Instantaneous Sequence-Components Resolution of 3-Phase Variables and Its Application to Dynamic Voltage Restoration

A technique for decomposing instantaneous 3-phase voltages and currents into sequence components has been described. The technique is based on a recursive, weighted, least-squares procedure. The main advantage of the proposed technique is the use of the same covariance and gain matrices for resolving any number of 3-phase variables into their respective sequence components. The proposed technique also estimates the dc-offset in the sensed variable and these are eliminated during the processing. Finally, the proposed technique has been implemented in a DSP and has been applied to the open-loop control of a laboratory-scale dynamic voltage restorer.