Practical experience of 23 kV cable upgrading operation in Shanghai

In 1987, a paper entitled `Reformation of the 23 kV cable network in Shanghai´ was accepted by CIRED. As described, the upgrade project of 23 kV cable network in Shanghai has been executed continuously as planned. Along with the reformation of the distribution network, however, the up-graded cable circuits and it´s total length varies, but up to now there are 26 circuits of 64.4 km in total length still in operation. Although these cables were made in the early period of this century and had been operated approximately 40 years before up-grade, they still keep a satisfied operation record with lower fault rate after up-grade. The author shows fault statistics and analysis of the cables