Elevating foundry efficiency through advanced power quality solutions

Segment background

Electricity providers are increasingly replacing overhead medium-voltage (MV) lines with underground cables to protect the environment and wildlife. At the same time, the growing use of modern electronic systems, such as LED lighting, solar power plants, and automated production lines, is increasing the proportion of capacitive loads on the MV network. This is especially relevant in industrial environments like foundries, where high-power equipment such as Arc Furnaces and Variable Frequency Drives (VFDs) are commonly used. These technologies distort the current waveform, leading to random disturbances, increased energy losses, and malfunctions in protective systems. As a result, the quality and reliability of the power supply can be compromised, potentially disrupting both the foundry’s operations and those of other users connected to the same network.

Challenges at the customer’s site

In the customer’s foundry, the increasing presence of capacitive loads caused significant challenges for the medium-voltage network. These loads damaged switching equipment, interfered with protection systems, and compromised the overall security of the energy supply. To counter overcompensation, the power provider had traditionally relied on Petersen coils—designed to manage symmetrical loads—but these could only be upgraded through complete replacement, offering little flexibility.

Moreover, the foundry’s modern equipment generated harmonic distortions that further strained the network. These user-induced harmonics led to higher energy losses, overheating of transformers and cables, voltage distortion, and malfunctions in sensitive systems. Collectively, these issues posed serious risks to both the reliability of the foundry’s operations and the stability of the broader MV network.

Our Merus^® Solution

Túróczi és Társa Erősáramú Mérnöki Iroda Kft. (TTEMI), Merus Power’s local partner, developed a compact, transportable compensation station optimized for versatile industrial use to address the harmonically distorted and often capacitive reactive current in the foundry.

This all-in-one solution integrates Merus^® A2 Active Harmonic Filters and all necessary components into a single unit that supports medium-voltage connection and full reactive power compensation. Each station can house up to six 200A filter modules, and for larger demands, up to five stations can be operated in parallel, supporting as many as 30 filters in total, to increase capacity and provide redundancy.

The station, designed and built by TTEMI, is modular, scalable from 0.3 to 4.0 MVA, and suitable for 1kV to 35kV systems operating at 50/60Hz. It compensates both capacitive currents and harmonic disturbances, making it ideal for deployment even in public or space-constrained areas. At the low-voltage level, the Merus^® A2 filters work effectively alongside VFDs to reduce harmonics and can also be configured to manage capacitive loads.