Computation of forces on devices carrying transport and eddy currents

A finite-element-based method for calculating the current, field, and force distribution in the conductors of power devices exhibiting skin effect is presented. A formulation in terms of magnetic-field strength is used to model the device in the plane of the current flow. The technique is demonstrated with an application to the computation of the forces acting upon the arm of a high-current circuit breaker. The electromagnetic forces and torques arising under fault conditions are found to be appreciable and must be taken into account when designing the circuit breaker and assessing its performance