Novel voltage stability assessment method based on reactive power reserve measurements

Voltage stability assessment methodology based on construction of equivalent reactive power reserve utilizing limited access to observables is described in the paper. The purpose of the method is to be able to evaluate voltage stability margin in an on-line manner without the need to perform voltage stability analysis every time a contingency occurs in the power system. It is shown that by using reactive power reserves of available resources and/or reactive power flows in important lines the current margin can be estimated with given accuracy. In addition, a visualization method is proposed to improve situation awareness both in system dispatch operators' room and in operation planning. The methodology is tested on a transmission grid model developed within FP7 IRP ELECTRA for several scenarios with different renewable generation level.