Solid-State Transformer
A medium-voltage to DC conversion platform for AI data centres, EV charging, renewable integration and smart grids. Medium-voltage AC in, 800 VDC out, through one controllable power interface.
Discuss an SST project →Four ratings. Two released — one of them running since 2023.
Ratings are released separately. A released rating means the design is frozen at the stated revision and can be quoted for a project — it does not by itself imply certification, which is tracked separately on the Quality page.
13.8 kV · 3.5 MW
Rev. A7 product, 800 VDC output. The rating with a full published parameter set.
10 kV · 2.5 MW
First deployment of this rating: three 10 kV / 2.42 MVA / 800 VDC AIDC units, in service since September 2023 and still running.
10 kV · 1 MW
Planned for a future release. Parameters are not frozen and are not quoted.
34.5 / 35 kV · 10 MW
Planned timing, subject to product plan. Not a contractual delivery commitment.
Not a laboratory prototype. Units in service, and units in build.
The SST platform behind our product line has been through successive field generations since 2017. For a buyer assessing it today, three deployments matter: units that have run for years, an export order now in delivery, and a grid connection that proves the DC output class outside a data hall.
3 × 10 kV / 2.42 MVA / 800 VDC
Three commercial AIDC units, energised at a data-centre campus in September 2023 and running since. As far as we are aware they are among the earliest commercial solid-state transformer deployments in an AI data centre — and they are still in service.
4 × 13.8 kV / 800 VDC
Four 13.8 kV units ordered in 2026 by an overseas AI computing developer for its own campuses. The first outbound order for this platform, currently in production and delivery.
10 kV / 2 MVA / 750 V
A separate 750 V series, grid-connected at an integrated solar-storage-charging park. It is not an AI data centre, and we list it as what it is: proof that the same conversion platform also runs grid-tied outside a data hall.
What this record does and does not mean
These are real units, real orders and a real supply chain, not a laboratory prototype. They are also not volume production. The platform is at demonstration and small-batch commercialisation: unit cost is still high, cloud operators have not yet put it into volume procurement, and industrialisation is early. We would rather you hear that from us now than discover it later.
Four statuses kept separate. One company accountable for all of them.
Quotable, in service, in delivery and type-tested are different things, and suppliers blur them on purpose. Here is each one, and where this platform actually stands on it.
| Status | What it means | Where this platform stands |
|---|---|---|
| Quotable | Design frozen at a stated revision. We can price it, contract it and ship it. | 13.8 kV / 3.5 MW (Rev. A7) · 10 kV / 2.5 MW |
| In service | Energised on a customer site and running under load. | Three units since September 2023 — 10 kV class, data centre |
| In delivery | Ordered, in production, on its way to site. | Four 13.8 kV units, 2026 export order |
| Type-tested | A third-party certificate against the standard that applies to the market. | Not yet — IEC 62477-1 remains open |
A configuration can be quotable and in service without yet being type-tested. We do not let the second fact hide the third: the Quality page tracks certification item by item, with the evidence held for each.
One contract, one warranty and one named engineer. Application study, single-line diagram and protection settings. Market-specific documents, commissioning, remote diagnostics and spare parts held locally. If something goes wrong at the interface, there is one number to call.
Production history since 2017. Medium-voltage manufacturing and test infrastructure. SiC devices and high-frequency magnetics. Field generations in data centres and parks. Type-test records available to qualified buyers under NDA.
Platform capability and the certification status of a specific offered configuration are separate pieces of evidence, and we treat them that way.
Four applications, one power interface.
The same conversion chain, configured four ways. The port count and the control mode are what change.
10–35 kV in · 800 VDC out
Rack-level or row-level distribution. Removes the LV switchgear and UPS stages; the DC bus feeds the racks directly.
10–35 kV in · 800–1000 VDC out
Megawatt charging without a separate substation building. V2G and PV/storage integration on the same DC bus.
PV and storage on a common DC bus
Large PV plants and storage connect at medium voltage through one conversion stage instead of two.
