120-Stall DC Fast Charging Hub
A turnkey 10MW prefabricated substation solution powering 120 ultra-fast 500kW DC chargers across five strategic locations. Deployed in record time with industry-leading power quality and uptime performance.
Powering the Next Generation of EV Charging
A flagship deployment combining GOHO’s full product lineup to deliver reliable, high-power charging infrastructure at unprecedented speed.
Project Background
Our client, a leading national EV charging network operator, approached GOHO with an ambitious mandate: deploy five large-scale DC fast charging hubs across key highway and urban locations in China, each capable of simultaneously charging 120 electric vehicles at 500kW per stall. The project required a total installed capacity of 50MW across all sites.
Traditional civil-built substations would have required 6–9 months per site — a timeline incompatible with the client’s aggressive rollout strategy. GOHO proposed a prefabricated substation approach that consolidates MV switchgear, transformers, LV distribution, and harmonic mitigation into a single factory-assembled enclosure.
Each site features two 1250kVA YB prefabricated substations operating in parallel, feeding KYN28-12 medium voltage switchgear and GCK low voltage switchgear with integrated harmonic filtering. The modular design allows each hub to start with 60 chargers and seamlessly expand to 120 as demand grows, protecting the operator’s capital investment.
Completed in 2024 and fully operational across all five sites, the project has set a new benchmark for fast deployment and power quality in the EV charging industry — achieving 99.9% uptime in its first year of operation while maintaining total harmonic distortion well below the 5% IEEE standard.
Project at a Glance
Key facts and specifications
Three Critical Challenges to Overcome
Large-scale DC fast charging hubs present unique engineering challenges that push conventional power distribution systems to their limits.
Aggressive Deployment Timeline
The client required energization within 90 days from order placement across all five sites. Traditional civil-constructed substations typically require 6–9 months of on-site work, including foundation pouring, cable trenching, equipment installation, and testing — a schedule that would have delayed revenue generation by two quarters.
Harmonic Distortion from High-Power Chargers
500kW DC fast chargers are nonlinear loads that generate significant harmonic current distortion. With 120 chargers operating simultaneously, total harmonic distortion (THD) posed a serious risk: overheating transformers, interfering with protection relays, reducing equipment lifespan, and potentially violating grid code requirements that mandate THD below 5%.
Scalable Design for Future Expansion
Each site needed to launch with 60 chargers in Phase 1 and expand to 120 chargers in Phase 2 as EV adoption accelerated. The infrastructure had to accommodate this doubling of capacity without requiring a full rebuild, extended downtime, or costly retrofitting — all while maintaining power quality and system redundancy.
Engineered Solutions That Deliver Results
Each challenge was met with a targeted, proven solution from GOHO’s comprehensive product portfolio.
Prefabricated Substation Approach
GOHO’s YB series prefabricated substations are fully assembled, wired, and tested in our factory before shipping. This means 80% of the work is completed under controlled factory conditions, reducing on-site installation time by 60%. Each unit arrives as a plug-and-play system — simply set it on the pre-prepared foundation, connect the incoming MV cable and outgoing LV feeders, and energize. Factory acceptance testing (FAT) is completed before shipment, eliminating on-site surprises.
60% faster on-site installationK-Factor Transformer + Harmonic Filter Package
We specified K-factor rated transformers designed to withstand the additional heating caused by harmonic currents, paired with an active harmonic filter (AHF) package integrated into the GCK LV switchgear. The system continuously monitors current waveforms and injects compensating currents to cancel out harmonic distortion. The result: THD maintained at 3.2% — well below the 5% IEEE 519 standard — ensuring transformer longevity, reliable protection relay operation, and full compliance with grid connection requirements.
THD maintained at 3.2% (<5% target)Modular Design for Seamless Expansion
The system was designed from the ground up for phased deployment. Each site’s two prefabricated substations operate in parallel via bus tie breakers in the KYN28 switchgear. Phase 1 activates one substation powering 60 chargers. Phase 2 simply energizes the second substation and closes the bus tie — doubling capacity without shutting down the operating chargers. All switchgear panels are pre-installed and pre-wired; expansion requires only cable connections and configuration updates, typically completed in a single weekend.
Expand from 60 to 120 stalls in 48 hoursComplete Power Infrastructure Package
GOHO supplied every major component of the power distribution system, ensuring compatibility and single-source accountability.
YB Prefabricated Substation
10kV/0.4kV, 1250kVA × 2 per site. European-style compact substation with IP54 enclosure.
KYN28-12 MV Switchgear
12kV metal-clad withdrawable switchgear with VD4 vacuum circuit breakers and protection relays.
GCK LV Switchgear
Low voltage draw-out switchgear with integrated harmonic mitigation and power factor correction.
DC Distribution for Chargers
DC distribution panels with 120-way output, surge protection, and overcurrent protection per circuit.
Measurable Performance That Speaks for Itself
After one full year of operation across all five sites, the project results exceed all initial performance targets.
Inside the Manufacturing & Deployment
A look at the factory production, quality assurance, and on-site installation of the 120-stall DC fast charging hub equipment.
Transformer Assembly Line
K-factor transformer winding and core assembly
MV Switchgear Production
KYN28-12 metal-clad switchgear assembly bay
LV Switchgear Assembly
GCK low voltage switchgear with harmonic filters
Factory Acceptance Testing
Comprehensive testing before shipment to site
Prefab Substation Final Assembly
YB series compact substation integration line
Quality Control Inspection
Routine and type testing for every unit produced
Project Equipment Certifications
All equipment supplied for this EV charging project holds CQC certification and has passed rigorous type tests according to IEC and GB standards, ensuring reliable performance for high-power DC fast charging applications.
Have a Similar Project?
Whether you need a single prefabricated substation or a complete multi-site charging hub deployment, our engineering team will design a custom solution tailored to your capacity requirements and timeline.
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Prefabricated Substation Solution
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