J.D. van Wyk

On a Future for Power Electronics

This paper presents a historical and philosophical perspective on a possible future for power electronics. Technologies have specific life cycles that are driven by internal innovation, subsequently reaching maturity. Power electronics appears to be a much more complex case, functioning as an enabling technology spanning an enormous range of power levels, functions and applications. Power electronics is also divided into many constituent technologies. Till now, the development of power electronics has been driven chiefly by internal semiconductor technology and converter circuit technology, approaching maturity in its internally set metrics, such as efficiency. This paper examines critically the fundamental functions found in electronic energy processing, the constituent technologies comprising power electronics, and the power electronics technology space in light of the internal driving philosophy of power electronics and its historical development. It is finally concluded that, although approaching the limits of its internal metrics indicates internal maturity, the external constituent technologies of packaging, manufacturing, electromagnetic and physical impact, and converter control technology still present remarkable opportunities for development. As power electronics is an enabling technology, its development, together with internal developments, such as wide bandgap semiconductors, will be driven externally by applications in the future.

A planar integrated RCD snubber/voltage clamp

In order to reduce the cost, size, and weight of power electronic systems, it has become necessary to integrate electromagnetic structures, which until now have been constructed with discrete components. This approach not only reduces the component count, but also gives much greater control over parasitic elements. In this article, the authors describe an electromagnetically integrated resistor-capacitor-diode (RCD) snubber/voltage clamp that uses a planar construction technique. The design and construction are described and the performance is verified experimentally. Some advantages of the integrated component over its discrete counterpart are also given. >

Problematic aspects when using a LISN for converter EMI characterisation

In this paper it is shown that conducted interference from a power converter differs when measured with and without a Line Impedance Stabilization Network (LISN). This is problematic as the true Electromagnetic Interference (EMI) of a converter is therefore difficult to characterize. Possible reasons for this difference are discussed showing to the influence of a LISN on measurements.

System integration of GaN technology

Gallium nitride (GaN) power semiconductor technology offers a potential for significant performance increase in power electronic converters. This potential cannot be fully exploited if GaN devices are used as drop-in replacement for silicon devices in existing systems. This paper investigates the switching limits influenced by the device output parasitic capacitance and parasitic inductance of the commutation cell capacitor. The trade-offs between thermal management and high frequency switching of GaN devices in power converters are explored. Finally, an outlook on technology needs for 3D integration of GaN converters for achieving high switching frequencies and power densities is given.

Some considerations for miniaturized measurement shunts in high frequency power electronic converters

Power semi-conductors are able to achieve switching transients within a few nanoseconds and possibly even faster. These fast switching transients will need to be measured and analyzed thoroughly. In this paper four different types of shunt constructions and installations are tested on the same power electronics circuit, giving widely diverse results. Interpreting and analyzing these measurement results will assist in developing accurate current measurement devices for fast switching transient power electronic converters of the future.

Package Alternatives for Integrated Power Electronic Modules (IPEM) with Improved Voltage Rating

The electric field in a baseline Integrated Power Electronic Module (IPEM) as a function of different parameters is evaluated. The electric field distribution inside the embedded insulation material in the IPEM is studied, and several improved structures are discussed. Simulation results suggest that the peak electric field intensity in the embedded insulation material can be reduced by 40%. The blocking capability of the improved structures is not degraded by voids inside the embedded insulation material. The experimental results agree with the simulation results.

An experimental study of switching GaN FETs in a coaxial transmission line

The switching characteristics of GaN FETs have not yet been measured accurately because of their small electromagnetic size in relation to the circuit and the electromagnetic environment the measurements are exposed to. Switching GaN FETs in a transmission line will allow for measurements to be taken in an electromagnetically defined environment. The transmission line is adapted to take optimum measurements. This is proven by the waveforms presented.

Power electronics quo vadis

Technologies have specific life cycles, driven by internal innovation, subsequently reaching maturity. Power electronics appears to be a much more complex case as an enabling technology spanning an enormous range of powers, functions and applications. Power electronics is also divided into many constituent technologies. Up to the present, the development of power electronics has been driven chiefly by internal semiconductor technology and converter circuit technology, approaching maturity in its internally set metrics (ex. efficiency). The fundamental functions found in electronic energy processing, the constituent technologies comprising power electronics and the power electronics technology space are examined critically in the light of the internal driving philosophy of power electronics and its historical development. It is finally concluded that, although approaching the limits of its internal metrics indicate internal maturity, the external constituent technologies of packaging, physical impact and converter control technology still present remarkable opportunities for development. As an enabling technology, these developments, together with internal developments such as wide band-gap semiconductors, will be driven externally by applications in future.

Packaging of Power Electronics Building Blocks

Abstract : The major objective of the PEBB research at CPES remains to support ONRs program to develop a new generation of electric ships based on the building block concept utilizing high voltage dc distribution. From the system point of view, the integrated power system (IPS) must be reliable and provide uninterrupted power supply to critical loads. The IPS should be based on the PEBB concept and should be reconfigurable and programmable via a high-level communication and control bus. This requires the development of programmable converters with high levels of intelligence and control autonomy, wide control bandwidths, and fail-safe capability. At present, high frequency power conversion technology has reached the point where further advances in semiconductor technology have limited benefit due to physical limitations of the current packaging methods. Package inductance, thermal handling, wire insulation, active and passive components, packaging materials, interconnect structures, thermal management, EMC and EMI, circuits and system integration, as well as manufacturing technologies are all important considerations for developing the correct packaging approach. At CPES we would adopt an integrated systems approach to standardize power electronics components and packaging techniques in the form of highly integrated Power Electronics Building Block modules. This approach makes possible an increased level of integration in the components that comprise a power electronics system: devices, circuits, controls, sensors, and actuators. These components are integrated into standardized manufacturable subassemblies and modules, which in turn, are customized for particular applications. By developing the PEBB based power electronics converters using an integrated systems approach, we will improve the quality, reliability, and cost-effectiveness of power electronics systems and reduce both the time and effort associated with design cycles for system application.