Grid-forming and ride-through
A controllable, bidirectional interface between medium-voltage AC and a DC network — including weak-grid and microgrid operation.
Cascaded AFE, isolated high-frequency DC/DC, parallel DC output.
Medium-voltage AC is actively rectified in a cascaded arrangement, buffered per module, then isolated and converted at high frequency before the parallel low-voltage output stage. Control targets are regulated input current, stable output voltage, module voltage balance, and coordinated protection and bypass.
Simplified for clarity, based on the Rev. A7 block diagram. Topology, switching frequency and control parameters depend on the project and the product revision.
13.8 kV / 3.5 MW, Rev. A7
| Rated power / voltage / current | 3.5 MW / 800 V / 4375 A |
| Steady-state accuracy / transient deviation | ±1% / ±5% |
| Voltage regulation | Ripple ≤0.5% / static ≤1% / dynamic ≤3% |
| Phases / frequency / input voltage | Three-phase / 50–60 Hz (±3 Hz) / 13.8 kV |
| Permissible voltage variation | −10% ~ +10% |
| Peak efficiency / THDi / power factor | 98.5% peak / <3% above 50% load / >0.98 |
| Output overload | 105% continuous / 110% 60 min / 125% 10 min / 150% 0.2 s |
| Short-circuit fault clearing | 150% / 180 ms |
| Insulation level (BIL) | >95 kV |
| Partial discharge | <10 pC |
| Ambient temperature | −30 °C to +50 °C |
| Altitude | ≤2000 m |
| Cooling / ingress protection | Air cooled / IP20 (main unit) |
| Container rating | NEMA 3R / C5 |
| Communication | RS485 / Ethernet · Modbus RTU/TCP · IEC 104 · IEC 61850 |
Values are nominal. 98.5% is the peak efficiency figure. Efficiency at part load is lower, and the figure to use in a savings calculation is the one read off the efficiency curve for the offered unit at your operating point, not this peak. Harmonics, overload and fault ride-through require testing under agreed conditions, and fault ride-through requires coordination with the energy storage system. Unlisted parameters should not be assumed compliant.
A released rating can be quoted before certification is complete. Where a project requires a certified unit, we say so in the proposal rather than afterwards.
Built from modules, with one spare in every string.
Each phase is a chain of nine two-in-one modules, each containing two identical submodules — 18 submodules per phase, one of them redundant. Per-phase cascading is what lets a single failed module be bypassed instead of taking the unit offline.
17 + 1 per phase
18 submodules per phase including one redundant module. Redundancy is a module count, not a claim about availability — actual availability depends on the redundancy strategy in your design.
Two-in-one modules
Nine two-in-one modules per phase, each containing two identical submodules. Fewer connectors and a shorter power path than discrete modules.
Online bypass
The design aims to reduce the effect of a module fault on delivery. Bypass conditions, derating and protection logic must be validated per project.
| Indoor core cabinet | 4700 × 1450 × 2300 mm · approx. 6 t · IP20 |
| 20-foot container solution | 6058 × 2438 × 2591 mm · NEMA 3R / C5 |
| Container contents | SST, fire protection, HVAC cooling |
| Derating above 40 °C | −0.5 MW per further 5 °C |
Final enclosure, weight, lifting points and interfaces follow approved customer drawings.
The SST is one layer, not the whole answer.
In an AI data centre the SST handles primary conversion, while storage, static var generation, high-voltage drives and an EMS coordinate around it. Each function sits in its own layer with its own protection boundary.
SST — primary conversion
MV AC to 800 VDC, with voltage regulation, power factor control and modular protection.
Energy storage PCS / BESS
Dynamic buffering and backup support. Capacity and connection point configured per project — and required for fault ride-through.
SVG — power quality
Campus-level reactive power and voltage support at the point of common coupling.
Drives + EMS
Energy efficiency for chiller pumps and fans, plus unified monitoring and energy dispatch.
