Improved reliability of critical processes in a British laboratory

Challenges in the customer’s laboratory

The laboratory consisted of several non-linear loads causing high harmonic current distortions. These loads include AC drives, Uninterruptable Power Supplies (UPS), Switch Mode Power Supplies (SMPS), and various laboratory equipment. These loads were fed by two separate transformers each rated at 2500kVA. The presence of high harmonic distortions threatens the reliability of operations and shortens the lifetime of expensive laboratory equipment.

As the medical facility is involved with cutting-edge research, the critical process needed to be protected from the impact of poor power quality, in particular high harmonic distortions. Several harmonic mitigation methods were evaluated in terms of performance, cost, and lead time. The customer selected Merus^® Active Harmonic Filters due to their excellent performance, shorter lead time, and overall better value for money.

Our Merus^® Solution

Merus Power’s partner in the UK, Power Capacitors Ltd proposed an active harmonic filtering solution to cancel the harmonic distortions at the laboratory. This solution offered a better value proposition to the customer in terms of shorter lead time with guaranteed compliance with the demanding power quality standards.

Compact Merus^® A2-series Active Harmonic Filter modules in IP20 protection were shipped from Finland to the UK. Cabinets to house the active harmonic filters were manufactured in the UK by Merus Power’s partner Power Capacitors Ltd to save shipping costs. The end customer received a free-standing active harmonic filtering cabinet with 450KVAr detuned capacitor banks. Installation was made in a closed-loop connection and selectable operation mode was chosen.

Results after installation

Before the installation, the Total Harmonic Distortion Current (THDI) percentage at the laboratory was measured at 14%. The measurement also revealed high 3rd, 5th, 7th, and 11th harmonic currents and exceeded the limits specified in the G5/4 power quality standard.

Merus^® Active Harmonic Filters were commissioned in selectable operation mode targeting all above mentioned high individual harmonics. Post commissioning report confirmed a total harmonic distortion current of less than 5% as well as individual high harmonics 3rd, 5th, 7th, and 11th harmonic currents were successfully brought under the desired limits.