All-electric Society
In power electronics, a fundamental change is happening. Two very dynamic sectors are currently automotive electronics and energy technology. In both application areas, there is a race for ever more efficient, high-performance and cost-effective power electronics systems. On top of this, there are increased requirements in terms of the reliability and service life of the electronic parts and components.

The main purpose of power electronics is the conversion and distribution of electrical energy using electronic switches between different sources, energy storages and loads that are electrically linked to each other. Power electronics fulfill these functions both in stationary applications, such as integrating renewable energy sources into the power grid, and more and more in mobile applications, like in battery electric vehicles. The central and crucial components here are the electrical converters, which can be used, for example, as chargers, voltage converters or drive inverters.

Faster - Stronger - Higher
With drive outputs of up to 1000 kW and ranges of over 1000 km, electric powertrains for electric cars have reached a new level. The electric converters are operating in the megawatt class. As a result, vehicle electronics are advancing vehemently into the area of larger drives and opening up further interesting fields of application. Outstanding examples are the emerging electrification in ships and aviation.

Hybridization, i.e., the combination of combustion engines or jet propulsion systems with fuel cell technology and battery storage, promises enormous savings in terms of fuel consumption and emissions. Alongside batteries, hydrogen is becoming an interesting energy carrier. The hydrogen technology in turn opens up its own technological possibilities, such as the design of cryogenic converters or the use of superconducting cables and motor windings. However, classic silicon components have reached their physical limits and the use of wide-bandgap semiconductors such as silicon carbide or gallium nitride is a necessity.

Taking off with WBG
WBG-based power devices offer low on-state losses, enable higher switching frequencies and can handle high currents at high operating voltages. They provide superior thermal properties and are suitable for operation in a wide temperature range. Customized device and process technologies, such as VDMOS, pave the way to fully exploit the potential of WBG semiconductors for power electronics.

In terms of industrial application, SiC (silicon carbide) and GaN (gallium nitride) semiconductor technologies have gained significant impact on the market. However, there are still unlocked advantages at system level in terms of cost, efficiency, and construction volume. Current research activities are focused on an in-depth understanding of device characteristics and materials properties, not only on device level.
In the development of WBG-capable modules, especially GaN and SiC power modules, various technical challenges remain to be investigated. So, to realize highest efficiency power electronic conversion with fast switching, parasitic effects have to be minimized. In this context, the spatial and functional integra-tion of the semiconductor switches with the driver control is crucial.

New challenges for WBG power modules come from extreme temperatures like cryogenic as well as high-temperature applications with appropriate adaptations to the packaging technology. Accordingly extended qualification measures and test procedures are required, that take novel failure mechanism into account. With special environmental and operational conditions, aviation is one of the hardest areas to conquer. Reliability is the key here, as failure rates must be precicely identified and extremely low. And all this with an outstanding power-to-weight ratio.

Power Meets Intelligence
Another trend in system development is apparent: the progressive integration of information and commu-nication technology.

On-board power grids for aircrafts and vessels are comparable with the local power grid of a small town in terms of their complexity and dimensions. The grids connect many distributed sources and loads via long cables and transfer high power simultaneously. As a result, the focus is shifting to grid stability and droop control, i.e., the control and synchronization of generators and converters. Additional functions for monitoring, management and communication, as well as intelligent capabilites need to be implemented in the grids: On-board grids are evolving into smart grids. In stationary grid technology, especially in smart grids or local DC grids, as well as in battery systems for battery management, this transformation has been visible for a while now.
The fusion with data processing requires an increasing integration of digital technology components. Microcontrollers and system on chips have long been used in drivers and control circuits for electronic power switches. Approaches from classic signal processing are also being applied, e.g., for forming the alternating current waveform to save space and material-intensive passive filter components. This is also exemplified by modular multi-level converters, which consist of a large number of freely configurable inverter cells and can be used to cover a very wide range of applications and performance.

The Perfect Match
A new class of intelligent power electronics with additional AI functionality, the so-called cognitive power electronics, is currently being developed further. These "perceptive systems" are equipped with sensors to detect various physical parameters and embedded electronics to record and analyze data in real time. Electric drives thereby become integrated intelligent systems that know about their present operating status. Based on methods of machine learning, cognitive power electronic systems can make predictions and react autonomously to internal and external influences and events.

The high demands imposed by system developers affect all stages of the power electronics value chain. It is already apparent today that the demanded performance characteristics of the new type of power electronics can no longer be achieved with the existing semiconductor devices and system features. Power semiconductors based on ultra-wide bandgap materials and other innovative devices, such as integrated snubbers or active circuit breakers, are in the pipeline. Accompanying, the transition towards an all-electric society pushes the power electronic systems development to new performance levels.

The integrated power electronic system - the symbiosis of innovative power semiconductor technologies, microelectronics and artificial intelligence - is becoming a reality.