48V POWER INFUSION Active suspension approaches on-ramp to more markets after 48V power infusion ISSUE 3 – September 2025 www.power-mag.com Also inside this issue News | Motion Control | Servo Motor Drive Circuits Industrial and Automotive Systems Silicon Carbide Solutions | PCIM 2025 Revue AC/DC DC/DC | Web Locator MICROMOBILITY
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CONTENTS www.power-mag.com Issue 3 2025 Power Electronics Europe 3 News & Features Editor Leslah Garland Tel: +44 (0)1732 370340 Email: leslah@dfamedia.co.uk Publisher Damien Oxlee Tel: +44 (0)1732 370342 Email: damien@dfamedia.co.uk www.power-mag.com Production Editor Chris Davis Tel: +44 (0)1732 370340 Email: chris@dfamedia.co.uk Financial Manager Joanne Morgan Tel: +44 (0)1732 370340 Email: accounts@dfamedia.co.uk Reader/Circulation Enquiries Perception Tel: +44 (0) 1825 701520 Email: dfamedia@dmags.co.uk INTERNATIONAL SALES OFFICES Mainland Europe: Victoria Hufmann Norbert Hufmann Tel: +49 911 9397 643 Fax: +49 911 9397 6459 Email: pee@hufmann.info Eastern US Damien Oxlee Tel: +44 (0)1732 370342 Email: damien@dfamedia.co.uk Western US and Canada Damien Oxlee Tel: +44 (0)1732 370342 Email: damien@dfamedia.co.uk Japan: Yoshinori Ikeda, Pacific Business Inc Tel: 81-(0)3-3661-6138 Fax: 81-(0)3-3661-6139 Email: pbi2010@gol.com Taiwan Prisco Ind. Service Corp. Tel: 886 2 2322 5266 Fax: 886 2 2322 2205 Circulation and subscription: Power Electronics Europe is available for the following subscription charges. Power Electronics Europe: annual charge UK/NI £95, overseas $160, EUR 150. Contact: DFA Manufacturing Media, 192 High Street, Tonbridge, Kent TN9 1BE Great Britain. Tel: +44 (0)1732 370340. Refunds on cancelled subscriptions will only be provided at the Publisher’s discretion, unless specifically guaranteed within the terms of subscription offer. Editorial information should be sent to The Editor, Power Electronics Europe, 192 High Street, Tonbridge TN9 1BE U.K. The contents of Power Electronics Europe are subject to reproduction in information storage and retrieval systems. All rights reserved. No part of this publication may be reproduced in any form or by any means, electronic or mechanical including photocopying, recording or any information storage or retrieval system without the express prior written consent of the publisher. Printed by: Warners. ISSN 1748-3530 PAGE 4 News PEE looks at the latest News and company developments PAGE 12 Flipping human motion detection on its head Automatic object detection is growing ever more sophisticated, yet the accurate detection of humans still poses unique challenges. Omron’s Gabriele Fulco explores what it is that makes humans so difficult to reliably detect, and how successfully navigating these obstacles could usher in a new era of productivity. PAGE 14 Protection and Layout Considerations to Maximize Efficiency in Servo Motor Drive Circuits Servo motors convert electrical energy into precise mechanical motion making them essential components in today’s motion control systems. Their widespread use spans from household appliances to industrial automation, where highperformance and accuracy are required. Known for their superior efficiency and responsiveness, servo motors are typically driven by high-frequency AC voltage, which necessitates specialized power conversion circuitry. PAGE 18 Not All Grounds Are 0V Sadia Khan - Systems Engineer, Isolation Products at Texas Instruments PAGE 22 UK can lead new grid tech to reduce likelihood of blackouts and provide smarter energy supply New report highlights the potential revolutionary role of solid-state transformers in providing a more flexible and intelligent energy grid PAGE 24 The PCIM Expo & Conference 2025 again proves to be a catalyst for innovation and progress in power electronics PAGE 26 Can You Drive GaNFETs with a DCto-DC Controller Originally Designed for Silicon MOSFETs? Kevin Thai, Applications Manager, Analog Devices PAGE 29 Web Locator Active suspension approaches on-ramp to more markets after 48V power infusion Hongfa solves age-old power challenge with 48V architecture and high-density power modules More details on page 8. FEATURE STORY Subscribe for your FREE copy now
4 NEWS Issue 3 2025 Power Electronics Europe www.power-mag.com With Axelera AI, Rutronik Elektronische Bauelemente says it is expanding its franchise portfolio to include a European pioneer in the field of AI inference at the edge. The Dutch company develops cutting-edge hardware and software solutions, targeting applications where energy efficiency, scalability, and real-time processing are paramount. Its Metis platform, based on RISC-V and digital in-memory computing, offers outstanding performance with lower energy consumption – positioning itself as a viable alternative to existing GPU-based solutions. With the Metis AIPU and the Voyager SDK, Axelera AI has created a platform that can implement machine learning models for Vision AI significantly faster, easier, and more cost-effectively than conventional cloud-based or GPU-centric architectures. Applications include automated checkout monitoring in retail, industrial security monitoring, and intelligent traffic control. “We’re working to establish a serious alternative to the current market leader, Nvidia, in the embedded market,” explains Anja Schaal, Senior Manager Product Marketing Boards & Storage. “With Axelera AI, our customers benefit from a significantly more attractive cost-benefit ratio and an optimal computing power-to-energy consumption ratio. Especially in the edge environment, specialized hardware with an innovative design is needed – and that’s exactly what Axelera delivers.” At the heart of the partnership is the vision of democratising artificial intelligence at the edge, making it independent of expensive cloud solutions or complex GPU setups. Rutronik is leveraging Axelera AI’s technological strengths: Digital In-Memory Computing (D-IMC), a proprietary RISC-V dataflow architecture, and an SDK that significantly simplifies integration for developers. Rutronik also offers full -service project support for companies that do not have their own AI teams or want to minimise development risks through its partner network, for example with COMI. The European Innovation Council Fund’s investment in Axelera AI underlines the company’s potential and its importance for the European technology location. “With Rutronik, we have found an experienced and strongly positioned distribution partner across Europe who shares our vision: to make artificial intelligence at the edge accessible, efficient, and less dependent on non-European platforms. In addition to its strong