Abstract: One disadvantage of traditional permanent magnetic actuators (PMA)
in vacuum circuit breakers (VCB) is that it is difficult to improve the
velocity characteristics so that the interruption capacity of VCBs will be
constrained. The objective of this paper is to propose a method for controlling
PMAs to enhance the velocity characteristics. In contrast to the traditional
control method that adopts only one coil in an opening or closing operation,
the new method adopts both coils in the PMA simultaneously and controls the
direction of the current in coils. Then a simulation model that involves
coupled physical fields is constructed according to the new method. Moreover,
the simulation results indicate that the initial velocity can be increased in
the opening operation and the velocity characteristics in the closing operation
can be optimized. In addition, the operating current can be reduced so that it
is easy to control. Finally, experimental results validate the simulation
results.
Keywords: Permanent magnetic actuators, vacuum circuit breakers, coupled physics fields
