| Abstract |
This paper investigates the use of deadbeat control on both output voltage and inductor current for the
inverter stage of Uninterruptible Power Supplies (UPS). Besides the linear state feedback which
allocates system poles in the origin so as to achieve deadbeat response for all state variables, this
paper proposes the use of a state observer and a disturbance observer for the compensation of the
computational delay and for the estimation of the load current, respectively. In the proposed solution,
undesired oscillations on the inductor current, which usually occur when the deadbeat control is
performed only on the output voltage, are avoided. Moreover, with a proper design of observer
parameters, it is possible to minimise the control sensitivity to model uncertainties, parameter
mismatches and noise on sensed variables, which usually characterize existing deadbeat control
techniques. Finally, an additional control provision is proposed for the implementation of the current
limitation of the power converter. Simulation and experimental results on a single-phase UPS
laboratory prototype (1 kVA) confirm the effectiveness of the proposed solution. |