market presence, we particularly value Rutronik’s deep technological understanding in the embedded and AI sectors – an ideal basis for jointly implementing innovative solutions for demanding edge applications and strategically developing our roadmap,” explains John Wilkins, Global Director of Channel Sales at Axelera AI. With this partnership, Rutronik reaffirms its role as a leading embedded and AI distributor in Europe and offers its customers access to pioneering technology – “Made in Europe”. www.rutronik.com European response to edge AI challenges: Rutronik adds Axelera AI to its portfolio Molex Introduces AirBorn 3U VPX Power Supply, Extending Innovation of Award-Winning 6U Molex, a global electronics leader and connectivity innovator, has announced it has introduced the AirBorn 3U VPX Power Supply, delivering clean power in a smaller form factor to unlock capacity in space-constrained aerospace, defence and commercial applications. As the latest innovation from AirBorn, a Molex Company, this newest VPX model is built on the robust architecture and award-winning innovation of the AirBorn 6U VPX Power Supply. The new 3U version has been engineered to offer unparalleled reliability and efficiency for the most challenging operational environments. “AirBorn’s line of VPX power systems sets new standards for power density and efficiency, based on our decades of experience developing, testing and deploying highly reliable power solutions for the aerospace and defense industry,” said Mike Cole, SVP and President, Aerospace and Defence Solutions, Molex. “With the new 3U VPX Power Supply, we continue to overcome the most formidable physical and electrical challenges in power supply design.” Reducing Design Complexity and Costs The company says AirBorn’s patent-pending VPX Power Supply family optimises size, weight, power and cost (SWaP-C) while meeting VPX and VITA 62 open architecture and performance requirements. Approximately one-third the size and weight of the 6U VPX Power Supply, the new SOSA-compliant 3U power system has been designed to achieve a maximum output of 1,000 watts and offers out-of-the-box compliance with MIL-STD-1275 and MIL-STD461 CE101/CE102 conducted emission test
NEWS 5 Power Electronics Europe Issue 3 2025 Power Electronics Europe Navitas Semiconductor, an industry leader in next-generation GaNFast gallium nitride (GaN) and GeneSiC silicon carbide (SiC) power semiconductors, has announced that Xiaomi’s next-generation 90W GaN charger will be powered by Navitas’ GaNSense Control ICs. Reportedly the world’s smallest 90 W charger, the company says this ultra-compact, high-power-density form-factor measures just 34 45 34 mm and weighs only 65 grams—approximately half the size and a third the weight of typical GaN chargers. The charger integrates Navitas’ NV9580 GaNSense Control power IC on the primary side and the NV9701 synchronous rectification controller IC on the secondary side. The GaNSense Control family combines 4th generation GaN power with high-frequency control functionality. It provides all the benefits of a monolithically integrated GaN power FET and GaN drive, plus a controller and protection features in a single surface-mount package for high-density, highefficiency chargers, adapters, and auxiliary power designs. GaNSense Control ICs are said to deliver the highest-frequency operation to minimise system size and weight. Integrated features such as lossless current sensing, high-voltage start-up, and elimination of VDD inductor reduce component count and increase system efficiency. With transient voltage breakdown up to 800 V and no PCB hotspots, Navitas’ GaNSense Control ICs can deliver best-inclass efficiency in the smallest form factor. “The launch of Xiaomi’s 90W GaN charger marks a new milestone in our long-standing collaboration with Xiaomi,” said Charles Zha, SVP and APAC GM of Navitas. “Combining the innovation of GaNSense Control ICs and Xiaomi’s leading system expertise, we have delivered a new benchmark for ultra-portable fast-chargers. Navitas will continue our partnership with Xiaomi to continue future innovations with our GaN technology.” https://navitassemi.com/ requirements. Adherence safeguards sensitive electronics from extreme voltage variations inherent in military ground vehicles, while saving time, effort and cost in product design, testing and qualification. Additionally, the 3U VPX Power Supply incorporates AirBorn’s advanced internal filtering to meet stringent EMI/RF requirements. Integrated EMI suppression capability is designed to meet MIL-STD-461-conducted EMI emission requirements without external filtering. A testament to AirBorn’s proven power engineering expertise, this unique functionality mitigates interference at the source to reduce signal degradation, lower crosstalk and enhance data transmission rates. “For customers building highly compact 3U VPX systems, the opportunity to leverage an ‘all-in-one’ power supply that handles power conversion and EMI filtering on a single printed circuit board is very compelling,” said Scott Poole, director, Design and Development Engineering at AirBorn. “We apply extensive engineering expertise and special processes to develop highly efficient power engines capable of achieving low noise switching, clean conducted emissions, ultra-clean output voltages and versatility in parallel VPX cards.” Meeting Bigger Power Demands in Smaller Footprints The AirBorn 3U VPX Power Supply is well positioned to deliver continuous operation in rigorous conditions common for military ground vehicles, which can create voltage spikes and surges. When space is at a premium, the new 3U VPX model can safeguard essential onboard systems and applications, such as Low Earth Orbit (LEO) satellites, unmanned aerial vehicles (UAVs), industrial automation, robotics and AI-driven distributed systems. This transfer of military-grade ruggedization and reliability to other applications and industries will be universally appealing to engineers and systems integrators committed to ensuring flawless power delivery and seamless systems integration of sensitive electronics. www.molex.com. Navitas Powers Xiaomi’s Next Generation GaN Charger
