IN Brief:
- The work uses commercial 3.3kV SiC half-bridge modules in a bidirectional solid-state circuit breaker design.
- Target applications include DC microgrids, energy storage, vehicle-to-grid systems, and medium-voltage DC infrastructure.
- Protection technology is becoming a central design constraint as high-voltage DC architectures move into data centres and industrial power systems.
The University of Arkansas has validated a bidirectional solid-state circuit breaker architecture using commercial half-bridge silicon carbide modules, advancing protection options for medium-voltage DC systems, grid-connected storage, renewable integration, and vehicle-to-grid infrastructure.
The design uses 3.3kV SiC half-bridge modules to support fast interruption of DC faults while allowing power flow and protection in both directions. That bidirectional capability is becoming more important as electrical systems shift from one-way distribution toward dynamic flows between storage, renewable generation, loads, and the grid.
Unlike AC systems, DC networks do not provide a natural current zero crossing to help interrupt a fault. Mechanical breakers can therefore face challenges around arcing, interruption time, contact wear, and let-through energy. Solid-state circuit breakers can act much faster, although their use introduces trade-offs around conduction loss, heat dissipation, sensing, control coordination, and fail-safe behaviour.
Silicon carbide is well suited to the protection role because it supports high-voltage, high-speed switching with lower losses than many silicon alternatives. In a circuit breaker, that speed affects how quickly fault current can be contained and how much energy reaches downstream electronics before the system is isolated.
Medium-voltage DC protection is becoming more urgent as power architectures change. Battery energy storage, renewable integration, EV charging, DC microgrids, marine power, and data-centre distribution are all increasing the need for fast, controllable DC fault isolation. In many of those applications, power can move in either direction depending on operating state, which makes unidirectional protection increasingly limiting.
Components such as Microchip’s 3.3kV SiC modules for medium-voltage power conversion are already supporting higher-density conversion in industrial and infrastructure systems. Protection has to advance alongside conversion, since higher-voltage DC distribution is only practical when faults can be detected, isolated, and coordinated quickly enough to preserve equipment and uptime.
Using commercial half-bridge modules gives the work a practical design path. Rather than relying solely on specialised laboratory devices, the architecture draws on module technology already moving toward industrial power applications. That makes it more relevant to engineers evaluating how solid-state protection could be implemented within available module ecosystems.
There are still design challenges. Solid-state breakers must manage continuous conduction losses during normal operation, thermal stress during interruption, and coordination with upstream and downstream protection. Gate-drive design, current sensing, snubber networks, and control algorithms all influence performance. In safety-critical installations, the breaker also has to fail predictably under abnormal conditions.
As higher-voltage DC moves into energy storage, data centres, charging infrastructure, and industrial power systems, protection will become a central part of the electrical architecture. Conversion efficiency and power density may drive the move to DC, but fast and reliable fault isolation will determine how far those architectures can be deployed at scale.
