The Advancing Assessment of Power System Stability Using Synchronized Phasor Measurements

The article presents the advancing assessment method of power system stability and increasing power flow on transmission lines. Electrical energy transmission through power lines of alternating current is limited by the amount of power flows on tie. Limit is determined by the capacity of an electrical network according to regulatory requirements by reliability assurance. Today, calculation programs define margin by search of static stability limits for the worst operating condition scenario. The existing margin on a power flow leads to deviation from an optimal condition of maintaining and, as a result, to decrease in economic indicators of power transmission systems. One of the solutions of this problem is the using the adaptive control method, on the basis of calculation on the design model formed in a controlling circuit. For forecasting of a static stability limit the approximating dependence of the Jacobian matrix determinant is used. Formation of the Jacobian matrix is carried out according to the synchronized phasor measurements data obtained from the WAMS. It makes possible to adapt the prediction of the static stability limit in real time. Approximating dependence is formed from the measurement data continuously and at each measurement the limit and static stability reserve are predicted. With a decrease in the stability reserve below the predetermined value, the conditions for the hazard of breaking static stability are formed. This makes it possible to perform an advanced assessment of power system stability and increasing power flow on tie. For implementation the presented adaptive control method requires the supplying monitoring of grid condition and creating the software of static stability limit forecasting with hardware complex, which functions in real time using data of the phasor measurement system. © 2020 School of Science, IHU. All Rights Reserved.