6 NEWS Issue 3 2025 Power Electronics Europe Power Electronics Europe Power electronics require efficient cooling Electric vehicles, renewable energies, digitalisation, automation – the trend toward electrification is growing in applications where reliability and durability are crucial. This also increases the demand for high-performance cooling solutions. Below CTX specifies three factors that are important for high-efficiency heat sinks. The most important requirement for effective cooling solutions is a sufficiently large surface. This enables fast heat dissipation in power electronics, and is why classic heat sinks are equipped with fins – the narrower and more numerous, the better. Typical manufacturing processes are extrusion and die-casting. In these processes, a forming tool is used to create the structures necessary for heat dissipation, in large quantities. The second efficiency factor is low thermal resistance. This can be achieved at the location where the fins are connected to the base plate. CTX adapts production-related transitions by means of CNC machining. Alternatively, the skived fin process can be used to pare the fins from a metal block. This produces very fine fins that remain connected to the heat sink base with no transitions. Finally, the choice of material is also crucial. Although copper offers the highest thermal conductivity (up to 400 W/mK), it is used only rarely due to its high price and weight. Aluminum is less expensive, lighter, and has a thermal conductivity of 180 to 235 W/mK, which is optimal with the right engineering and manufacturing process. One example is cold forging. This process produces an extremely homogeneous and dense material structure. As a result, the thermal conductivity of the heat sink is higher than that of the feedstock. CTX Thermal Solutions overs one of the leading product ranges for heat sinks in Europe. In addition to standard heat sinks, the company also manufactures applicationspecific cooling solutions. www.ctx.eu Bourns, a global manufacturer and supplier of electronic components for power, protection, and sensing solutions, has announced its SRP3220A Series Shielded Power Inductors. Designed with Bourns’ uniquely-formulated metal alloy powder core, the series can handle high currents up to 11 A without saturating, and supports reliable operation in high-temperature environments. These automotive grade, AEC-Q200 compliant power inductors feature a high heating current rating and shielded construction that minimises magnetic field radiation. The capabilities delivered with the SRP3220A Series also help enhance performance, thermal stability and meet demanding automotive temperature requirements making Bourns’ latest power inductors a costeffective and efficient power management solution for a growing range of automotive systems. https://bourns.com/ Bourns Introduces Shielded Power Inductor Series with Metal Alloy Powder Core Capable of Handling High Currents with Very Low DCR
8 48V POWER INFUSIONS www.vicorpower.com Issue 3 2025 Power Electronics Europe www.power-mag.com Active suspension approaches on-ramp to more markets after 48V power infusion Hongfa solves age-old power challenge with 48V architecture and high-density power modules Vehicle electrification still grabs the lion’s share of automotive technology headlines, but active suspension systems are transforming the driving experience for millions of car owners. Joining the ranks of anti-lock brakes, lane-departure warnings and back-up cameras, active suspension technology, which is currently found only in luxury vehicles, is on the fast track to enter the mid-range auto market. Xiamen Hongfa Electroacoustic Co., Ltd. (Hongfa), one of the world’s largest manufacturers of power relays, has been advancing the automotive market for nearly three decades. Hongfa specializes in automotive power management and distribution, and they are squarely focused on the future of EVs and how to support better electrification in power systems. Hongfa relays are foundational to electric vehicle design and are enabling breakthrough developments where 48V networks are replacing 12V systems to improve efficiency and reduce vehicle size and weight. Hongfa is infusing its electrical hardware, software and structural design expertise to propel the next generation of xEVs. Among other innovations Hongfa has designed the highest performance and smallest active suspension power system on the market (Figure 1). Their bold, innovative design projects to soon make this long-time high-end feature common among mid-range vehicles, improving the ride and safety for more drivers. 48V and evolutionary power technology drive smaller systems and better performance Active suspension systems are highly complex. They use a network of sensors, electromechanical actuators and sophisticated software to adjust vehicle suspension in real time. This results in better handling, a smoother, safer ride and reduced road noise even under the worst road conditions—from navigating suburban potholes to a rural dirt road. Appreciating what Hongfa has achieved requires understanding the active suspension in its infancy. Starting in the 1970s active suspension used complicated electromagnetic solutions which strained the capabilities of 12V battery power systems. It required four 200-pound electromagnetic motors— adding an extra 800lbs to the vehicle, limiting mass adoption. Top technical challenges facing active suspension PDNs Generally, there are two options for the active suspension system power delivery network (PDN). First, the system can be connected directly to the high-voltage battery, which is the current standard for plug-in hybrid vehicles. Here, active suspension is linked directly to the car’s 800V battery, which is efficient and enables energy recuperation through regenerative charging. However, this architecture requires the OEM to run heavy, expensive high-voltage cables all around the car. Alternatively, active suspension can be achieved via the lower-voltage bus, which is either 12V or the increasingly popular 48V. Within the low-voltage option, systems can either rely on an intermediary battery or use DC-DC converters to step down the high-voltage battery rail for use in active suspension. For the latter, the technical revolve around: 1. Small system size. Today’s active suspension systems require 10 – 15kW of power, which traditionally requires a very large and heavy DC-DC converter to support this power level. 2. Rapid regenerative DC-DC converter speeds. Achieving energy recuperation in active suspension systems requires very dynamic, Figure 1 Hongfa has designed the smallest and lightest active suspension power delivery network on the market by combining a 48V architecture and high-density power modules. Four Vicor fixed-ratio BCM6135, 800V-to-48V DC-DC bus converters are used to convert high voltage to 48V and route power to each wheel. The BCM6135 is bidirectional and provides the fastest transient response of any DC-DC converter. This symmetrical switching speed enables optimal energy regeneration when directly linked to the DC-DC converter.
