Active Harmonic Filtering with GEMActive
The GE GEMActive® cancels harmonics by dynamically injecting out of phase harmonic current. GEMActive installation will allow for compliance with IEEE 519 – 1992 recommended harmonic limits. Reduced harmonic levels results in improved electrical network reliability and reduced operating costs. Nuisance tripping of protective devices and nuisance clearing of fuses due to harmonic heating effects is greatly reduced.
Overheating of motors, transformers, switchgear and cables is also reduced which increases their life expectancy and reduces maintenance costs. For new installations, over-sizing of distribution equipment to reduce harmonic susceptibility can be reconsidered.
GEMActive reduces current distortion that, in turn, reduces voltage distortion. Unlike passive devices, GEMActive is easy to install and cannot be overloaded. When required harmonic compensation exceeds capacity, GEMActive will simply supply its maximum continuously. Multiple GEMActive units can be connected in parallel to increase compensation.
Closed-loop control allows for high accuracy and self-adaptive harmonic control. GEMActive determines the harmonic compensation required by using current transformers to measure the network current. The GEMActive control logic removes the fundamental frequency component (50 or 60 Hz) from this waveform. The remaining waveform is then inverted and GEMActive fires its IGBTs to inject this waveform on to the network to compensate for the harmonics. The result is a waveform with greatly reduced harmonic content as seen by the upstream electrical system.