The 42 MW ultra-high-power DC power supply manufactured by Sichuan Kulun Electric Co., Ltd. for the Tongwei Cangxi industrial silicon project has completed on-site commissioning and officially gone into operation, providing stable, controllable high-power DC power for the industrial silicon submerged arc furnace.
The industrial rectifier power supply has a rated output power of 42 MW and a rated output current of 130,000 A. It adopts a double-star inverse-parallel topology with in-phase reverse-parallel arrangement and a fully water-cooled design — a large-capacity DC power system for industrial silicon smelting.
Serving the Tongwei Cangxi industrial silicon project
Tongwei Group’s business covers photovoltaic manufacturing and new energy, and industrial silicon is an important upstream raw material of the photovoltaic industry chain. The 42 MW DC power supply commissioned in Cangxi, Sichuan, mainly provides stable DC energy for the high-power submerged arc furnace, meeting the power supply needs of continuous industrial silicon smelting.
KULUN Electric was responsible for the design, manufacturing, factory testing and on-site commissioning of the DC power supply system. The complete system includes the rectifier cabinet, control cabinet, water-cooling unit, protection system and host monitoring unit, enabling centralized control and monitoring of the high-power DC output, power supply operating status and system protection information.
Main technical parameters
| Rated output power | 42 MW |
| Rated output current | 130,000 A |
| Rated output voltage | Configured according to the industrial silicon smelting process |
| Topology | Double-star inverse-parallel with in-phase reverse-parallel arrangement |
| Cooling | Closed-loop full water cooling |
| Control | Digital thyristor triggering with host computer communication |
| Protection | Short circuit, overcurrent, overvoltage, phase loss, overheating, water pressure and flow anomaly protection |
| Commissioning | August 2025 |
Eight core technologies integrated
1. Double-star inverse-parallel topology
The equipment adopts a double-star inverse-parallel rectifier topology in which two rectifier branches of opposite phase run in parallel with opposite busbar current directions. Under high-current operation this weakens part of the magnetic field, reducing the electromagnetic impact of the high-current DC system on structural parts and nearby equipment.
2. Full water-cooling design
The main power devices are cooled by closed-loop circulating water, which removes heat quickly. Compared with traditional air cooling, the full water-cooling design offers high heat dissipation efficiency, low operating noise and strong environmental adaptability, and reduces the impact of dust on power devices and cooling channels.
3. Intelligent current sharing
A current-sharing control algorithm monitors the current distribution of each parallel rectifier branch in real time and dynamically adjusts the thyristor firing angle, keeping the current of multiple parallel branches reasonably balanced and improving operating stability under ultra-high-current conditions.
4. Multi-branch load balancing
In multi-unit or multi-branch power supply scenarios, the system automatically distributes the load according to the operating status of each branch, reducing the risk of long-term overload of a single branch and helping extend the service life of power devices and related electrical components.
5. Fast short-circuit protection
The fast short-circuit protection cuts off the main circuit before the fault current rises to a dangerous value, providing rapid protection for the 130,000 A class high-current DC power supply and the upstream power system.
6. Dual-unit hot redundancy
Two DC power supplies of the same specification can run in parallel with dual-unit hot redundancy control. If one unit fails, the other takes over the corresponding load according to the system control logic, reducing the risk of production interruption caused by a single-unit failure.
7. Fiber-optic triggering
To counter the strong electromagnetic interference possible in a 130,000 A operating environment, the system transmits thyristor trigger signals over optical fiber, improving electrical isolation and noise immunity and ensuring the synchronization and reliability of rectifier control.
8. High-reliability design for industrial sites
Power device selection, control system design, PCB layout, signal shielding, EMC design and protection logic all take into account the strong magnetic fields, high voltage, high current and high temperature of industrial silicon smelting sites, meeting the needs of long-term continuous operation of high-power industrial rectifier power supplies.
Three years from contract to commissioning
From contract signing to on-site commissioning, the project took about three years, covering solution design, equipment manufacturing, in-plant assembly, factory testing, packaging and transportation, on-site positioning, electrical installation, water-cooling system commissioning, control system joint debugging and load trial operation.
After on-site commissioning and operational verification, the 42 MW DC power supply was put into operation successfully on the first attempt, with all control, protection, cooling and monitoring functions meeting the project’s operating requirements.
- Manufacturing of the rectifier cabinet, control cabinet and supporting systems completed.
- Installation and circulation commissioning of the full water-cooling system completed.
- Joint debugging of the control system, protection system and host monitoring completed.
- On-site electrical installation and system wiring completed.
- Load trial operation completed and formal industrial production started.
Significance for industrial silicon smelting
The successful commissioning of the 42 MW DC power supply at the Tongwei Cangxi project further validates KULUN Electric’s engineering capabilities in high-power industrial rectifier power supplies, ultra-high-current output, full water-cooling, parallel current sharing and high-reliability protection.
In operation, the equipment provides continuous, stable DC power support for the industrial silicon production line at the Tongwei Cangxi base, and underpins the continuous operation, production stability and energy efficiency optimization of the submerged arc furnace.
Continuing to serve the high-power industrial power supply field
Sichuan Kulun Electric Co., Ltd. has long focused on the R&D, manufacturing and application of industrial power supplies and power electronics equipment. Its products include SCR power controllers, thyristor power control cabinets, high-voltage power control cabinets, industrial rectifier power supplies, AC power supplies and DC power supplies, widely used in industrial electric heating, new energy, metallurgy, electrolysis, chemical industry, electroplating, glass, semiconductors and equipment manufacturing.
Around industrial high-power rectification and power control needs, KULUN Electric continues to advance digital, closed-loop and intelligent power supply technologies, and can provide engineering solutions ranging from a single industrial power supply to a complete high-power power supply system according to customer process parameters, load characteristics and site conditions.
The successful commissioning of the Tongwei Cangxi 42 MW DC power supply marks a new engineering achievement of KULUN Electric in the field of ultra-large-capacity industrial rectifier power supplies. From industrial rectifier power supplies to high-power power electronics systems, KULUN Electric continues to provide stable, reliable and controllable electrical energy for industrial production.
Project information
| Project | Tongwei Cangxi industrial silicon project |
| Location | Cangxi, Sichuan, China |
| Application | DC power supply for an industrial silicon submerged arc furnace |
| Equipment | 42 MW ultra-high-power DC power supply |
| Rated output power | 42 MW |
| Rated output current | 130,000 A |
| Topology | Double-star inverse-parallel |
| Cooling | Full water cooling |
| Supplier | Sichuan Kulun Electric Co., Ltd. |
| Commissioning | August 2025 |
FAQ
What is the 42 MW DC power supply mainly used for?
In this project it serves the Tongwei Cangxi industrial silicon project, providing continuous, stable and controllable DC power for the industrial silicon submerged arc furnace.
What are its core parameters?
Rated output power 42 MW, rated output current 130,000 A, double-star inverse-parallel topology, and full water cooling.
What was KULUN Electric responsible for in this project?
Design, manufacturing, factory testing and on-site commissioning of the DC power supply system, including the rectifier cabinet, control cabinet, water-cooling unit, protection system and host monitoring unit.
