4. Impact on system safety

4.1 How does an electrical system work?

The problem for the Transmission System Operator (TSO) is twofold. It must at all times :

• make sure there is equality between production and consumption;

• ensure that the power transited on network facilities (lines and transformers) does not exceed their capacity. In other words: managing congestion.

This problem quickly becomes complex:

• by taking into account operating contingencies affecting network elements or generation plants, consumption levels ;

• by the need to control the safe operation of the power system – maintaining the voltage, frequency...