Problem

The pumping requirement was immense at one of the largest aquariums in the world, in the southeastern region of the United States. The large number of pumps and horsepower required to move so much water resulted in enough VFD load to require significant harmonic mitigation. An initial set of active harmonic filters from another manufacturer was installed for the application. Immediately there were problems between the active filters and the VFDs. The drives were tripping due to an inrush of current from the active filters coming online. The pumps were not able to move water with the drives offline due to the harmonic filters.

Solution

The facility was retrofitted with TCI HGA active harmonic filters. The HGA is designed with a pre-charge circuit that allows for the filter to slowly come online, which allows the VFDs to operate continuously. The pre-charge circuit enables the harmonic filters to softly engage with the system. The operation is not affected by any inrush surges from the HGA active filters but receives the benefit of the harmonic mitigation.