Solution boundary: this layered view is a concept, not a standard scope of supply. Protection zones, the 2N strategy, storage connection points and emergency power logic require joint design with the customer.
Three ways to place an SST in a live facility.
The choice follows your POD design, redundancy strategy and retrofit scope — not a vendor preference. These are discussion models; the final architecture depends on your reliability target and site conditions.
One SST per POD
Dedicated conversion close to the load. Smaller fault domain, and capacity can be added POD by POD as phases come online.
Several SSTs, one DC bus
Multiple units feed a centralised DC bus. Requires parallel operation, coordinated protection and an availability design that is agreed up front.
Keep one path conventional
Retain one side of the existing 2N pair and add SST on the other. Limits the risk of a one-time retrofit while the new path proves itself.
Medium-voltage charging, without the substation between.
The SST takes 10–35 kV directly and puts out adjustable DC. The line-frequency transformer and its building disappear from the layout.
Direct MV connection
10 kV or 35 kV in, adjustable high-voltage DC out. No step-down transformer, no separate LV room.
Bidirectional by design
Vehicle-to-grid is a control mode, not extra hardware. Energy flows back during peak hours.
PV and storage on the DC bus
Solar and batteries connect to the same DC ports, so the site runs as one energy hub rather than three systems with three meters.
Typical megawatt charging configuration. Actual power, voltage and port count are set per site.
One platform, in the field since 2017.
The SST we supply is not a new design. It is a platform that has been through successive field generations, each one now shipping.
First MV SST
National R&D programme prototype, ±10 kV / ±375 V / 1 MW
DC transformer
±10 kV / ±375 V / 2 MW, demonstration grid
Multi-port router
3 MW IGCT-based DC transformer, park deployment
Data centre SST
3 × 10 kV / 2.42 MVA / 800 VDC, in service since September 2023
SiC generation
10 kV SiC devices, higher switching frequency
800 VDC platform
MW-class cabinets for AI data centres · first export order: four 13.8 kV units, in delivery
- Every entry is programme history of the platform behind our SST range.
- Our own engineering, warranty, commissioning and service sit in front of that platform; the record above is why we can stand behind it.
- Deployment references and type-test records are available under NDA to qualified projects.
- Which ratings we can quote today is stated earlier on this page, revision by revision.
How the pieces connect.
Three reference configurations. Each is a starting point for a system study, not a catalogue item.
Data centre
Renewable plant
EV + PV + storage
Port counts, voltage classes and protection settings are fixed by the system study. We do not quote a combination before that study is done.
Six steps from design target to operating data.
A new platform closes reliability risk step by step. We publish which step each item has reached, so you can see where a claim is backed by a test report and where it is still a design target.
Design & failure analysis
Failure modes identified at design level, before hardware exists.
Component / module testing
Critical components and the module itself validated on the bench.
System-level testing
Full converter behaviour: control, protection, thermal path and bypass.
Third-party validation
Type testing against the standard that applies to the target market.
Demonstration data
Operating record from a live site, over a defined period and load profile.
Failure closure & consistency
Field failures closed out, and production consistency demonstrated across units.
- Voltage and short-circuit capacity at the point of connection
- Load profile, including the transient envelope
- POD and redundancy strategy
- Storage interface and control coordination
- Communication points and protocol list
- Environmental and fire protection requirements
- Certification path and acceptance criteria
- Feasibility discussion — whether the architecture suits your site
- Reference design — system configuration, interfaces and protection zones
- Joint validation plan — agreed milestones where evidence is still missing
- Or an honest "not yet" — if the timing does not work, we say so
A note on where this product actually stands
Two ratings are released and can be quoted, and the platform has units in service and an export order in delivery. What it does not yet have is a type-test certificate, or a place in a cloud operator's volume procurement. We would rather state both halves in the same paragraph than let you discover the second one after the first. If your project needs a type-tested SST for delivery this quarter, we will tell you that we are not there yet.