In this paper, the effect of Static VAr Compensator (SVC) parameters on the nonlinear interaction of steam power plant turbine-generator set is studied using the Modal Series (MS) and Normal Form (NF) methods. A second order representation of a power system equipped with SVC is developed. Then by MS and NF methods, the nonlinear interaction of torsional modes is assessed under various conditions and the most influencing factors are determined. Furthermore, to better analysis the nonlinear interaction between torsional modes and SVC controllers new nonlinear interaction index is defined. The results show that the stress conditions and some SVC control parameters will adversely affect the dynamic performance of a power system by increasing the nonlinear interaction of torsional modes. In this situation, the nonlinear modal analysis techniques especially MS method can precisely provide a reliable prediction of the torsional oscillations amplitudes and the frequency content of the output system response. As the angle and speed of turbine generator segments are used as input signals in several controllers, the frequency content of these signals are quite important in designing such controllers. This analysis is performed on a 4-areas WSCC system, which is equipped with a SVC.

Shock vectoring control (SVC) is an important method of fluidic thrust vectoring (FTV) for aero-engine exhaust system. It behaves better on nozzle of high pressure ratio, and is considered as an alternative TV technology for a future aero-engine with high thrust-to-weight ratio. In this paper, the flow mechanism and vector performance, including the vector angle (δ p) and thrust coefficient (Cfg), of 2D and axisymmetric SVC nozzles were investigated after the validation of turbulence models by experimental data. The influence of aerodynamic parameters, e. g. nozzle pressure ratio (NPR), secondary pressure ratio (SPR) and free-stream Ma number (M∞ ) on flow characteristics and vector performance were studied numerically, and results show that unbalanced pressure distributions on nozzle internal walls determine δ p, while shock waves dominate thrust loss, referring to Cfg. The “ pressure release mechanism” of an axisymmetric SVC nozzle causes vector angle about 16. 54% smaller than that of a 2D SVC nozzle at NPR of 6. The induced shock wave interacts with nozzle upper wall at SPR of 1. 5, and results in the δ p of a 2D SVC nozzle 12% smaller. A new parameter (Fy, modi) of side-force was redefined for free-stream conditions, taking the pressure distributions on nozzle external walls into account. Results indicate that pressure connection on nozzle external walls of an axisymmetric SVC nozzle causes vector performance better at M∞ >0. 3 and the δ p is about 11. 2% larger at transonic conditions of M∞ of 0. 9 and 1. 1.

In this paper, power system restoration in the presence of SVC and TCSC in partial outage conditions is considered and a new method for maximum load restoration using different control variables is presented. Control variables are tap of transformers, generation rescheduling and operating points of FACTS devices. Objective function is restored load (to be maximized) and constraints are voltage magnitudes in buses, carrying load in lines and power generation limits in generators. Also SPA limits in voltage angles in both sides of circuit breakers before closing are considered. With respect to the number of control variables, optimization is done using Genetic Algorithm with IEEE-118bus network as the test system.

Superior vena cava (SVC) syndrome, a potentially life threatening medical emergency, occurs due to SVC obstruction caused by extrinsic compression, intrinsic stenosis or thrombosis. Malignant mediastinal tumours account for more than 80% of cases of SVC syndrome. We hereby report a case of SVC syndrome who came with clinical features suggestive of SVC syndrome with dyspnea managed and diagnosed in the Intensive Care Unit with a multidisciplinary approach.

There are relatively few literatures about Flexible AC Transmission Systems (FACTS) in reliability aspects, particularly in composite system reliability evaluation. Reliability of the power system could be studied by some indices that help to compare power system under different conditions from reliability point of view. The actual benefits of the FACTS can be quantitatively estimated using suitable models and techniques. Corrective control as an alternative for the system reinforcement is proposed in this paper as a suitable way to ease the challenges related to building new transmission lines or reconstruction of power grid. Static Var Compensator (SVC) as a member of FACTS family has been used as corrective control. A test case with three scenarios is considered for comparing the effect of SVC on the reliability of the power system. It will be seen that the correct SVC replacement has a great influence on the reliability indices of power grid and losses could be diminished.

One of the issues of reliable performance in the power grid is the existence of electromechanical oscillations between interconnected generators. The number of generators participating in each electromechanical oscillation mode and the frequency oscillation depends on the structure and function of the power grid. In this paper, to improve the transient nature of the network and damping electromechanical fluctuations, a decentralized robust adaptive control method based on dynamic programming has been used to design a stabilizing power system and a complementary static var compensator (SVC) controller. By applying a single line to ground fault in the network, the robustness of the designed control systems is demonstrated. Also, the simulation results of the method used in this paper are compared with controllers whose parameters are adjusted using the PSO algorithm. The simulation results show the superiority of the decentralized robust adaptive control method based on dynamic programming for the stabilizing design of the power system and the complementary SVC controller. The performance of the control method is tested using the IEEE 16-machine, 68-bus, 5-area is verified with time domain simulation.

This paper describes the application of static var compensators, (SVC) on an electrical ‎distribution network containing two large synchronous motors, one of which is ‎excited via a three-phase thyristor bridge rectifier. The second machine is excited via ‎a diode bridge rectifier. Based on linear optimization control (LOC), the measurable ‎feedback signals are applied to the control system loops of SVC and the excitation ‎control loop of the first synchronous motor. The phase equations method was used to ‎develop a computer program to model the distribution network. Computer results ‎were obtained to demonstrate the system performance for some abnormal modes of ‎operation. These results show that employing SVC based on the LOC design for ‎electrical distribution networks containing large synchronous motors is beneficial and ‎may be considered a first stage of the system design‏.‏