Senior 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 $1.5 billion from long-time investors such as Sam Altman, Mithril, and Capricorn Investment Group as well as new investors including Thrive Capital, LightSpeed Venture Capital, SoftBank, and others to propel us forward. Our current prototype, Polaris, has reached record-breaking plasma temperatures of 150 million degrees Celsius (13 keV). Helion is continuing to iterate and on the path to the world's first fusion power plant, Orion. 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. WHY THIS ROLE MATTERS Fusion happens in the power electronics. At Helion, plasma is compressed to fusion conditions by pulsed electromagnetic fields — so the machine's performance is, quite literally, defined by the circuits that store, switch, and recover energy. The power electronics are the product, and few engineering problems anywhere carry this much weight. For a power electronics engineer, that makes this a rare kind of role. You'll take designs from concept through bring-up, commissioning, and operation on a working fusion machine — owning real outcomes, not a narrow slice of someone else's system. Small teams and fast build-test-learn cycles mean your decisions reach hardware in weeks, not years. And you'll work at a scale with almost no commercial analog: converters that move energy with near-total efficiency, and switching systems that deliver kiloamps at kilovolts in under a millisecond. If you've never worked at those extremes, that's expected — most engineers haven't. We hire strong power electronics engineers and grow them into the high-voltage and pulsed-power work. The fundamentals you already have are the foundation; the rest we build together.   WHAT YOU WILL BE DOING Our power electronics work spans three focus areas. Depending on your background, interests, and level, you may go deep in one or work across several — many of our engineers own problems that touch all three. Controls & protection for the power stage. Design the low-voltage electronics that command, monitor, and protect the pulsed-power circuits — EtherCAT-networked control boards that command charge and dump, synchronize triggering across many switches, capture high-speed diagnostics inside a high-voltage environment, and drive the fault protection that keeps a multi-megajoule system safe. This spans precision analog sensing, digital logic, FPGA-based monitoring, driver circuits, and dynamic snubbing. High voltage & pulsed power. Design, build, and commission the pulsed-power systems that compress plasma to fusion conditions — capacitor banks, switching (thyristor/SCR and solid-state), triggering, and protection at kilovolt and kiloampere scale with sub-millisecond pulses. Characterize components under real pulsed conditions and turn test data into design guidance the team relies on. Power electronics design. Design the power-conversion hardware that charges, controls, and recovers energy across the machine — high-efficiency converters, chargers, and energy-recovery circuits. Select devices, design magnetics and thermal paths, and optimize for efficiency, density, and manufacturability as we scale from prototype toward a production power plant.   REQUIRED SKILLS - A degree in Electrical Engineering or a related field, or equivalent hands-on experience. - Demonstrated experience designing and building power electronics or power-conversion hardware — from schematic through board bring-up, debug, and test. (The depth and independence we look for scale with level: from owning defined circuits and boards, to owning complex, loosely-defined systems, generating requirements for others, and setting technical direction.) - A solid grounding in power electronics fundamentals: switching topologies, semiconductor device selection (IGBTs, MOSFETs, thyristors/SCRs), gate drive, magnetics, thermal design, and loss analysis. - Proficiency with PCBA design (Altium, KiCad, or equivalent) and circuit simulation (SIMetrix, PLECS, LTspice, PSIM, or equivalent). - Strong hands-on lab skills: bench bring-up, characterization, and debugging with oscilloscopes, DMMs, and related instrumentation. - Comfort working across the hardware–firmware boundary; familiarity with real-time interfaces such as EtherCAT and with FPGA or embedded monitoring is an asset. High-voltage or pulsed-power experience is welcome but not required. We actively support strong power electronics engineers in growing into our high-voltage and pulsed-power work. Tools matter less than capability. If you've done the equivalent work in a different tool or stack, tell us — we care about what you can design and debug, not which software you learned it in. #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 PTO (21 vacation days and 10 sick days) - 10 Paid holidays, plus company-wide winter break - Up to 5% employer 401(k) match - Short term disability, long term disability, and life insurance - Paid parental leave and support (up to 16 weeks) - Annual wellness stipend Helion is an equal opportunity employer and value diversity at our company. We do not discriminate based on race, religion, color, national origin, gender, sexual orientation, age, marital status, veteran status, or disability status. 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