AMS extension of the VHDL language for power electronics

The various disciplines of electronics use computer-aided design tools and flows to varying degrees. But if we consider power electronics, static converters are designed largely thanks to engineers' acute experience and the development of prototypes based on error detection and correction cycles.

The design is carried out in stages, sizing the various parts of the converter, but is not computer-aided, apart from a few calculations or database searches. First of all, the engineer chooses an architecture compatible with the specifications. The choice of components depends largely on the engineer's knowledge of the technologies involved. To simplify his work, the engineer separates certain points: the converter in the sense of its primary function, the control and regulation system, the Joule effect loss dissipation system, and the means to ensure the converter's minimum quality with regard to electromagnetic standards. The design of the converter is successful if the engineer's experience enables him, at each stage, to make choices that do not make it impossible to solve the problem at the next stage.

In a converter, all phenomena are linked. For example, if we consider the switching of power components, which is the basis of energy chopping techniques: the faster this switching, the fewer Joule losses are dissipated by the component, but the greater its contribution to the electromagnetic pollution generated by the converter. Slower switching improves electromagnetic compliance, but requires a more efficient Joule loss dissipation device, which is therefore larger and more expensive. What's more, a bulky converter distances active devices from one another, which leads to connectivity problems; yet connections also play a part in switching quality... Such coupled physical phenomena make the current design approach rather irrelevant. However, new description languages and analysis tools make it possible to take account of this profusion of phenomena and their diverse couplings.

The power electronics industry seems to shun computer-aided design methods and tools. Physical prototyping is still a safe bet, due to the lack of tried-and-tested tools and methodologies, but this is changing due to economic constraints and a strong trend towards integration. In fact, the number and variety of power converters are set to increase dramatically in the years to come. The industry must therefore prepare for competitiveness by working on the price per switched kilowatt. This price has been falling for the past twenty years, and sectors such as the automotive industry are still imposing significant reductions. Whatever technological developments are underway, power electronics will inevitably have to implement virtual prototyping. By this we mean the whole...