Optimal sizing and location of DG considering harmonics pollution and system losses

The use of distributed generators (DGs) driven by renewable energy in power distribution networks has increased significantly as a result of their technical, financial, and environmental benefits. On the other hand, power electronics converters are typically installed in DGs units, which causes harmonic pollution. Additionally, the harmonic levels may exceed the acceptable standard due to the growth of modern nonlinear loads. This research proposes a methodology for optimal integration of inverter-based distributed generation for minimizing power losses, enhancing the voltage profile, and limiting both the total and individual harmonic distortion according to the IEEE-519 standard. The proposed methodology comprises two stages. Each stage involves both fundamental and harmonic power flow analysis. The first stage establishes the optimal size and location of the DG, considering the base load. The second stage reallocates the obtained DG size of the first stage to mitigate the harmonics and optimize the system at different levels of nonlinear load penetration. The suggested approach is evaluated on IEEE 69-bus distribution systems for various combinations of linear and nonlinear loads.