Zhuhai Jiuyuan 400kW high‑voltage DC‑input inverter optimizes piling rig impact‑load power supply. Achieves 44% fuel reduction, strong overload capacity for construction pile‑driving operations.
Zhuhai Jiuyuan’s custom‑developed 400kW high‑voltage DC‑input inverter for construction piling has entered commercial service, successfully completing 500 foundation piles with stable performance and high customer recognition.
Piling rigs are classic impact loads—each impact instantaneously draws more than twice the rated power. Conventional solutions must oversize the diesel generator (e.g. 600kW) to handle peaks, leaving the generator running at low load and poor efficiency for most of the cycle, wasting significant fuel.
We designed an intelligent fuel‑efficient diesel‑electric system comprising: diesel generator + lithium‑battery pack + 400kW high‑voltage DC inverter. The inverter converts the battery pack’s DC630V–800V (nominal 740V) via IGBT power conversion, LC filtering, and an external isolation transformer (delta/star, 402.68kW rated) to deliver AC380V three‑phase, four‑wire power for the piling rig. Through CAN communication, the system coordinates generator and battery output in real time: the battery delivers instantaneous high power during impact strokes, while the generator recharges it during idle intervals—smoothing peaks and filling valleys, so the diesel engine always operates in its optimal fuel‑consumption zone. Meanwhile, the inverter’s AC‑DC conversion efficiency reaches 99.24% (at 4.2kHz switching frequency, 120°C junction / 40°C ambient), minimising electrical losses.
This innovative design drastically reduces the required diesel generator capacity—from 600kW down to 400kW, with plans to test further reduction to 250kW—and significantly improves fuel utilisation. Measured data shows 44% lower overall fuel consumption, along with reduced noise and carbon emissions. The battery’s rapid response effectively stabilises voltage fluctuations, ensuring smooth and continuous piling operations. The solution successfully resolves the energy‑matching challenge of impact loads, offering a replicable, high‑efficiency blueprint for green retrofitting of heavy machinery—delivering both economic and environmental benefits.
Robust overload capacity: 120% load for ≥600s, 150% for 60s, 200% for 1s—perfectly matched to piling rig impact characteristics, far exceeding ordinary inverters.
Wide DC input range: DC630V–790V (max 800V, min 630V, nominal 740V), compatible with mainstream lithium‑battery voltage platforms. DC bus max current 540A; rated inverter output current 626A (converter‑side line voltage 371.29V, phase voltage 214.37V); single IGBT current 208.71A; three‑phase inductance 0.1417mH; reactor current 626.14A—fully satisfying high‑power output demands.
High‑precision output: Star‑side rated line voltage 380V, output voltage 370V±5V (steady‑state accuracy ±1.3%), frequency 50Hz±0.1Hz, waveform distortion ≤3%, meeting requirements for piling motors and auxiliary equipment.
Comprehensive protection: Input over‑/undervoltage, reverse‑polarity alarm, output overload/short‑circuit, over‑temperature (heatsink >85°C protection), phase loss, and over‑/under‑frequency protection ensure equipment safety.
Compact footprint: Cabinet width ≤1m, depth ≤1m, height ≤2m; bottom‑in/bottom‑out cabling, front‑to‑rear airflow with top exhaust, intelligent forced‑air cooling—convenient for indoor installation.
On‑site data shows that with the “400kW generator + energy storage” system, average fuel consumption per pile is just 200 litres—compared to 360 litres when using a standalone 600kW generator, saving 160 litres per pile, a 44% reduction. With approximately 800 piles in total, projected diesel savings reach 128,000 litres, translating to over RMB 850,000 in direct fuel cost savings.
The site construction manager added: “Once the 250kW generator arrives, we’ll test a few more piles for comparison. Fuel consumption varies with different geological conditions—200 litres is our current average.”
As the next step, the project will further reduce the generator from 400kW to 250kW to validate system compatibility and fuel‑saving performance under even smaller capacity, potentially lowering equipment costs and carbon footprint further.
Every inverter undergoes full‑load burn‑in testing before delivery, with test reports provided. On‑site acceptance includes verifying output voltage regulation accuracy at DC input extremes (630V and 790V), and actual 150% overload for 60 seconds—ensuring robust performance in harsh job‑site conditions. To date, the equipment has operated continuously for over 500 piles with consistent stability, fully demonstrating the solution’s maturity and reliability.
Zhuhai Jiuyuan remains committed to delivering high‑reliability, high‑efficiency custom power‑electronics solutions for heavy construction, mining, emergency power, and other high‑power impact‑load applications. Contact us for more technical data or to arrange a site visit.
Zhuhai Jiuyuan Power Electric Co., Ltd. – Powering Smarter, Greener Heavy Industry.
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