A discrete-time, closed loop power factor corrector system controls the coupling of a delta-connected switched capacitor array to a 3- or 4-wire power line which may have time-varying, unbalanced, inductive loads. For inductive loads that cannot be exactly compensated with a delta-connected capacitance,...http://www.google.fr/patents/US4356440?utm_source=gb-gplus-shareBrevet US4356440 - Power factor correction system
