36.5kV 6300 kVA Oil-Immersed Transformers for Xinjiang Data Center: Powering Western China’s Digital Infrastructure

Batch dispatch: watch 18 units of S11-6300/36.5 oil-immersed transformers — three per truck across six heavy vehicles — depart Zhongxin General’s Sichuan factory as part of the phased delivery of a 42-unit order for the Xinjiang Altay data center project.

Project Snapshot

Background: Why Western China Needs High-Capacity Power Infrastructure Now

China’s national “East Data, West Computing” (东数西算) strategy has redirected billions in digital infrastructure investment toward its western regions. The logic is straightforward: western China offers cooler ambient temperatures that reduce data center cooling costs, abundant renewable energy from solar and wind, lower land costs, and improving logistics connectivity. Xinjiang’s Altay Region has emerged as one of the frontrunners in this transformation — a fast-developing hub attracting data center developers who require industrial-grade, highly reliable power distribution infrastructure.

Data centers place uniquely demanding requirements on power transformers. A facility running thousands of servers around the clock needs transformers that deliver ultra-low no-load losses (since units stay energized 24/7 even during low server utilization periods), stable voltage regulation across rapidly shifting load profiles, and outdoor-rated durability to handle Xinjiang’s extreme temperature swings — from harsh winters to hot summers.

When the project developer issued procurement requirements for high-capacity oil-immersed power transformers, they needed a supplier capable of meeting stringent technical specifications, demonstrating compliance with China’s latest national standards, and executing delivery to a remote location on a fixed schedule. After a competitive evaluation process, Zhongxin General Electric Energy Co., Ltd. (Zhongxin General) was selected.

From Raw Material to Finished Unit: The Manufacturing Process

Every S11-6300/36.5 transformer in this batch was built entirely in-house at Zhongxin General’s 20,000 m² production facility in Sichuan.

The manufacturing process begins with silicon steel sheet cutting, where core laminations are precision-sheared to specification. The geometry and grade of the silicon steel directly determine the transformer’s no-load loss performance — a metric that matters enormously for data center operators focused on lifecycle energy costs. From our experience supplying international markets — including a 1,250 kVA dry-type transformer exported to Europe under EU Commission Regulation 548/2014 energy efficiency requirements — we understand that no-load loss performance is the first thing technically sophisticated buyers scrutinize, regardless of whether they are working to GB, IEC, or EU standards.

Following core assembly, the active part — comprising the wound coils, insulation system, and laminated core — is carefully lowered into the transformer tank before vacuum oil-filling under controlled conditions. Each unit undergoes full factory acceptance testing prior to release, verifying insulation resistance, voltage ratio, vector group, no-load loss, load loss, and short-circuit impedance against nameplate values.

Full Technical Specifications

The S11-6300/36.5 is a three-phase, outdoor-rated oil-immersed distribution transformer designed for demanding industrial and infrastructure applications. The S11 series designation reflects its low-loss design generation, engineered to comply with China’s GB 20052-2024 energy efficiency standard — the most stringent efficiency requirement in the country’s regulatory history for distribution transformers.

Core Nameplate Data:

Tap Changer Voltage Settings (5-Position Off-Circuit):

Compliance Standards:

• GB 1094.1/2-2013 — Power transformers: general requirements and temperature rise
• GB 1094.3-2017 — Insulation levels, dielectric tests and external clearances
• GB/T 6451-2023 — Technical parameters and requirements for oil-immersed transformers
• GB 20052-2024 — Energy efficiency limits and evaluation for distribution transformers

International Voltage Compatibility: Ordering for Your Local Grid Standard

The transformer delivered in this project is rated at 36.5 kV on the high-voltage side, which is higher China’s GB national grid standard normal voltage 35 kV. However, Zhongxin General routinely manufactures the same S11 series to alternative high-voltage ratings for international customers — with no compromise to core performance parameters, cooling design, or energy efficiency classification.

For international procurement, the high-voltage winding is redesigned to the specified system voltage while all other parameters — rated capacity, vector group, cooling method, loss values, and mechanical dimensions — remain consistent with the standard product. Lead times, pricing, and delivery logistics for a 33 kV or 34.5 kV variant are directly comparable to the GB-standard unit described in this case study.

If your project operates on a 33 kV, 34.5 kV, 35 kV, or 36 kV network, contact our engineering team with your local grid specifications. We will confirm the applicable insulation levels, bushing ratings, and any additional compliance requirements — such as IEC type test certificates or CE documentation — as part of the quotation process.

Why These Specifications Matter for Data Centers

Three technical choices in this design are particularly relevant to data center power supply applications:

Dyn11 vector group. Data centers are filled with non-linear loads — server PSUs, UPS systems, and rectifiers — that generate harmonic currents, particularly third-order harmonics. The delta-connected primary winding in the Dyn11 configuration circulates these harmonic currents within the primary winding rather than propagating them back onto the utility grid, protecting power quality across the entire facility.

Low no-load loss (5,167 W). Because data center transformers remain energized continuously — even when server utilization drops overnight — no-load losses accumulate relentlessly. At 5,167 W and 8,760 operating hours per year, this unit consumes approximately 45 MWh per year at no load. Compared to older-generation designs, the S11 series delivers meaningful annual energy savings that compound across a full fleet of transformers on a large data center campus.

