Harmonic resonance characteristics of large-scale distributed power plant in wideband frequency domain

For the sake of systematically investigating the propagation and magnification of harmonic currents inside large-scale distributed power plants (LDPP), firstly, the model of LDPP is built, in which the topology of multiple overhead feeders, the distributed capacitances of feeders, the stray capacitances of transformers, and the control strategy of DG units are taken into account. Secondly, the model reveals the distributions and movements of several resonance bands along with the length variations of feeders. Then, these resonance bands could be classified into three basic types: extrinsic resonance band, filter resonance band, and ring resonance band. Furthermore, the ring resonance band will be in collusion with the filter resonance band at specific length of feeders. As a result, a superimposition resonance band will emerge and high harmonic currents are produced. Finally, some simulation cases and experiments are conducted to verify the correctness of the harmonic resonance modeling, also the feasibility of proposed hybrid active power filter (HAPF) to attenuate the wideband-frequency harmonic currents is testified.