01-10-2012, 11:26 AM
Field Analysis of S/f6 Gas Insulated Cables and Its Application to Spacer Design
Introduction
The problem of compressed gas insulated cables has been studied
by many reseachers from different points of view. Lately, the number
of these reports has been increasing. The authors were given many
useful suggestions by several papers wi.ich explained the breakdown
characteristics in a compressed gas such as SF6' [1,2,3,4)
The purpose of this paper is to investigate by calculation and
experiment ,~ the effects of the inSUlating spacers upon the
breakdown characteristics and also to present basic data of a
practical spacer design. Each phase of the cable system consists of
a single conductor, a cylindrical metal sheath, the spacers which
support the conductor within the sheath, and SF6 gas between two
metal electrodes. Irithis case two relative dielectric constants
exist:that of the epoxy spacers and that of the surrounding SF6 gas.
Conclusions
In this paper, the potential distribution and the maximum electric
stress within SF6 gas insulated cables having various shaped spacers
were obtained by using a numerical method. The conclusions can be
summarized as follows:
1. It is recognized that the breakdown voltage depends linearly on
the calculated values.
2. If electric stresses for the vatious parameters are obtained by
a numerical method, optimum spacer design may become .possible.
3. For the application to the EHV cables, it will be necessary to
continue experiments to get full scale data.
Introduction
The problem of compressed gas insulated cables has been studied
by many reseachers from different points of view. Lately, the number
of these reports has been increasing. The authors were given many
useful suggestions by several papers wi.ich explained the breakdown
characteristics in a compressed gas such as SF6' [1,2,3,4)
The purpose of this paper is to investigate by calculation and
experiment ,~ the effects of the inSUlating spacers upon the
breakdown characteristics and also to present basic data of a
practical spacer design. Each phase of the cable system consists of
a single conductor, a cylindrical metal sheath, the spacers which
support the conductor within the sheath, and SF6 gas between two
metal electrodes. Irithis case two relative dielectric constants
exist:that of the epoxy spacers and that of the surrounding SF6 gas.
Conclusions
In this paper, the potential distribution and the maximum electric
stress within SF6 gas insulated cables having various shaped spacers
were obtained by using a numerical method. The conclusions can be
summarized as follows:
1. It is recognized that the breakdown voltage depends linearly on
the calculated values.
2. If electric stresses for the vatious parameters are obtained by
a numerical method, optimum spacer design may become .possible.
3. For the application to the EHV cables, it will be necessary to
continue experiments to get full scale data.