A new approach solving the interface error problem of finite element field calculation methods by means of fictitious interface current sheets or interface charges

A method of improving the accuracy of potential finite-element formulations using interface error current sheets or charges at interelement boundaries is presented, including the procedures required for implementation. It is demonstrated that the compensation of the interface error in potential formulations of the finite-element methods by means of surface current sheets or charges in combination with error-oriented adaptive mesh refinement considerably improves the accuracy, reduces the effort, smooths the results, and requires only a few additional iterations (⩽4). The implementation of the method in standard 2-D finite-element programs is easy. The method is applicable to higher-order elements, 3-D problems, and electrostatic problems