How Baidu’s Hanhai U Series Cuts 3 Million Yuan Cost for 10 MW High‑Density AI Data Centers

With the rapid growth of AI compute, high‑density compute scenarios have become a core direction for data‑center construction, prompting a key innovation in power‑supply systems.

Two mainstream supply architectures exist today: the 800 V DC solution, praised for its inherent high density, efficiency and low loss, and the traditional AC UPS solution, which still dominates existing data centers and cannot be replaced in the short term.

Three major challenges of traditional IDC power systems

Capacity mismatch: a 2500 kVA transformer paired with 600 kVA UPS units leaves 100 kVA idle (four × 600 kVA = 2400 kVA) or forces over‑capacity (two × 500 kVA + three × 600 kVA = 2800 kVA, exceeding the transformer).

Low power density: UPS and switchgear occupy about 60% of the power‑module footprint, making distribution‑room area a bottleneck as rack density rises.

Structural waste of breaker capacity: breakers are often oversized (e.g., a 1600 A frame used for a 1250 A UPS), leading to unnecessary cost.

To address these issues, Baidu introduced the self‑developed Hanhai U series centralized power solution. By reconstructing the system‑level architecture, it places a high‑power‑density UPS at the core, re‑defines the UPS‑breaker relationship, fully utilizes the 1600 A frame, and dramatically compresses the distribution path.

Four core values delivered

High density & efficiency: single‑unit UPS capacity reaches 875 kVA, efficiency hits 97.5%, height compressed to 1.5 m, achieving more than double the power density.

Space consolidation: distribution‑room area drops from 900 m² to 400 m², a 55% reduction.

Simplified compliance: each system length stays under 15 m, eliminating the need for segmented designs while supporting easy UPS replacement and cross‑vendor compatibility.

Cost‑effectiveness: copper bus usage falls by 30%, overall power‑system cost decreases by about 10%.

Technical innovations (three dimensions)

Innovation 1 – Capacity reconstruction : modular 125 kVA units can be combined into 625 kVA, 750 kVA or 875 kVA configurations, delivering efficiency above 97.5% (industry‑leading). For a 2500 kVA transformer, four × 750 kVA UPS matches the transformer capacity, while three × 875 kVA UPS replaces a complex 2 × 500 kVA + 3 × 600 kVA scheme, simplifying the system.

Additionally, the new UPS supports internal module redundancy, allowing continued operation during module failures.

Innovation 2 – Space reconstruction : the traditional side‑by‑side layout of switchgear and UPS is changed to a stacked layout, reducing UPS height from 2 m to 1.5 m. Power density rises from 357 kVA/m² to 911 kVA/m² (≈2.5×). Module length shortens by over 20%, copper bus usage drops >30%, and the UPS is fully decoupled from low‑voltage cabinets, standardising external interfaces.

Innovation 3 – Device reconstruction : by re‑matching UPS and breaker capacities, both 1250 A and 4000 A breakers are fully utilized, reducing the number of UPS units and associated breakers, simplifying the system and cutting cost.

Typical application cases

Case 1 – 2500 kVA transformer with four × 750 kVA UPS : replaces the previous 2 × 500 kVA + 3 × 600 kVA arrangement, achieving precise capacity matching and a 15% Capex reduction. For a 10 MW single‑module data center, the solution saves more than 3 million yuan.

Case 2 – 2500 kVA transformer with three × 875 kVA UPS : substitutes the traditional four × 600 kVA setup, maintaining capacity even if one UPS fails. Capex drops 10%, saving over 1.8 million yuan for a 10 MW module.

Future outlook

Baidu’s AIDC portfolio now includes both the previously released high‑voltage DC power system and the new Hanhai U series UPS, forming a dual‑track strategy that addresses the emerging DC trend while serving the current UPS market. Baidu will continue R&D on power, liquid‑cooling and other key technologies to match diverse workloads and data‑center environments.