Improved power grid voltage out-of-limit risk assessment method considering source load uncertainty

The invention discloses an improved power grid voltage out-of-limit risk assessment method considering source load uncertainty. The method comprises the following steps: establishing a source-load prediction error probability distribution model based on a deviation between a wind-light load prediction value and an actual value; based on the charging load of the electric vehicle, a charging probability distribution model including normal distribution of the initial charging moment of the vehicle, daily mileage distribution of the electric vehicle, the SOC state of the initial grid-connected moment of the vehicle, the charging duration and the off-grid moment is established; and establishing a distribution network voltage out-of-limit risk assessment method based on the source-load prediction error probability distribution model and the charging uncertainty probability model. According to the method, by evaluating the voltage out-of-limit risk, planning guidance is provided for reducing the voltage out-of-limit