"This project aims to reduce costs, time to market and required design expertise and to increase market share by setting up a development environment , assisting the designer and allows building of resonant operated power supplies applied for VLF-based true sinus HV-test systems (HVTS) and dc-sources. The structure of the development environment (CAD-HVCT) will be open and flexible. Its innovative methodology will in conjunction with using novel European power electronic simulator toolbox PLECS/MATLAB include and support the following functions: a. A computer aided DC and AC analysis (CAA) of resonant operated power electronic circuitry based on a computer algebra system generating input for improved model libraries of PLECS, b. Design of power electronic and control circuitry based on HV-cascade, R-controller models and generalized averaging techniques. It is supported by a. c. Design of magnetic components, taking care of intra/inter winding and stray capacitances of high voltage windings and high-frequency effects, using (CAD-MAG) d. Thermal design using approximate thermal modelling of power semiconductors and magnetic components. e. The availability of novel macro models for power electronic circuits and characteristics for loaded HV-cascades (b) supporting small and large signal modelling should enable total VLF-generator simulation e.g. for control design, models for magnetic components with respect to electrical (c) and thermal behaviour (d) upgrades PLECS and simulation results. f. Computer aided optimisation (CAO) of the power circuitry and magnetic components with respect to selected cost functions which might be efficiency, weight, current and voltage stress of components by applying modern numerical optimisation algorithms. Validation of models and the tool is by building of selected HVTS demonstrators and dc-sources."