Method for controlling the voltage in a grid comprising decentralised sources

The method involves measuring voltage on an electrical supply network at a connection point. A photovoltaic inverter is controlled to control reactive power (Qref) exchanged to absorb overpressures on the electrical supply network, where a value of the reactive power exchanged by the inverter is given according to a value of the voltage at the connection point, and the voltage used to determine the value of the reactive power is voltage temporal average measured at the connection point. Independent claims are also included for the following: (1) a decentralized photovoltaic electricity production unit (2) an electricity distribution network.