Patent ID: 6864660
Filing Date: 2005-03-08
Classification: H02M

Abstract:
1. A method for realizing an effective value of a quantity to be varied in an electrical load connected to a multi-phase switchable DC/AC frequency convertor comprising a plurality of controllable switches, wherein said value is realized by varying a current or a voltage delivered by the DC/AC frequency convertor through suitable switching of the switches thereof, and wherein said quantity exhibits a load angle which, averaged in time, leads or lags the voltage or current being delivered, which method comprises the steps of: defining a dead zone having dimensions representative of an allowable amplitude and phase angle deviation in the quantity to be realized; orienting the dead zone with respect to the voltage or current delivered by the DC/AC frequency convertor by rotating the dead zone through the load angle in the direction of the delivered voltage or current; and switching at least one of the switches on the basis of the manner in which the deviation in the quantity to be realized extends beyond the dead zone, for the purpose of realizing said quantity during operation with an amplitude and phase angle deviation ranging within the dead zone.