Alhough electrification driven by the increasing integration of renewable energy sources such as wind and solar is the future, they share a fundamental limitation which is intermittency.

Sujay Ramalingam, our next pathbreaker, works as Technical Hardware Lead at Stercom Power Solutions ( Germany), a company that develops and manufactures energy storage systems, charging technology, and power electronics for e-mobility and stationary applications.

Sujay talks to Shyam Krishnamurthy from The Interview Portal about how enabling all these key technologies depends on efficient “power conversion systems”, which form the critical link connecting renewable energy generation, battery storage, and electric vehicles into a cohesive, reliable ecosystem.

For students, no matter how advanced technology becomes, a strong foundation in fundamentals is what allows you to understand and adapt to anything new.

Sujay, what were your initial years like?

I was born in Vanavasi, Salem district, Tamilnadu and brought up in the Silicon Valley of India or Garden city “Namma Bengaluru”. Right from my childhood days, I was always fond of electronics, machines and how the things worked, along with engineering & precision technologies that go into those systems.

I grew up in an average middle class family, my father was working then in the South Western Railway, Bengaluru Division and mom was a home maker, and I have a younger sister. I spend most of our childhood days and my memories go way back to days in Railway quarters – which offered a unique, close-knit and self-contained community experience where neighbours share a common workplace bond and come from diverse backgrounds. I grew up in the Baiyappanahalli railway community, which shaped so much of who I am today. Living close to the railway yard, open access and close proximity to the railway station meant, the rhythm of my childhood was set by the distant clatter of couplings, the hiss of brakes, and the deep rumble of locomotives rolling in and out around the clock. I’d spend countless afternoons during cricket play breaks with my friends watching the engines being shunted in and out, fascinated by the sheer electro-mechanical systems and power of it all — the way a single locomotive could haul so much weight, the intricate signalling that kept everything moving safely, the diesel fumes mixing with the smell of hot metal and grease and the arcing of the pantograph contact with the overhead catenary. Those early experiences weren’t just childhood curiosity; they planted a seed which gave me an early exposure to the railway technologies and became the foundation for everything that followed in my interest in the railway domain and my future work follows over the years.

What did you do for graduation / post-graduation?

My passion for Electronics made me choose and pursue my bachelor’s in electrical and Electronics engineering from M.S. Ramaiah Institute of Technology, Bengaluru.

After completing my undergraduate studies, I worked in the Electrical manufacturing industry for a year as Graduate Engineer Trainee (GET) at Kirloskar Electric company, the biggest manufacturer of motors, alternators and generators for industrial and railway applications. Though I learned many engineering and valuable design skills there, it also provided me with time in parallel to prepare for the next step of my journey.

I moved to Germany in 2009 to pursue my international master’s in Electrical Power Engineering (EPE) from prestigious RWTH Aachen, part of TU9, an alliance of 9 leading and highly reputed universities of technology in Germany.

During my master studies, I had an opportunity throughout the course work as a student assistant (HiWi) in the “Institute of Power Electronics & Electrical Drives (ISEA) which provided me with a platform to work with different research groups and assist the Phd students. I had worked in a government sponsored project called “Project -E-Mobility” where I was involved in development of Battery Models using MATLAB Simulink, laboratory testing of different Battery technologies, building battery packs and development of Battery Management System (BMS) for electric vehicles. As part of my course work, I spend one year in Railway Mobility division of SIEMENS AG in Erlangen where I spend my first six months as an Intern where I was involved learning of different tractions systems, simulation of different railway traction propulsion drives and developing traction cooling models with MATLAB Simulink and followed by the last six months writing my master thesis titled “Optimization of Train energy consumption by the use of Permanent Magnet Synchronous Motors (PMSM)”. Permanent Magnet Motors were the key-enabling technology then and needed new propulsion architecture and control strategies. My task involved comparing distributed traction over traditional concentrated railway traction systems, comparing system level efficiencies and the energy savings between PMSM and Induction motors for traction applications.

