Research on Ion Current Density Measurement under HVDC Transmission Line Based on Inversion Algorithm

To maintain the normal and stable operation of high voltage direct current (HVDC) transmission facilities and ensure the quality of HVDC electromagnetic environment, the measurement results of the electric field and the ion current density under the HVDC transmission line need attention. A simple measurement method can reduce the workload of operation and maintenance personnel. However, the ion current density measuring device and electric field measuring device are still two independent devices, which is not convenient enough. In this study, an inversion algorithm is presented to establish the relationship between electric field and ion current density. Then the ground-level ion current density can be obtained directly based on the measurement results of the electric field, which can simplify the measurement process. First, an ion flow field inversion model is established. Second, an example is used to compare the generalized inversion method and the regularization inversion method, which shows that the regularization inversion method is more accurate. Hence, it is selected to participate in subsequent calculations. Third, the inversion results are discussed and compared with the measurement results. Finally, the electric field on the wire and ground-level ion current density, which is calculated at different areas of the used conductor using the inversion algorithm, are studied. It is found that the results of the inversion algorithm are in good agreement with the measurement results of the Wilson plate, and this work provides a new idea for ion current density measurement.