Pavlovsky V. Power system states’ analysis and control methods with Flexible Alternative Currents Transmission Systems

The object of research: analysis and control of power systems states with flexible alternating current transmission systems (FACTS). The purpose of the research: development of theory of control and simulation of power systems with FACTS, including development of methods for FACTS selection and allocation, improvement of models for anti-emergency control, creation of the strategies to increase interface transfer capacity and improve transmission efficiency, the formation of guidance on the utilization of FACTS in perspective system planning . Methods of research: methods of mathematical simulation, numerical solution of nonlinear algebraic and differential equations, stochastic simulation, heuristic search, theory of electric circuits, transients, probability, sensitivity and stability. Theoretical and practical results and innovation: a new effect is discovered (critical voltage increasing for interfaces equipped with SVC of deficient power systems); using reserve of reactive power as a new criterion to measure the distance to the threshold states taking into account the principle of N-1 is proposed; the impact of the FACTS on power system small-signal stability has been demonstrated: SVC is able to increase the margin for voltage stability and TCSC is able to increase the margin for angle stability; the new statement is formulated: SVC applications are more effective means of increasing transfer capacity for transmission line with length up to 300 km and active power which exceeds SIL (OHL natural power) than their reconstruction; the methodology has been improved and "heuristic strategies" has been proposed to select right place, size and type of FACTS in power systems to increase transfer capacity of interfaces; to improve anti-emergency control in interfaces with unsupervised OHLs it has been firstly shown feasibility of applying the principle of emergencies reverse simulation, which increases the maximum allowable transfers in controlled interfaces. Degree of implementation: results of the thesis have been introduced and used in Ukrenergo, NERC of Ukraine, JSC Donetskoblenergo, OJSC EC Khersonoblenergo. Applications: power systems.