www.vicorpower.com 48V POWER INFUSIONS 9 www.power-mag.com Issue 3 2025 Power Electronics Europe bidirectional power switching capability. It’s imperative that the direction of the current change rapidly for top performance in each direction. 3. Fast transient response times. A DC-DC converter with high slew rate is critical for active suspension. With anything less, a battery or supercapacitors must be added to compensate for inadequate transient performance. The Hongfa approach to solving these tough system challenges was to rely on the benefits of a 48-volt PDN without an intermediary battery. The main challenge was that, even while some conventional DC-DC converters can deliver power without the need for an intermediate battery, they face a tradeoff in that they are bulky and lack the fast response time required to meet the regenerative demands to recoup and store power. Hongfa uses Sine Amplitude Converter Technology to address top technical challenges Alternatively, Vicor bidirectional, fixed-ratio 800V-to-48V DC-DC bus converters provide the fastest transient response of any DC-DC converter. They also have industry-leading power density and efficiency and are designed specifically for a 48V-centric power delivery architecture. Their advanced planar packaging simplifies thermal management systems design further reducing overall footprint and weight. Unique among DC-DC converters, they offer symmetrical performance with their ability to buck or boost with the same level of power (Figure 2). This feature, which is essential to deliver optimal power regeneration for active suspension, is a result of proprietary Vicor Sine Amplitude Converter (SAC™) technology. The SAC uses a zero-current and zero-voltage soft-switching technique and fixed switching frequency in excess of 1MHz to provide fixed-ratio DC-DC conversion. The SAC output voltage (VOUT) is proportional to its input voltage (VIN) at no load per Equation 1. VOUT = K•VIN (1) In Equation 1, K is commonly referred to as the transformation ratio and is defined as the ratio of output voltage and input voltage. K is a fixed value for a given model of SAC. In bidirectional mode, a single SAC can be deployed with the intent that once excited, the module is to deliver power in either the forward or reverse direction, depending on the way in which the SAC is being actively driven at a given instant in time. Such performance is essential to deliver optimal power regeneration for active suspension. Linking active suspension directly to the main battery with a bidirectional power converter enables top energy recuperation. Similar to how a spring absorbs and releases energy, active suspension uses regenerative shock absorbers to collect kinetic energy that is returned to the battery. While this can be done with a conventional bidirectional DC-DC converter, few manufacturers can design a system with the performance necessary for transient response, peak power slew rate (about 8 million amps per second), and power efficiency to manage the bidirectional power flow between the converter and battery power source (Figure 3). Fully capitalizing on these advantages, Hongfa has designed and developed a compact system that includes CAN communication, high-voltage protection and EMI filtering. Their innovative mechanical assembly optimizes thermal dissipation within a very compact footprint. In the regenerative active suspension application, the 800V battery sources current when the vehicle travels over smooth road surfaces, and the suspension actuation motor is the 48V load. When the vehicle traverses a bumpy road, the linear motors in the suspension system momentarily become generators (compression), increasing the voltage on Figure 2 Sine Amplitude Converter (SAC) -- with TM SAC™ application topology options.The SAC operates as forward, reverse or bidirectional power converters which have isolation barriers set between their primary and secondary power ports. The gray bar represents the SAC inbuilt galvanic isolation barrier between the input and output power ports Figure 3 Vicor BCM6135 DC-DC converter di/dt is 8 million amps per second, offering an unrivaled slew rate which is essential to support optimal energy recuperation and storage for the Hongfa active suspension system.
10 48V POWER INFUSIONS www.vicorpower.com Issue 3 2025 Power Electronics Europe www.power-mag.com the low side of the converter which is then multiplied by the conversion ratio of the converter (in this case 16/1) increasing the voltage on the input side above the 800V battery voltage. This difference in voltage reverses the direction of current flow without internal loop controller intervention. The 800V battery then momentarily becomes the load (rebound) and recovers energy by charging through its battery management control system. Once the displacement from the bumpy road has subsided, the bus converter will once again step down the 800V battery and supply current to the suspension linear motors – all without intervention from the vehicle’s onboard processors. Hongfa introduces smallest active suspension power supply using power modules and 48 volts For Hongfa, active suspension design is defined by the need to balance size and weight against the requirement for higher efficiency, improved EMI and thermal performance. These system requirements brought Hongfa and Vicor together on the development of an 800V-to-48V DC-DC converter to build the ultimate active suspension system. The Hongfa solution leverages the Vicor power density advantage to create compact (197 x 201 x 71mm) 5kW power supplies for each actuator. The system can process up to 6kW of peak power in either direction. The design of the converter is greatly simplified by using a pair of Vicor BCM6135 bus converters operating in parallel, instead of several hundred discrete components. The converter is optimized to work with 800V battery systems and has an operating range of 420 to 920V. With liquid cooling it can deliver up to 100A of current with 97.3% efficiency. The system housing volume is under 1.8l and total system weighs in at 2.6kg, providing a major weight reduction (Figure 4). “When it comes to active suspension, our OEM customers require a DC-DC converter with a response rate measured in milliseconds,” said Mr. Peter Li Research & Development Director at Hongfa, “otherwise, additional battery support is needed. Vicor BCM6135 power modules enable the competitive performance we need.” Together Hongfa and Vicor have collaborated to develop the smallest active suspension system today – almost half the size of the nearest competitor – that delivers the industry’s fastest power conversion response. At the low end of its operating voltage range the guaranteed peak power rating of the BCM6135 model is 3.1kW for 20ms with a 25 percent duty cycle (Figure 5). As Hongfa can attest, developing an active suspension power system is complex: worst-case road surface profiles, cooling methods, size, weight and cost constraints can vary enormously. “Vicor power modules not only deliver the performance we need but they also significantly shorten our development time and have made designing this type of system much easier for us,” said Mr. Li at Hongfa. The combination of 48V and highdensity power modules are enabling new levels of innovation in automotive electrification — reducing space, weight and delivering superior performance. The BCM6135 is critically important to delivering top performance for high voltage Figure 4 The Hongfa active suspension system (Power System Specs HF3661 800V48V DC-DC System) is liquid cooled and is the most compact on the market, weighing 2.6kg and measuring 197 x 201 x 71mm. Figure 5 In laboratory testing, a BCM bus converter with a 16:1 transformation ratio was provided an 800V input to produce a 50V output. Without an attached heat sink, the module outputted a peak current of 90A. Even though the module is rated for only 3.1kW, it was able to support peak output power of 4kW in testing.
