An on-load
voltage regulating and
capacitance regulating tapping switch comprises three operating mechanisms, three
capacitance regulating switches and two
voltage regulating switches, each operating mechanism is provided with a bi-
stable state permanent
magnet assembly and a poking rod of the bi-
stable state permanent
magnet assembly, each switch comprises a sealed vacuum insulating cylinder, and the switching surfaces of movable contacts and static contacts are located in vacuum cylinder cavities of the insulating cylinders; the width of the switching surface of the static contacts on the
high voltage sides of the three
capacitance regulating switches is smaller than that of the switching surface of the static contacts on the
low voltage sides. As the switching surfaces of the movable contacts and the static contacts are located inside the vacuum cylinder cavities, the on-load
voltage regulating and capacitance regulating tapping switch has the advantages that the arc extinguishing performance is reliable, the service life is long and oil of a
transformer is not polluted by electric arcs; besides, the technology that a high-voltage winding is
cut off firstly, then a low-voltage winding is
cut off, the low-voltage winding is switched on, and then the high-voltage winding is switched on is adopted, so that the electric arcs are small, residual
magnetism inside an iron core of the
transformer is eliminated conveniently, flashy flow and
overvoltage generated when the high-voltage winding is switched on again are avoided, and the
voltage fluctuation amplitude is effectively reduced in the switching process.