Rockwill × PCsemic SST Solution—MV/HV Manufacturing Expertise Driving the Third-Gen Semiconductor Revolution

Deep Penetration of the ANSI/IEEE Market: Capabilities and Track Record

Rockwill has comprehensive custom design, manufacturing, and testing capabilities for the North American standard market, fully compliant with ANSI C57, IEEE, CSA, DOE 2016, and other standards.

Core ANSI Standard Products

• Pad-Mounted Transformers (75 kVA–5,000 kVA): Meet ANSI C57 and DOE 2016 efficiency requirements; Zone 4 seismic qualification; withstand -40°C to +50°C; pass ASTM B117 salt spray testing; integrated high-voltage fuses, switches, and elbow connectors; support safe live operation.

Single Phase Pad Mounted Transformer for North American residential subdivisions

• Single-Phase Pole-Mounted Transformers: Compliant with ANSI/IEEE standards; input voltage fluctuation ±10%, output accuracy ±3%; designed for 120/240 V residential supply in the US. Fe-based amorphous alloy core reduces core loss by 70%–80% compared to silicon steel — a 10 kVA transformer saves approximately 1,000 kWh per year.

Pole Mounted Single Phase CSP Transformers 6kV 13.2kV 13.8kV

• Step Voltage Regulators (RVR-1 Type AVR): Passed ANSI C57.15 full type tests; electrical/mechanical life of 1 million operations; regulation range ±10%, step size 0.625% or 1.25%; single-phase 32-step fine regulation; supports pad-mounted, substation, or pole-mounted installation.

Single Phase Automatic Voltage Regulator 7.62 kV 13.8 kV 19.92 kV 34.5 kV

• Industrial Three-Phase Power Transformers (up to 360 MVA): Compliant with ANSI/IEEE C57.110 for harmonic-resistant design; available with IP55/C5-M corrosion protection and ONAN/ONAF cooling.

Neutral Grounding/earthing Transformer Dry Type Power Transformer direct supply

• ANSI Earthing Transformers (22 kV–66 kV): Zig-zag winding configuration, providing a stable neutral point for ungrounded systems.

Customization 15kV 30kV 33kV 34.5kV 36kV Three Phase Neutral Grounding/earthing Transformer direct supply

Competitive Advantages

With the US transformer market facing supply-demand tightness, Rockwill leverages digital manufacturing and a factory-direct model to deliver highly competitive, fast-response products. The products are CSA, ANSI C57, and DOE certified, featuring ultra-low losses, noise levels below NEMA standards, and 150% emergency overload capacity.

Performance Highlight

On July 12, 2025, 36 units of ANSI-standard AVRs (400 A) passed Factory Acceptance Testing (FAT), receiving a "very satisfied" rating from the customer. They fully passed ANSI C57.15 type tests, strongly validating Rockwill's engineering delivery capability and quality reliability in the ANSI market.

Since 2019, Rockwill has been strategically investing in Solid-State Transformers (SST). Facing the extreme load demands of new power systems and AI computing centers, Rockwill has adopted a dual-track strategy: "in-house system-level solutions + external expansion into key materials and devices." In the SST domain, Rockwill partners with PCsemic to jointly develop a full product series and solutions, achieving global coverage of grids, frequencies, and voltage ranges.

Global Application Coverage

Rockwill and PCsemic's jointly developed SST is compatible with 50/60 Hz grid frequencies. The MV side covers global typical distribution voltages including 10 kV, 13.8 kV, 20 kV, 33 kV, and 35 kV (with upward scalability). The LV side provides 400 V AC, 480 V AC, 800 V DC, and other outputs — fully adaptable to IEC, ANSI/IEEE, GB, and other major standards. This enables "one unit, global compatibility." Key scenarios:

• North America & IEEE Markets: 60 Hz grids — providing MV-to-800 V DC high-efficiency power supply for AI computing centers and industrial/commercial parks.
• Europe & IEC Markets: 50 Hz grids — providing intelligent grid interconnection interfaces for distributed renewable energy and EV charging infrastructure.
• Southeast Asia, Africa & Belt & Road Emerging Markets: Compatible with 11 kV and 33 kV — providing microgrid, voltage support, and black start functionality for weak grid regions.
• Global Renewable Energy Bases: Direct connection to 35 kV or 33 kV collector lines — performing millisecond-level reactive power compensation, harmonic filtering, and bidirectional power flow control, improving renewable energy utilization and generation revenue.

