7th International Ege Energy Symposium and Exhibition, Uşak, Türkiye, 18 - 20 Haziran 2014, ss.1-13
With the increasing size of photovoltaic distributed generation (PV-DG), which is one of the most important renewable energy resources, harmonic distortion levels also rise due to the inevitable effects of photovoltaic featured inverters in power networks. Nonlinear characteristics of the widely utilized electronic devices significantly enhance harmonic distortions. Beside of nonlinear units, the shunt capacitor also has an influence on the distortion in the network. In this paper, nonlinear loads and PV-DGs are considered as harmonic sources. In first phase of the study, the decoupled harmonic power flow method is utilized to obtain the voltage and current harmonics in PV-DGs integrated power networks. With the aid of this method, nonlinear loads and PV-DGs are interfaced to the system by using the harmonic admittance matrix and decoupled harmonic current sources. In the second part, the optimum sizes of capacitors are determined for the weak buses in the distorted power network to improve the power factor. Moreover, the effects of harmonics on power factor and total harmonic distortion are investigated simultaneously. The utilized methodology is implemented on the IEEE 14-bus and 33-bus power networks. The results show that total harmonic distortion increases while the optimum power factor correction is achieved. This indicates that an acceptable range of total harmonic distortion should be taken into account according to the standards while placing shunt capacitors in the presence of harmonics.