Experimental Study on Ion-Flow Fields Inside Greenhouse Models Underneath the DC Test Wire

With more HVDC transmission lines being built in China, the situation of the plastic greenhouses existing underneath the HVDC lines is becoming more common when the transmission lines pass over the farmland. The ionic space charges generated by corona discharge of HVDC transmission lines strengthen the electric field at the ground level. And with the accumulation of the ionic space charges on the surface of the plastic greenhouses, the ion-flow fields are highly perturbed. In this paper, a set of single conductor experiments is performed in the laboratory. Extensive measurements are carried out for different voltages and polarities with different types of plastic greenhouse models. The main goal of this work is to make it clear that whether or not the presence of greenhouses would affect the ion-flow fields and ion current density inside the greenhouse models. And through the analysis and discussion, we find out the differences of the ion-flow fields when the greenhouse models exist or not, which is the foundation of the future research.