Joint Development & Performance

Rockwill provides grid application scenarios and system validation platforms, while PCsemic contributes core power devices and packaging technology. Together, they have developed a fully solid-state Power Electronic Transformer (PET).

• Architecture: SiC MOSFET + nanocrystalline magnetic core, AC-DC-AC three-stage topology, millisecond-level dynamic response.
• Performance: Full-load efficiency 99.1%; no-load loss reduced by 81%; THD <1.5%; features active filtering, zero-voltage ride-through, black start, and ±100% continuous reactive power compensation.
• Field Validation: Wind farm curtailment rate reduced by 12%; PV plant STATCOM reactive support at night, 7%–15% generation revenue improvement during daytime.

Key Materials and Devices — Independent Capability

PCsemic is a Rockwill strategic investee, focused on SiC, GaN, and other third-generation semiconductors. It spans the entire chain from "materials → chips → devices → systems," with a CNAS-accredited laboratory and a national post-doctoral workstation (10 post-docs currently, 7 full-time). Core achievements:

• World-leading Nano Copper Paste: Independently developed — the world's only mass-produced and vehicle-qualified pressure-sintered nano copper paste. Sintering at 200°C / 5 MPa within 5 minutes. Cost 70% lower than imported silver paste; 100% domestically sourced raw materials; power module lifespan extended by over 30%. Now expanded into PV inverters, energy storage, low-altitude aircraft, AI servers, and other fields — with a long-term market size reaching tens of billions.
• Device Product Line: Covers SiC-SBD, SiC-MOSFET, IGBT modules, and nano silver solder paste. Has launched the first domestically mass-produced portable SST mobile power station, sold to more than 20 countries, validating multi-country grid environmental adaptability.

The Disruptive Potential of SST

• Restructuring Power Supply Logic: SST evolves from a fixed-ratio passive device into an "all-in-one" intelligent energy terminal — achieving millisecond dynamic response, active harmonic filtering, bidirectional power flow, and reactive power compensation.
• Ultimate Solution for AI Computing Centers: Single-rack power is approaching 1 MW. Traditional power supplies face three bottlenecks: current density, losses, and volume. SST directly converts 10 kV MV to 800 V DC — system efficiency 98.5%, volume reduced by over 60%, copper consumption reduced by approximately 45%. NVIDIA's white paper explicitly requires SST for next-generation AI computing centers; China's MIIT and other ministries have included it in key promotion equipment.
• Reshaping Industry Structure: SST eliminates redundant traditional distribution and UPS hardware, pushing manufacturers toward modular system integration upgrades — order value multiplies, and distribution channels move "outside the wall" to "inside the server room."
• Market Inflection Point Has Arrived: The global SST market was approximately $169millionin2024,projectedtoreach$936 million by 2030 (CAGR 32%). The Chinese market is expected to grow from approximately ¥10 billion in 2026 to over ¥100 billion by 2030. By end of 2026, all new AI computing centers built by China's top 10 cloud providers will fully adopt "SST + HVDC," with penetration exceeding 30%. North America, Europe, and Southeast Asia are simultaneously entering their technology transition windows.

Rockwill and PCsemic have formed a complete closed loop of "materials → chips → devices → systems" in the SST field. Driven by both system-level solutions and core material/device capabilities, Rockwill is evolving from a power equipment supplier into a global smart energy router and ecosystem builder.

Summary

Rockwill possesses world-class manufacturing capabilities in medium and high voltage transformers, with unit capacities ranging from 3 kVA to 360 MVA and ANSI market track record validated by authoritative customers. At the same time, the company has strategically positioned itself in the solid-state transformer and third-generation semiconductor industry chain. Partnering with PCsemic to jointly develop a full SST product series, with independent breakthroughs in key materials and devices, the product line comprehensively covers global grid frequencies and mainstream distribution voltages, adapting to IEC, IEEE, GB, and other international standards. Through this dual-wheel drive model, Rockwill is accelerating its transformation into a global smart energy router and ecosystem builder, delivering efficient and reliable power conversion solutions to the world.