Power optimization and static performance investigation of an island-mode doubly-fed induction generator (DFIG)
This paper presents a performance investigation of power optimization by using a Proportional-Integral (PI) controller in a doubly-fed induction generator (DFIG). A detailed, dynamic model of a DFIG based on variable speed systems is presented in the dq-synchronous reference frame. Along with different controller types, a PI controller is chosen. Moreover, besides active and reactive power control, constraints and power optimization are discussed. Matlab software was used for simulation.
Energy storage systems in modern grids—Matrix of technologies and applications
Abstract Energy storage technologies are used in modern grids for a variety of applications and with different techniques. The range of applications and technologies is very broad, and finding the right storage solution for the job at hand can be difficult. In order to simplify the selection, this paper presents a matrix of the available technologies and applications. Along with proposing the matrix, the technologies and applications of Energy Storage Systems (ESSs) are described thoroughly and are compared on the basis of many different parameters, such as capacity, storage power, response time, discharge time, and life time. Moreover, the structure of energy storage, which is constituted of different steps and parts, is investigated. Since the implementing of an ESS is expensive, this paper also analyzes the possibility of integrating different types of ESSs and presents a comprehensive diagram to show the ESS technologies that can be integrated together in order to provide the needed performance in a cost-optimal way. Finally, the key results of this comprehensive study are summarized in a number of tables.
Energy skin effect of propellant particles in Electrothermal-Chemical Launcher
A numerical model of the radiation has been employed by a Monte Carlo method and statistical physics to simulate the process of a capillary plasma source for Electrothermal-Chemical (ETC) Launcher. The effect on propellants with different physical parameters is discussed. The plasma-propellant interaction is also discussed when combined with a thermal model. Results show that radiant energy only causes a small field around the plasma injector in the propellant bed. The responses of energy flux and propellant particles on radiation are both in the order of picosecond. The strong instantaneous radiation is responsible for the transmission of energy to the propellant particles leading to ignition. Compared with conventional ignition, the energy absorbed by propellant particles is used to increase quickly the temperature in the surface layer of propellant particles. This energy skin effect in the propellant particle surface appears to be the main cause of plasma ignition.