In August this year, two leading Solid State Transformer (SST) companies disclosed their order signings and delivery volumes, drawing widespread attention in the industry.
On August 13, Delta Electronics issued a seemingly ordinary announcement: global SST orders have surpassed 500MW. However, industry insiders know exactly what this figure implies.
Based on a rough estimate using the quotation of approximately 1.2 RMB/W from domestic SST manufacturers, the 500MW orders correspond to a production value of at least over 600 million RMB—and Delta's actual SST production value could be even higher.
Prior to this, Weiguang Energy also disclosed in its Series B financing announcement that, as of now, it has cumulatively delivered over 300 SST units. Assuming a rough estimate of 1.5MW per unit at a unit price of 1.2 RMB/W, Weiguang Energy's cumulative SST orders could also exceed 400 million RMB. Meanwhile, the company has some newly signed orders that remain undisclosed, meaning the actual total order value could be even higher.
The order boom is not limited to Delta and Weiguang Energy; multiple other SST manufacturers, including Sungrow, Eaton, and Zhiguang Electric, have also disclosed their order and cooperation progress this year.
"500MW + over 300 units" is just the beginning. Ye Xinping, Product Marketing Director of the Information and Communication Business Group at Delta (Zhongda Dientong), pointed out that computing power scenarios are the breakthrough point for SST commercialization. However, data center power consumption accounts for only 1%–2% of total societal usage, which is just the tip of the iceberg. High energy-consuming manufacturing, DC factories, transportation energy replenishment, and DC microgrids represent a much larger blue ocean.
Ye Xinping estimates that 2026 will be the first year of SST commercialization, 2027 will see multi-scenario pilot deployments, and by 2030, the market will sprint toward 100 billion RMB. Weiguang Energy's financing announcement also mentioned that the SST market scale is expected to reach the trillion-RMB level by 2035.
Direct Migration of Automotive-Grade SiC Technology
SST Achieves Commercialization After Decades of Silence
Regarding the deployment and order boom of SST, Delta attributes it to the natural outcome of its 55 years of technological accumulation. But why exactly at this time point in 2026?
The answer lies in another hidden yet critical industry chain—the increasing maturity of SiC MOSFET technology and its underlying supply chain. It has allowed SST, a technology that has lain dormant in laboratories for decades, to finally welcome its first year of commercialization in 2026.
Compared to traditional transformers, SSTs are smaller in size, lighter in weight, and eliminate the need for large amounts of copper materials. They also maintain higher efficiency across the full load range, fundamentally resolving the inherent bottlenecks of traditional transformers being "bulky, material-intensive, and inefficient."
It sounds ideal, but over the past few decades, the SST industry has repeatedly tried and failed to cross the "valley of death" of "excellent performance but high cost." The primary industrialization bottleneck mainly lies in power devices—silicon-based IGBTs have low switching frequencies and high losses, while SiC MOSFETs lacked cost-effectiveness and technological maturity at the time.
The critical turning point occurred with the large-scale adoption of SiC MOSFETs in New Energy Vehicle (NEV) main drives. Over the past few years, the installation and verification of millions of electric vehicles annually have not only proven the reliability of SiC but also driven chip prices down from their highs. It is precisely the reliability data and mass production processes accumulated under the extreme operating conditions of automotive main drives that have been directly migrated to SST scenarios. Coupled with the significant drop in SiC MOSFET costs, this has finally allowed SST to cross the industrialization threshold from "laboratory technology" to "commercial deployment."
SST Is a Key Stepping Stone Toward Ultra-High Voltage
SiC Reliability Testing Faces Three Major Challenges
Industry experts believe that SST holds a dual significance for the development of the silicon carbide industry.
The first is "volume." The SiC MOSFET chip usage in a single SST module can approach 1,000 units. The initially scaled hundred-billion-level SST market typically corresponds to an incremental demand of hundreds of thousands of SiC wafers.
The second significance is even more profound—SST is a key stepping stone for SiC to enter high-voltage markets such as high-speed rail and power grids. The SiC devices currently used in SSTs will shift from 1200V to 2300V and 3300V ratings. The massive installation of medium- and high-voltage SiC devices in SST scenarios will continuously test their reliability, refine processes, and reduce costs. This will lay the market foundation for the large-scale commercialization of high-voltage SiC above 6500V. Therefore, winning the SST battle will propel the entire industry to add another hundred-billion-level market.
However, there is a hidden concern that many have overlooked: SST's reliability requirements for silicon carbide may be higher and more concealed than those for automotive main drives.
On the one hand, a single SST integrates dozens of high-voltage SiC modules, with hundreds or even thousands of chips operating in parallel or in series. If any single chip experiences gate oxide degradation or solder fatigue due to long-term high dv/dt and thermal cycling, it could trigger a complete system shutdown. Traditional static aging equipment can only apply steady-state bias and cannot simulate high-frequency dynamic switching and temperature alternation processes, making it difficult to reproduce failure mechanisms under actual operating conditions.
On the other hand, SSTs use 2300V or even 3300V SiC devices, which can significantly reduce the technical difficulty and cost of the system. However, upgrading the voltage rating of SiC devices from 1200V to 2300V/3300V poses new challenges for reliability testing equipment. In addition to significantly strengthening withstand voltage insulation and safety protection designs, the testing equipment must also possess richer bias configurations and more precise leakage current monitoring capabilities.
