Published by MVSST Power · October 2026
For a decade the medium-voltage solid-state transformer (MV SST) was a laboratory result looking for a customer. Between 2 July and 28 September 2026 that changed in a checkable way: five named projects or platforms reached milestones confirmed by the organisations themselves — a commissioned commercial project in Hebei, a government-recognised demonstration base in Guangzhou, a launched product with a signed framework pipeline, a European industrialisation partnership, and a device-supply announcement naming the exact SiC module.
Only those events are compiled here. Company announcements and government sites are cited as such; every efficiency, density and redundancy figure is a manufacturer-stated specification, not an independent benchmark; no market forecast is reproduced.
The strongest industrial signal is not any single product but the fact that competing vendors converged on one electrical interface. Every platform entering field deployment in this window takes medium-voltage AC in and delivers an 800 VDC bus: Eaton's MV SST 2.0 converts 10 kV AC directly, Delta's platform 6.6–35 kV AC, Sungrow's EnerNeo 10–13.8 kV AC, and the Siemens–Reinhausen unit up to 36 kV [1][4][5].
That convergence is driven from the load side. The Open Compute Project's 800 VDC work, whose named participants include Google, Microsoft and Nvidia, describes two paths in August 2026 material: a near-term power rack converting 480 V AC beside the servers, and a longer-term architecture in which megawatt-scale transformer-rectifier units or SST skids convert medium-voltage AC directly to 800 VDC [4]. For a component supplier that second path is the specification that matters: it fixes input voltage class, isolation and DC bus voltage in one decision.
On 4 September 2026, Infineon and Eaton disclosed that Infineon's 1200 V Easy™ SiC modules are used in Eaton's 800 VDC MV SST 2.0 platform, developed and manufactured by Eaton's Shenzhen team for APAC and EMEA. The same announcement states that the two companies are working on a next-generation SST platform based on EasyPACK™ 2C SiC modules at 2.3 kV and 3.3 kV [2].
Two points follow. First, 1200 V remains the workhorse class for series-stacked converter cells — Eaton's earlier SST design used a 1200 V SiC M1H module on an AlN ceramic substrate to reach its power-density target [2]. Second, the move to 2.3 kV and 3.3 kV is a component-qualification problem before it is a system problem: a higher-voltage module cuts the number of series cells for a given MV input, reducing gate-drive channels, insulation-coordination points and assembly labour — but only if module, gate driver, cooling interface and partial-discharge performance are qualified together. Sungrow uses SiC devices in an optimised H-bridge series architecture [3]. Different module counts, one constraint: the available SiC voltage class sets the architecture.
Reliability architecture is where this generation separates from earlier prototypes. Eaton specifies N+1 module redundancy and N+3 conversion-unit redundancy with availability above 99.999% [1]. Sungrow's published EnerNeo specification claims 6+3 per-phase elastic redundancy, tolerating three failed modules at 75% derated output with 15-minute hot-swap maintenance [3]. Delta's Huailai project uses a distributed-SST-plus-DC-bus architecture placing conversion beside the IT racks [7]. The consequence: DC-side busway, breakers, fuses and contactors are now part of the SST specification rather than a separate purchase [8].
With 10–36 kV on one side of a device the size of a cabinet row, insulation decides whether a design is deployable. Eaton's MV SST 2.0 is specified with 42 kV insulation withstand and 75 kV lightning impulse testing [1]. Sungrow claims cabinet-level zero partial discharge up to 21 kV, 42 kV power-frequency withstand and 95 kV lightning impulse, using integrated vacuum insulation around the high-frequency transformer [3]. Third-party certification is now a differentiator in itself: Eaton's MV SST was reported at Semicon Taiwan in September 2026 as having passed TÜV SÜD testing against IEC 62477-2, with volume production targeted for the first quarter of 2027 [9].
Hitachi Energy has also cautioned publicly that operating at 34.5 kV while keeping an SST compact demands stringent insulation systems and high manufacturing quality to ensure a 20-year service life [4].
The commercial argument in 2026 is not cheaper transformation; it is fewer cubic metres and fewer months. Eaton states a 2.5 MW system at 278 kW/m², more than 40% less floor area than the conventional arrangement, roughly one week of on-site installation and a delivery cycle shortened by 50% [1]. Sungrow claims 312 kW/m² [3]; Zhiguang Electric claims over 60% area saving and 80% lower copper losses for Coota [10].
The counter-argument deserves equal weight. SPOC Energy argues that SST technology still lacks the maturity and supply-chain depth for broad rollout, and promotes a transformer-plus-rectifier route reaching about 97.3% grid-to-rack efficiency on the existing MV transformer supply chain. The same review cites the U.S. Department of Energy: conventional large power transformers have demonstrated field lifetimes beyond 40 years, whereas SSTs contain many semiconductors exposed to transient overvoltage and overcurrent, with device coordination and fault protection listed as unresolved [4].
| Platform | MV input → output | Rating | Stated efficiency | Status |
|---|---|---|---|---|
| Eaton MV SST 2.0 | 10 kV AC → 800 VDC | 2.5 MW per system; 278 kW/m² | 98.5% full chain | Benchmark project running >1 year per company; TÜV SÜD testing to IEC 62477-2 reported Sept 2026; volume production targeted Q1 2027 [9] |
| Delta SST smart DC supply (with Chindata, Meituan, HEC) | 10 kV AC → 800 VDC | 1 MW per power cabinet, ≈1 m² | 98.5% | Commissioned 2 July 2026 at Chindata's Sangyuan campus, Huailai; described by the partners as the industry's first commercial SST DC supply project [7] |
| Sungrow EnerNeo™ | 10–13.8 kV AC → 800 VDC | 1.5 / 3 / 4.5 MW; 312 kW/m² | 98.5% | Launched 9 July 2026; SST units for a new computing centre expected to be commissioned in Q4 2026 per the company's investor disclosure [3] |
| Zhiguang Electric Coota | 10 kV AC → 800 VDC | 4.2 MW grid-forming | >98.5% per company | Huangpu demonstration base commissioned 7 August 2026 — the first fully self-developed SST demonstration project in Guangdong [6] |
| Siemens + Reinhausen modular SST | up to 36 kV AC → 800 VDC | Not disclosed | Not disclosed | Announced 14 August 2026 as a development and industrialisation partnership; no capacity, customer or shipment date disclosed [5] |
Figures above are manufacturer-stated, typically measured at favourable operating points; they are not independent benchmarks and are not comparable across vendors without a common test definition.
Related: Medium-Voltage SST Topologies, Control and the Engineering Gap · SiC Power Module Guide · White Papers & Insights
Disclaimer: This article is an industry summary compiled from the publicly available company announcements, government publications, listed-company disclosures and trade media listed above, for industry information purposes only. All performance figures are manufacturer-stated unless a third-party source is named. No market forecast or non-public information is reproduced. Project decisions require project-specific engineering analysis.
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