www.vicorpower.com 48V POWER INFUSIONS 11 www.power-mag.com Issue 3 2025 Power Electronics Europe to SELV conversion (Figure 6) . No other DC-DC converter can match the size, transient speed and bidirectional switching performance of the BCM. It stands alone in this capacity and offers an enormous size advantage versus every other converter. This infusion of power electronics technology has solved a decades-old active suspension power system design problem. Together Hongfa and Vicor are delivering the smallest and highestperforming active suspension system on the market. This is just the beginning for Hongfa and Vicor as they partner to advance automotive electrification. Figure 6 Inherently bidirectional, the BCM6135 rapid current transient response rate of 8 million amps/second is a perfect match for the power profiles of active suspension and power regeneration in electrified vehicles. The BCM6135 is a 95% efficient 3.5kW peak power bus converter that converts 800V from the traction battery to 48V. To receive your own copy of Power Electronics Europe subscribe today at: www.power-mag.com Name: Company Name: Address: Post Code: Tel: Total Number of Copies @ £ p+p Total £ Drives S & S Hyd H/B Pne H/B Ind Mot Comp H/B H/B Air QUANTITY QUANTITY Hydraulics & Pneumatics There are now 6 of these handy reference books from the publishers of the Drives & Controls and Hydraulics & Pneumatics magazines. Published in an easily readable style and designed to help answer basic questions and everyday problems without the need to refer to weighty textbooks. We believe you’ll find them invaluable items to have within arms reach. From the publishers of QUANTITY QUANTITY QUANTITY 2-5 copies £4.30, 6-20 copies £4.10, 20+ copies £3.75. QUANTITY PRACTICAL ENGINEER’S HANDBOOKS HYDRAULICS INDUSTRIAL MOTORS SERVOS AND STEPPERS PNEUMATICS COMPRESSED AIR INDUSTRIAL ELECTRIC DRIVES PLEASE ALLOW UPTO 28 DAYS FOR DELIVERY $&! -!.5&!#452).' -%$)! ,4$ 4HE (IGH 3TREET 4ONBRIDGE +ENT 4. "% Postage and Packaging: 1-3 copies: £2.99 4-6 copies: £4.99 7 or more copies: £6.99 If you would like to obtain additional copies of the handbooks, please email info@dfamedia.co.uk or call us on 01732 370340. Alternatively you can return the completed form below to: Engineers Handbook, DFA MANUFACTURING MEDIA LTD, 192 The High Street, Tonbridge, Kent TN9 1BE #HEQUES SHOULD BE MADE PAYABLE TO $&! -ANUFACTURING -EDIA ,TD AND CROSSED ! # 0AYEE #OPIES OF THE HANDBOOKS ARE AVAILABLE AT a PER COPY $ISCOUNTS ARE AVAILABLE FOR MULTIPLE COPIES
12 MOTION CONTROL http://components.omron.com/eu-en Issue 3 2025 Power Electronics Europe www.power-mag.com Flipping human motion detection on its head Automatic object detection is growing ever more sophisticated, yet the accurate detection of humans still poses unique challenges. Omron’s Gabriele Fulco explores what it is that makes humans so difficult to reliably detect, and how successfully navigating these obstacles could usher in a new era of productivity. Efforts to mimic human vision to identify objects are nothing new. The first digital image processing technologies were first developed in the 1960s, and have been constantly refined and improved ever since. Recent advances in AI have served to intensify these efforts further. Achieving a computer-based vision system that can not just match but exceed the accuracy and understanding of human vision combined with a human brain has been notoriously difficult. Unlocking this technology could potentially herald a revolution in human progress, revolutionising everything from agriculture to medical science, as well as industrial operations. The human body is the product of hundreds of thousands of years of evolution, and as such is incredibly sophisticated. Computers have long been able to detect and understand 2D pictures, but dynamic three-dimensional environments are a step far beyond this. Indeed, human vision is not just about simply perceiving the world around us; it is also about understanding it. Our brains are able to constantly provide the vital contextual information to allow us to make sense of our surroundings in realtime. Computers have traditionally been unable to match this level of sophistication, that is until recently. Training a machine to not only perceive but understand the world around it presents complex technological and computational challenges. Detecting humans adds yet another layer of complexity. Indeed, the uniqueness and diversity of humans themselves make them one of the most challenging subjects to reliably detect without training any system extensively on specific individuals. Even a change of clothing or hairstyle can present problems. When you add in additional factors such as the wider environment with which humans are interacting, combined with the unpredictability of human behaviour, the technical challenges quickly mount up. Any viable solution also has to be cost-effective and economical in size in order to be practical in everyday environments. Solving these problems is not easy. In fast-moving industrial settings for instance, several humans may all be working at speed, carrying out various different duties within the same space. Attempting to track their movement from a side-on or even an isometric view has traditionally proven an imperfect solution, as this requires the system to have an understanding of the depth of vision. In a single-camera configuration, one person can also very easily obscure another from view and create blind spots. In addition, one of the major challenges in the development of vision sensing technologies is not so much in the capture of images, but in processing them. For a machine to understand human movement in real-time requires a large amount of computational power to ensure high speed and accuracy. Since no two environments are the same, developing a system that can not only understand the nuances of human Gabriele Fulco
