Improved power quality for
efficient cold storage operations

Harmonic distortion was reduced from over 28% to approximately 5%, while power factor improved to above 0.98, helping ensure reliable refrigeration and more energy-efficient cold storage operations.

Segment background

Cold storage warehouses depend on continuous and reliable electrical power to maintain stable temperatures for food, pharmaceutical, and other temperature-sensitive products. Any degradation in power quality can directly impact product safety, operational continuity, and energy efficiency. These facilities rely heavily on large refrigeration systems, where compressors, fans, and pumps are commonly controlled by Variable Frequency Drives (VFDs) to optimize performance and reduce energy consumption.

While this approach improves efficiency, the widespread use of VFDs, automated controls, and modern lighting solutions introduces nonlinear loads into the electrical network. These loads generate harmonic currents that can degrade power quality, increase electrical losses, and place additional stress on critical equipment if not properly mitigated.

Challenges at the customer’s cold storage

In this project, a large cold storage warehouse began experiencing increasing harmonic distortion as electrical demand grew, creating a clear need to improve power quality and protect critical equipment.

During periods of high demand, the facility recorded harmonic current distortion levels exceeding 28% THDi. Such high harmonic levels posed a risk to the reliable operation of refrigeration systems and electrical infrastructure. Elevated distortion can cause overheating of components, reduced efficiency, and premature wear of motors, drives, and transformers. The customer required a solution that would reliably reduce harmonic distortion, improve power factor, and ensure stable operation under varying load conditions, while minimizing the risk of downtime and product loss.

Our Merus^® Solution

To address these challenges, a Merus^® A2 Active Harmonic Filter rated at 300 A was installed by Ampcontrol, Merus Power’s local partner for the project. The system was connected in a shunt configuration to the common bus of the main chiller mechanical board, allowing it to compensate harmonics across the entire refrigeration load.

The Merus^® A2 Active Harmonic Filter continuously measures network conditions and injects compensating currents in real time. This ensures effective harmonic mitigation and power factor improvement, even as load profiles change throughout daily operation.

Results after installation

Following commissioning, total harmonic distortion was reduced to approximately 5% THDi, bringing power quality well within recommended limits. The power factor is now maintained above 0.98, supporting efficient use of electrical capacity and stable operation of critical equipment.

As a result, the cold storage warehouse benefits from improved reliability, reduced risk of equipment failure, and lower energy costs through demand reduction. The solution supports long-term operational efficiency and provides confidence in the continuity of the cold chain.

THDi levels before installing
the Merus^® solution.

THDi levels after installing
the Merus^® solution.