High short-circuit impedance (8.62%). A higher impedance value limits fault current magnitude during a grid short-circuit event. For a data center operator, this translates to reduced stress on downstream switchgear and busbars, lower mechanical forces during fault events, and better protection for the IT equipment housed in the facility.

Delivery: From Sichuan Factory to Xinjiang Site

The total order comprised 42 units of S11-6300/36.5 transformers, dispatched in multiple batches from Zhongxin General’s Sichuan facility to the Xinjiang Altay project site. With manufacturing and testing complete, the team moved to the logistics phase. At approximately 11,500 kg per unit, transport planning, loading rigging, and in-transit securing all required careful engineering — not unlike the logistics planning we executed for our 63 MVA/110 kV OLTC transformer delivery to Ningxia, where a 80-ton unit required specialized heavy transport vehicles, route surveys, and police escort coordination across a 1,500 km route.

The transformers departed from Zhongxin General’s Sichuan facility bound for Xinjiang Altay — a journey spanning thousands of kilometers through western China. Full-batch delivery was completed on schedule in Q4 2025, meeting the project’s construction timeline.

Our Track Record Across Sectors and Borders

The Xinjiang data center project is the latest in a growing portfolio of domestic and international deployments. Across eight years of operation, Zhongxin General has supplied power equipment to clients spanning energy, healthcare, industrial, and digital infrastructure sectors.

Selected recent projects:

63 MVA/110 kV OLTC Transformer — Ningxia LNG & Helium Project → A 150-ton oil-immersed OLTC transformer delivered to Ningxia Helium Technology Co., Ltd., supporting a 2 million m³/day LNG and 600,000 m³/year high-purity helium production facility. Six months of zero unplanned downtime since commissioning in July 2025.

Intelligent Power Distribution System — Xinjin District People’s Hospital → A 16,730 kVA intelligent power distribution system for a 129,900 m² hospital campus in Chengdu — featuring 12 dry-type transformers, 133 switchgear cabinets, a Three-in-One intelligent monitoring platform, and 72-hour battery backup storage. Zhongxin General served as both equipment manufacturer and EPC contractor.

Exporting High-Standard Dry-Type Transformers to Europe → A 1,250 kVA dry-type transformer exported to a European client under EU Commission Regulation 548/2014 energy efficiency requirements. A first-hand account of navigating CE documentation, ITP/FAT reporting to international standards, and the technical refinements that opened the door to high-end export markets.

EV Charging Station — 5-Year Operational Case Study → Zhongxin General’s own factory-gate EV charging station: five years of continuous operation under heavy-duty commercial truck loads, generating approximately USD 10,000/month in profit share — a live demonstration of our box-type substation technology and a practical reference for customers evaluating charging infrastructure projects.

International project footprint:

• 🇰🇿 Kazakhstan — Aktau Port infrastructure project
• 🇨🇩 Democratic Republic of Congo — utility-scale power infrastructure
• 🇦🇷 Argentina — distribution transformers for industrial clients
• 🇨🇳 Domestic — Xinjiang, Tibet, Chongqing, Ningxia, Chengdu and beyond

About Zhongxin General Electric Energy Co., Ltd.

Founded in Sichuan, China, Zhongxin General has built an eight-year track record as a manufacturer of green intelligent power equipment. The company’s product portfolio covers oil-immersed transformers (30 kVA to 100 MVA, up to 132kV), dry-type transformers, switchgear assemblies, prefabricated substations, enterprise-grade microgrids, energy storage systems, EV charging infrastructure, and cloud-based power monitoring platforms.

Certifications & Recognitions:

• National “Specialized, Refined, Distinctive & Innovative” (Little Giant) Enterprise
• National High-Tech Enterprise
• Sichuan Provincial Enterprise Technology Center
• Provincial Leading Enterprise
• CCC & CQC certified · CE and UL certifications in progress

Strategic cooperation partnerships with State Grid Corporation of China and China Southern Power Grid validate the company’s quality management systems and delivery capability at utility scale. In 2025, Zhongxin General is targeting annual output exceeding RMB 300 million (≈ USD 42 million).

Planning a Similar Project?

Whether you are procuring power transformers for a data center, an industrial facility, a port, or a utility project — and whether your grid runs on 33 kV, 34.5 kV, 35 kV, 36 kV, or 36.5 kV — Zhongxin General’s engineering team can help you identify the right specification, navigate compliance requirements, and execute delivery to your site.

→ Contact Our Engineering Team → View Oil-Immersed Transformer Product Range → Browse All Case Studies

About the Author

Kevin Z

Kevin holds dual academic backgrounds in Electrical Engineering and English Language. He is a core member of two selective professional communities — a group of elite electrical engineers and a high-level ESL learning circle. With over 15 years of experience in international marketing and sales, Kevin currently serves as Director of International Trade at Zhongxin General.

Beyond his corporate role, Kevin is also a key member of a distinguished export business network based in Ningbo, Zhejiang — one of China’s most dynamic trade hubs. Through this circle of outstanding export enterprises, he gains deep exposure to best practices in business operations, management strategies, and global trade — insights he brings directly to his work and writing.