Ancillary servicesVoltage stability
The voltage in a power grid must shift within a defined range. The transmission system operators maintain the effective value (root mean square) of the AC voltage within these limits by applying different measures. For example, power plants can supply a customised voltage, reactive power compensation can be provided or transformers can be adjusted. With the decentralised infeed of energy in the low- and medium-voltage range, the distribution grids are also instrumental in ensuring the voltage stability and require appropriate adjustments.