Part of the design specification was a defined electrical harmonic level for the site. The majority of the load comprises of VSD’s and the Engineering team decided to use an Active Harmonic Filter to mitigate the harmonics at the main switchboard and comply with the requirements. The electricity supply to the site consists of the local grid and two generators. When running at full load all three of these supplies are required to power the site.

Fuseco selected the Sinexcel 200A Active Harmonic Filter (AHF) due to its exceptional performance, small footprint and flexibility. In this case an IP54 version was installed to comply with the customer’s requirements. One of the challenges of this site was that the incoming supply was soft and unpredictable which necessitated the use of two large generators on-site. It was deemed important for the AHF to be able to operate efficiently in such an environment that often had three independent synchronised power supplies.

The results were immediate and the performance of the AHF was above and beyond the requirements of the specification, the Supply Authority and the manufacturer of the two generators.  
If we refer to the screen shot from the AHF’s touch screen post installation, we can note the following points:

1. The harmonic content of the load is 32%, which is quite typical of VSD loads (top left)
2. The Sinexcel AHF mitigated the load harmonics down to approx. 3% (bottom right)  
3. As a result of the compensation by the AHF the corresponding grid voltage harmonics is approx. 2% (bottom left)