Applied Digital Control for Localization of the Maximum Power of Photovoltaic Generators
This paper describe the development of a digital control applied in energy generation using photovoltaic cells in joint with the other generator system (a diesel generator, for example) the technique consist in the localization of the maximum power point (pick power tracking) of photovoltaic cells utilizing digital control. Its application is attractive to isolated load system, such as isolated communication system and data transmission located in remote Amazon areas
Exact analytical solutions of the forward non-ideal diode equation with series and shunt parasitic resistances
Abstract Exact closed form solutions based on the Lambert W -function are presented to express the forward current–voltage characteristics of non-ideal single-exponential diodes containing all possible combinations of series and shunt parasitic resistances. It is shown that these expressions could be useful for carrying out highly accurate computations at speeds almost as fast as those possible when using less precise approximate solutions based on common elementary functions.
HYPERGOLIC REACTION MECHANISMS OF CATALYTICALLY PROMOTED FUELS WITH ROCKET GRADE HYDROGEN PEROXIDE
Abstract The coupling of the physical and chemical processes controlling the ignition delays (τ ign ) of hypergolic propellants complicates the direct analysis of the transient ignition processes. The transport properties of both the propellants and the ambient gas, and the heat of vaporization and reaction affect τ ign and must be considered experimentally. Furthermore, since hypergolic ignition occurs, by definition, on contact, the mechanics of initial contact and subsequent mixing can affect τ ign and must also be considered. Experimental results from a study of the hypergolic ignition of a catalytically promoted fuel with rocket grade hydrogen peroxide (RGHP) are presented. Statistical analysis of the experimental data was conducted to evaluate the relative effects of RGHP concentration, initial ambient pressure, and the ambient gas on τ ign . At RGHP concentrations of less than 92% in water, stable ignition was difficult to achieve. At sufficiently high Lewis number, an oscillatory ignition process is observed. A phenomenological model comprising mixing, RGHP decomposition, fuel heating and vaporization, and auto-ignition is presented and compared to the experimental results.