Excellent flicker and harmonic reduction yields enhanced productivity in Electric Arc Furnace

At Merus Power, we have developed effective power quality solutions for our steel industry customers. For instance, our Merus^® STATCOM minimizes voltage variations and mitigates flicker caused by heavy industrial loads, such as Electric Arc Furnaces (EAF). With stable voltage, our customers are able to melt steel faster, increasing the production rate even up to 20%. With our solution, significant improvements were achieved in our customer’s steel plant.

Challenges in the customer’s steel plant

Melting of the steel scrap is carried out with a 50-ton EAF rated at 30 MVA. The steel plant is connected to the public network and is fed from a substation located 7km away, making it a weak network. Rapid fluctuations in the demand for reactive power were caused by the dynamic operation of the EAF. The inability of the supply grid to deliver the reactive power demand in an efficient manner were resulting in high voltage fluctuations and flicker. High flicker was also being experienced by the other customers connected to the same busbar. As a result of poor power quality, melting time at the plant was longer and maintenance costs were higher.

Our Merus^® Solution

Merus Power delivered a 16 MVAr Merus^® STATCOM system as a turnkey project. The delivery included Merus^® STATCOM modules, a control and protection system, a cooling system, a filter capacitor bank, filter reactors, and complete engineering.

The total compensation of 16 MVAr was equally divided between active compensation and fixed compensation. 8 MVAr of active compensation was provided by 6 pieces of Merus™ M1000 STATCOM modules whereas the remaining 8 MVAr consisted of capacitor banks.

Results after installation

Merus^® STATCOM system was connected to the medium voltage 33 kV busbar. As per the post-commissioning report, the Merus™ STATCOM flicker reduction factor was from 4.5pu up to 5.5pu. The real-time response of Merus^® STATCOM not only met the dynamic demand created by EAF operation in an efficient way but also reduced the harmonic distortions significantly.

As a result, the melt time was reduced which resulted in increased revenues for the steel plant due to higher productivity. Mitigation of harmonic distortions has extended the lifetime of the entire steel plant. The steel plant has also successfully met the grid codes and other customers on the same bus bar face no negative impact on the steel plant operations.