Power Electronics Engineer

About Helion We are a fusion power company based in Everett, WA, with the mission to build the world's first fusion power plant, enabling a future with unlimited clean electricity. Our vision is a world with clean, reliable, and affordable energy for everyone. Since Helion's founding in 2013, we have raised over $1 billion from long-time investors such as Sam Altman, Mithril, and Capricorn Investment Group as well as new investors SoftBank and Lightspeed to propel us forward. Our last prototype, Trenta, completed 10,000 high-power pulses and reached plasma temperatures of 100 million degrees Celsius (9 keV). We are now operating Polaris, our next prototype on the path to the world's first fusion power plant. This is a pivotal time to join Helion. You will tackle real-world challenges with a team that prizes urgency, rigor, ownership, and a commitment to delivering hard truths – values essential to achieving what no one has before. Together, we will change the future of energy, because the world can't wait. What You Will Be Doing: You will play a critical role in supporting the core electrical energy management systems that power our fusion generators. Our work spans pulsed power delivery to magnetics, power electronics and fusion energy recovery, low voltage controls and networking, and precision sensing in electrically noisy environments. We look for strong electrical engineers who bring deep expertise in a few areas and give them real ownership immediately. You’ll focus on the areas where your strengths drive the most impact today, while gaining hands-on opportunities to grow into expanded scopes and solve system-level challenges. Focus Areas: 1. High Voltage/Pulsed Power Systems - Design, test, troubleshoot, support, and scale high-voltage systems for driving pulsed magnetic coils (1<ms) at currents up to 5MA and voltage up to 40kV - Evaluate and apply solid-state switching devices (IGBTs, MOSFETs, SCRs/thyristors) with attention to losses, protection, di/dt, dv/dt, and thermal performance - Specify and integrate high energy components (capacitors, switches, pulse forming networks, buswork, protection, grounding) 2. Power Electronics - Design, test, scale, and integrate DC/DC, AC/DC, DC/AC converters used for energy delivery, energy recovery, and distribution ranging from hundreds of volts to thousands of volts - Develop switching-stage designs including half/full bridges, phase-shifted/full-bridge, LLC/series-resonant, or buck/boost-derived converters (topology selection based on efficiency, controllability, and fault behavior) 3. Low Voltage Control and Diagnostics - Design low voltage control electronics and PCBAs that interface with high energy systems - Own schematic capture and support layout, help scale PCBA deliveries to tens of thousands of boards - Build analog front ends for current/voltage/field/temp and other diagnostics: amplification, filtering, isolation, ADC interfacing - Ensure measurement integrity in high EMI environments (noise mitigation, grounding, shielding, calibration strategies) - Partner with firmware/software teams on acquisition requirements and data quality Required Skills: - 2+ years experience in power electronics, solving complex electrical engineering problems from design to delivery - Bachelor’s or Master’s level degree in Electrical Engineering, Physics, or a related technical field - Demonstrated strength in at least one of the focus areas above - Hands-on troubleshooting ability with standard lab equipment (oscilloscope, DMM, power supplies, loads, function/pulse generators, etc) - Comfortable working in high-energy or electrically noisy environments with strong safety mindset and disciplined documentation - Experience with Microsoft Suite, LTSpice, SIMetrix/SIMPLIS, Simulink, Python, and/or MATLAB #LI-Onsite #LI-KL1 Benefits Our total compensation package includes benefits, including but not limited to: • Medical, Dental, and Vision plans for employees and their families • 31 Days of