http://components.omron.com/eu-en MOTION CONTROL 13 www.power-mag.com Issue 3 2025 Power Electronics Europe movement, but also adapt to different scenes and lighting levels, has traditionally been a barrier to such technologies becoming viable on a wide scale. Omron’s AM1 human detection system tackles these challenges quite literally from a different perspective. Designed for optimising human productivity in industrial settings, it utilises a single top-down camera, combined with sophisticated software optimised specifically to detect and interpret human movement. In doing so, it can provide a more accurate picture of where in a given space human workers are located, while also reducing the likelihood of overlapping and blind spots. The AM1 software has been trained to understand typical patterns of human movement, and can track up to 10 individuals within a 7m x 7m area with an accuracy exceeding 95 percent. Having this capability allows organisations to track where and how workers are moving, or how long they’re staying at a particular station for. This information can in turn be used to detect bottlenecks, and ensure that space utilisation and workflows are as efficient as possible. In practice this could mean removing obstacles, or shortening routes that are most frequently used, or reducing the likelihood of workers having to cross each other’s path. By identifying and understanding the problems earlier, solutions can be found more quickly, underpinned by a data-driven approach. AM1’s accuracy is achieved through the system’s 10fps frame rate. Image data from the camera (or multiple cameras) is fed into a processing hub via Ethernet, which is powered by an Intel OpenVINO TM accelerator. This is the crucial innovation that allows the system to turn raw data into useful information quickly. Once processed, the information is then conveyed for human operators to a standard PC or PLC. Omron’s vast library of data, accumulated through years of developing vision solutions, means that the system does not need to be trained on particular individuals, and can detect any human body type. As such, no specific programming skills are required for users. Aside from optimising productivity, other potential uses for this technology could involve occupancy detection to determine the appropriate HVAC conditions, or intrusion detection during non-work hours. There are also potential use cases in shared residences for optimising the layout and environment of communal areas. While the accurate detection of humans across all environments continues to present challenges, systems like Omron’s AM1 are proving that human motion detection has finally reached maturity as a viable technological solution. In the future these systems hold immense promise for revolutionising productivity, as well as other aspects of society. Gabriele Fulco, Product Marketing Manager, Omron Electronic Components Europe B.V. http://components.omron.com/ eu-en
14 SERVO MOTOR DRIVE CIRCUITS https://bourns.com/ Issue 3 2025 Power Electronics Europe www.power-mag.com Protection and Layout Considerations to Maximize Efficiency in Servo Motor Drive Circuits Servo motors convert electrical energy into precise mechanical motion making them essential components in today’s motion control systems. Their widespread use spans from household appliances to industrial automation, where high-performance and accuracy are required. Known for their superior efficiency and responsiveness, servo motors are typically driven by high-frequency AC voltage, which necessitates specialized power conversion circuitry. To deliver the appropriate power to these motors, a combination of stages is used to convert and condition electrical energy. These stages perform everything from rectifying AC mains, correcting power factor, and generating high-frequency signals, to providing robust protection and accurate feedback. Each stage presents design challenges that can include a reduction in power quality, the need to deal with electromagnetic interference, conditions that require additional thermal management measures, and added requirements for effective surge protection. This article explores the components required along with the layout considerations in designing servo motor drive circuits. It focuses on the power conversion, circuit protection, and current sensing components that are employed to help designers enhance performance, reliability, and efficiency. Whether powering a compact servo in a precision tool or a large industrial motor, the principles outlined here serve as a foundation for creating robust and energy-efficient drive systems. Servo Motor Drive Circuits Layout The most common application of a servo motor circuit is to convert AC main power into a significantly higher frequency to drive AC or DC servo motors. Figure 1 shows a block diagram of a typical servo motor drive circuit. As shown, the circuit uses a full-bridge rectifier with a filtering capacitor to transform the AC signal into a DC voltage. However, due to the rectified nature of the DC voltage, there are highvalue current harmonics present within the power. The presence of these current harmonics can potentially cause outages in the connecting power grid. To prevent outages, Power Factor Correction (PFC) circuits are implemented to increase the power factor. An H-bridge then converts the DC bus voltage after the rectification and PFC stages to a workable PWM or AC singlephase waveform for the motor. The Hbridge can be replaced for a three-phase, half-bridge design that incorporates similar characteristics but designed for threephase motors. These connected circuits are typically controlled and monitored by a microcontroller, which handles and operates the high-precision operation of the motor drive circuit. By using a servo motor drive circuit, power is conserved by converting a low-frequency input into a high-frequency signal suitable for servo motor applications. Power Protection Incoming power from the electrical grid is vulnerable to frequent overvoltage and overcurrent events, which pose a risk to drive circuits. Caused by lightning strikes, grid switching transients, or inductive kickback, these surge events are often thousands of volts and amps; much higher than the rated voltages of any connected Figure 1. Block diagram of circuits that make up a servo motor drive circuit.
