7631 FFWD Sum04.qxd - ABB
7631 FFWD Sum04.qxd - ABB
7631 FFWD Sum04.qxd - ABB
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RVT – the ultimate power factor controller<strong>ABB</strong>’s RVT power factorcontroller is the‘ultimate’ controller for theflexible monitoring andswitching of capacitor banksin power factor control (PFC)applications. It features easycommissioning and automaticset-up, a user-friendly menubasedoperator interface witha full graphic display, and ahighly efficient switchingstrategy that combinesintegral, direct and circularswitching.product roundupThe RVT providescomprehensive measurement,monitoring and event-logging ofnetwork and capacitor bankinformation including: active andapparent power; reactive power;voltage and current; temperature;total harmonic distortion onvoltage (THDV) and totalharmonic distortion on current(THD I); and frequency.Programmable parameter settingenables the operator to set theswitching strategy, with theflexibility to determine differentcontrol targets for day and nightoperation, and to enter alarmthresholds to protect the capacitorbank against such events as overandunder-voltage, overtemperatureand excessiveharmonic distortion.The standard RVT has thefacility to trigger external alarms,while the RVT-Modbus versionis fitted with an RS485 Modbusadapter which makes all itsoperational parameters accessibleand downloadable for fullintegration within a BMS.New-generation PQF activefilters<strong>ABB</strong> has launched a new generation ofits PQF (Power Quality Filter) range ofmicroprocessor controlled active filters designedto solve the growing problem of harmonics inlow voltage electrical networks. Two newmodels are now available, the PQFM for smallto medium three-phase industrial loads and thePQFK, a three-phase, four-wire unit for industrialand commercial networks with high triplen (thirdand its odd multiple) harmonics.The increasing use of non-linear loads in alltypes of industrial and commercial applicationshas resulted in the introduction of potentiallyharmful harmonics into the power network thatcan lead to overheating of cables, motors andtransformers, damage to sensitive equipment,tripping of circuit breakers and blowing of fusesas well as premature ageing of the installation.<strong>ABB</strong> PQF active filters provide a reliableand cost-effective solution to this problem bycontinuously monitoring the current in real timeto determine which harmonics are present andthen injecting harmonic currents in the networkwith exactly the opposite phase to thecomponents that are to be filtered. The twoharmonics effectively cancel each other out sothat the feeding transformer sees a clean sinewave.<strong>ABB</strong> PQF active filters are factoryassembled and tested, ready to install and useat site. They have a modular construction,which allows easy extension to cater for futureload growth. There is also no need to apply ade-rating factor when PQF units are coupled inparallel, which makes it feasible to achieve ahigh rating within a small footprint. Since thePQF does not operate according to theconventional low harmonic impedance principleemployed by passive filters, it remainsunaffected by changes in network parametersand can not be overloaded.The PQF offers features such as: eventlogging with real-time stamp, programmableload balancing, isolation between control andpower units by optical fibre link, digital I/O andModbus communication.The fully programmable filters can either bepre-programmed by <strong>ABB</strong> or programmed onsite using PQF-Manager, a simple, user-friendlyfront panel module that offers direct control,programming and monitoring capability. ThePQF can also be controlled by a standard PCvia its RS232 port and the optional PQF-Linksoftware. PQF units can also adopt thesecondary roles of reactive powercompensation and load balancing.Summer 2004 >> <strong>FFWD</strong> 11