Modern practice in Germany and the European continent with regard to supervisory control systems as applied to large interconnected supply areas

The paper first describes the development of the use of remote-control equipment on power systems, and then outlines the constitution and duties of the staff required for operating a large load-despatching plant. The difficulties associated with the control of generation, particularly during peak-load periods, are next discussed, and the starting characteristics of various large turbo-generators installed at the stations of the Berlin municipal undertaking are given. Steam-accumulator sets, Diesel sets, and storage hydro-electric pumping plants, are relied upon in Continental practice to provide reserve power. In the operation of large systems, frequency meters are now being supplemented by remote-metering devices for use in balancing output and demand. Where a large numbner of generators feed into the network, both the individual outputs and the summated values for the various groups are transmitted to the load dispatcher by the remote-indicating equipment. This is usually operated on the impulse-frequency system, either over pilot wires or by means of carrier-current circuits. Network compensation is obtained by adjusting the earth-leakage coils so that their inductance balances the total capacitance of the interconnected system. The necessary adjustments to the coils are made of local attendants under the direction of the load dispastcher. Carrier-current telephony is commonly used for communication between the load dispatcher´s office and the various control points, on account of its lower cost and greater ease of fault location as compared with other systems. Supplies to medium-sized towns, densely-populated rural areas, and electric railways, are given from secondary networks, each of which is controlled from a district load-dispatcher´s office situated at a power station or substation. The results of remote control on such networks have been very satisfactory.