Harmonic Studies in OpenDSS Considering Renewable DG and Aggregate Linear Load Models

The electrical distribution system is undergoing major changes as distributed generators, power electronic devices and smarter grids applications are inserted in the system networks. Although the changes are beneficial for satisfying the needs of local loads, electrical performance parameters issues may arise due to the impact of the changes in the network. In order to perform studies and verify the impact of new elements in distribution systems, simulation tools are important resources for planning by researchers and engineers. This paper aims a discussion on how linear aggregate loads affects harmonic studies. Simulations are performed using different load models to verify the impact and sensitivity of the system impedance and resultant harmonic voltages. Harmonic sources produced by typical distributed generators are connected into the system in order to analyze the harmonic voltage distortion at different buses regarding the simulated network. The systems were modeled and simulated in an OpenDSS Matlab interface. Results shown that both load model types and composition have a significant impact on the system impedance and parallel resonance damping.