compressor. A homogeneous mixture of 1:4) composition.

Example 3: Providing a ground cable containing the dielectric insulating gas of Example 2

The gas mixture from Example 2 was fed directly into a high voltage ground cable until the total pressure in the cable reached 10 bar (absolute).

Example 4: Switching gearbox containing CF ₃ -C(O)-C(CF ₃ ) ₂ F and N ₂ in a volume ratio of 1:4

A switching transmission is used herein that includes a switch surrounded by a gas tight metal casing. The gas mixture of Example 2 was passed through a valve into the hermetic metal casing until the pressure reached 18 bar (absolute).

Example 5: Providing a gas insulated transmission line containing the dielectric insulating gas of Example 3.

The gas mixture from Example 2 was injected directly into a high voltage ground cable until the total pressure in the cable reached 10 bar (absolute).

Claims (14)

A method of dielectrically insulating an active electrical component, wherein the active electrical component is disposed in a hermetic housing containing an insulating gas containing CF ₃ -C(O)-C(CF ₃ ) ₂ F or consists of CF ₃ -C(O)-C(CF ₃ ) ₂ F. The method of claim 1, wherein the insulating gas is at a pressure equal to or greater than 0.1 bar (absolute). The method of claim 1, wherein the insulating gas is at a pressure equal to or lower than 30 bar (absolute). The method of claim 1, wherein the insulating gas comprises CF ₃ -C(O)-C(CF ₃ ) ₂ F and an inert gas. The method of claim 4, wherein the inert gas is selected from the group consisting of nitrogen and helium. The method of claim 1, wherein the insulating gas comprises CF ₃ -C(O)-C(CF ₃ ) ₂ F and air or synthetic air. The method of claim 4, wherein the content of CF ₃ -C(O)-C(CF ₃ ) ₂ F in the insulating gas is more than 0 to 80% by volume. The method of claim 7, wherein the insulating gas contains CF ₃ -C(O)-C(CF ₃ ) ₂ F in an amount of 5 to 25% by volume. The method of claim 1, wherein the active electrical component is a component of an electrical device or an electrical device selected from the group consisting of medium voltage or high voltage devices. The method of claim 9, wherein the active electrical component is selected from the group consisting of: a switch, a fast grounding switch, and a break Connector, load interrupt switch or circuit breaker or gas circuit breaker, especially medium voltage circuit breaker, generator circuit breaker, high voltage circuit breaker, bus bar, bushing, cable, gas insulated cable, gas insulated transmission line, cable Connector, converter, transformer or surge protector. The method of claim 1, wherein the active electrical component is a component of a rotating electrical machine, a generator, an electric motor, a driver, a semiconductor device, a computer, or a power electronic device. The method of claim 1, wherein the active electrical component is a component of the device, such as a switching transmission, in particular an air-insulated or gas-insulated metal-encapsulated switching transmission, a transformer, such as a distribution transformer Ultra-high voltage transformers and power transformers for particle accelerator systems. The method of claim 12, wherein the switching transmission is a gas-insulated metal-encapsulated switching transmission. A use of CF ₃ -C(O)-C(CF ₃ ) ₂ F as a dielectric insulating gas.