⚡ Grid

Solid-State Transformers


Solid-State Transformers (SSTs) are advanced, power-electronics-based replacements for conventional transformers. More than just voltage converters, SSTs are intelligent energy routers capable of real-time voltage and frequency regulation, AC/DC transformation, bidirectional flow control, and embedded grid protection.

SSTs bridge AC legacy systems with DC-native future applications, and integrate seamlessly with digital twins, cybersecurity protocols, and real-time optimization layers. As grid systems evolve to accommodate renewable generation, energy storage, EV infrastructure, and DC-native loads, SSTs offer a modular, programmable foundation for building flexible, efficient, and resilient power distribution architectures.

SST Advantages

SST transformers offer several clear advantages over their traditional analog counterparts:

  • AC/DC Interfacing: Multi-port AC/DC/LVDC possible.
  • Programmability: Software-defined setpoints and control.
  • Real-Time Monitoring: Built-in sensors, telemetry, and diagnostics.
  • Protection: Active fault detection and fast isolation integrated in unit.

  • Size & Weight

    : Compact, modular (higher power density).

Technology Components

  • High-Frequency Transformers: Reduce size/weight and enable rapid switching.
  • Modular Multilevel Converters (MMC): Provide scalable voltage/power control.

  • Wide-Bandgap Semiconductors (SiC/GaN)

    : Enable higher switching speeds and efficiency.
  • Integrated Protection & Telemetry: Real-time diagnostics, remote reconfiguration.
  • Communication Interfaces: Compatible with SCADA, DERMS, and digital twins.

Emerging Architectures

  • Solid-State Substations: Replacing all passive transformers and switchgear with SSTs and solid-state circuit breakers.
  • MVDC Feeders: SSTs used at MVAC/MVDC interconnect points in flexible distribution loops.
  • DC Distribution Zones: SSTs powering localized LVDC networks in buildings, data centers, and ports.
  • Hybrid AC/DC Microgrids: Multi-port SSTs managing diverse energy flows across grid-forming and grid-following resources.

Current Technical Limitations

SSTs show great promise, but several challenges limit their widespread deployment today:

  • Voltage range – Most SSTs are limited to about 15 kV input and 1.5 kV DC output. High-voltage versions for HVDC or large substations are still in R&D.
  • Power rating – Commercial systems are typically in the 100 kVA to 2.5 MVA range, far below conventional transformers that can scale to hundreds of MVA.
  • Cost and maturity – SSTs are considerably more expensive than legacy transformers, and deployments are still limited to pilots and demonstration projects.
  • Thermal management – High switching frequencies require advanced cooling techniques to prevent overheating.
  • DC fault protection – Handling arcing and isolating faults on DC buses is technically more complex than in AC systems.

  • Interoperability

    – A lack of industry standards makes integration across different vendors and architectures challenging.

Vendors and Pilots

Several vendors and startups are leading SST development and deployment:

  • Hitachi Energy – Developing power electronics-based platforms and MVDC pilots for utilities.

  • Siemens Energy

    – Focused on SSTs for distribution grids and urban energy systems.
  • Eaton – Targeting SSTs for EV charging depots, DER-rich feeders, and integration with solid-state breakers.
  • ABB – Piloting SST solutions for marine applications, campus microgrids, and industrial power systems.
  • STMicroelectronics and Wolfspeed – Providing silicon carbide (SiC) and gallium nitride (GaN) semiconductors that enable SST switching performance.
  • Heron Power – A new entrant founded by ex-Tesla executive Drew Baglino, building medium-voltage SSTs for data centers, EV infrastructure, and utility modernization (first production line targeted for 2027).



Software Solutions