Combining DVR and UPS Techniques for an Uninterruptable Supply of Ultra-Sensitive Non-Linear Appliances

Abstract

The paper deals with an application of combined techniques of dynamical voltage restorer (DVR) and uninterruptible power supply (UPS) that make possible both the short voltage sags compensation, as well as longer power supply interruptions, under the simultaneous operation of equipment and network. This is enabled mainly by an instantaneous voltage sag detection, quick bidirectional over-switches, and an instantaneous control method of the output voltage. This needs a fast control method, which can provide a voltage recovery for phase-sensitive loads during several calculation steps, so the dead-beat regulator is used. Such a system even compensates for the influence of non-linear loads on the power supply network without a change of a phase and amplitude of the supply voltage. The simulation results in Matlab/Simulink, as well as real experiments and their comparison results, are given in the paper.