Patent · US Expired

Power distribution circuit with power factor correction and independent harmonic current filter

US5387821A · kind A · utility

13Cited by
8References
10Claims
0Family size

Assignee

Inventors

Key dates

Filing dateNov 12, 1992
Grant dateFeb 7, 1995
Priority date
Expiry dateNov 12, 2012

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY02P80/10
  • WIPO fieldElectrical machinery, apparatus, energy
  • WIPO sectorElectrical engineering

Abstract

An electrical power distribution system of an industrial plant or a commercial building and having a capacity for delivering at least 500 KVA, includes a voltage step-down transformer connected between an AC source of electrical energy and a pair of power distribution line conductors across which there is connected a pulsed inductive load, such as a motor with a thyrister speed controller. The power factor of the system is corrected by a power factor correction capacitor connected directly across the system power distribution line conductors. Pulsed inductive loads tend to excite large harmonic currents in such systems having both a transformer and a power factor correction capacitor directly across the distribution line conductors. A filter, made up of a filter capacitor and a filter inductor tuned exactly to one harmonic, are connected in a series circuit branch that is connected directly across the system power distribution line conductors. The name plate KVAR rating of and capacitance of the filter capacitor is chosen to be much smaller than corresponding KVAR rating and capacitance of the power factor correction capacitor in order to make the function of the power factor corre…

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.