Reasonable disposal of resource, development of double parent pipe action and application of ring pipe net are presented and the meaning of which to assuring production and energy saving is alse presented.

In the project to expand the 500 kV FuyangⅡline in the 500 kV JingTing transformer substation,casts the generatrix is suspension type and heavy-caliber casts the generatrix which is separated to pull slantingly.

Problems encountered during the retrofit and debugging of bus protections for dual-bus dual-subsection wiring were analyzed and solutions were proposed.