Patent ID: 7710082
Filing Date: 2010-05-04
Classification: H02J,H02M,Y02E

Abstract:
1. A controller providing a control vector to a cascade H-bridge three-phase multilevel converter used as a shunt active filter, each phase of the multilevel converter composed of a series connection of two H-bridge cells, each of said phases of the multilevel converter providing a five-level voltage signal, each of said H-bridge cells composed of an H-bridge inverter having an output capacitor and an output resistor coupled across the said H-bridge, each of said H-bridge cells providing an output voltage, each of said phases of the multilevel converter coupled to a corresponding phase of a three-phase power distribution system via a corresponding inductor, each of said phases of the multilevel converter providing an injected current across the corresponding inductor, the said three phases of the multilevel converter connected among them in a star connection, the three phase power distribution system providing a source voltage and a source current for each phase to a corresponding three phase load, the controller comprising: a source current module operative to provide a signal indicative of the value of the source current in each phase; a source voltage module operative to provide a signal indicative of the value of the source voltage in each phase; an output voltage module operative to provide a signal indicative of the output voltage across the output capacitor of each H-bridge cell; a three-phase to stationary coordinate converter operative to convert the measured three-phase source current value into a source current value and to convert the three-phase source voltage value into a source voltage value in stationary coordinates; a voltages transformation processor a voltages transformation processor a voltages transformation processor a coordinates transformation processor coupled to voltages transformation processors references for variables x a control processor including: a regulation controller receiving variables x a tracking controller coupled to the regulation controller receiving the source voltage vector value, the source current reference vector, and the source current reference vector value in stationary coordinates, the tracking controller configured and arranged to provide control variables e a balance controller receiving variables x a duty ratios processor a duty ratios processor a duty ratios processor