New energy power system weak point positioning method and system

The invention provides a weak point positioning method and system for a new energy power system, and the method comprises the steps: obtaining the broadband impedance of a new energy station at a grid-connected point and the broadband impedance of an AC power grid online through employing a new energy station impedance identification method driven by the combination of data and knowledge; evaluating the stability of the system on line by adopting an impedance stability criterion, and obtaining the phase margin and the potential oscillation frequency of the system; if the system phase margin is lower than the threshold value, calculating the impedance real part of each new energy station at the potential oscillation frequency according to the broadband impedance identified online; sequencing is carried out according to the size of the impedance real part, and one or more new energy field stations with the minimum impedance real part are weak points of the system; and if the phase margin of the system is greate