Power Electronics Engineer

About Thea Energy:
Thea Energy is leveraging recent breakthroughs in stellarator physics and engineering to create a faster and simpler approach to commercializing fusion energy. The company is reinventing the stellarator using computer-controlled arrays of planar coils thereby replacing the intricate, complex modular magnets required in all other stellarator architectures. Thea Energy is on a mission to create a limitless source of zero emission energy for a sustainable future.

Position Overview:
Thea Energy is seeking a Power Electronics Engineer to design and develop the HTS magnet power supply systems for the company’s Eos integrated stellarator. This role focuses on building a high-current AC-DC converter for HTS magnets, requiring precision current regulation, high reliability, and scalable architecture.

This role will be responsible for power stage design, topology selection, control algorithm interface, and protection systems, as well as thermal and mechanical integration. This is a high-impact engineering role with hands-on prototyping, testbed validation, and cross-functional collaboration with embedded systems and instrumentation teams.

As part of a rapidly growing team, you’ll be part of the organizational build-up of a leading fusion energy company. This role will have a high degree of autonomy and must be able to move quickly. The Thea Energy team is comprised of self-motivated, creative, and fun individuals with an excitement for solving complex problems.

Key Responsibility Areas::
• Lead the topology selection, component specification, and schematic design of the HTS Magnet PSU.
• Design modular power converters with potential for arrayed operation and independent control.
• Analyze and simulate power converter behavior (steady-state, dynamic, fault response) using PLECS, LTspice, or Simulink.
• Integrate with embedded control hardware and firmware, ensuring proper current regulation, fast feedback, and fault handling.
• Define and implement magnet protection mechanisms, including overcurrent shutdown, fast discharge, and crowbar circuits if needed.
• Design thermal management systems, including heat sink layout, forced air/water cooling, and temperature monitoring for continuous operation.
• Design PCB layout and support mechanical integration, cabling, and in-house assembly.
• Develop test plans and perform hardware bring-up, debugging, and parameter optimization under staged load conditions.

Ideal Experience & Skillsets::
• Bachelor’s or Master’s degree in Electrical Engineering, Power Electronics, or a related field.
• 5+ years of hands-on experience designing and testing power converters, preferably in high-current or magnet power supply applications.
• Proficiency in power stage design for DC/DC converters, buck/boost, full-bridge, or current-regulated linear stages.
• Strong simulation and modeling skills using tools such as PLECS, LTspice, PSIM, Simulink, or Simplorer.
• Experience with IGBTs, MOSFETs, SiC/GaN devices, and high-current busbar and interconnect layout.
• Familiarity with current sensors, signal conditioning, and analog control circuits.
• Experience with magnet power supplies, fusion, accelerator, or industrial high-current systems.
• Knowledge of quench detection, crowbar protection, and superconducting magnet interface requirements.
• Experience with thermal design and integration of cooling solutions in power electronics.
• Exposure to EMI/EMC mitigation strategies and compliance testing.
• Familiarity with FPGA- or DSP-based digital control systems.
• Simulation: PLECS, LTspice, PSIM, Simulink.
• CAD: Altium Designer, OrCAD.
• Measurement: Oscilloscopes, Power Analyzers, Electronic Loads.
• Communication: CAN, RS-485, Modbus.
• Thermal: Flotherm, SolidWorks for mechanical integration.

Company Benefits::
• Salary range $95,000-$160,000
• Comprehensive health benefits (e.g. medical/dental/vision)
• Employee equity stock options
• 20 days PTO

Requirements::
• Ability to occasionally lift up to 50 lbs.
• Ability to perform activities such as typing, standing, or sitting for extended periods of time.
• Willingness to occasionally travel or work required nights/weekends/on-call.
• Ability to work in a facility that contains industrial hazards including heat, cold, noise, fumes, strong magnets, high voltage, high current, pressure systems, and cryogenics.

It’s not necessary to meet all of the skillsets outlined above. Please feel free to send us a note and tell us why you would still be a great fit for this role or Thea Energy.

Diversity and Inclusion:
Thea Energy is an equal opportunity employer committed to creating a company of diverse backgrounds. By creating a diverse environment, we will bring new ideas and approaches to solving some of the world’s hardest (and most important) problems. All qualified applicants will receive consideration for employment without regard to race, color, religion, sex, gender, sexual orientation, gender identity or expression, national origin, family or marital status, age, disability, veteran’s status, or other characteristic protected by applicable laws and regulations.