Characterization of accumulated space charge and charge-caused AC gas discharge characteristics in enclosed air spaces with novel electrostatic induction method
摘要
Space charges affect the discharge process in an enclosed space of an electrical device. Due to the limitations of the measurement technique, it is difficult to study charge accumulation and its effect on discharges. In this paper, a characterization of the space charges and the charge-caused discharge characteristics via electrostatic induction is proposed. For a 10 mm needle-plate model, numerical relations between the induced voltage and the space charge is derived, enabling the calculation of real-time space charge quantities. Then the characteristic space charge parameters are extracted and verified to be able to represent the accumulation of space charge and discharge characteristics. Variations of the parameters at different applied voltages are also investigated. Over a single AC voltage cycle, the equivalent charge quantity Q and the charge change rate dQ can represent pulse characteristics such as amplitude and repetition rate. With the phase φi and φt where the dQ curve undergoes significantly, the charge effect during the initial and final discharge can be analyzed. At different DC and AC-DC superimposed voltages, the discharge stages are distinguished based on the characteristic charge parameter versus applied voltage curve, and charge effect at different applied voltages are concluded according to φi and φt.