Method and system for evaluating state and voltage stability of power distribution network

The invention discloses a method for evaluating the state and voltage stability of a power distribution network, and the method comprises the steps: carrying out the distribution and detection of a target power grid region, obtaining measurement data through the two regions, and calculating a node voltage proportionality coefficient matrix K between the nodes of the two regions; calculating a measurement model of the power distribution network, and minimizing an objective function; carrying out optimization calculation on a target function, and taking the target function as an iterative solution processing model when the node voltage proportionality coefficient matrix K is not updated; a multi-port node admittance matrix model is proposed by using the obtained state data of the target power distribution network, Thevenin equivalent impedance and equivalent voltage are solved, an impedance modulus margin is calculated, and the voltage stability is evaluated by using the impedance modulus margin. By means of mi