What were some of the influences that led you to such an offbeat, unconventional and uncommon career in Power Electronics?

Ever since I was a child, I had a deep fascination with the electrical, electronic and machines domain — I was always curious about how they worked and what made them function. This childhood passion gradually grew into a clear dream: to become an engineer in this field. Driven by that dream, I worked hard throughout my schooling to build a strong foundation in mathematics and science, which eventually helped me secure admission into a Bachelor’s degree program in Electrical and Electronics Engineering. Beyond just fulfilling a childhood ambition, I chose this career because it constantly challenges me to learn new technologies and stay updated in a rapidly evolving field. I find genuine satisfaction in acquiring new skills and applying them to design and build things that are not only functional but also elegant and efficient. This combination of curiosity, continuous learning, and the joy of creating meaningful solutions is what confirmed this as the right career path for me.

First and foremost, my family — my parents, who have always supported my passions and dreams, and my close friends, who have stood by me at every turn. From my school days onward, they stood behind every decision I made, acknowledging and encouraging each step of my educational journey, from school through my bachelor’s and master’s degrees.

I would also like to acknowledge the mentors, friends and sources of inspiration who have played an instrumental role in shaping every stage of my life:

  • School: My teachers, Ms. Anandavalli Amma (Mathematics), Ms. Rajeshwari (Science), and Ms. Valasamma (Mathematics), who nurtured my early curiosity and discipline.
  • Bachelor’s Degree: Dr. V. Krishnan (Head of Department, Electrical Engineering) and Dr. Premila Manohar (Electrical Engineering), who strengthened my technical foundation.
  • Master’s Degree: Dr. Martin Glinka (Siemens AG) and Dr. Ansgar Brockmeyer (Stadler Rail AG), who guided my transition into advanced engineering thinking and Railway technologies during my studies in Germany.
  • Professional Career: Mr. Martin Kutschker and Dr. Jie Liu (both from Stercom), who have continued to mentor and shape my growth as an engineer throughout my professional journey.

Tell us about your career path

After completing my bachelor’s degree, I began my professional journey as a Graduate Engineer Trainee at Kirloskar Electric Company Ltd. in Bengaluru, where I worked for over a year. This period turned out to be pivotal — it was during this time that I started actively planning and preparing for my master’s degree abroad.

A turning point came in early 2008 which I can clearly recollect, when the German Academic Exchange Service (DAAD) organized an education event at the Taj Hotel to introduce Indian students to opportunities in Germany. While most of my peers were leaning toward traditional destinations like the US, Australia, and the UK, this event gave me valuable insight into the German education system and opened my eyes to a different path. I discussed this opportunity with my close friends, and together we prepared for it as a team. Eventually, three of us secured admission to the same university and moved together to RWTH Aachen University, Germany, for the winter intake in 2009 — having friends by my side made the transition to a new country and culture much smoother.

After completing my master’s degree, I took up a time-limited contract as a Research Assistant at the Zurich University of Applied Sciences (ZHAW) in Winterthur, Switzerland, which gave me valuable exposure to applied research in close collaboration with industry partners.

My work at Winterthur was closely related to my master’s studies. I worked as a Research Assistant at the Institute of Energy Systems and Fluid Engineering (IEFE), Zurich University of Applied Sciences (ZHAW), Winterthur. In this role, I collaborated with industry partners, including ABB, on projects focused on the large-scale integration of renewable energy and energy storage systems.

My responsibilities included conducting experimental studies on the integration of Battery Energy Storage Systems (BESS) for peak shaving applications, as well as developing and validating MATLAB/Simulink models for large-scale solar energy integration. I also worked on the design and implementation of Model Predictive Control (MPC) strategies to optimize system performance, enhance grid stability, and improve the efficiency of renewable energy integration.

This experience allowed me to bridge academic research with real-world industrial applications, deepening my expertise in energy systems, control engineering, and renewable energy technologies.

