Özet:

In grid-connected photovoltaic (PV) systems, power electronic converters are needed to transfer direct current (DC) power output to the grid and DC-AC (alternating current) causes harmonics to occur during power conversion. Total harmonic distortions have a negative effect on power systems and cause undesirable problems in power quality. There are hardware and software solutions to reduce the effects of harmonics. In order to improve the power quality in the grid connected PV system, the reference current and voltage values, including the control structures of the converter and inverter circuits, must be measured with high accuracy. The high accuracy of the power calculation of the control structures of these circuits will cause the electrical parameters of the PV system such as active power, reactive power and phase angle to be obtained without error. In this study, Butterworth and Bessel digital filters are used in order to contribute to the power calculation by minimizing the distortions in the electrical signals, instead of the traditional power analysis block used in the literature for high accuracy power calculation and analysis in PV systems. In the simulation study performed in LabVIEW environment, the noisy reference signal has been successfully reduced by providing high accuracy power calculation in both filter types. In this way, the total harmonic distortion (THB) values of the Butterworth filter are also improved. The Butterworth filter used in the study was more successful than the Bessel filter in power calculation and THB.

Anahtar Kelimeler: