Digital Control of Three Phase PWM Inverter for UPS Application based on Disturbance Observer and Deadbeat Control.

Abstract

A new approach to digital feedback control of PWM inverter is proposed, in which an output DB (dead beat) control is achieved with a disturbance observer. In this scheme, the state observer and disturbance observer are used, and pole placement of these two observers are chosen separately. When these observers employ the same pole placement, the system has tendency to become unstable. By selecting the different pole placement, the disturbance observer only eliminates the disturbance, and state observer only estimates the state variable of the next sampling instant.From the view point of UPS applications, the advantages and disadvantages are discussed through simulations and experiments.