This paper deals with the two-axis sun tracking system for a photovoltaic system. The trajectories of the sun tracking system are determined in an optimization procedure. The optimization goal is maximization of an electric energy production in the photovoltaic system considering the tracking system consumption. Determination of the tilt angle and azimuth angle trajectories is described as a nonlinear and bounded optimization problem, where the objective function is not available in the explicit form. A stochastic search algorithm called Differential Evolution is used as an optimization tool. In the optimization procedure, the objective function is evaluated by using the models of available solar radiation, tracking system consumption, and the efficiency of solar cells with the appropriate dc/dc converters. The problem bounds are given in the form of lower and upper bounds for both angles and time and angle quantization. The results presented in the paper show, that the optimal trajectories for the tilt and azimuth angle depend on the available solar radiation, solar cell efficiency, tracking system consumption and the optimization bounds.
COBISS.SI-ID: 14971926
This paper presents a new general method for determining the optimal arrangements of overhead power line phase conductors by optimization. The main criteria used in this optimization procedure, are the root mean square values of the magnetic flux density and the electric field strength on the border of the overhead power line's right of way. The position of each power line phase conductor is determined using the stochastic search algorithm called Differential Evolution. In the given case, the optimization goal is to find such an arrangement of phase conductors so that the tower height is minimal, whereas the values of the magnetic and electric fields on the border of the overhead power line's right of way are under the limits prescribed in the national regulations. This method is applied in order to investigate how the optimal positions of the overhead power line phase conductors change, depending on the clearances between the phase conductors of a two-conductor bundle, in the case of a vertical - double tower configuration with one overhead earth-wire.
COBISS.SI-ID: 15208726
Preventive and corrective approach is used for maintenance of the electric power system. Recent trend in maintenance branch is preventive maintenance, which is adequately logistically supported. This paper presents existent way of maintaining overhead distribution lines. Project of building a modern and effective maintaining system with use of the advanced maintaining systems for electrical infrastructure is also presented. Usage of advanced logistical technologies is based on collecting infrastructure information about overhead power lines and belonging equipment of the electric power system with the use of laser monitoring. The core of the suggested maintenance system is grid monitoring system (GMS) program tool, which offers a support for decision of reliability centered maintenance (RCM). The new suggested way of maintenance is applied to a practical problem. The paper also reflects the comparison between suggested and existing practice.
COBISS.SI-ID: 15119382