In early 2015, I then moved into the industry, joining Knorr-Bremse Powertech, where I spent four years working in the railway domain and gained deep, specialized experience in that field.

Knorr-Bremse Powertech is a leading OEM and global supplier of electrical systems for the railway industry, specializing in auxiliary power converters, HVAC inverters, battery chargers, and onboard power supply systems. Their products were used in a wide range of rolling stock, including metro trains, regional passenger trains, high-speed rail, and long-distance railway systems operated by national and state-owned railway companies around the world.

The company’s solutions play a critical role in powering onboard auxiliary systems such as air conditioning, lighting, heating, ventilation, compressors, and battery charging, ensuring reliable operation and passenger comfort throughout the train’s service life.

I joined Knorr-Bremse Powertech as a Development Engineer, where I was responsible for the design and development of HVAC inverters used in train air-conditioning systems, as well as auxiliary power converters that supplied power to onboard loads such as lighting, heating, and compressors. My work involved power electronics design, system development, testing, and validation to meet the stringent reliability and safety requirements of the railway industry.

This role gave me valuable hands-on experience in developing high-reliability power conversion systems for transportation applications and deepened my expertise in power electronics, converter design, and railway electrification technologies.

Subsequently, Knorr-Bremse Powertech was acquired and became part of ABB Traction Converter GmbH, further strengthening its position in the global rail electrification and traction power market.

Following that, I transitioned to Stercom Power Solutions in 2019, where I currently work and continue to grow professionally.

Looking back, my career path was shaped by a combination of careful planning, timely opportunities, and the courage to choose a less conventional route — one that ultimately gave me rich international exposure across India, Germany, and Switzerland, along with diverse experiences spanning research and industry.

How did you get your first break?

My first real break came in 2015, when I relocated back to Germany and stepped into the role of Development Engineer at Knorr-Bremse Powertech. It was here that I finally found myself working in an area I was truly passionate about — developing auxiliary power converters, HVAC inverters, and battery chargers for the railway domain. Looking back, this moment marked the true beginning of my professional journey in power electronics, setting the foundation for everything that followed.

Securing a role in core engineering, especially as an international candidate, can be challenging, but it is certainly not impossible. In my experience, success comes from a combination of continuous learning, consistent upskilling, and perseverance.

Completing my master’s degree in Germany significantly strengthened my profile, as it provided exposure to the local industry, advanced technical knowledge, and valuable professional connections. Additionally, Germany’s EU Blue Card program, a residence and work permit designed for highly qualified professionals from non-EU countries, created a favourable pathway for employers to hire international talent with specialized skills.

Looking back, I would say it was not just networking or qualifications alone that helped me secure the role. Rather, it was a combination of technical expertise, continuous self-development, professional connections, and being in the right ecosystem that values skilled engineers. With persistence and a clear focus on developing in-demand technical skills, opportunities in core engineering are achievable.

What were some of the challenges you faced? How did you address them?

Life is never a straight line — it’s always a mix of ups and downs, and my journey was no exception. Throughout my bachelor’s degree, I stayed focused, consistent, performing above average and steadily building the technical foundation I knew I would need for my career ahead. From early on, I held a clear vision in my mind — a childhood dream of working for an electrical or electronics manufacturing company, where I could apply my passion for product development in a real, tangible way. However, turning that dream into reality wasn’t straightforward. During campus placements, the market was flooded with opportunities in the IT sector, while roles in hardware, electrical, or product development companies were few and far between. It would have been easy to take the safer, more readily available path into IT, as many of my peers did — but I chose to stay true to what I truly wanted.

It was a challenging period, filled with uncertainty, but I believed that staying aligned with my passion would pay off in the long run. That determination finally paid off in 2008, when I got my breakthrough and joined Kirloskar Electric Company Ltd. — a moment that felt like the true beginning of the career I had always envisioned for myself. Looking back, this experience taught me an important lesson: staying committed to your goals, even when the easier path is right in front of you, is what ultimately leads to a career that feels genuinely fulfilling.

