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.‏

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

In this paper, the performance of two types of FACTS devices in order to enhance the power system static voltage stability has been investigated. These devices include Static Var Compensator (SVC) and Thyristor Controlled Series Capacitor (TCSC). The modeling of the Single Machine Infinite Bus (SMIB) and aforesaid devices has been made up in steady state mode with disregarding of the generator limitations. The incremental load changes will cause the voltage collapse phenomenon, load power factor decrease and load current increase. Consequently, the voltage will have more decrement and therefore voltage will collapse, and then the power system will be encountered with instability problem. This paper presents a scale of the Voltage Collapse Proximity Indicator (VCPI) for evaluation of voltage stability and its role in transmission line power flow. APPLICATION of the mentioned compensators in power system will improve the voltage stability and power flow in transmission line. The simulation results of this paper reveal the good efficiency of TCSC and SVC in reducing the voltage collapse and improving the bus voltage.

The paper presents a simple yet powerful fuzzy logic based static VAR compensator (FLSVC) applied to an industrial power system consisting of three phase induction motors and static loads. In the proposed fuzzy logic controller (FLC), the speed and acceleration variations of a specific machine are taken as the inputs. To demonstrate the effectiveness and capabilities of the employed FLSVC, some extensive and comparative non-linear time domain digital simulation tests are performed. The results show that over a wide range of operating conditions and disturbances, the FLSVC remarkably improves the voltage profile and the overall dynamic performance.

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.

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.

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.