Centralized supervision of a 65 kilovolt power. Network

The h.v. network receives energy from a central power station and supplies 20 unattended transformer substations from which energy is distributed at 3-5 kV to a number of coal mines and coking plants. The whole of the switching and telemetering is effected from 2 control stations, a total of 10 000 relays of the telephone type being employed for the supervision of 1300 individual elements in the substations. The operation of the remote control system is described in detail and illustrations show typical installations of relays and equipment. Data are given of the control circuits and the items in the substation on which information can be obtained. Methods of testing and checking the control system are also described. The remote control system has enabled 4 control operators to supervise the whole h.v. and l.v. networks, which with manual control would have required a staff of 60.