Lead Power Electronics Engineer – High-Power Inverter Systems

About the role

Sapphire Technologies delivers power and cooling to energy infrastructure. Our FreeSpin® In-line Turboexpander recovers the energy wasted when high-pressure gas is stepped down, converting it into clean electricity and low-temperature cooling. To better serve our customers in the data center industry, we are now expanding our high-speed turbomachinery offerings into oil-free compressors for chilling applications. Our hands-on engineering team takes products from concept to field deployment, with work spanning rotating machinery, power electronics, controls, and systems integration. We are a mission-driven organization with one common goal: building a more sustainable world. Our employees are our biggest asset, and we are looking for change agents to join us on our journey.

Position Summary: Sapphire Technologies is seeking a Lead Power Electronics Engineer to lead the architecture, development, validation, and production launch of advanced inverter systems for high-speed rotating machinery. The role will support a major new product platform serving rapidly growing data-center infrastructure applications. The system integrates high-power electronics, high-speed electric machines, active magnetic bearings, liquid cooling, controls, and precision electromechanical hardware and is expected to undergo a significant production scale-up. This is a hands-on technical leadership role with primary responsibility for inverter system architecture, power-stage design, cost reduction, design for manufacturing, thermal integration, validation, and certification readiness. The successful candidate will work closely with mechanical, controls, manufacturing, supply chain, certification, and Calnetix engineering teams. Hands-on laboratory and prototype-development work is required. Approximately 10% travel may be required for suppliers, certification testing, customers, commissioning, or field support.

Responsibilities

• Serve as Sapphire’s primary technical authority for the inverter system.
• Translate system and customer requirements into inverter architecture, technical specifications, and interface requirements.
• Lead topology selection and trade studies involving: Semiconductor technology and switching frequency, Switching and conduction losses, Harmonic performance and filter losses, Efficiency, power density, thermal margin, cost, and manufacturability.
• Lead the design and validation of power stages, gate drives, DC-link systems, filters, sensing, protection circuits, bus structures, and high-power interconnections.
• Define and manage electrical, mechanical, and thermal interfaces, including water-cooled cold plates, coolant requirements, pressure-drop constraints, and component junction-temperature limits.
• Drive cost reduction through architecture optimization, component standardization, supplier engagement, value engineering, and design for manufacturing and assembly.
• Coordinate with Sapphire’s certification engineer and external certifying bodies to ensure compliance requirements are incorporated into the design early.
• Support EMC/EMI, electrical safety, environmental, and applicable UL and IEC certification testing.
• Define production-test requirements and support new-product introduction, supplier qualification, and manufacturing scale-up.
• Support root-cause investigations for production and field issues.
• Mentor engineers and manage technical work performed by contractors and external development partners.

Requirements

• Masters degree in Electrical Engineering with emphasis in power electronics or equivalent experience, similar degree is