Optimal Choice and Allocation of FACTS Devices for Security-Constrained Economic Dispatch

Flexible AC transmission systems (FACTS) devices have provided new control facilities in power systems. Simultaneous optimization of type, location and parameters for FACTS devices is an important issue when a given number of FACTS devices are applied to the power system with the purpose of increasing system loadability. This paper presents the application of simulated annealing algorism (SA) to find optimal type, location and parameters of FACTS devices to achieve security-constrained economic dispatch (SCED). The overall cost function, which includes generation cost and installation cost of FACTS devices, should be minimized. The SCED constraints are generators, transmission lines and FACTS limits. Two types of FACTS devices are utilized in this study namely STATCOM as a shunt type and TCSC as a series type. In this study simulations were performed on IEEE 14-bus. Results of simulations are encouraging and could efficiently be employed for power system operations. Keywords: Allocation, Security-constrained economic dispatch (SCED), FACTS and simulated annealing (SA)

Physiological Comparison of Two Salt-Excluder Hybrid Grapevine Rootstocks under Salinity Reveals Different Adaptation Qualities

Like other plant stresses, salinity is a central agricultural problem, mainly in arid or semi-arid regions. Therefore, salt-adapted plants have evolved several adaptation strategies to counteract salt-related events, such as photosynthesis inhibition, metabolic toxicity, and reactive oxygen species (ROS) formation. European grapes are usually grafted onto salt-tolerant rootstocks as a cultivation practice to alleviate salinity-dependent damage. In the current study, two grape rootstocks, 140 Ruggeri (RUG) and Millardet et de Grasset 420A (MGT), were utilized to evaluate the diversity of their salinity adaptation strategies. The results showed that RUG is able to maintain higher levels of the photosynthetic pigments (Chl-T, Chl-a, and Chl-b) under salt stress, and hence accumulates higher levels of total soluble sugars (TSS), monosaccharides, and disaccharides compared with the MGT rootstock. Moreover, it was revealed that the RUG rootstock maintains and/or increases the enzymatic activities of catalase, GPX, and SOD under salinity, giving it a more efficient ROS detoxification machinery under stress