Determining an optimised mesh will facilitate a faster computation time without reducing the accuracy of the result. Mesh discretisation of the insulator domain problem can be seen in Figure 6.6.The insulator model was simulated in the FEM analysis using an AC/DC module (Static Electric mode), which assumes that currents and electromagnetic fields vary slowly. This mode is valid for many HV applications including outdoor insulators that operate at power frequencies of 50-60 Hz[6.4].