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In this paper we propose three mathematical models for photovoltaic solar panels. The mathematical modeling of photovoltaic solar panels (PVSP) is essential in the analysis of solar power systems operation. The simulations can predict the performance of different configurations of solar energy conversion systems in power, and allow the choice of the technically and economically optimal variants. Mathematical...
The article is focused on specific issues arising for a photovoltaic panel (PV). In this case, the short circuit current is measured to determine the value of prescribed current corresponding to maximum power point. The results obtained by imposing a load resistance with this method are energy maximum possible, thus justifying the usefulness of this process very simple and inexpensive applied in practice.
This paper proposes an original method of determining the maximum power function point of a wind turbine at variable wind speeds. There are presented the non-linear equations which model the wind turbine (WT), the diesel engine (DE) and the asynchronous generator (AG). The advantages of using the asynchronous versus synchronous generators are also outlined.
The present paper presents specific issues that arise in Photovoltaic Energy Conversion Systems, being focused on maximizing the output power. There is proposed a model for Photovoltaic PV panel external characteristics. The coordinates of maximum power point are determined and used for imposing the appropriate load resistance to maximize the provided power. A comparison is made considering the classical...
This paper tries to solve for limited time intervals, by measuring the wind, the following fundamental problems: determining the optimal wind generator rotation to capture the maximum energy, the relationship between the optimal rotation of the permanent magnet synchronous generator (PMSG) and the wind speed variation which determines the kinetic energy variation of the rotating mass, flattening the...
This paper validates the proposed mathematical models for solving the fundamental problems which occur in the operation of wind power systems: determining the optimal wind generator rotation to capture the maximum energy, the relationship between the optimal rotation of the permanent magnet synchronous generator (PMSG) and the wind speed variation which determines the kinetic energy variation of the...
Based on the mathematical model of the wind turbine at a wind speed modeled as a sin wave in time, this paper analyses the behavior of the system with P, PI and PID regulators. We determine the speed at which the system must work in order to obtain a maximum amount of electricity in a time interval of hours and days. For this purpose, we measure the wind speed and knowing the mechanical characteristic...
The Diesel engine — synchronous generator system (DE-SG) is widely used in applications where the power distribution grid is absent. This system can ensure, in certain constructive and control (regulation) conditions, the electric energy at nominal values (U = 400 V, f = 50 Hz). This paper shows that is necessary for the SG to have the excitation in direct current, and so, to control the excitation...
The paper aims to demonstrate that an wind system (wind turbine — WT + synchronous generator-SG), (WT + SG) cannot actually work at its maximum power points because of the rapid variation of the wind speed value and of the increased value of the inertia moments. The considered system (WT+SG) was mathematically modelled based upon the mathematical models of WT and SG, and the analysis focuses its bearing...
The last decade's research has highlighted the necessity of using of wind aggregates' at full capacity, fact that involves the functioning at a imposed precise value of rotation and torque at certain wind speed values (on the maximum power point located on the wind turbine characteristic). The autonomous power energy system composed from a synchronous generator (SG), wind turbine and the load is dynamically...
This paper considers the induction generator having two similar separate three-phase stator windings, wound for the same number of poles and a standard squirrel rotor (IG2). Here is given the mathematical model of such induction machine, which is based on our previous results, namely, the two separate stator windings must be space-displaced at 90 electrical degrees, one from the other (orthogonal...
The research was oriented to the problems of the double wound stator induction generator. Currently now, this generator is more and more considered in the technical literature, as an alternative to the synchronous generator. In the case of nonconventional generator systems, especially in the case of wind systems, the dynamic regimes of electrical generators show interest due to the random character...
In the present paper we introduce an analytic approximation technique based on harmonic analysis for the solution of differential equations, and we apply this technique in two concrete cases. First we study the differential equation obtained by the law of electromagnetic induction for reluctance motors. The exact analytical solution of this equation can be determined only for a few particular cases...
In the Synchronous Generator (SG)+Asynchronous Generator (AG)+Load (L) system there are, for certain load values, one or three working points. In this paper, we present the correct assessment of the working point with a view to building a mathematical model of generators valid both in stationary and transitory regimes. Numerical simulations and modelling of a stand-alone electric power system has...
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