About H-55

As the technological spin-off of Solar Impulse, the first electric airplane to fly around the world, the mission of H55, is to make aviation clean, safe, and affordable.

The company’s strengths and competencies lie in developing propulsion and energy storage solutions which are modular, lightweight, and certifiable.

Having integrated and flown 4 electric airplanes, the Swiss start-up has been selected by Pratt & Whitney Canada to provide the battery pack for its regional hybrid-electric flight demonstrator. This recent announcement is a further illustration of H55’s position as a major enabler in the electric commuter market.

About the role
We are looking for a Hardware Power Electronics Engineer to join our innovative team as we continue to drive advancements in electric propulsion systems for aerospace applications. In this role, you will play a critical role in the design, analysis, test and certification of power electronics hardware for high-efficiency electric drive systems (EDS), adhering to aerospace standards such as DO-178C, DO-254, and ARP4754A. You will contribute to the development of cutting-edge power conversion systems and drive electronics, focusing on high-reliability hardware design, testing, and system integration for electrified propulsion.
Specifically, you will be responsible for:

• Power Electronics Design & Optimization: Design and develop power electronics hardware (e.g., converters, gate driver, EMI filters, DC/DC power module architecture, digital/analogic circuits) to optimize performance for electric drive systems while ensuring compliance with DO-160 and MIL-STD-704 standards.
• Component Selection and Circuit Design: Select appropriate components and perform detailed circuit design for high-voltage and high-power systems. You will be deeply involved in schematic design, PCB layout, and design for manufacturability (DFM).
• Testing and Validation: Conduct testing at board level, provide support during item integration and work closely with the testing team to validate and verify hardware performance under various operational conditions. Define test procedures for V&V, perform debugging, and troubleshoot hardware issues to ensure reliability.
• Certification and Compliance: Collaborate with the certification team to ensure hardware meets EASA CS-23, CS-25, and FAA Part 23 standards. Contribute to rigorous verification and validation (V&V) processes according to DO-254 and ARP4754A requirements.
• Documentation: Develop and maintain detailed technical documentation, including Interface Control Documents (ICDs), Failure Mode and Effects Analysis (FMEA), test plans, and results reports (QTP, VTP) in compliance with AS9100 standards.
• System Integration: Work closely with cross-functional teams, including software, control systems, and mechanical engineers, to integrate power electronics within the broader electric drive system.
• Continuous Improvement: Participate in continuous improvement initiatives to enhance power electronics hardware reliability, efficiency, and performance.

• Education: University degree in Electrical Engineering, Power Electronics, or a related field.
• Experience: 5+ years of experience in power electronics hardware design, high-power system development, or electric drive systems, preferably in aerospace, automotive, or eVTOL applications.
• Knowledge about state-of-the-art conversions structures, understanding of switching mechanism in power transistors, EMI filter selection, gate driver design, low-level sensors driving and formatting circuits
• Profound understanding of various PCB manufacturing technologies and awareness about their associated constraints (Classic PCB, HDI, flex, rigid-rigid flex, heavy copper…)
• Being able to design digital and/or analogue circuits while providing design justification evidences (Design report, worst case analysis, part stress analysis,…)
• Strong expertise in component selection, PCB layout, and thermal management for high-power applications.
• Good experience with lab equipment (Oscilloscope, power supplies, active loads, network analyzer, hi-pot testing …)
• Familiarity with aerospace and safety standards (e.g., EASA, FAA, DO-254, DO-160) is an advantage
• Proficiency in simulation and modeling tools such as SPICE, MATLAB/Simulink, PLECS.
• Proactive, solution-oriented mindset with strong problem-solving skills and an ability to work collaboratively in cross-functional teams.
• Keen to learn from others and to educate others
• Excellent technical documentation and communication skills.
• Languages: Fluency in English is required; proficiency in French is a plus.

What we offer

• An amazing work Location in Sion, Valais in the heart of Swiss Alps.
• A highly dynamic and multicultural environment where you can grow and learn by working on ambitious challenges to shape the future of Electric Aviation.
• We offer a position which contributes to valuable and impactful work in a stimulating an international environment

Sounds interesting? We look forward to meeting you!

H55 is an equal opportunity employer and welcomes applications from all qualified individuals regardless of race, sex, disability, religion/belief, sexual orientation or age. All aspects of employment including the decision to hire, promote, discipline, or discharge, will be based on competence, performance, and business needs.