AC and DC facilities in electrical station services of major power plant types

In a power plant, the electrical station services (abbreviated to SS in the following) consist of all the DC facilities from 24 to 220 V and AC facilities up to about 20 kV for controlling and supplying power to the equipment needed to keep the plant running. Hence, these auxiliary services clearly play a vital role in assuring the plant’s reliable operation.

Close attention must therefore be paid to requirements affecting the particular plant and the safety considerations, such as the provision of backup systems.