Where do you work now?

I am currently working as a Technical Hardware Lead at Stercom Power Solutions GmbH in Germany, which was founded in 2014 and is based in Weyarn, Germany, We are a product based company that develops and manufactures energy storage systems, charging technology, and power electronics for e-mobility and stationary applications. Our product portfolio spans high-power boosters, energy storage systems based on lithium-ion batteries and ultracapacitors, battery management systems, and both wired and inductive charging solutions, including a 22kW on-board charger and a bidirectional OBC V2X that enables Vehicle-to-Grid and Vehicle-to-Building functionality.

What problems do you solve?

My current responsibilities are driving electrification for the future, specifically through the conceptual design, system definition, and development of a Bidirectional On-Board Charger (OBC V2X) for Commercial, Construction, and Agricultural Vehicles (CAV). This involves solving problems around how energy flows bidirectionally between the vehicle and the grid, ensuring the system is efficient, reliable, and adaptable across diverse vehicle platforms and operating conditions.

In parallel, as a certified Functional Safety Engineer (IEC 61508) from TÜV SÜD, Germany, I address a different but equally critical class of problems: minimizing system risks and hazards. This involves designing and implementing automatic protection mechanisms and safety instrumented functions so that equipment responds to faults or failures in a predictable, safe manner — without causing harm to people or property. In essence, one side of my work focuses on enabling the technology of the future, while the other ensures that this technology remains safe and trustworthy as it’s deployed in the real world.

What skills are needed for your role? How did you acquire the skills?

The role requires a solid technical foundation: knowledge of basic electronics, a good understanding of system design and PCB design, proficiency with simulation software tools, and hands-on experience working with high-voltage electrical equipment.

Beyond technical know-how, certain personal qualities are equally essential — a positive attitude, a willingness to learn by doing, the humility to make mistakes and learn from them, adaptability, and above all, genuine passion for electronics. Since my day-to-day work takes place in laboratories dealing with high AC and DC voltages of up to 1500V, safety consciousness and attentiveness are non-negotiable. Testing new systems inherently means working in complex, evolving conditions where behaviour can deviate from nominal operating parameters, so engineering awareness and sound judgment under uncertainty are just as critical as technical skill.

What’s a typical day like?

A typical day starts with checking important emails and reviewing pending tasks, which I then prioritize based on urgency and impact. I follow this with a discussion with my team to allocate tasks, address bottlenecks, and align on priorities for the day. A significant part of my day is then spent in the laboratory alongside colleagues, working through carefully planned tests on the system. Beyond these core activities, my role also involves staying connected with emerging technologies and industry trends — this means regular communication with suppliers and semiconductor manufacturers, as well as attending seminars and technical trade fairs around the world to keep pace with the latest developments in the field.

What is it you love about this job?

What I love most about this job is the complete ownership and freedom I’ve been given — not just in product development, but across the entire product lifecycle. I’ve had the opportunity to be involved from the earliest stages of concept and design, through prototyping and testing, all the way to iterative improvements, production planning, and final serial release. Being trusted with this end-to-end involvement rather than being confined to a single stage has been incredibly rewarding – it lets me see how early design decisions ripple through to manufacturing and real-world performance, and it keeps the work varied, challenging, and genuinely engaging every step of the way.

How does your work benefit society?

I firmly believe that electrification is the future, driven by the increasing integration of renewable energy sources. Wind and solar have become central to the shift away from fossil fuels, but they share a fundamental limitation: intermittency. The wind doesn’t always blow and the sun doesn’t always shine, which means these sources produce power unpredictably rather than on demand — a mismatch that creates real challenges for grid operators who need supply to match demand in real time. This gap can be addressed through large-scale integration of Battery Energy Storage Systems (BESS), alongside the adoption of electric vehicles as an alternative mode of transportation that further reduces reliance on fossil fuels. Enabling all these key technologies, however, depends on efficient “power conversion systems”, which form the critical link connecting renewable energy generation, battery storage, and electric vehicles into a cohesive, reliable ecosystem. My work in developing and optimizing these power conversion systems directly supports this transition — making renewable integration more viable, storage more efficient, and e-mobility more accessible. In doing so, it contributes to a broader societal shift toward a cleaner, more resilient, and sustainable energy future.

