Estimation of the electric strength of insulation system of an HV combinedinstrument transformer using 3D analysis

The methods of shaping an insulation system of a voltage and current Part o f nit HV combined instrument transformer are considered Electrostatic shiel ds, modifying the electric field inside the winding insulation, have been a pplied. The author's software was used to optimise the number, dimension an d position of the electrostatic control shields in the voltage and current windings. Field computations, permitting the estimate of insulation systems ' effectiveness and optimising the insulation systems' geometry, were carri ed out. Computations of thc 3D electric field distributions for several dif ferent versions of insulation systems are compared The equipotential lines and diagrams of the electric field strength are presented, allowing conclus ions concerning shapes of constructions to be made. Conclusions concerning constructional modifications ai-E given also. The author has shown? the use of numerical methods in the designing Process.