Assessment of Potential Harmonic Problems for Systems with Distributed or Random Harmonic Sources

Harmonic problems in a system with distributed or random harmonic sources are most likely caused by the resonance phenomena. The evaluation of such problem is difficult as harmonic study needs to be carried out for all the buses in the system. Traditional frequency scan approach becomes complicated and inefficient. Resonance mode analysis approach associates a complex harmonic problem caused by resonance phenomena with a simple critical mode. Critical vectors of the mode define the obeservability and excitability of each bus to the resonance. Sensitivity information evaluates the involvement of network components to a resonance state. It is useful in helping understand the nature of a harmonic problem and locate effective harmonic mitigation means. Case study results confirmed that the proposed approach is an effective tool for harmonic evaluation of systems with distributed or random harmonic sources.