Search results for "Maxim"
showing 10 items of 1236 documents
Comparison of power quality impact of different photovoltaic inverters- the viewpoint of the grid
2005
This paper presents the results of an experimental analysis performed with the aim of evaluating the effect of many photovoltaic plants on power quality of the grid. Several parameters as voltage and current distortion, flicker, voltage variations at fundamental frequency and power factor have been observed. The measured values have been compared with the limits reported in the standards and, when possibiIe, their dependence on the characteristics of the grid in terms of its impedance has been pointed out.
Controlled Fault-Tolerant Power Converters for Power Quality Enhancement
2013
Power quality depends generally on the interaction of electrical power with electrical equipments. If electrical equipments operate correctly and reliably without being damaged or stressed, a suitable level of power quality is assured. On the other hand, if the electrical equipment malfunctions, is unreliable, or is damaged during normal usage, power quality is poor and probably the economical loss could be important like the technical one. In the scenario of the Distributed Generation, power quality issues will be moreover important because an higher dissemination of power conditioning equipment will be requested and this obviously increases the sources of vulnerability of the electrical s…
Active power maximizing for Wind Electrical Energy Generating Systems moved by a Modular Multiple Blade Fixed Pitch Wind Turbine
2008
This paper proposes a new solution for wind electrical energy generating system (WEEGS). The system here taken into account is moved by a modular multiple blade fixed pitch wind turbine (MMBFPWT) and foresees a new MPPT algorithm whose main characteristics are low cost, low noise, buildings simplicity and modularity. The mathematical model of the entire WEEGS has been here developed taking into account all the components starting from the wind turbine and ending with the electrical grid. The WEEGS mathematical model has been implemented in Matlab-Simulink in order to carry out the simulations needed to test the effectiveness of the proposed WEEGS. The simulations results show the effectiven…
Sliding-mode observer based sensor-less control of a small wind energy conversion system
2015
Small wind turbines are becoming an attractive solution for household applications. These micro generation units can be used as standalone applications or grid connected applications. However to get the full potential benefits of these wind turbines, systems should be low cost and reliable. Introducing the wind speed and rotor speed sensors at the generator shaft may reduce the reliability of small wind turbines. In this study, a grid connected sensor-less 5 kW small wind energy conversion system has been studied. The maximum power point tracking method of the wind turbine is totally independent from wind speed and rotor speed measurements. Optimum rotor speed and actual rotor speed are est…
Sensorless small wind turbine with a sliding-mode observer for water heating applications
2015
Water heating applications consume a considerable portion of electricity demand in most of countries. Small wind turbines are one of attractive alternatives for grid electricity based water heating systems. Wind energy can be converted to heat energy in a high efficient manner. However it is essential that wind turbine based water heating systems should be economical and reliable. Maximum power point tracking algorithm of most of available wind turbines requires information from a wind speed sensor and a rotor speed sensor which reduces the reliability of the system. In this paper, the proposed 5 kW wind turbine does not require external wind speed sensors and rotor speed sensors. The syste…
Efficiency Maximization of Permanent Magnet Synchronous Generators Coupled to Wind Turbines
2007
In this paper a control algorithm for the efficiency improvement of permanent magnet synchronous generators (PMSG), the relative simulations and their results are presented. The proposed algorithm reduces the losses of the generator without affecting its performances. In details, after a description of a dynamic model of the PMSG, which has been modified in order to take into account the iron losses, the basic methodologies to obtain the loss minimization are presented and discussed. Many simulations of a specific PMSG employing the proposed algorithm were carried out and are presented. The results of these simulations show that enhancement of the efficiency up to 3% and more can be reached…
A mathematical model to determine the electrical energy production in photovoltaic fields under mismatch effect
2009
Among the electrical energy production systems from renewable sources, the photovoltaic one represents today one of the most efficient and technically tested choice. In this paper the authors present a mathematical model that allows the maximization of the generated power of photovoltaic (PV) plants under unequally radiation conditions. In particular, thanks to the model of a PV plant, unequally radiated, developed in Matlab-Simulink environment, in this paper the mismatch problem of PV plants is dealt with. The simulations curried out allow to assert that by putting into action re-configuration techniques of series-parallel connections of PV plants, under unequally radiation, can allow to …
Physiological compatibility of wireless chargers for electric bicycles
2015
The Inductive Power Transfer represents a viable solution of wireless battery charging for all users of electric mobility. This method brings some benefits to the electric vehicles, being a convenient technique, compared to the conventional wire-based battery charging. Among the electric vehicles, the electric bicycles particularly fit with this innovative method of battery charging. Nevertheless, the physiological effects of the produced magnetic fields need to be taken into account. In this paper, the design of an Inductive Power Transfer system for E-bike wireless battery charging is presented and the measurements concerning the surrounding magnetic field are provided in order to validat…
Compressive behaviour of concrete elliptical columns confined by single hoops
2007
The compressive behaviour of short concrete members having elliptical cross-sections and confined with single steel hoops is investigated. An analytical model is given for calculation of the stress-strain curves of compressed members also including the valuation of the ultimate stress corresponding to formation of a complete failure plane in the concrete core. The model is able to evaluate the confining pressure due to steel hoops referring to a fictitious reduced area of the confined core and to the effective stresses in the hoops, which are variable along the perimeter; moreover, it makes it possible to determine the maximum compressive strength and the corresponding strain of the confine…
Power tracking with maximum efficiency for wireless charging of E-bikes
2014
Wireless charging techniques, based on Inductive Power Transfer (IPT), are attractive for Electric Vehicles (EV), due to benefits such as convenience and safety. An accurate valuation of the maximum achievable efficiency in an IPT system is extremely unlikely due to the high sensitivity to parasitic elements variations. Therefore, an “on site” procedure of power efficiency characterization is useful to get a precise description of the efficiency curve and obtain the actual maximum efficiency. In this paper, a power tracking algorithm aiming at efficiency maximization is proposed for a Wireless Charging system. The algorithm aims at finding the maximum power transfer efficiency with respect …