Cases-GoLead Intelligent

An Electrolytic Aluminum Plant in Chongqing

Overview

At a major aluminum electrolysis plant in Chongqing, the rectifier transformer in use has a capacity of 120 MVA and a rated voltage of 220 kV. To reduce electricity costs, the customer built a self‑owned power plant near the production workshop.

However, every time the transformer is shut down and re‑energized, it generates significant inrush current. Because the transformer is located close to the generator, this inrush current often causes generator power fluctuations, disrupting the entire production process — a long‑standing issue the customer had been unable to resolve.

Pain Points & Solutions

Pain Point 1: Transformer Service Life Affected

After replacing raw materials, energizing the transformer can generate a large inrush current due to residual magnetism in the transformer core, negatively impacting transformer lifespan.
Solution 1

GoLead Intelligent’s proprietary online residual magnetism calculation algorithm calculates the residual magnetism value of the transformer in real time after de‑energization. Based on the three‑phase residual magnetism, it determines the optimal closing angle, enabling the breaker to close with minimal inrush current and preventing damage to the transformer over time.
Pain Point 2: Production Continuity Affected

Because the transformer is located close to the self‑owned power plant, inrush current causes active power fluctuations in the generator, which disrupts the continuity of production.
Solution 2

For the first energization after transformer maintenance — when residual magnetism is unknown — a quantitative magnetizing device is used to preset the transformer’s residual magnetism. Closing at the angle corresponding to this preset value ensures that almost no inrush current is generated, preventing any impact on the generator and maintaining stable production.

Values

Cost Reduction

Extends the service life of primary equipment, saving users the cost of equipment replacement.
Efficiency Improvement

Ensures continuous production and helps customers generate greater value.

Client Comments

The quantitative magnetizing solutionprovided by GoLead Intelligent Electric Power Technology Co., Ltd.,combined with the inrush current suppression device, helped us solve the long‑standing issue of production continuity caused by transformer excitationinrush.

Its proprietary residual magnetism algorithm and quantitativemagnetizing technology effectively address both initial energization andrepeated switching conditions. The inrush suppression results are remarkableand have greatly contributed to our efficient production.

──────────── Project Manager, Chongqing Aluminum Co., Ltd.

Case Gallery