Power Electronics Europe February/March 2022

www.pcim-europe.com PCIM EUROPE 2022 21 www.power-mag.com Issue 1 2022 Power Electronics Europe IISB, Germany (www.iisb.fraunhofer.de ). Power electronic devices are at the heart of modern electrical and electronic equipment and applications in households, industrial plants or in mobility. They convert electrical energy, switch loads, control electrical drives and much more. For this purpose, they continuously record and frequently control parameters such as current, voltage and their change over time. When combined with artificial intelligence, such intelligent power electronics evolve to what we call “Cognitive Power Electronics 4.0” - an enabler for the aforementioned systems to become a smart energy network, a smart production plant, or a smart electric motor. At Fraunhofer IISB, the new research field “Cognitive Power Electronics 4.0” (CPE4.0) was established to develop power electronic converters that can be used as intelligent edge devices and are able to make intelligent decisions regarding the connected system - not least in the context of smart drives or Industry 4.0. Cognitive Power Electronics for Smart Drives in Unmanned Aerial Vehicles , are presented by Georg Roeder, also from Fraunhofer IISB. Unmanned aerial vehicles (UAV) with electric propulsion rely, amongst other conditions, on the motor and the rotor for safe operation. The propulsion system can be exposed to harsh operating conditions, which poses stress to the motor bearings, typically limiting the service interval of the whole UAV. A frequent estimation of bearing condition can help to reduce maintenance efforts. The solution proposed is based on the measurement of the motor phase currents, and a machine learning approach based on manifold learning to detect bearing faults as anomalies from healthy motor states. “Modular ultra-low-power IoT-Core – Bridging the gap between power electronics and distributed sensor networks” , is the title of the fourth paper given by Carsten Brockmann from Fraunhofer IZM (www.izm.fraunhofer.de ). In this paper, the authors present an innovative ultra- low-power IoT-Core that can be used as an extension for efficient DC/DC converters. The module equips the overall system with computation and communication capabilities for Industry 4.0 and IoT applications without adding significant power requirements. The research focuses on optimizing energy consumption by taking an overarching view of hardware and software at the system level. In the active state, the IoT-Core can adjust its power consumption at runtime by matching the application demands to the existing energy budget. In sleep state, the module uses a novel wake-up receiver in the 868 MHz frequency band with an average power consumption of 3.5 W, allowing the system to wake up in 32 ms. The results are demonstrated on a DC/DC converter, with an efficiency of up to 99.8 %, which uses the plug-and-play IoT-Core to become a smart device that can save additional energy when being in idle mode. In parallel an other Special Session “Advanced Measurement Technology in Power The Thursday keynote “From State of the Art to Future Development Trends of Power Supply Technologies” will be given by Peter Wallmeier, Senior Director, Delta Energy Systems, Germany. The application of Switched Mode Power Conversion technology started in consumer electronics and information technology more than 40 years ago. It spread out to almost all industries over the past decades to benefit from higher power conversion efficiency, lighter weight and increased power density at lower costs. The presentation will review the technology innovations increasing the conversion efficiency from below 75 % to now 98 % at power densities from initial 0.2 kW/l to now 6 kW/l over the past decades. It will outline future trends to achieve ultra-efficient and ultra-dense power conversion technology. This “innovation-rallye” from past to future is detailed out showing the persistent conflict between higher conversion frequency to reduce the size of passives and magnetics and at the same time increased switching losses, ZVS/ZCS circuit losses, eddy current and hysteresis losses in the magnetics. Insert Wallmeier.JPG !!! Special sessions On the Tuesday May 10. 11:00 – 12:30, after the opening and award ceremony, the first Special Session on “Cognitive Power Electronics” will take place. The opening paper is entitled 0 , and will be presented by Nicolas Lehment from NXP Semiconductors (www.nxp.com) . Evolving sensing and AI-compute capabilities realized in modern silicon products enable novel architectural choices in embedded controllers and the power systems they govern. This contribution explores the impact of high precision analog measurement when paired with embedded AI and emerging new network technologies. NXP considers both the individual elements realizing these capabilities and the overall architectures enabled by them. To show the resulting impact on overall system design, the concepts will be illustrated with the example of an industrial robot. “Cognitive Power Electronics 4.0 –An Enabler for Smart Systems” , will be introduced by Martin Schellenberger from Fraunhofer Institute for Integrated Systems and Device Technology Electronics” covering four papers is taking place. The first “Common-Mode / Differential- Mode Noise Separation Using Oscilloscopes for More Efficient EMC Filter Design” is presented by Markus Herdin, Rohde&Schwarz, Germany. Nowadays, conducted emissions testing often happens already as pre-compliance test performed during development phase. In this case, the designer can obtain an early feedback whether the EMC filter design has to be optimized. In most cases, adjustments to the input filter are necessary because of passive component value variations and limitations in the accuracy of simulations done during the filter design process. For an effective iterative filter design process, the designer needs to know some details on the noise spectrum, in particular whether the noise is generated by a common mode source or by a differential mode source. While a separation of common-mode and differential-mode noise can be done by external combiners, it is also possible to do this using two input channels of an oscilloscope without any additional combiner hardware. Calculating the sum and difference signals after A/D conversion and converting into spectral domain via FFT directly delivers common-mode and differential-mode noise. In this presentation this measurement method as well as practical aspects and limitations will be discussed. Finally, we also the method by showing measurement results with different common-mode and differential-mode filter components will be verified. “Probing Techniques for GaN Power Electronics: How to Obtain 400+ MHz Voltage and Current Measurement Bandwidths without Compromising PCB Layout” by Harry Dymond from the University of Bristol/GB (www.bristol.ac.uk) are introduced in the second paper. PCB layout critically influences the performance of wide-bandgap power electronic circuits, in terms of switching speed, overshoots, ringing, and generated EMI. Typically, low-impedance layout of gate-drive loops and switching cells is vital for performance. This paper briefly examines the bandwidth needed for measurement of GaN switching waveforms, and the circuit impedances required for adequate performance. This leads to many high-bandwidth voltage and current probing methods not being compatible with the circuit-layout requirements. The paper then presents PCB layout and probing techniques that achieve both high-fidelity, wide- bandwidth (400+ MHz) voltage and current measurements, and clean, efficient switching. “Using Near Field Probes in Electronic Circuits” by the University of Zaragoza, and “How IsoVu Probe Breaks the Barrier of Wide Bandgap Dynamic Testing” by Tektronix, are the subjects of the other papers within this session. The “DC-DC Converters” session covering four papers also runs between 11:00 and 12:30 on May 10. A high-power density GaN converter introduces Michael de Rooij from EPC/USA with the paper “Exceeding 5 kW/in3 Power-Density in a 48 V to 12 V LLC Resonant DC-DC Bus Converter Using GaN FETs” . High power density converter Peter Wallmeier