3. Why adjust voltage and frequency?

Along with continuity of electricity supply, compliance with contractual voltage and frequency characteristics is one of the key criteria for assessing the quality of service provided by network operators.

But voltage and frequency are also invaluable indicators of the proper technical and economic operation of the generation-transmission system, and are fundamental parameters in the operation of any electrical power system.

We will not consider here the choice of nominal values for these quantities, which are considered optimal, but the variations that affect them. After recalling the causes of voltage and frequency variations, we'll examine the acceptable limits of these variations.