Low-harmonic drives need no outboard kit

ABB has developed a range of low-harmonic drives which do need multi-pulse transformers, filters or other external equipment to reduce harmonics and thus to produce "clean power". The compact low-voltage drives use the company`s DTC (direct torque control) technology to eliminate low-order harmonics, and an LCL line filter to tackle high-order harmonics.

This combination is said to cut total harmonic distortion to less than 5% - thus meeting stringent harmonic standards such as the UK`s G5/4 regulations and IEEE 519. The drives always operate with unity power factor.

The ready-to-install drives cover the power range 55kW-2.5MW at 380-415V, 380-500V and 575-690V. They can be supplied in cabinets protected to IP54.