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

Station services switchgear in power plants

In a power plant, the electrical station services (abbreviated to SS in the following) consists 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 plants 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.

Table of contents:

1. Alternating current (AC) station services
2. Direct current (DC) station services
3. Station services in power plants
   1. Hydro power plants
   2. Diesel power plants
   3. Gas turbine / combined-cycle power plants
   4. Conventional steam thermal power plant
   5. Combined heat and power stations
4. Automatic station service power transfer
   1. Switchgear configuration with two circuit breakers