Method and system for determining polynomial fitting node voltage effective value based on WANS

The invention discloses a method and system for determining a polynomial fitting node voltage effective value based on WANS, and belongs to the technical field of power system voltage stability prediction. The method comprises the following steps: acquiring historical data and processing data; obtaining a residual error sequence of the historical data, carrying out stability check on the residualerror sequence, and after the check is passed, carrying out WAMS measurement and WAMS prediction on the processed data at a prediction moment according to the residual error sequence to determine a WAMS measurement value and a WAMS prediction value; taking an absolute value of a difference value between the WAMS measured value and the WAMS predicted value, and determining whether the WAMS predicted value reaches a WAMS critical value or not when the absolute value of the difference value is smaller than a preset threshold value; and when the WAMS predicted value reaches the WAMS critical value, determining a polynomia