Tell us an example of a specific memorable work you did that is very close to you!

I’d like to share two experiences that remain close to my heart. The first dates back to my time as Lead Engineer at Knorr-Bremse Powertech, where I played an instrumental role in the development, validation, and verification of an Auxiliary Power Converter for railway traction applications, built on a DC bus concept. What made this project particularly memorable was its scope — the converter was originally engineered in Germany but designed for the Chinese market, which meant the work didn’t end at development. It extended into a full localization effort, where I worked closely with the engineering team to identify and validate Chinese alternative materials, ensuring the product remained both technically robust and commercially viable in its new market. Leading a cross-functional team of 15 members across this project was an experience, but what I remember most vividly is the role I took on as a bridge between our German and Chinese teams — not just technically, but culturally and linguistically. Engineering challenges are one thing, but navigating differences in communication styles, work culture, and decision-making approaches between two very different professional environments requires patience, empathy, and constant translation — not just of language, but of intent and expectation.

Secondly, as a Senior Development Engineer at Stercom, I was part of the team that embarked on an entirely new product development journey — the On-Board Charger (OBC). I joined this effort in early 2019, when it was still just a handful of engineers working to bring this power converter system to life. The path ahead was anything but straightforward: we were navigating through immense complexity, pushing for a smaller form factor, working at high switching frequencies, and designing for multiple grid compatibility as a “Universal Charger”. It was a journey defined by constant learning, unlearning, and relearning — making changes, refining our approach, and continuously improving with every iteration. That perseverance paid off — the product has been in commercial production since 2022, a milestone that stands as one of the proudest achievements of my career. Its success in the market also opened the next chapter for me: I was entrusted with the next task within the hardware team, and since 2023, I have continued this journey as Technical Hardware Lead, now driving the development of the bidirectional On-Board Charger (OBC V2X). Looking back, this project has been as much about personal growth as technical achievement — starting as one engineer among a small, determined team, and evolving into a leadership role shaping the next generation of the very product I helped bring into existence.

Your advice to students based on your experience?

My advice to students would be this: First, follow your passion — choose a path that genuinely excites you, because that curiosity will carry you through the difficult days. Second, never neglect the basics — no matter how advanced technology becomes, a strong foundation in fundamentals is what allows you to understand and adapt to anything new. Third, don’t be afraid to make mistakes; they are often the best teachers, and the lessons you learn from failure tend to stick with you far longer than the ones you learn from success. Fourth, stay updated — keep sharpening your skills in line with current trends and emerging technologies, because the world keeps changing and so should you. And finally, think beyond the immediate task — learn to scale your work and your thinking, so that what you build today can grow into something bigger tomorrow.

Future Plans?

Looking back on my journey, I realize it began years ago when I left India carrying a simple yet powerful aspiration — to learn, to grow, and to immerse myself in new technologies and a new culture. That aspiration led me to Germany, where I pursued my master’s studies and have since spent more than 15 years building my professional career. Yet, through all these years, I carried within me a quiet awareness that my time here was always transitional in nature rather than permanent — a chapter meant to shape me for something greater, rather than an ending in itself. Germany has given me invaluable technical expertise, a disciplined engineering mindset, and exposure to some of the most advanced technologies in the world, but more than that, it has shaped how I think, how I adapt, and how I approach problems. Now, I feel it is time to complete the circle — to return to India and give back to my home country the knowledge, skills, and lessons this journey has gathered in me. I see this not as a conclusion, but as the next meaningful chapter in my professional leadership path: one where continuous learning meets purposeful contribution, and where I can help shape the future of my homeland with everything I have learned abroad.