Investigations on Harmonics in Smart Distribution Grid with Solar PV Integration

Abstract

Integration of solar PV into the grid poses many challenges in the power system. One such serious challenge is harmonics penetration into the system. Harmonics are generated by the solar PV and the associated power electronics circuitry. Moreover, the loads connected to the distribution system are usually nonlinear and harmonic rich in nature. Therefore, a lot of harmonics gets introduced into the system from the source as well from load ends, and thereby affecting the power system performance. In this paper, harmonic distortion issues associated with solar PV integration are analyzed considering the limits of IEEE 519-1992 standard. The Newton-Raphson algorithm is modified with solar PV integration for harmonic power flow study. The formulated approach is employed to determine the discrete harmonic components, total harmonic distortion (THD) levels, and values of the system power flow variables. The developed approach is tested on a smart radial distribution feeder and the results show that with solar PV integration, the harmonic distortion increases above acceptable limits. In order to have a vision of smart grids for providing clean power supply, the authors feel that there is a serious need to study the issues related to harmonic generation, and further to develop control strategies to eliminate them.