IN Brief:
- SolarEdge and Infineon are extending their data-centre power work into 800VDC solid-state circuit breakers.
- SolarEdge will design the protection system around Infineon CoolSiC JFET switching technology.
- The breaker layer is intended to provide fast DC fault isolation within a grid-to-rack power architecture.
SolarEdge and Infineon are extending their collaboration into solid-state circuit breakers for 800VDC distribution in AI and hyperscale data centres, addressing the fault-protection layer between high-voltage conversion equipment and increasingly power-dense compute racks.
SolarEdge is leading the circuit-breaker design, with Infineon supplying CoolSiC JFET technology for the switching devices. The companies are positioning the work within a wider DC power chain running from medium-voltage grid input through conversion, distribution, protection, and the rack.
Fault interruption becomes more demanding as DC voltage and power density increase. Alternating current naturally passes through zero during every cycle, helping conventional interruption equipment extinguish an electrical arc. DC has no equivalent regular zero crossing, so mechanical interruption has to control the arc while disconnecting the faulty circuit rapidly enough to limit damage.
The proposed solid-state breaker removes the need to wait for mechanical contacts to separate. SolarEdge and Infineon say the architecture is intended to interrupt faults within a few microseconds, using semiconductor switches to isolate a section of the distribution network electronically.
Infineon’s CoolSiC JFET devices are central to that approach, with SolarEdge integrating them into the protection architecture. The design has to combine low conduction loss during normal operation with fast switching during a fault, while remaining capable of withstanding the electrical and thermal stress generated when a high-power DC circuit is interrupted.
Shuki Nir, Chief Executive Officer of SolarEdge, said: “High-density AI infrastructure at 800 VDC demands uncompromising efficiency and protection.” Raising distribution voltage reduces current for a given level of power, but it also places greater demands on insulation, protection coordination, switching hardware, and fault management.
The breaker programme follows earlier SolarEdge work on a solid-state transformer using Infineon silicon carbide devices. That system is designed to convert medium-voltage inputs between 13.8kV and 34.5kV directly to between 800VDC and 1,500VDC at more than 99% efficiency, reducing the number of conversion stages before power reaches downstream equipment.
Infineon is tackling neighbouring data-centre power constraints through other partnerships. Its recent work with Skeleton Technologies combines solid-state transformer technology with supercapacitor systems intended to improve conversion efficiency and cope with rapid load changes. The SolarEdge collaboration addresses the separate task of fault interruption after conversion.
Semiconductor protection introduces its own design penalties. Solid-state switches conduct continuously while the circuit is operating, generating heat and conduction loss that mechanical contacts largely avoid once closed. Gate drive, fault sensing, parasitic inductance, packaging, thermal management, and protection algorithms therefore become part of the breaker rather than supporting circuitry around a mechanical device.
Coordination is another constraint. A fast breaker has to identify the correct fault and isolate the appropriate section without unnecessarily disconnecting healthy downstream or upstream equipment. In large data centres, where power infrastructure is increasingly modular, the value of microsecond switching depends on selectivity and predictable behaviour across the wider protection system.
SolarEdge and Infineon have not disclosed interrupting-current ratings, qualification schedules, commercial deployment dates, or a production configuration. Those specifications will determine where solid-state protection can displace or complement established mechanical devices. The collaboration nevertheless addresses a defined engineering gap in 800VDC distribution: efficient conversion alone is of limited value if high-energy DC faults cannot be isolated quickly and selectively.