Cost comparison of 10kV SST PEBB cascade quantities based on 1200V/3300V. Source: Zhenqu Technology
The third aspect is that China currently lacks domestic reliability testing equipment capable of covering high voltages above 2000V, supporting dynamic power cycling, and conducting accelerated aging for over a thousand hours. Although overseas equipment offers mature performance, its unit price is high, and the delivery time is generally over half a year, severely constraining the pace of SST industrialization.
It is evident that SST is a critical battleground for silicon carbide to scale to the hundred-billion level, and reliability testing equipment is the indispensable winning move in this campaign.
Broad Demand for SST Testing Equipment
Hangke Takes the Lead in Solving High-Voltage SiC Testing Pain Points
SST not only benefits silicon carbide devices but will also significantly drive the demand for reliability testing equipment. However, not all equipment companies can enjoy this piece of the cake—the high-voltage, high-reliability, and large-scale parallel testing requirements of SST keep the vast majority of companies out.
Hangke Instrument has already taken a leading step in the field of SST testing.
Hangke Instrument is one of the few domestic equipment manufacturers capable of covering 2000V–5000V medium- and high-voltage silicon carbide reliability testing. Its HTRB testing voltage can be customized up to 20,000V. The static reliability testing system comprehensively covers the testing needs for 2300V/3300V SiC devices used in SSTs, effectively solving the industry pain points of "unable to test" and "inaccurate testing" for SST high-voltage silicon carbide devices.
Meanwhile, against the backdrop of long delivery times, high unit prices, and import restrictions for overseas equipment, Hangke Instrument has significantly reduced procurement and time costs with its localized equipment, making high-voltage SiC reliability testing for SSTs "usable and affordable."
In terms of equipment coverage, Hangke Instrument possesses a complete product matrix for silicon carbide reliability testing. Among them, the static reliability testing system covers three voltage levels: low voltage (<2000V, automotive-grade), medium voltage (2000V–5000V, solid-state transformers), and high voltage (>5000V, photovoltaic energy storage). In terms of specific testing items, it can provide various testing solutions such as High Temperature Reverse Bias (HTRB), High Temperature Gate Bias (HTGB), High Temperature High Humidity Reverse Bias (H3TRB), and High Temperature Bias (HTXB, supporting both RB+GB simultaneously).
In terms of dynamic testing capabilities, Hangke Instrument has launched a high-temperature dynamic gate bias aging testing system. It can support SiC MOSFET device testing from room temperature to 200°C (some up to 230°C), featuring independent pulse configuration and automatic fault device disconnection. It fully aligns with the AQG-324 automotive-grade standard and can accurately reproduce the real dynamic operating conditions of high frequency and high dv/dt in SST scenarios. In addition, the company holds a patented wafer aging system technology with HTGB and HTRB switching functions, allowing a single device to autonomously switch between the two testing modes.
It is revealed that currently, Hangke Instrument's power cycle testing systems have been widely used in the production lines and laboratories of leading domestic and international SiC manufacturers such as onsemi, Infineon, ROHM, Huawei, UMC (SiLC), StarPower, Silan Micro, and Fangzheng Micro, providing core testing capabilities for their automotive-grade certifications. In the new cycle of high-voltage silicon carbide triggered by SST, these reliability testing equipment validated by leading customers are expected to become the invisible foundation for the SiC industry to leap from the hundred-billion to the trillion level.
Broad Demand for SST Testing Equipment
Hangke Instrument Has Globally Secured Its Position
In fact, the demand for silicon carbide reliability testing extends far beyond SST. As NEV main drives continue to evolve toward 800V high-voltage platforms and the power density of AI (Artificial Intelligence) data center PSU power supplies keeps climbing, the penetration rate of silicon carbide in both markets is rapidly increasing. The demand for reliability testing equipment is already very strong and has broad prospects.
In this comprehensive reliability exam, the cards in Hangke Instrument's hand go far beyond just high-voltage SiC testing.
The first card is a comprehensive product matrix. Hangke Instrument has built a full-process reliability testing product line covering silicon carbide from the wafer level to the module level. This includes wafer-level testing before packaging, as well as a full series of aging and screening solutions after packaging, such as power cycling (a mandatory test item for automotive-grade AQG-324), static (HTRB/HTGB/H3TRB/HTXB), and dynamic (DHTRB/DHTGB/DH3TRB/HTFB). It completely covers the verification needs of the entire chain from manufacturing to finished products for third-generation semiconductors.
The second card is widespread market recognition. Taking the power cycle testing system as an example, Hangke Instrument's PC (Power Cycle) series testing system has been recognized as the first set of its kind in Zhejiang Province. Its market share in the domestic market is significantly leading, and it has been widely used in the production lines and laboratories of leading domestic and international SiC manufacturers. It firmly stands in the first echelon in the domestic semiconductor device special equipment manufacturing field and is one of the leading domestic enterprises in the field of semiconductor reliability testing.
The third card is the precious gift of time. From the founding of Hangzhou Reliability Instrument Factory in 1984 to the present, as a national-level specialized, refined, differential, and innovative "little giant" enterprise, Hangke Instrument has continuously深耕 (deeply cultivated) the field of electronic component reliability testing for over 40 years. It is a pioneer in technological innovation in China, dedicated to providing professional testing solutions with functional modularity, system integration, and product diversification.
The reliability of silicon carbide determines whether it can move from the hundred-billion to the trillion level. In this wave ignited by SST and relayed by automotive and AI data centers, only enterprises with high-voltage testing capabilities, technological accumulation, and endorsements from leading customers are qualified to stand on the main stage. Hangke Instrument is accelerating its strategic positioning.