The object of this diploma thesis was to test the existing prototype of a MECOS highfrequency converter with regard to the EMC guidelines (electromagnetic compatibility) and to ensure the latter are being met.

At the beginning of our work it was necessary to select the relevant standards. There is a mandatory product standard for the highfrequency converter (EN 61800-3). From the customer's point of view it is important for the highfrequency converter to keep the standards of the customer's system, which in our case are the EMC generic standards for industrial environments (EN 50081-2 and EN 61000-6-2). We tried to take into consideration both the position of the customer and of the manufacturer. The manufacturer tries to keep the costs for the certification as low as possible, at the same time for marketing reasons he has to take into consideration the expectations of his clients. Taking this into account we decided to examine the converter with regard to all above mentioned standards.

After several measurements and modifications of the highfrequency converter it was possible to remain within the limits. The modification included changes of the construction and the replacement of the MECOS filter by a standard filter.

During the measurements with high load current a resonant vibration was detected in the intermediate circuit. The cause of this to a large extent is the concept of the construction of the MECOS highfrequency converter. In conclusion it can be said that the EMC certification of the MECOS highfrequency converter will cause no more problems. However the elimination of the resonance problem may entail also modifications in the filter measures selected by us.

It was the goal of these diploma, to develop, coming from an existing 2-canal amplifier with 8A/300V, a 2-canal amplifier with 16A/300V. Especially the power semiconductors in the current path, as well as the driving elements for the increased current, were new selected.

The criteria lay in the reduction of the power losses and the guarantee of the short circuit security.

Because of the long delivery time periods, the calculations had to be made based on measurements at the forerunner model.

A selection of possible component combinations was found.

Because of the increased switching power, the power losses climb. Therefore the existing heat sink arrangement had to be reviewed on efficiency.

On account of the hard switching, dissipation currents in the shielded cable arise. The currents caused oscillations at high frequency entailing EMC-problems. In addition, these currents stress the semiconductors and increase the losses. Therefore some discharge network for 16A and a cable length of up to 30m were looked at.

The efficient use of energy is an important aspect in the present field of power electronics. Integrated power modules, which could be used in four-quadrant inverters, are in increasing demand in today?s market.

Our thesis deals with an ac-to-dc converter, which should be developed in cooperation with the IDS AG in Zurich. The goal of the thesis was the realization of an interface between a given controller and an IGBT-module, which should take up as little space as possible. The task includes the specification, a circuit-design and several tests of different circuit-parts.

The functional specification of the whole ac-to-dc converter as well as the conception of the interface were made during the first phase of the work. The interface was subdivided into different circuit-parts, which were each provided with its own list of requirements. Afterwards the circuits of these parts could be developed and drawn. The power supply unit and the gatedriver of an individual IGBT were built up and tested for their right function, whereby the first corrections and improvements could already be made. The result of this thesis is a scheme, in which our circuit-parts were drawn and dimensioned. The space requirements could not be analyzed, because it was not possible to make a layout-design within a useful time.

Continuing the project our scheme has to be converted into a layout-design. Afterwards the first prototype could be built up, with which our circuits could be tested in a wide range.