The new Ecosine active filters from Schaffner are suited to harmonic distortion mitigation as well as power factor correction for three phase circuits (three and four wire). Utilising Fast Fourier Transform (FFT) analysis to the 50th order, and performing the operation and consequent corrective current injection within 300 microseconds, the Schaffner Ecosine active filters provide a tailored solution to harmonics compensation.
The response time is fast so that the Ecosine active filters combine the advantages of attaching to FFT methodology with the response speed associated with broadband active filters. The disadvantage of the latter is that they are unable to provide harmonic details and correct only the overall current distortion.
The Schaffner Ecosine active filters, available from Westek Electronics , have high response speed and are suitable for power factor correction and also for inrush current compensation, thus making them suitable for taxing applications involving stand-by generator systems supplying mission critical loads where UPS systems are also in use, or in MG set applications where the loads demand a high inrush current.
The Schaffner Ecosine active filters are available in various frame sizes with compensating current ratings varying from 30 to 300 Amps, and in line voltages to 480 volts. Overload capacities are considerable in order to allow for high transients. As an example, the 300 Amp rated model has an overload capacity of 750 Amps for 10 milliseconds. The Ecosine active filters can be operated in parallel with up to 5 units in circuit.
The Ecosine active filters calculate compensating current profiles in microseconds, and permit the programming of harmonics to be compensated for. This advantage allows the selective elimination of those harmonics likely to induce resonance conditions (circuits with fixed or variable capacitive loads as encountered in displacement power factor correction equipment). The Schaffner Ecosine active filters are suitable for smooth installation into existing electrical reticulation networks.
The Schaffner Ecosine active filters are serviceable, incorporating a modular construction, permitting extraction of various modules from the front, and also for safe, convenient disconnection of liquid cooling lines (used in filters with ratings above 100 Amps). The Ecosine active filters are provided with Ethernet, RS485 and Modbus interfaces.