Development and study on iron core style bipolar axial magnetic field vacuum interrupter

In this paper, a new style of bipolar axial magnetic field electrode structure used in vacuum interrupters is developed and studied, which results in symmetric alternating axial magnetic field distributing intensively and evenly between the electrodes. Thus, no slots on the electrode are needed and the structure strength of the whole electrode is increased. Replacement of solid block iron core by a stromatolithic iron core reduces the eddy current and the lag time of the axial magnetic field behind the arc current. The results of tests show that this electrode structure can reduce the arc voltage and increase the interrupting current capacity of vacuum interrupters.