Jae-Young Jang, Kyo-Beum Lee, Joong-Ho Song, and Ick Choy, "Disturbance Observer-Based Digital Control for Single-Phase UPS Inverters," in Proc. IEEE ISIE Conf., Jun. 2001, pp. 1095–1099. > Paper

Design and analysis of disturbance observer-based deadbeat control for single-phase inverter applications are comprehensively

presented in this paper. Load current can be estimated by disturbance observer, which is basically structured with the first order

equation in this case and is regarded as a relatively simple method in comparison with conventional full-order Luenberger observer.

Also, an inherent one-step delay problem appeared in the deadbeat control method is overcome by a simple prediction technique

proposed. Output voltage dip is reduced by the feed forward control with the change rate of the estimated load current involved in

the deadbeat current control loop. The proposed algorithms are verified by the respective simulation and experiment results.