ABB has launched a new generation of PQF (Power Quality Filter)
ABB has launched a new generation of its PQF (Power Quality Filter) range of microprocessor controlled active filters designed to solve the growing problem of harmonics in low voltage electrical networks. Two new models are now available, the PQFM for small to medium three-phase industrial loads and the PQFK, a three-phase, four-wire unit for industrial and commercial networks having high triplen (third and its odd multiple) harmonics.
The increasing use of non-linear loads in all types of industrial and commercial applications has resulted in the introduction of potentially harmful harmonics into the power network that can lead to overheating of cables, motors and transformers, damage to sensitive equipment, tripping of circuit breakers and blowing of fuses as well as premature ageing of the installation. ABB PQF active filters provide a reliable and cost-effective solution to this problem by continuously monitoring the current in real time to determine what harmonics are present and then injecting harmonic currents in the network with exactly the opposite phase to the components that are to be filtered. The two harmonics effectively cancel each other out so that the feeding transformer sees a clean sine wave.
ABB PQF active filters are factory assembled and tested, ready to install and use at site. They have a modular construction, which allows easy extension to cater for future load growth. There is also no need to apply a de-rating factor when PQF units are coupled in parallel, which makes it feasible to achieve a high rating within a small footprint. Since the PQF does not operate according to the conventional low harmonic impedance principle employed by passive filters it remains unaffected by changes in network parameters and can not be overloaded.
The PQF offers features such as: event logging with real time stamp, programmable load balancing, isolation between control and power units by optical fibre link, digital I/O and Modbus communication. The fully programmable filters can either be pre-programmed by ABB or programmed on site using PQF-Manager, a simple, user-friendly front panel module that offers direct control, programming and monitoring capability. The PQF can also be controlled by a standard PC via its RS232 port and the optional PQF-Link software. PQF units can also adopt the secondary roles of reactive power compensation and load balancing.