How does a small enterprise registered in Weng'yang, Yueqing, Zhejiang, with fewer than 80 insured employees, grow into a global energy leader operating under the brand Rockwill Electric Group—serving customers in over 100 countries?
By 2026, Rockwill pushed its product envelope to the highest industry standards: 550kV GIS (Gas-Insulated Switchgear), 550kV Dead-Tank & Live-Tank SF6 Circuit Breakers, and 500–800kV Power Transformers. Simultaneously, through a strategic partnership with PCsemic (Chongqing Pingchuang Semiconductor), Rockwill expanded into Silicon Carbide (SiC) Solid-State Transformers (SST) and third-generation semiconductor technologies.
This is the remarkable 18-year journey of Rockwill Electric.
1. "Rockwill": A Grassroots Manifesto Built on Resilience
In the group overview, founder Chen Chengming penned the founding philosophy: "The Grassroots Will of Ordinary Stones."
Reflecting on the early days, he described starting with limited resources and near-zero backing—until December 8, 2008, when Wenzhou Rockwill Electric Co., Ltd. was officially registered with a capital of 50 million RMB. The business license encompassed distribution switchgear, transformers, power engineering design, and international trade.
From day one, Rockwill aligned its product engineering with both IEC and ANSI-IEEE standards. Maintaining a humble "grassroots" mindset, the company set uncompromised quality baselines. This dual-standard commitment became its golden ticket to enter the vendor lists of national utilities worldwide, including BPDB (Bangladesh), EDCL (Rwanda), and KPLC (Kenya).
2. Starting in Medium Voltage: Evolving from Hardware to Integrated Solutions
Rockwill’s initial stronghold was Medium-Voltage (MV) power distribution:
Outdoor Vacuum Auto-Reclosers (RCW Series): Covering 6.6kV, 11kV, 15kV, 22kV, 24kV, 33kV, and 38kV.
SF6 Gas-Insulated Ring Main Units (RMU).
Oil-Immersed and Dry-Type Distribution Transformers.
Rather than getting trapped in price wars over standard commodity hardware, Rockwill pivoted to a value-driven model: Customized Engineering + Factory Acceptance Testing (FAT) + Localized O&M Training.
Early Benchmark Projects
Philippines: Mass delivery of 15kV outdoor intelligent auto-reclosers designed for industrial feeders in high-temperature, high-humidity environments. The RCW series achieved rated currents up to 1250A and breaking capacities of 25kA, fully compliant with IEC 62271-111 and IEEE C37.60.
Tanzania: Delivery of 1,500 units of 35kV oil-immersed transformers.
Kenya: Deployment of 170 sets of 11kV RCW12M auto-reclosers across urban and rural grids for millisecond-level fault isolation.
South Africa: Custom-designed 15kV oil-immersed distribution transformers.
Every project was tailored to exact grid conditions, building customer loyalty through a 100% FAT first-time pass rate.
3. The Lishui Smart Manufacturing Base: Raising the Ceiling to 550kV
By late 2025, Zhejiang Rockwill Electric Smart Manufacturing Co., Ltd. was established in the Lishui Li-Jing Ethnic Industrial Park with a registered capital of 50 million RMB.
This created a dual manufacturing matrix across Wenzhou and Lishui, covering 250,000 square meters with a monthly capacity of 400 to 500 transformers, extending Rockwill's voltage coverage from 2.4kV up to 550kV EHV (Extra High Voltage) levels.
High-Voltage Product Portfolio
ZF27-550 550kV GIS: Self-developed single-break arc extinguishing, rated current of 6300A, featuring a fully integrated internal hydraulic operating mechanism.
RHG-550 / ZF28 Series 550kV H-GIS & GIS: Dual-break arc extinguishing with parallel capacitor voltage balancing, short-circuit breaking capacity of 63kA, and partial discharge below 5pC—exceeding standard IEC requirements.
RHD / LW10B-550 Dead-Tank $\text{SF}_6$ Circuit Breakers: Integrated interrupter, current transformers (CT), and operating mechanism in a grounded tank—engineered for seismic resilience and harsh coastal or high-altitude environments.