https://bourns.com/ SERVO MOTOR DRIVE CIRCUITS 15 www.power-mag.com Issue 3 2025 Power Electronics Europe device. The industrial standard to prevent these random surges is to implement a surge protective device (SPD) that are specifically designed to absorb incoming energy. SPDs are commonly positioned in the circuit as the first line of defense from potential lightning strikes. These devices are proven to deliver effective protection from their advanced design that uses discrete components like metal-oxide varistors (MOVs) and Gas Discharge Tubes (GDTs). If a surge that exceeds the rated voltage of the SPD occurs, then the device will shunt excess energy away from the motor drive system. This feature helps ensure that even during extremely high voltage surges, the potentially damaging threat would be isolated to the SPD. To provide a motor drive circuit with complete power protection, the recommended protection design should include a fuse, Negative Temperature Coefficient (NTC) device, a MOV, hybrid protectors, and a GDT. Each device fulfills its niche in protecting the motor circuit. The MOV works as a clamping device, absorbing high voltages. The GDT is a low-capacitance component that, when connected in parallel to the protected circuit, diverts high currents away from the circuit, ‘crowbarring’ the power. Currently available hybrid protection devices combine MOV and GDT technology in a single space-saving package. NTCs are especially important in highinductive motor circuits, where stored energy kickback and inrush currents are commonly present. NTCs operate normally open, but when current is applied, the device warms up and acts as a short. This behavior protects the circuit from an initial current spike. Despite implementing these multiple layers of protection, redundancy is necessary to effectively protect a motor drive circuit. Fuses are considered the most reliable solution for redundant protection as they act to safeguard the circuit if every other device has failed. The Need for Rectification Full-bridge rectification converts an AC signal into a DC voltage. This is accomplished by implementing diodes into a bridge arrangement. The effect of the rectification is like the mathematical function of the absolute value of a sine wave. The resulting signal is completely positive voltage; however, it retains a strong variance and frequency from the original AC input. To achieve a stable DC voltage, designers implement a capacitor low-pass filter, which filters the 50 or 60 Hz frequency harmonics, leaving only the DC voltage. This filtering capacitor smooths out the curve, removing most of the variance in the signal. The efficacy of the filtering— reducing ripple in the voltage waveform—is determined by the capacitance value of the capacitor, which is where the cost and size constraints of the circuit must be considered when designing the filter. Power Factor Correction Some circuit designers settle for a low-pass filter, where there is a small ripple of voltage present in the rectified voltage. However, due to the shape of the waveform, the capacitor experiences large current harmonics. These harmonics are derived from the constant charging and discharging of the capacitor at a constant frequency. The resulting current waveform that flows through the capacitor contains errant harmonics, which, when reentering the electrical grid, cause disturbances and fluctuations. On a large scale, such disturbances can cause damage and power outages within buildings and to associated infrastructure. Another reason the current waveform is undesirable is the low power factor (PF), which is the ratio of real ‘useful’ power to total apparent power. The PF is affected by low real power consumption and relatively high reactive power. Real power is determined from the definition of electrical power—the multiplication of current and voltage in the component. As the current from the AC main resembles a nonsinusoidal waveform and the voltage is sinusoidal, the real, ‘useful’ power provided is low compared to the total apparent power. While real power is consumed by resistive loads, reactive power is consumed by capacitive and inductive loads (which dominate inside a servo motor system). Reactive power results from voltage and current waveforms being out of phase due to the inductive load. This power does not generate mechanical work; however, it still pulls current through the wire. The current sloshes back and forth from the electrical grid to the motor, heating up the wires, lowering the maximum voltage possible, and slowly damaging the connections. This results in the total apparent power—the Pythagorean sum of the real and reactive power—being greater than the real power. This issue shows the inefficiencies of the system that need to be corrected. A Power Factor Correction (PFC) circuit is implemented to remedy both issues of the current waveform. The most common type of PFC circuit is the high-frequency boost converter. These circuits operate by using a rapidly switching transistor to charge and discharge an inductor. Bourns’ recommendation for transistors is its Insulated Gate Bipolar Transistor (IGBT), a high-performance transistor with the characteristics of both the MOSFET and the BJT. Bourns IsoMOV hybrid protection devices operate similarly to an MOV, but leverage the low capacitance levels of the GDT, resulting in a higher performance and more reliable solution.
