Research on DC electric field measurement considering ion flow near HVDC transmission line

Measuring electric field has a very wide range of applications in the power system, but for the ion field under the HVDC transmission lines, the current measurements are insufficient. In this paper, effects of interventional measurement, theoretical analysis, measuring programs are researched. Sensors in a Poisson field sense an electric field Ein, which consists of three parts. E0 is the origin electric field, E1 indicates the field generated by charges attached on the sensor, E2 represents the influence of the redistribution of ion flow after the sensor is put into the field. Based on multi-physics simulation, this paper figures out the effects of sensor's intervention through analysing the movement of charged particles and found that when the charging process is completed, there is a spherical region around the sensor where the charge density is zero, which is called the “empty zone”. This paper figures out the relationship between inside field and outside field. The electric field directly measured by the sensor kernel module can be approximately regarded as the sum of the space field which we aim to measure and the self-generated electric field of the charge accumulated on the metal shell of sensor's shell. A structure of two-MEMS-device is promoted to deal with the effect of the ion flow, and it could applied in the ion field or nominal electric field without ion flow and ignore the angular offsets of placing, according to the simulations.