500kV–800kV Power Transformers: Single-phase oil-immersed self-cooled three-winding off-excitation autotransformers, with capacities reaching up to 480MVA.
In early 2026, a delegation from the Rwanda Energy Development Corporation (EDCL) completed Factory Acceptance Testing (FAT) at the Lishui base for MV/HV switchgear and dry-type transformers, achieving a 100% first-time pass rate across all test items. Rockwill also provided comprehensive grid-connection guidance and O&M training for Rwandan engineers.
Recent Global Project Highlights
Namibia (20MW Solar PV): Delivered 38 units of 2500kVA step-up transformers with high-altitude derating and C5-M heavy anti-corrosion coating.
Bangladesh Grid Upgrade: Deployed 263 units of 33kV 32-step oil-immersed voltage regulators, maintaining output stability within +1% under input fluctuations of +20%.
France: Delivered 15 sets of compact package substations.
North America (ANSI Market): 36 ANSI-compliant Automatic Voltage Regulators (AVR) passed FAT with exceptional customer feedback.
Poland (Budowa Project): 145kV eco-friendly GIS made its debut entry into the high-end European Union market.
4. The Generational Leap: From Heavy Hardware to SiC Power Electronics
Beginning in 2019, Rockwill strategically expanded upstream into third-generation semiconductors. Through equity and commercial integration with PCsemic, Rockwill closed the loop on Key Materials > Chips > Power Devices > Terminal Systems.
Core Innovations by PCsemic
Mass production of pressure-sintered nano-copper paste for automotive applications—reducing raw material costs by ~70% compared to imported silver paste, with 100% supply chain localization.
Self-developed 650V to 3300V SiC Diodes & MOSFET wafers, IGBT modules, and dual-side cooling packaging technology.
Jointly Developed Solid-State Transformers (SST)
High Efficiency: Utilizes a three-stage topology powered by SiC MOSFETs and nanocrystalline cores, achieving 99.1% full-load efficiency and an 81% reduction in no-load losses.
Multi-Voltage Flexibility: MV side covers 10 / 13.8 / 20 / 33 / 35kV; LV side outputs 400V / 480V AC and 800V DC, fully compliant with IEC, ANSI-IEEE, and GB standards.
Global Applications: Launched China’s first mass-produced portable SST mobile power station (exported to over 20 countries). Key applications include 800V DC power supply for North American AI data centers, European distributed PV-storage grid integration, and black-start capabilities for weak grids in Africa.
Anchored by SST technology, Rockwill has evolved into a comprehensive solution provider across Auto-Reclosers, Transformers, Switchgear, EV Chargers, and Digital Power Stations. Product lines now include 60–180kW integrated EV chargers, 300/600kW split charging stacks, commercial & industrial energy storage systems (BESS), and digital solar inverter substations.
5. Five Core Pillars Behind the Growth Strategy
Uncompromised Quality Standards: Humble beginnings, but strict adherence to international standards from day one—avoiding race-to-the-bottom price wars.
Aggressive Technology Transitions: Moving seamlessly from MV distribution components to EHV transmission systems, and further into semiconductor-based power electronics.
Agile Operational Structure: The Wenzhou entity handles compliance and branding, the Lishui base executes high-end manufacturing, and PCsemic drives chip and material R&D.
Upstream Integration in 3rd-Gen Semiconductors: Securing next-generation energy efficiency advantages using domestic nano-copper materials and SiC devices.
Trust Built on 100% FAT First-Time Pass Rates: Global power utility delegations (from Rwanda, North America, Poland, the Philippines, and beyond) serve as living proof of quality, letting performance speak louder than marketing.
Conclusion
Rockwill’s story is not defined solely by numbers, but by its relentless "Will of Ordinary Stones"—pushing a regional workshop into 550kV state-grid level engineering, SiC semiconductor innovation, and 800V DC power architectures for AI data centers.
From a modest local business license in Weng'yang in 2008 to 550kV GIS deployments, international FAT approvals, and global SST rollouts in 2026, Rockwill stands as a masterclass in organic engineering excellence: the extraordinary drive of ordinary stones.
"The Grassroots Will of Ordinary Stones." — Rockwill Electric Group
Login