16 SERVO MOTOR DRIVE CIRCUITS https://bourns.com/ Issue 3 2025 Power Electronics Europe www.power-mag.com SiC Schottky barrier diodes can also be used to increase power efficiency for most systems. SiC diodes exhibit negligible reverse recovery charge (Qrr). This drastically reduces switching losses in the PFC switching element where reverse recovery of the diode would otherwise cause high losses and EMI in Si-based solutions. SiC devices can also operate at higher junction temperatures (often up to 175° C), reducing the need for bulky heat sinks or forced-air cooling. PFC designs can be tricky, but with proper tuning of the frequency, duty cycle, and values of the inductor and filtering capacitor, it is possible to make the current waveform resemble a sinusoidal waveform that is in phase with the AC main voltage. By using a PFC circuit, the unintended effects of a servo motor are minimized, reducing costs in maintenance and electricity fees. Implementing an H-Bridge Once the incoming power has been filtered and passed through the PFC, the power must be reconverted into a highfrequency AC or trapezoidal waveform. An H-bridge configuration is commonly used to convert DC power into a high-frequency signal. The H-bridge uses high frequency PWM signals to control high-performance transistors, similar to the operation of IGBTs. The frequency in an H-bridge is often adjustable, allowing for precision speed and torque control of the motor. Accurate Current Sensing The servo motor drive circuit requires almost constant measurement and adjustment of the switching frequencies of the PFC and the H-bridge, as they are critical motor control operational elements. The most important measurement is the current sensing of the various stages of power conversion. The preferred current sensing solution for servo motor circuits is its high-powered current sensing shunts. These robust devices are known to excel at delivering high precision current measurement. Current shunt resistors operate by providing a low voltage drop through an accurate resistance. By measuring the voltage drop across the resistor, the current can be calculated and monitored. Constant current sensing is required in motor drive circuits as they use a closed-loop feedback system that helps maintain efficient operation. Benefits Servo motor drive circuits are essential in modern motion control systems requiring precise power conversion, protection, and control. The key stages of a typical drive circuit—from rectification and power factor correction to high-frequency AC and trapezoidal generation and current sensing present unique challenges. To remedy the identified harmonic distortion, surge vulnerability, and efficiency loss issues presented, servo motor drive circuits require a high-performance, integrated protection design that can meet manufacturers’ efficiency and control goals. Key components are SPDs that provide robust and rugged solutions that can withstand potentially damaging overvoltage and overcurrent events. Another component in the protection arsenal are today’s innovative hybrid protection devices, which combine the fast clamping of MOVs with the low capacitance of GDTs. In addition, IGBTs and SiC diodes support high-frequency switching in PFC and H-bridge stages, reducing power losses, and enabling higher motor speeds. Plus, advanced current sensing shunts provide a high-precision solution for realtime control feedback necessary in servo motors. These components allow designers to build more compact and accurate servo motor drive circuits that meet ongoing requirements for greater control or adjustment capabilities in increasingly expensive industrial motors as well as in small servo motors. As servo motor applications continue to expand across automation, robotics, and electric mobility, the importance of reliable drive circuit design will only grow necessitating ever more advanced protection devices to safeguard these essential control systems. To receive your own copy of Power Electronics Europe subscribe today at: www.power-mag.com Bourns® SiC Schottky diodes enable designers to increase power efficiency and decrease noise in PFC designs.
18 INDUSTRIAL AND AUTOMOTIVE SYSTEMS https://www.ti.com/ Issue 3 2025 Power Electronics Europe www.power-mag.com Not All Grounds Are 0V Sadia Khan - Systems Engineer, Isolation Products at Texas Instruments Industrial and automotive systems are using mixed-voltage designs for power optimization, improved performance, and cost reduction. Integration of diverse power domains become a challenge due to unintended ground mismatch. This occurs when the ground reference voltage between domains deviates from the expected 0V reference, ranging from a few volts to tens of volts. Ground shifts can disrupt communication between systems. Addressing this concern is key to reliable system performance. How is Ground Mismatch Solved Today? There are multiple methods today used by designers to address ground mismatch in systems. First, proper PCB grounding techniques are used such as dedicated ground planes, star grounding technique, and separating analog and digital grounds. However, this requires careful layout planning and can consume additional board space. If ground shift occurs after the board is already designed, this requires a complete redesign, leading to increased development time. Discrete level shifting is another technique, using resistor dividers or transistor- based circuits to interface across grounds. However, this design is not well-suited for systems with large ground potential differences, suffers from poor signal integrity and timing characteristics, and requires significant board space. Lastly, and perhaps the most commonly used, are galvanic based isolators which are used to decouple subsystems with different ground potentials. Isolators are often associated with higher costs and can introduce additional signal delays. This can also complicate power supply design since isolated sections require separate power sources. TI’s Latest Voltage and Ground-Level Translator Texas Instrument’s TXG family introduces a new method of mitigating ground mismatch in your system with a translator that can level shift both voltage and ground to enable communication across different power domains. TXG804x, TXG802x, and TXG8010 handles ground mismatch up to ±80V, level shifting of I/O voltages from 1.71V to 5.5V, and has a push-pull output for interfaces such as SPI, UART, I2S, and GPIOs. These devices support very high data rates of >250Mbps and low latency with <5ns propagation delay and 0.35ns channel- channel skew. TXG8122 also handles ground mismatch up to ±80V, level shifting of I/O voltages between 3V to 5.5V (Side 1) to 2.25V to 5.5V (Side 2), and has an open-drain output for interfaces like I2C. Examples of Ground Shifting There are several uses cases where ground mismatch can be an issue and is summarized below under three types of ground shifting: DC shift, AC Ground Noise, and Intentional Ground Shift. DC Shift Ground mismatch can occur due to DC shifts in a system and is shown in Figure 1. DC Shifts can be found when current flowing through a ground path causes a voltage drop because of the wire’s parasitics. This creates a ground mismatch between two systems. This phenomenon is particularly common in systems with high current loads or long ground paths. Figure 2 gives an example of an Electrical Power Steering (EPS) System. In this system, two microcontrollers (MCUs) are used to maintain continued operation during a failure event. Both MCUs communicate with each other, but one serves as a redundant backup in case the primary MCU stops functioning. While both MCUs are typically referenced to a common ground, high current loads in the system can introduce ground shifts between the two domains. Traditionally, digital isolators are used to manage these Figure 1. DC Shift Figure 2. Electric Power Steering with TXG Secondary Primary (Redundant)
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