7. Network coupling

The quality of the network on which the turbine's alternator operates is an important factor in the availability of gas turbines. Indeed, some networks are subject to sudden changes in power demand, resulting in variations in electrical frequency: on an isolated network such as an island, for example, the tripping of a means of generation can lead to a drop in frequency of up to 47.5 Hz. Naturally, under steady-state conditions, a gas turbine with reduced rotation speed produces less power when more is required: the gas turbine control system must compensate for this without tripping.

Faced with a network disturbance, the network operator can specify three types of gas turbine response:

— maintain power output or obtain maximum power without tripping ;

— support the grid by generating reserve power;